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mariadb/sql/slave.cc
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/* Copyright (C) 2000-2003 MySQL AB, 2008-2009 Sun Microsystems, Inc
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/**
@addtogroup Replication
@{
@file
@brief Code to run the io thread and the sql thread on the
replication slave.
*/
#include "sql_priv.h"
#include "my_global.h"
#include "slave.h"
#include "sql_parse.h" // execute_init_command
#include "sql_table.h" // mysql_rm_table
#include "rpl_mi.h"
#include "rpl_rli.h"
#include "sql_repl.h"
#include "rpl_filter.h"
#include "repl_failsafe.h"
#include "transaction.h"
#include <thr_alarm.h>
#include <my_dir.h>
#include <sql_common.h>
#include <errmsg.h>
#include <mysqld_error.h>
#include <mysys_err.h>
#include "rpl_handler.h"
#include <signal.h>
#include <mysql.h>
#include <myisam.h>
#include "sql_base.h" // close_thread_tables
#include "tztime.h" // struct Time_zone
#include "log_event.h" // Rotate_log_event,
// Create_file_log_event,
// Format_description_log_event
#ifdef HAVE_REPLICATION
#include "rpl_tblmap.h"
#include "debug_sync.h"
#define FLAGSTR(V,F) ((V)&(F)?#F" ":"")
#define MAX_SLAVE_RETRY_PAUSE 5
/*
a parameter of sql_slave_killed() to defer the killed status
*/
#define SLAVE_WAIT_GROUP_DONE 60
bool use_slave_mask = 0;
MY_BITMAP slave_error_mask;
char slave_skip_error_names[SHOW_VAR_FUNC_BUFF_SIZE];
typedef bool (*CHECK_KILLED_FUNC)(THD*,void*);
char* slave_load_tmpdir = 0;
Master_info *active_mi= 0;
my_bool replicate_same_server_id;
ulonglong relay_log_space_limit = 0;
/*
When slave thread exits, we need to remember the temporary tables so we
can re-use them on slave start.
TODO: move the vars below under Master_info
*/
int disconnect_slave_event_count = 0, abort_slave_event_count = 0;
static pthread_key(Master_info*, RPL_MASTER_INFO);
enum enum_slave_reconnect_actions
{
SLAVE_RECON_ACT_REG= 0,
SLAVE_RECON_ACT_DUMP= 1,
SLAVE_RECON_ACT_EVENT= 2,
SLAVE_RECON_ACT_MAX
};
enum enum_slave_reconnect_messages
{
SLAVE_RECON_MSG_WAIT= 0,
SLAVE_RECON_MSG_KILLED_WAITING= 1,
SLAVE_RECON_MSG_AFTER= 2,
SLAVE_RECON_MSG_FAILED= 3,
SLAVE_RECON_MSG_COMMAND= 4,
SLAVE_RECON_MSG_KILLED_AFTER= 5,
SLAVE_RECON_MSG_MAX
};
static const char *reconnect_messages[SLAVE_RECON_ACT_MAX][SLAVE_RECON_MSG_MAX]=
{
{
"Waiting to reconnect after a failed registration on master",
"Slave I/O thread killed while waitnig to reconnect after a failed \
registration on master",
"Reconnecting after a failed registration on master",
"failed registering on master, reconnecting to try again, \
log '%s' at postion %s",
"COM_REGISTER_SLAVE",
"Slave I/O thread killed during or after reconnect"
},
{
"Waiting to reconnect after a failed binlog dump request",
"Slave I/O thread killed while retrying master dump",
"Reconnecting after a failed binlog dump request",
"failed dump request, reconnecting to try again, log '%s' at postion %s",
"COM_BINLOG_DUMP",
"Slave I/O thread killed during or after reconnect"
},
{
"Waiting to reconnect after a failed master event read",
"Slave I/O thread killed while waiting to reconnect after a failed read",
"Reconnecting after a failed master event read",
"Slave I/O thread: Failed reading log event, reconnecting to retry, \
log '%s' at postion %s",
"",
"Slave I/O thread killed during or after a reconnect done to recover from \
failed read"
}
};
typedef enum { SLAVE_THD_IO, SLAVE_THD_SQL} SLAVE_THD_TYPE;
static int process_io_rotate(Master_info* mi, Rotate_log_event* rev);
static int process_io_create_file(Master_info* mi, Create_file_log_event* cev);
static bool wait_for_relay_log_space(Relay_log_info* rli);
static inline bool io_slave_killed(THD* thd,Master_info* mi);
static inline bool sql_slave_killed(THD* thd,Relay_log_info* rli);
static int init_slave_thread(THD* thd, SLAVE_THD_TYPE thd_type);
static void print_slave_skip_errors(void);
static int safe_connect(THD* thd, MYSQL* mysql, Master_info* mi);
static int safe_reconnect(THD* thd, MYSQL* mysql, Master_info* mi,
bool suppress_warnings);
static int connect_to_master(THD* thd, MYSQL* mysql, Master_info* mi,
bool reconnect, bool suppress_warnings);
static int safe_sleep(THD* thd, int sec, CHECK_KILLED_FUNC thread_killed,
void* thread_killed_arg);
static int get_master_version_and_clock(MYSQL* mysql, Master_info* mi);
static Log_event* next_event(Relay_log_info* rli);
static int queue_event(Master_info* mi,const char* buf,ulong event_len);
static int terminate_slave_thread(THD *thd,
mysql_mutex_t *term_lock,
mysql_cond_t *term_cond,
volatile uint *slave_running,
bool skip_lock);
static bool check_io_slave_killed(THD *thd, Master_info *mi, const char *info);
/*
Find out which replications threads are running
SYNOPSIS
init_thread_mask()
mask Return value here
mi master_info for slave
inverse If set, returns which threads are not running
IMPLEMENTATION
Get a bit mask for which threads are running so that we can later restart
these threads.
RETURN
mask If inverse == 0, running threads
If inverse == 1, stopped threads
*/
void init_thread_mask(int* mask,Master_info* mi,bool inverse)
{
bool set_io = mi->slave_running, set_sql = mi->rli.slave_running;
register int tmp_mask=0;
DBUG_ENTER("init_thread_mask");
if (set_io)
tmp_mask |= SLAVE_IO;
if (set_sql)
tmp_mask |= SLAVE_SQL;
if (inverse)
tmp_mask^= (SLAVE_IO | SLAVE_SQL);
*mask = tmp_mask;
DBUG_VOID_RETURN;
}
/*
lock_slave_threads()
*/
void lock_slave_threads(Master_info* mi)
{
DBUG_ENTER("lock_slave_threads");
//TODO: see if we can do this without dual mutex
mysql_mutex_lock(&mi->run_lock);
mysql_mutex_lock(&mi->rli.run_lock);
DBUG_VOID_RETURN;
}
/*
unlock_slave_threads()
*/
void unlock_slave_threads(Master_info* mi)
{
DBUG_ENTER("unlock_slave_threads");
//TODO: see if we can do this without dual mutex
mysql_mutex_unlock(&mi->rli.run_lock);
mysql_mutex_unlock(&mi->run_lock);
DBUG_VOID_RETURN;
}
#ifdef HAVE_PSI_INTERFACE
static PSI_thread_key key_thread_slave_io, key_thread_slave_sql;
static PSI_thread_info all_slave_threads[]=
{
{ &key_thread_slave_io, "slave_io", PSI_FLAG_GLOBAL},
{ &key_thread_slave_sql, "slave_sql", PSI_FLAG_GLOBAL}
};
static void init_slave_psi_keys(void)
{
const char* category= "sql";
int count;
if (PSI_server == NULL)
return;
count= array_elements(all_slave_threads);
PSI_server->register_thread(category, all_slave_threads, count);
}
#endif /* HAVE_PSI_INTERFACE */
/* Initialize slave structures */
int init_slave()
{
DBUG_ENTER("init_slave");
int error= 0;
#ifdef HAVE_PSI_INTERFACE
init_slave_psi_keys();
#endif
/*
This is called when mysqld starts. Before client connections are
accepted. However bootstrap may conflict with us if it does START SLAVE.
So it's safer to take the lock.
*/
mysql_mutex_lock(&LOCK_active_mi);
/*
TODO: re-write this to interate through the list of files
for multi-master
*/
active_mi= new Master_info(relay_log_recovery);
if (pthread_key_create(&RPL_MASTER_INFO, NULL))
goto err;
/*
If --slave-skip-errors=... was not used, the string value for the
system variable has not been set up yet. Do it now.
*/
if (!use_slave_mask)
{
print_slave_skip_errors();
}
/*
If master_host is not specified, try to read it from the master_info file.
If master_host is specified, create the master_info file if it doesn't
exists.
*/
if (!active_mi)
{
sql_print_error("Failed to allocate memory for the master info structure");
error= 1;
goto err;
}
if (init_master_info(active_mi,master_info_file,relay_log_info_file,
1, (SLAVE_IO | SLAVE_SQL)))
{
sql_print_error("Failed to initialize the master info structure");
error= 1;
goto err;
}
/* If server id is not set, start_slave_thread() will say it */
if (active_mi->host[0] && !opt_skip_slave_start)
{
if (start_slave_threads(1 /* need mutex */,
0 /* no wait for start*/,
active_mi,
master_info_file,
relay_log_info_file,
SLAVE_IO | SLAVE_SQL))
{
sql_print_error("Failed to create slave threads");
error= 1;
goto err;
}
}
err:
mysql_mutex_unlock(&LOCK_active_mi);
DBUG_RETURN(error);
}
/*
Updates the master info based on the information stored in the
relay info and ignores relay logs previously retrieved by the IO
thread, which thus starts fetching again based on to the
group_master_log_pos and group_master_log_name. Eventually, the old
relay logs will be purged by the normal purge mechanism.
In the feature, we should improve this routine in order to avoid throwing
away logs that are safely stored in the disk. Note also that this recovery
routine relies on the correctness of the relay-log.info and only tolerates
coordinate problems in master.info.
In this function, there is no need for a mutex as the caller
(i.e. init_slave) already has one acquired.
Specifically, the following structures are updated:
1 - mi->master_log_pos <-- rli->group_master_log_pos
2 - mi->master_log_name <-- rli->group_master_log_name
3 - It moves the relay log to the new relay log file, by
rli->group_relay_log_pos <-- BIN_LOG_HEADER_SIZE;
rli->event_relay_log_pos <-- BIN_LOG_HEADER_SIZE;
rli->group_relay_log_name <-- rli->relay_log.get_log_fname();
rli->event_relay_log_name <-- rli->relay_log.get_log_fname();
If there is an error, it returns (1), otherwise returns (0).
*/
int init_recovery(Master_info* mi, const char** errmsg)
{
DBUG_ENTER("init_recovery");
Relay_log_info *rli= &mi->rli;
if (rli->group_master_log_name[0])
{
mi->master_log_pos= max(BIN_LOG_HEADER_SIZE,
rli->group_master_log_pos);
strmake(mi->master_log_name, rli->group_master_log_name,
sizeof(mi->master_log_name)-1);
sql_print_warning("Recovery from master pos %ld and file %s.",
(ulong) mi->master_log_pos, mi->master_log_name);
strmake(rli->group_relay_log_name, rli->relay_log.get_log_fname(),
sizeof(rli->group_relay_log_name)-1);
strmake(rli->event_relay_log_name, rli->relay_log.get_log_fname(),
sizeof(mi->rli.event_relay_log_name)-1);
rli->group_relay_log_pos= rli->event_relay_log_pos= BIN_LOG_HEADER_SIZE;
}
DBUG_RETURN(0);
}
/**
Convert slave skip errors bitmap into a printable string.
*/
static void print_slave_skip_errors(void)
{
/*
To be safe, we want 10 characters of room in the buffer for a number
plus terminators. Also, we need some space for constant strings.
10 characters must be sufficient for a number plus {',' | '...'}
plus a NUL terminator. That is a max 6 digit number.
*/
const size_t MIN_ROOM= 10;
DBUG_ENTER("print_slave_skip_errors");
DBUG_ASSERT(sizeof(slave_skip_error_names) > MIN_ROOM);
DBUG_ASSERT(MAX_SLAVE_ERROR <= 999999); // 6 digits
/* Make @@slave_skip_errors show the nice human-readable value. */
opt_slave_skip_errors= slave_skip_error_names;
if (!use_slave_mask || bitmap_is_clear_all(&slave_error_mask))
{
/* purecov: begin tested */
memcpy(slave_skip_error_names, STRING_WITH_LEN("OFF"));
/* purecov: end */
}
else if (bitmap_is_set_all(&slave_error_mask))
{
/* purecov: begin tested */
memcpy(slave_skip_error_names, STRING_WITH_LEN("ALL"));
/* purecov: end */
}
else
{
char *buff= slave_skip_error_names;
char *bend= buff + sizeof(slave_skip_error_names);
int errnum;
for (errnum= 0; errnum < MAX_SLAVE_ERROR; errnum++)
{
if (bitmap_is_set(&slave_error_mask, errnum))
{
if (buff + MIN_ROOM >= bend)
break; /* purecov: tested */
buff= int10_to_str(errnum, buff, 10);
*buff++= ',';
}
}
if (buff != slave_skip_error_names)
buff--; // Remove last ','
if (errnum < MAX_SLAVE_ERROR)
{
/* Couldn't show all errors */
buff= strmov(buff, "..."); /* purecov: tested */
}
*buff=0;
}
DBUG_PRINT("init", ("error_names: '%s'", slave_skip_error_names));
DBUG_VOID_RETURN;
}
/*
Init function to set up array for errors that should be skipped for slave
SYNOPSIS
init_slave_skip_errors()
arg List of errors numbers to skip, separated with ','
NOTES
Called from get_options() in mysqld.cc on start-up
*/
void init_slave_skip_errors(const char* arg)
{
const char *p;
DBUG_ENTER("init_slave_skip_errors");
if (bitmap_init(&slave_error_mask,0,MAX_SLAVE_ERROR,0))
{
fprintf(stderr, "Badly out of memory, please check your system status\n");
exit(1);
}
use_slave_mask = 1;
for (;my_isspace(system_charset_info,*arg);++arg)
/* empty */;
if (!my_strnncoll(system_charset_info,(uchar*)arg,4,(const uchar*)"all",4))
{
bitmap_set_all(&slave_error_mask);
print_slave_skip_errors();
DBUG_VOID_RETURN;
}
for (p= arg ; *p; )
{
long err_code;
if (!(p= str2int(p, 10, 0, LONG_MAX, &err_code)))
break;
if (err_code < MAX_SLAVE_ERROR)
bitmap_set_bit(&slave_error_mask,(uint)err_code);
while (!my_isdigit(system_charset_info,*p) && *p)
p++;
}
/* Convert slave skip errors bitmap into a printable string. */
print_slave_skip_errors();
DBUG_VOID_RETURN;
}
static void set_thd_in_use_temporary_tables(Relay_log_info *rli)
{
TABLE *table;
for (table= rli->save_temporary_tables ; table ; table= table->next)
table->in_use= rli->sql_thd;
}
int terminate_slave_threads(Master_info* mi,int thread_mask,bool skip_lock)
{
DBUG_ENTER("terminate_slave_threads");
if (!mi->inited)
DBUG_RETURN(0); /* successfully do nothing */
int error,force_all = (thread_mask & SLAVE_FORCE_ALL);
mysql_mutex_t *sql_lock = &mi->rli.run_lock, *io_lock = &mi->run_lock;
mysql_mutex_t *log_lock= mi->rli.relay_log.get_log_lock();
if (thread_mask & (SLAVE_IO|SLAVE_FORCE_ALL))
{
DBUG_PRINT("info",("Terminating IO thread"));
mi->abort_slave=1;
if ((error=terminate_slave_thread(mi->io_thd, io_lock,
&mi->stop_cond,
&mi->slave_running,
skip_lock)) &&
!force_all)
DBUG_RETURN(error);
mysql_mutex_lock(log_lock);
DBUG_PRINT("info",("Flushing relay log and master info file."));
if (current_thd)
thd_proc_info(current_thd, "Flushing relay log and master info files.");
if (flush_master_info(mi, TRUE, FALSE))
DBUG_RETURN(ER_ERROR_DURING_FLUSH_LOGS);
if (my_sync(mi->rli.relay_log.get_log_file()->file, MYF(MY_WME)))
DBUG_RETURN(ER_ERROR_DURING_FLUSH_LOGS);
if (my_sync(mi->fd, MYF(MY_WME)))
DBUG_RETURN(ER_ERROR_DURING_FLUSH_LOGS);
mysql_mutex_unlock(log_lock);
}
if (thread_mask & (SLAVE_SQL|SLAVE_FORCE_ALL))
{
DBUG_PRINT("info",("Terminating SQL thread"));
mi->rli.abort_slave=1;
if ((error=terminate_slave_thread(mi->rli.sql_thd, sql_lock,
&mi->rli.stop_cond,
&mi->rli.slave_running,
skip_lock)) &&
!force_all)
DBUG_RETURN(error);
mysql_mutex_lock(log_lock);
DBUG_PRINT("info",("Flushing relay-log info file."));
if (current_thd)
thd_proc_info(current_thd, "Flushing relay-log info file.");
if (flush_relay_log_info(&mi->rli))
DBUG_RETURN(ER_ERROR_DURING_FLUSH_LOGS);
if (my_sync(mi->rli.info_fd, MYF(MY_WME)))
DBUG_RETURN(ER_ERROR_DURING_FLUSH_LOGS);
mysql_mutex_unlock(log_lock);
}
DBUG_RETURN(0);
}
/**
Wait for a slave thread to terminate.
This function is called after requesting the thread to terminate
(by setting @c abort_slave member of @c Relay_log_info or @c
Master_info structure to 1). Termination of the thread is
controlled with the the predicate <code>*slave_running</code>.
Function will acquire @c term_lock before waiting on the condition
unless @c skip_lock is true in which case the mutex should be owned
by the caller of this function and will remain acquired after
return from the function.
@param term_lock
Associated lock to use when waiting for @c term_cond
@param term_cond
Condition that is signalled when the thread has terminated
@param slave_running
Pointer to predicate to check for slave thread termination
@param skip_lock
If @c true the lock will not be acquired before waiting on
the condition. In this case, it is assumed that the calling
function acquires the lock before calling this function.
@retval 0 All OK ER_SLAVE_NOT_RUNNING otherwise.
@note If the executing thread has to acquire term_lock (skip_lock
is false), the negative running status does not represent
any issue therefore no error is reported.
*/
static int
terminate_slave_thread(THD *thd,
mysql_mutex_t *term_lock,
mysql_cond_t *term_cond,
volatile uint *slave_running,
bool skip_lock)
{
DBUG_ENTER("terminate_slave_thread");
if (!skip_lock)
{
mysql_mutex_lock(term_lock);
}
else
{
mysql_mutex_assert_owner(term_lock);
}
if (!*slave_running)
{
if (!skip_lock)
{
/*
if run_lock (term_lock) is acquired locally then either
slave_running status is fine
*/
mysql_mutex_unlock(term_lock);
DBUG_RETURN(0);
}
else
{
DBUG_RETURN(ER_SLAVE_NOT_RUNNING);
}
}
DBUG_ASSERT(thd != 0);
THD_CHECK_SENTRY(thd);
/*
Is is critical to test if the slave is running. Otherwise, we might
be referening freed memory trying to kick it
*/
while (*slave_running) // Should always be true
{
int error;
DBUG_PRINT("loop", ("killing slave thread"));
mysql_mutex_lock(&thd->LOCK_thd_data);
#ifndef DONT_USE_THR_ALARM
/*
Error codes from pthread_kill are:
EINVAL: invalid signal number (can't happen)
ESRCH: thread already killed (can happen, should be ignored)
*/
int err __attribute__((unused))= pthread_kill(thd->real_id, thr_client_alarm);
DBUG_ASSERT(err != EINVAL);
#endif
thd->awake(THD::NOT_KILLED);
mysql_mutex_unlock(&thd->LOCK_thd_data);
/*
There is a small chance that slave thread might miss the first
alarm. To protect againts it, resend the signal until it reacts
*/
struct timespec abstime;
set_timespec(abstime,2);
error= mysql_cond_timedwait(term_cond, term_lock, &abstime);
DBUG_ASSERT(error == ETIMEDOUT || error == 0);
}
DBUG_ASSERT(*slave_running == 0);
if (!skip_lock)
mysql_mutex_unlock(term_lock);
DBUG_RETURN(0);
}
int start_slave_thread(
#ifdef HAVE_PSI_INTERFACE
PSI_thread_key thread_key,
#endif
pthread_handler h_func, mysql_mutex_t *start_lock,
mysql_mutex_t *cond_lock,
mysql_cond_t *start_cond,
volatile uint *slave_running,
volatile ulong *slave_run_id,
Master_info* mi)
{
pthread_t th;
ulong start_id;
DBUG_ENTER("start_slave_thread");
DBUG_ASSERT(mi->inited);
if (start_lock)
mysql_mutex_lock(start_lock);
if (!server_id)
{
if (start_cond)
mysql_cond_broadcast(start_cond);
if (start_lock)
mysql_mutex_unlock(start_lock);
sql_print_error("Server id not set, will not start slave");
DBUG_RETURN(ER_BAD_SLAVE);
}
if (*slave_running)
{
if (start_cond)
mysql_cond_broadcast(start_cond);
if (start_lock)
mysql_mutex_unlock(start_lock);
DBUG_RETURN(ER_SLAVE_MUST_STOP);
}
start_id= *slave_run_id;
DBUG_PRINT("info",("Creating new slave thread"));
if (mysql_thread_create(thread_key,
&th, &connection_attrib, h_func, (void*)mi))
{
if (start_lock)
mysql_mutex_unlock(start_lock);
DBUG_RETURN(ER_SLAVE_THREAD);
}
if (start_cond && cond_lock) // caller has cond_lock
{
THD* thd = current_thd;
while (start_id == *slave_run_id)
{
DBUG_PRINT("sleep",("Waiting for slave thread to start"));
const char* old_msg = thd->enter_cond(start_cond,cond_lock,
"Waiting for slave thread to start");
mysql_cond_wait(start_cond, cond_lock);
thd->exit_cond(old_msg);
mysql_mutex_lock(cond_lock); // re-acquire it as exit_cond() released
if (thd->killed)
{
if (start_lock)
mysql_mutex_unlock(start_lock);
DBUG_RETURN(thd->killed_errno());
}
}
}
if (start_lock)
mysql_mutex_unlock(start_lock);
DBUG_RETURN(0);
}
/*
start_slave_threads()
NOTES
SLAVE_FORCE_ALL is not implemented here on purpose since it does not make
sense to do that for starting a slave--we always care if it actually
started the threads that were not previously running
*/
int start_slave_threads(bool need_slave_mutex, bool wait_for_start,
Master_info* mi, const char* master_info_fname,
const char* slave_info_fname, int thread_mask)
{
mysql_mutex_t *lock_io=0, *lock_sql=0, *lock_cond_io=0, *lock_cond_sql=0;
mysql_cond_t* cond_io=0, *cond_sql=0;
int error=0;
DBUG_ENTER("start_slave_threads");
if (need_slave_mutex)
{
lock_io = &mi->run_lock;
lock_sql = &mi->rli.run_lock;
}
if (wait_for_start)
{
cond_io = &mi->start_cond;
cond_sql = &mi->rli.start_cond;
lock_cond_io = &mi->run_lock;
lock_cond_sql = &mi->rli.run_lock;
}
if (thread_mask & SLAVE_IO)
error= start_slave_thread(
#ifdef HAVE_PSI_INTERFACE
key_thread_slave_io,
#endif
handle_slave_io, lock_io, lock_cond_io,
cond_io,
&mi->slave_running, &mi->slave_run_id,
mi);
if (!error && (thread_mask & SLAVE_SQL))
{
error= start_slave_thread(
#ifdef HAVE_PSI_INTERFACE
key_thread_slave_sql,
#endif
handle_slave_sql, lock_sql, lock_cond_sql,
cond_sql,
&mi->rli.slave_running, &mi->rli.slave_run_id,
mi);
if (error)
terminate_slave_threads(mi, thread_mask & SLAVE_IO, !need_slave_mutex);
}
DBUG_RETURN(error);
}
/*
Release slave threads at time of executing shutdown.
SYNOPSIS
end_slave()
*/
void end_slave()
{
DBUG_ENTER("end_slave");
/*
This is called when the server terminates, in close_connections().
It terminates slave threads. However, some CHANGE MASTER etc may still be
running presently. If a START SLAVE was in progress, the mutex lock below
will make us wait until slave threads have started, and START SLAVE
returns, then we terminate them here.
*/
mysql_mutex_lock(&LOCK_active_mi);
if (active_mi)
{
/*
TODO: replace the line below with
list_walk(&master_list, (list_walk_action)end_slave_on_walk,0);
once multi-master code is ready.
*/
terminate_slave_threads(active_mi,SLAVE_FORCE_ALL);
}
mysql_mutex_unlock(&LOCK_active_mi);
DBUG_VOID_RETURN;
}
/**
Free all resources used by slave threads at time of executing shutdown.
The routine must be called after all possible users of @c active_mi
have left.
SYNOPSIS
close_active_mi()
*/
void close_active_mi()
{
mysql_mutex_lock(&LOCK_active_mi);
if (active_mi)
{
end_master_info(active_mi);
delete active_mi;
active_mi= 0;
}
mysql_mutex_unlock(&LOCK_active_mi);
}
static bool io_slave_killed(THD* thd, Master_info* mi)
{
DBUG_ENTER("io_slave_killed");
DBUG_ASSERT(mi->io_thd == thd);
DBUG_ASSERT(mi->slave_running); // tracking buffer overrun
DBUG_RETURN(mi->abort_slave || abort_loop || thd->killed);
}
/**
The function analyzes a possible killed status and makes
a decision whether to accept it or not.
Normally upon accepting the sql thread goes to shutdown.
In the event of deffering decision @rli->last_event_start_time waiting
timer is set to force the killed status be accepted upon its expiration.
@param thd pointer to a THD instance
@param rli pointer to Relay_log_info instance
@return TRUE the killed status is recognized, FALSE a possible killed
status is deferred.
*/
static bool sql_slave_killed(THD* thd, Relay_log_info* rli)
{
bool ret= FALSE;
DBUG_ENTER("sql_slave_killed");
DBUG_ASSERT(rli->sql_thd == thd);
DBUG_ASSERT(rli->slave_running == 1);// tracking buffer overrun
if (abort_loop || thd->killed || rli->abort_slave)
{
/*
The transaction should always be binlogged if OPTION_KEEP_LOG is set
(it implies that something can not be rolled back). And such case
should be regarded similarly as modifing a non-transactional table
because retrying of the transaction will lead to an error or inconsistency
as well.
Example: OPTION_KEEP_LOG is set if a temporary table is created or dropped.
*/
if ((thd->transaction.all.modified_non_trans_table ||
(thd->variables.option_bits & OPTION_KEEP_LOG))
&& rli->is_in_group())
{
char msg_stopped[]=
"... The slave SQL is stopped, leaving the current group "
"of events unfinished with a non-transaction table changed. "
"If the group consists solely of Row-based events, you can try "
"restarting the slave with --slave-exec-mode=IDEMPOTENT, which "
"ignores duplicate key, key not found, and similar errors (see "
"documentation for details).";
if (rli->abort_slave)
{
DBUG_PRINT("info", ("Slave SQL thread is being stopped in the middle of"
" a group having updated a non-trans table, giving"
" it some grace period"));
/*
Slave sql thread shutdown in face of unfinished group modified
Non-trans table is handled via a timer. The slave may eventually
give out to complete the current group and in that case there
might be issues at consequent slave restart, see the error message.
WL#2975 offers a robust solution requiring to store the last exectuted
event's coordinates along with the group's coordianates
instead of waiting with @c last_event_start_time the timer.
*/
if (rli->last_event_start_time == 0)
rli->last_event_start_time= my_time(0);
ret= difftime(my_time(0), rli->last_event_start_time) <=
SLAVE_WAIT_GROUP_DONE ? FALSE : TRUE;
DBUG_EXECUTE_IF("stop_slave_middle_group",
DBUG_EXECUTE_IF("incomplete_group_in_relay_log",
ret= TRUE;);); // time is over
if (ret == 0)
{
rli->report(WARNING_LEVEL, 0,
"slave SQL thread is being stopped in the middle "
"of applying of a group having updated a non-transaction "
"table; waiting for the group completion ... ");
}
else
{
rli->report(ERROR_LEVEL, ER_SLAVE_FATAL_ERROR,
ER(ER_SLAVE_FATAL_ERROR), msg_stopped);
}
}
else
{
ret= TRUE;
rli->report(ERROR_LEVEL, ER_SLAVE_FATAL_ERROR, ER(ER_SLAVE_FATAL_ERROR),
msg_stopped);
}
}
else
{
ret= TRUE;
}
}
if (ret)
rli->last_event_start_time= 0;
DBUG_RETURN(ret);
}
/*
skip_load_data_infile()
NOTES
This is used to tell a 3.23 master to break send_file()
*/
void skip_load_data_infile(NET *net)
{
DBUG_ENTER("skip_load_data_infile");
(void)net_request_file(net, "/dev/null");
(void)my_net_read(net); // discard response
(void)net_write_command(net, 0, (uchar*) "", 0, (uchar*) "", 0); // ok
DBUG_VOID_RETURN;
}
bool net_request_file(NET* net, const char* fname)
{
DBUG_ENTER("net_request_file");
DBUG_RETURN(net_write_command(net, 251, (uchar*) fname, strlen(fname),
(uchar*) "", 0));
}
/*
From other comments and tests in code, it looks like
sometimes Query_log_event and Load_log_event can have db == 0
(see rewrite_db() above for example)
(cases where this happens are unclear; it may be when the master is 3.23).
*/
const char *print_slave_db_safe(const char* db)
{
DBUG_ENTER("*print_slave_db_safe");
DBUG_RETURN((db ? db : ""));
}
int init_strvar_from_file(char *var, int max_size, IO_CACHE *f,
const char *default_val)
{
uint length;
DBUG_ENTER("init_strvar_from_file");
if ((length=my_b_gets(f,var, max_size)))
{
char* last_p = var + length -1;
if (*last_p == '\n')
*last_p = 0; // if we stopped on newline, kill it
else
{
/*
If we truncated a line or stopped on last char, remove all chars
up to and including newline.
*/
int c;
while (((c=my_b_get(f)) != '\n' && c != my_b_EOF)) ;
}
DBUG_RETURN(0);
}
else if (default_val)
{
strmake(var, default_val, max_size-1);
DBUG_RETURN(0);
}
DBUG_RETURN(1);
}
int init_intvar_from_file(int* var, IO_CACHE* f, int default_val)
{
char buf[32];
DBUG_ENTER("init_intvar_from_file");
if (my_b_gets(f, buf, sizeof(buf)))
{
*var = atoi(buf);
DBUG_RETURN(0);
}
else if (default_val)
{
*var = default_val;
DBUG_RETURN(0);
}
DBUG_RETURN(1);
}
int init_floatvar_from_file(float* var, IO_CACHE* f, float default_val)
{
char buf[16];
DBUG_ENTER("init_floatvar_from_file");
if (my_b_gets(f, buf, sizeof(buf)))
{
if (sscanf(buf, "%f", var) != 1)
DBUG_RETURN(1);
else
DBUG_RETURN(0);
}
else if (default_val != 0.0)
{
*var = default_val;
DBUG_RETURN(0);
}
DBUG_RETURN(1);
}
/**
A master info read method
This function is called from @c init_master_info() along with
relatives to restore some of @c active_mi members.
Particularly, this function is responsible for restoring
IGNORE_SERVER_IDS list of servers whose events the slave is
going to ignore (to not log them in the relay log).
Items being read are supposed to be decimal output of values of a
type shorter or equal of @c long and separated by the single space.
@param arr @c DYNAMIC_ARRAY pointer to storage for servers id
@param f @c IO_CACHE pointer to the source file
@retval 0 All OK
@retval non-zero An error
*/
int init_dynarray_intvar_from_file(DYNAMIC_ARRAY* arr, IO_CACHE* f)
{
int ret= 0;
char buf[16 * (sizeof(long)*4 + 1)]; // static buffer to use most of times
char *buf_act= buf; // actual buffer can be dynamic if static is short
char *token, *last;
uint num_items; // number of items of `arr'
size_t read_size;
DBUG_ENTER("init_dynarray_intvar_from_file");
if ((read_size= my_b_gets(f, buf_act, sizeof(buf))) == 0)
{
return 0; // no line in master.info
}
if (read_size + 1 == sizeof(buf) && buf[sizeof(buf) - 2] != '\n')
{
/*
short read happend; allocate sufficient memory and make the 2nd read
*/
char buf_work[(sizeof(long)*3 + 1)*16];
memcpy(buf_work, buf, sizeof(buf_work));
num_items= atoi(strtok_r(buf_work, " ", &last));
size_t snd_size;
/*
max size lower bound approximate estimation bases on the formula:
(the items number + items themselves) *
(decimal size + space) - 1 + `\n' + '\0'
*/
size_t max_size= (1 + num_items) * (sizeof(long)*3 + 1) + 1;
buf_act= (char*) my_malloc(max_size, MYF(MY_WME));
memcpy(buf_act, buf, read_size);
snd_size= my_b_gets(f, buf_act + read_size, max_size - read_size);
if (snd_size == 0 ||
((snd_size + 1 == max_size - read_size) && buf[max_size - 2] != '\n'))
{
/*
failure to make the 2nd read or short read again
*/
ret= 1;
goto err;
}
}
token= strtok_r(buf_act, " ", &last);
if (token == NULL)
{
ret= 1;
goto err;
}
num_items= atoi(token);
for (uint i=0; i < num_items; i++)
{
token= strtok_r(NULL, " ", &last);
if (token == NULL)
{
ret= 1;
goto err;
}
else
{
ulong val= atol(token);
insert_dynamic(arr, (uchar *) &val);
}
}
err:
if (buf_act != buf)
my_free(buf_act);
DBUG_RETURN(ret);
}
/*
Check if the error is caused by network.
@param[in] errorno Number of the error.
RETURNS:
TRUE network error
FALSE not network error
*/
bool is_network_error(uint errorno)
{
if (errorno == CR_CONNECTION_ERROR ||
errorno == CR_CONN_HOST_ERROR ||
errorno == CR_SERVER_GONE_ERROR ||
errorno == CR_SERVER_LOST ||
errorno == ER_CON_COUNT_ERROR ||
errorno == ER_SERVER_SHUTDOWN)
return TRUE;
return FALSE;
}
/*
Note that we rely on the master's version (3.23, 4.0.14 etc) instead of
relying on the binlog's version. This is not perfect: imagine an upgrade
of the master without waiting that all slaves are in sync with the master;
then a slave could be fooled about the binlog's format. This is what happens
when people upgrade a 3.23 master to 4.0 without doing RESET MASTER: 4.0
slaves are fooled. So we do this only to distinguish between 3.23 and more
recent masters (it's too late to change things for 3.23).
RETURNS
0 ok
1 error
2 transient network problem, the caller should try to reconnect
*/
static int get_master_version_and_clock(MYSQL* mysql, Master_info* mi)
{
char err_buff[MAX_SLAVE_ERRMSG];
const char* errmsg= 0;
int err_code= 0;
MYSQL_RES *master_res= 0;
MYSQL_ROW master_row;
DBUG_ENTER("get_master_version_and_clock");
/*
Free old description_event_for_queue (that is needed if we are in
a reconnection).
*/
delete mi->rli.relay_log.description_event_for_queue;
mi->rli.relay_log.description_event_for_queue= 0;
if (!my_isdigit(&my_charset_bin,*mysql->server_version))
{
errmsg = "Master reported unrecognized MySQL version";
err_code= ER_SLAVE_FATAL_ERROR;
sprintf(err_buff, ER(err_code), errmsg);
}
else
{
/*
Note the following switch will bug when we have MySQL branch 30 ;)
*/
switch (*mysql->server_version)
{
case '0':
case '1':
case '2':
errmsg = "Master reported unrecognized MySQL version";
err_code= ER_SLAVE_FATAL_ERROR;
sprintf(err_buff, ER(err_code), errmsg);
break;
case '3':
mi->rli.relay_log.description_event_for_queue= new
Format_description_log_event(1, mysql->server_version);
break;
case '4':
mi->rli.relay_log.description_event_for_queue= new
Format_description_log_event(3, mysql->server_version);
break;
default:
/*
Master is MySQL >=5.0. Give a default Format_desc event, so that we can
take the early steps (like tests for "is this a 3.23 master") which we
have to take before we receive the real master's Format_desc which will
override this one. Note that the Format_desc we create below is garbage
(it has the format of the *slave*); it's only good to help know if the
master is 3.23, 4.0, etc.
*/
mi->rli.relay_log.description_event_for_queue= new
Format_description_log_event(4, mysql->server_version);
break;
}
}
/*
This does not mean that a 5.0 slave will be able to read a 6.0 master; but
as we don't know yet, we don't want to forbid this for now. If a 5.0 slave
can't read a 6.0 master, this will show up when the slave can't read some
events sent by the master, and there will be error messages.
*/
if (errmsg)
goto err;
/* as we are here, we tried to allocate the event */
if (!mi->rli.relay_log.description_event_for_queue)
{
errmsg= "default Format_description_log_event";
err_code= ER_SLAVE_CREATE_EVENT_FAILURE;
sprintf(err_buff, ER(err_code), errmsg);
goto err;
}
/*
Compare the master and slave's clock. Do not die if master's clock is
unavailable (very old master not supporting UNIX_TIMESTAMP()?).
*/
DBUG_EXECUTE_IF("dbug.before_get_UNIX_TIMESTAMP",
{
const char act[]=
"now "
"wait_for signal.get_unix_timestamp";
DBUG_ASSERT(opt_debug_sync_timeout > 0);
DBUG_ASSERT(!debug_sync_set_action(current_thd,
STRING_WITH_LEN(act)));
};);
master_res= NULL;
if (!mysql_real_query(mysql, STRING_WITH_LEN("SELECT UNIX_TIMESTAMP()")) &&
(master_res= mysql_store_result(mysql)) &&
(master_row= mysql_fetch_row(master_res)))
{
mi->clock_diff_with_master=
(long) (time((time_t*) 0) - strtoul(master_row[0], 0, 10));
}
else if (check_io_slave_killed(mi->io_thd, mi, NULL))
goto slave_killed_err;
else if (is_network_error(mysql_errno(mysql)))
{
mi->report(WARNING_LEVEL, mysql_errno(mysql),
"Get master clock failed with error: %s", mysql_error(mysql));
goto network_err;
}
else
{
mi->clock_diff_with_master= 0; /* The "most sensible" value */
sql_print_warning("\"SELECT UNIX_TIMESTAMP()\" failed on master, "
"do not trust column Seconds_Behind_Master of SHOW "
"SLAVE STATUS. Error: %s (%d)",
mysql_error(mysql), mysql_errno(mysql));
}
if (master_res)
{
mysql_free_result(master_res);
master_res= NULL;
}
/*
Check that the master's server id and ours are different. Because if they
are equal (which can result from a simple copy of master's datadir to slave,
thus copying some my.cnf), replication will work but all events will be
skipped.
Do not die if SHOW VARIABLES LIKE 'SERVER_ID' fails on master (very old
master?).
Note: we could have put a @@SERVER_ID in the previous SELECT
UNIX_TIMESTAMP() instead, but this would not have worked on 3.23 masters.
*/
DBUG_EXECUTE_IF("dbug.before_get_SERVER_ID",
{
const char act[]=
"now "
"wait_for signal.get_server_id";
DBUG_ASSERT(opt_debug_sync_timeout > 0);
DBUG_ASSERT(!debug_sync_set_action(current_thd,
STRING_WITH_LEN(act)));
};);
master_res= NULL;
master_row= NULL;
if (!mysql_real_query(mysql,
STRING_WITH_LEN("SHOW VARIABLES LIKE 'SERVER_ID'")) &&
(master_res= mysql_store_result(mysql)) &&
(master_row= mysql_fetch_row(master_res)))
{
if ((::server_id == (mi->master_id= strtoul(master_row[1], 0, 10))) &&
!mi->rli.replicate_same_server_id)
{
errmsg= "The slave I/O thread stops because master and slave have equal \
MySQL server ids; these ids must be different for replication to work (or \
the --replicate-same-server-id option must be used on slave but this does \
not always make sense; please check the manual before using it).";
err_code= ER_SLAVE_FATAL_ERROR;
sprintf(err_buff, ER(err_code), errmsg);
goto err;
}
}
else if (mysql_errno(mysql))
{
if (check_io_slave_killed(mi->io_thd, mi, NULL))
goto slave_killed_err;
else if (is_network_error(mysql_errno(mysql)))
{
mi->report(WARNING_LEVEL, mysql_errno(mysql),
"Get master SERVER_ID failed with error: %s", mysql_error(mysql));
goto network_err;
}
/* Fatal error */
errmsg= "The slave I/O thread stops because a fatal error is encountered \
when it try to get the value of SERVER_ID variable from master.";
err_code= mysql_errno(mysql);
sprintf(err_buff, "%s Error: %s", errmsg, mysql_error(mysql));
goto err;
}
else if (!master_row && master_res)
{
mi->report(WARNING_LEVEL, ER_UNKNOWN_SYSTEM_VARIABLE,
"Unknown system variable 'SERVER_ID' on master, \
maybe it is a *VERY OLD MASTER*.");
}
if (master_res)
{
mysql_free_result(master_res);
master_res= NULL;
}
if (mi->master_id == 0 && mi->ignore_server_ids.elements > 0)
{
errmsg= "Slave configured with server id filtering could not detect the master server id.";
err_code= ER_SLAVE_FATAL_ERROR;
sprintf(err_buff, ER(err_code), errmsg);
goto err;
}
/*
Check that the master's global character_set_server and ours are the same.
Not fatal if query fails (old master?).
Note that we don't check for equality of global character_set_client and
collation_connection (neither do we prevent their setting in
set_var.cc). That's because from what I (Guilhem) have tested, the global
values of these 2 are never used (new connections don't use them).
We don't test equality of global collation_database either as it's is
going to be deprecated (made read-only) in 4.1 very soon.
The test is only relevant if master < 5.0.3 (we'll test only if it's older
than the 5 branch; < 5.0.3 was alpha...), as >= 5.0.3 master stores
charset info in each binlog event.
We don't do it for 3.23 because masters <3.23.50 hang on
SELECT @@unknown_var (BUG#7965 - see changelog of 3.23.50). So finally we
test only if master is 4.x.
*/
/* redundant with rest of code but safer against later additions */
if (*mysql->server_version == '3')
goto err;
if (*mysql->server_version == '4')
{
master_res= NULL;
if (!mysql_real_query(mysql,
STRING_WITH_LEN("SELECT @@GLOBAL.COLLATION_SERVER")) &&
(master_res= mysql_store_result(mysql)) &&
(master_row= mysql_fetch_row(master_res)))
{
if (strcmp(master_row[0], global_system_variables.collation_server->name))
{
errmsg= "The slave I/O thread stops because master and slave have \
different values for the COLLATION_SERVER global variable. The values must \
be equal for the Statement-format replication to work";
err_code= ER_SLAVE_FATAL_ERROR;
sprintf(err_buff, ER(err_code), errmsg);
goto err;
}
}
else if (check_io_slave_killed(mi->io_thd, mi, NULL))
goto slave_killed_err;
else if (is_network_error(mysql_errno(mysql)))
{
mi->report(WARNING_LEVEL, mysql_errno(mysql),
"Get master COLLATION_SERVER failed with error: %s", mysql_error(mysql));
goto network_err;
}
else if (mysql_errno(mysql) != ER_UNKNOWN_SYSTEM_VARIABLE)
{
/* Fatal error */
errmsg= "The slave I/O thread stops because a fatal error is encountered \
when it try to get the value of COLLATION_SERVER global variable from master.";
err_code= mysql_errno(mysql);
sprintf(err_buff, "%s Error: %s", errmsg, mysql_error(mysql));
goto err;
}
else
mi->report(WARNING_LEVEL, ER_UNKNOWN_SYSTEM_VARIABLE,
"Unknown system variable 'COLLATION_SERVER' on master, \
maybe it is a *VERY OLD MASTER*. *NOTE*: slave may experience \
inconsistency if replicated data deals with collation.");
if (master_res)
{
mysql_free_result(master_res);
master_res= NULL;
}
}
/*
Perform analogous check for time zone. Theoretically we also should
perform check here to verify that SYSTEM time zones are the same on
slave and master, but we can't rely on value of @@system_time_zone
variable (it is time zone abbreviation) since it determined at start
time and so could differ for slave and master even if they are really
in the same system time zone. So we are omiting this check and just
relying on documentation. Also according to Monty there are many users
who are using replication between servers in various time zones. Hence
such check will broke everything for them. (And now everything will
work for them because by default both their master and slave will have
'SYSTEM' time zone).
This check is only necessary for 4.x masters (and < 5.0.4 masters but
those were alpha).
*/
if (*mysql->server_version == '4')
{
master_res= NULL;
if (!mysql_real_query(mysql, STRING_WITH_LEN("SELECT @@GLOBAL.TIME_ZONE")) &&
(master_res= mysql_store_result(mysql)) &&
(master_row= mysql_fetch_row(master_res)))
{
if (strcmp(master_row[0],
global_system_variables.time_zone->get_name()->ptr()))
{
errmsg= "The slave I/O thread stops because master and slave have \
different values for the TIME_ZONE global variable. The values must \
be equal for the Statement-format replication to work";
err_code= ER_SLAVE_FATAL_ERROR;
sprintf(err_buff, ER(err_code), errmsg);
goto err;
}
}
else if (check_io_slave_killed(mi->io_thd, mi, NULL))
goto slave_killed_err;
else if (is_network_error(mysql_errno(mysql)))
{
mi->report(WARNING_LEVEL, mysql_errno(mysql),
"Get master TIME_ZONE failed with error: %s", mysql_error(mysql));
goto network_err;
}
else
{
/* Fatal error */
errmsg= "The slave I/O thread stops because a fatal error is encountered \
when it try to get the value of TIME_ZONE global variable from master.";
err_code= mysql_errno(mysql);
sprintf(err_buff, "%s Error: %s", errmsg, mysql_error(mysql));
goto err;
}
if (master_res)
{
mysql_free_result(master_res);
master_res= NULL;
}
}
if (mi->heartbeat_period != 0.0)
{
char llbuf[22];
const char query_format[]= "SET @master_heartbeat_period= %s";
char query[sizeof(query_format) - 2 + sizeof(llbuf)];
/*
the period is an ulonglong of nano-secs.
*/
llstr((ulonglong) (mi->heartbeat_period*1000000000UL), llbuf);
sprintf(query, query_format, llbuf);
if (mysql_real_query(mysql, query, strlen(query))
&& !check_io_slave_killed(mi->io_thd, mi, NULL))
{
errmsg= "The slave I/O thread stops because SET @master_heartbeat_period "
"on master failed.";
err_code= ER_SLAVE_FATAL_ERROR;
sprintf(err_buff, "%s Error: %s", errmsg, mysql_error(mysql));
mysql_free_result(mysql_store_result(mysql));
goto err;
}
mysql_free_result(mysql_store_result(mysql));
}
err:
if (errmsg)
{
if (master_res)
mysql_free_result(master_res);
DBUG_ASSERT(err_code != 0);
mi->report(ERROR_LEVEL, err_code, "%s", err_buff);
DBUG_RETURN(1);
}
DBUG_RETURN(0);
network_err:
if (master_res)
mysql_free_result(master_res);
DBUG_RETURN(2);
slave_killed_err:
if (master_res)
mysql_free_result(master_res);
DBUG_RETURN(2);
}
static bool wait_for_relay_log_space(Relay_log_info* rli)
{
bool slave_killed=0;
Master_info* mi = rli->mi;
const char *save_proc_info;
THD* thd = mi->io_thd;
DBUG_ENTER("wait_for_relay_log_space");
mysql_mutex_lock(&rli->log_space_lock);
save_proc_info= thd->enter_cond(&rli->log_space_cond,
&rli->log_space_lock,
"\
Waiting for the slave SQL thread to free enough relay log space");
while (rli->log_space_limit < rli->log_space_total &&
!(slave_killed=io_slave_killed(thd,mi)) &&
!rli->ignore_log_space_limit)
mysql_cond_wait(&rli->log_space_cond, &rli->log_space_lock);
thd->exit_cond(save_proc_info);
DBUG_RETURN(slave_killed);
}
/*
Builds a Rotate from the ignored events' info and writes it to relay log.
SYNOPSIS
write_ignored_events_info_to_relay_log()
thd pointer to I/O thread's thd
mi
DESCRIPTION
Slave I/O thread, going to die, must leave a durable trace of the
ignored events' end position for the use of the slave SQL thread, by
calling this function. Only that thread can call it (see assertion).
*/
static void write_ignored_events_info_to_relay_log(THD *thd, Master_info *mi)
{
Relay_log_info *rli= &mi->rli;
mysql_mutex_t *log_lock= rli->relay_log.get_log_lock();
DBUG_ENTER("write_ignored_events_info_to_relay_log");
DBUG_ASSERT(thd == mi->io_thd);
mysql_mutex_lock(log_lock);
if (rli->ign_master_log_name_end[0])
{
DBUG_PRINT("info",("writing a Rotate event to track down ignored events"));
Rotate_log_event *ev= new Rotate_log_event(rli->ign_master_log_name_end,
0, rli->ign_master_log_pos_end,
Rotate_log_event::DUP_NAME);
rli->ign_master_log_name_end[0]= 0;
/* can unlock before writing as slave SQL thd will soon see our Rotate */
mysql_mutex_unlock(log_lock);
if (likely((bool)ev))
{
ev->server_id= 0; // don't be ignored by slave SQL thread
if (unlikely(rli->relay_log.append(ev)))
mi->report(ERROR_LEVEL, ER_SLAVE_RELAY_LOG_WRITE_FAILURE,
ER(ER_SLAVE_RELAY_LOG_WRITE_FAILURE),
"failed to write a Rotate event"
" to the relay log, SHOW SLAVE STATUS may be"
" inaccurate");
rli->relay_log.harvest_bytes_written(&rli->log_space_total);
if (flush_master_info(mi, TRUE, TRUE))
sql_print_error("Failed to flush master info file");
delete ev;
}
else
mi->report(ERROR_LEVEL, ER_SLAVE_CREATE_EVENT_FAILURE,
ER(ER_SLAVE_CREATE_EVENT_FAILURE),
"Rotate_event (out of memory?),"
" SHOW SLAVE STATUS may be inaccurate");
}
else
mysql_mutex_unlock(log_lock);
DBUG_VOID_RETURN;
}
int register_slave_on_master(MYSQL* mysql, Master_info *mi,
bool *suppress_warnings)
{
uchar buf[1024], *pos= buf;
uint report_host_len=0, report_user_len=0, report_password_len=0;
DBUG_ENTER("register_slave_on_master");
*suppress_warnings= FALSE;
if (report_host)
report_host_len= strlen(report_host);
if (report_host_len > HOSTNAME_LENGTH)
{
sql_print_warning("The length of report_host is %d. "
"It is larger than the max length(%d), so this "
"slave cannot be registered to the master.",
report_host_len, HOSTNAME_LENGTH);
DBUG_RETURN(0);
}
if (report_user)
report_user_len= strlen(report_user);
if (report_user_len > USERNAME_LENGTH)
{
sql_print_warning("The length of report_user is %d. "
"It is larger than the max length(%d), so this "
"slave cannot be registered to the master.",
report_user_len, USERNAME_LENGTH);
DBUG_RETURN(0);
}
if (report_password)
report_password_len= strlen(report_password);
if (report_password_len > MAX_PASSWORD_LENGTH)
{
sql_print_warning("The length of report_password is %d. "
"It is larger than the max length(%d), so this "
"slave cannot be registered to the master.",
report_password_len, MAX_PASSWORD_LENGTH);
DBUG_RETURN(0);
}
int4store(pos, server_id); pos+= 4;
pos= net_store_data(pos, (uchar*) report_host, report_host_len);
pos= net_store_data(pos, (uchar*) report_user, report_user_len);
pos= net_store_data(pos, (uchar*) report_password, report_password_len);
int2store(pos, (uint16) report_port); pos+= 2;
/*
Fake rpl_recovery_rank, which was removed in BUG#13963,
so that this server can register itself on old servers,
see BUG#49259.
*/
int4store(pos, /* rpl_recovery_rank */ 0); pos+= 4;
/* The master will fill in master_id */
int4store(pos, 0); pos+= 4;
if (simple_command(mysql, COM_REGISTER_SLAVE, buf, (size_t) (pos- buf), 0))
{
if (mysql_errno(mysql) == ER_NET_READ_INTERRUPTED)
{
*suppress_warnings= TRUE; // Suppress reconnect warning
}
else if (!check_io_slave_killed(mi->io_thd, mi, NULL))
{
char buf[256];
my_snprintf(buf, sizeof(buf), "%s (Errno: %d)", mysql_error(mysql),
mysql_errno(mysql));
mi->report(ERROR_LEVEL, ER_SLAVE_MASTER_COM_FAILURE,
ER(ER_SLAVE_MASTER_COM_FAILURE), "COM_REGISTER_SLAVE", buf);
}
DBUG_RETURN(1);
}
DBUG_RETURN(0);
}
/**
Execute a SHOW SLAVE STATUS statement.
@param thd Pointer to THD object for the client thread executing the
statement.
@param mi Pointer to Master_info object for the IO thread.
@retval FALSE success
@retval TRUE failure
*/
bool show_master_info(THD* thd, Master_info* mi)
{
// TODO: fix this for multi-master
List<Item> field_list;
Protocol *protocol= thd->protocol;
DBUG_ENTER("show_master_info");
field_list.push_back(new Item_empty_string("Slave_IO_State",
14));
field_list.push_back(new Item_empty_string("Master_Host",
sizeof(mi->host)));
field_list.push_back(new Item_empty_string("Master_User",
sizeof(mi->user)));
field_list.push_back(new Item_return_int("Master_Port", 7,
MYSQL_TYPE_LONG));
field_list.push_back(new Item_return_int("Connect_Retry", 10,
MYSQL_TYPE_LONG));
field_list.push_back(new Item_empty_string("Master_Log_File",
FN_REFLEN));
field_list.push_back(new Item_return_int("Read_Master_Log_Pos", 10,
MYSQL_TYPE_LONGLONG));
field_list.push_back(new Item_empty_string("Relay_Log_File",
FN_REFLEN));
field_list.push_back(new Item_return_int("Relay_Log_Pos", 10,
MYSQL_TYPE_LONGLONG));
field_list.push_back(new Item_empty_string("Relay_Master_Log_File",
FN_REFLEN));
field_list.push_back(new Item_empty_string("Slave_IO_Running", 3));
field_list.push_back(new Item_empty_string("Slave_SQL_Running", 3));
field_list.push_back(new Item_empty_string("Replicate_Do_DB", 20));
field_list.push_back(new Item_empty_string("Replicate_Ignore_DB", 20));
field_list.push_back(new Item_empty_string("Replicate_Do_Table", 20));
field_list.push_back(new Item_empty_string("Replicate_Ignore_Table", 23));
field_list.push_back(new Item_empty_string("Replicate_Wild_Do_Table", 24));
field_list.push_back(new Item_empty_string("Replicate_Wild_Ignore_Table",
28));
field_list.push_back(new Item_return_int("Last_Errno", 4, MYSQL_TYPE_LONG));
field_list.push_back(new Item_empty_string("Last_Error", 20));
field_list.push_back(new Item_return_int("Skip_Counter", 10,
MYSQL_TYPE_LONG));
field_list.push_back(new Item_return_int("Exec_Master_Log_Pos", 10,
MYSQL_TYPE_LONGLONG));
field_list.push_back(new Item_return_int("Relay_Log_Space", 10,
MYSQL_TYPE_LONGLONG));
field_list.push_back(new Item_empty_string("Until_Condition", 6));
field_list.push_back(new Item_empty_string("Until_Log_File", FN_REFLEN));
field_list.push_back(new Item_return_int("Until_Log_Pos", 10,
MYSQL_TYPE_LONGLONG));
field_list.push_back(new Item_empty_string("Master_SSL_Allowed", 7));
field_list.push_back(new Item_empty_string("Master_SSL_CA_File",
sizeof(mi->ssl_ca)));
field_list.push_back(new Item_empty_string("Master_SSL_CA_Path",
sizeof(mi->ssl_capath)));
field_list.push_back(new Item_empty_string("Master_SSL_Cert",
sizeof(mi->ssl_cert)));
field_list.push_back(new Item_empty_string("Master_SSL_Cipher",
sizeof(mi->ssl_cipher)));
field_list.push_back(new Item_empty_string("Master_SSL_Key",
sizeof(mi->ssl_key)));
field_list.push_back(new Item_return_int("Seconds_Behind_Master", 10,
MYSQL_TYPE_LONGLONG));
field_list.push_back(new Item_empty_string("Master_SSL_Verify_Server_Cert",
3));
field_list.push_back(new Item_return_int("Last_IO_Errno", 4, MYSQL_TYPE_LONG));
field_list.push_back(new Item_empty_string("Last_IO_Error", 20));
field_list.push_back(new Item_return_int("Last_SQL_Errno", 4, MYSQL_TYPE_LONG));
field_list.push_back(new Item_empty_string("Last_SQL_Error", 20));
field_list.push_back(new Item_empty_string("Replicate_Ignore_Server_Ids",
FN_REFLEN));
field_list.push_back(new Item_return_int("Master_Server_Id", sizeof(ulong),
MYSQL_TYPE_LONG));
if (protocol->send_result_set_metadata(&field_list,
Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF))
DBUG_RETURN(TRUE);
if (mi->host[0])
{
DBUG_PRINT("info",("host is set: '%s'", mi->host));
String *packet= &thd->packet;
protocol->prepare_for_resend();
/*
slave_running can be accessed without run_lock but not other
non-volotile members like mi->io_thd, which is guarded by the mutex.
*/
mysql_mutex_lock(&mi->run_lock);
protocol->store(mi->io_thd ? mi->io_thd->proc_info : "", &my_charset_bin);
mysql_mutex_unlock(&mi->run_lock);
mysql_mutex_lock(&mi->data_lock);
mysql_mutex_lock(&mi->rli.data_lock);
mysql_mutex_lock(&mi->err_lock);
mysql_mutex_lock(&mi->rli.err_lock);
protocol->store(mi->host, &my_charset_bin);
protocol->store(mi->user, &my_charset_bin);
protocol->store((uint32) mi->port);
protocol->store((uint32) mi->connect_retry);
protocol->store(mi->master_log_name, &my_charset_bin);
protocol->store((ulonglong) mi->master_log_pos);
protocol->store(mi->rli.group_relay_log_name +
dirname_length(mi->rli.group_relay_log_name),
&my_charset_bin);
protocol->store((ulonglong) mi->rli.group_relay_log_pos);
protocol->store(mi->rli.group_master_log_name, &my_charset_bin);
protocol->store(mi->slave_running == MYSQL_SLAVE_RUN_CONNECT ?
"Yes" : (mi->slave_running == MYSQL_SLAVE_RUN_NOT_CONNECT ?
"Connecting" : "No"), &my_charset_bin);
protocol->store(mi->rli.slave_running ? "Yes":"No", &my_charset_bin);
protocol->store(rpl_filter->get_do_db());
protocol->store(rpl_filter->get_ignore_db());
char buf[256];
String tmp(buf, sizeof(buf), &my_charset_bin);
rpl_filter->get_do_table(&tmp);
protocol->store(&tmp);
rpl_filter->get_ignore_table(&tmp);
protocol->store(&tmp);
rpl_filter->get_wild_do_table(&tmp);
protocol->store(&tmp);
rpl_filter->get_wild_ignore_table(&tmp);
protocol->store(&tmp);
protocol->store(mi->rli.last_error().number);
protocol->store(mi->rli.last_error().message, &my_charset_bin);
protocol->store((uint32) mi->rli.slave_skip_counter);
protocol->store((ulonglong) mi->rli.group_master_log_pos);
protocol->store((ulonglong) mi->rli.log_space_total);
protocol->store(
mi->rli.until_condition==Relay_log_info::UNTIL_NONE ? "None":
( mi->rli.until_condition==Relay_log_info::UNTIL_MASTER_POS? "Master":
"Relay"), &my_charset_bin);
protocol->store(mi->rli.until_log_name, &my_charset_bin);
protocol->store((ulonglong) mi->rli.until_log_pos);
#ifdef HAVE_OPENSSL
protocol->store(mi->ssl? "Yes":"No", &my_charset_bin);
#else
protocol->store(mi->ssl? "Ignored":"No", &my_charset_bin);
#endif
protocol->store(mi->ssl_ca, &my_charset_bin);
protocol->store(mi->ssl_capath, &my_charset_bin);
protocol->store(mi->ssl_cert, &my_charset_bin);
protocol->store(mi->ssl_cipher, &my_charset_bin);
protocol->store(mi->ssl_key, &my_charset_bin);
/*
Seconds_Behind_Master: if SQL thread is running and I/O thread is
connected, we can compute it otherwise show NULL (i.e. unknown).
*/
if ((mi->slave_running == MYSQL_SLAVE_RUN_CONNECT) &&
mi->rli.slave_running)
{
long time_diff= ((long)(time(0) - mi->rli.last_master_timestamp)
- mi->clock_diff_with_master);
/*
Apparently on some systems time_diff can be <0. Here are possible
reasons related to MySQL:
- the master is itself a slave of another master whose time is ahead.
- somebody used an explicit SET TIMESTAMP on the master.
Possible reason related to granularity-to-second of time functions
(nothing to do with MySQL), which can explain a value of -1:
assume the master's and slave's time are perfectly synchronized, and
that at slave's connection time, when the master's timestamp is read,
it is at the very end of second 1, and (a very short time later) when
the slave's timestamp is read it is at the very beginning of second
2. Then the recorded value for master is 1 and the recorded value for
slave is 2. At SHOW SLAVE STATUS time, assume that the difference
between timestamp of slave and rli->last_master_timestamp is 0
(i.e. they are in the same second), then we get 0-(2-1)=-1 as a result.
This confuses users, so we don't go below 0: hence the max().
last_master_timestamp == 0 (an "impossible" timestamp 1970) is a
special marker to say "consider we have caught up".
*/
protocol->store((longlong)(mi->rli.last_master_timestamp ?
max(0, time_diff) : 0));
}
else
{
protocol->store_null();
}
protocol->store(mi->ssl_verify_server_cert? "Yes":"No", &my_charset_bin);
// Last_IO_Errno
protocol->store(mi->last_error().number);
// Last_IO_Error
protocol->store(mi->last_error().message, &my_charset_bin);
// Last_SQL_Errno
protocol->store(mi->rli.last_error().number);
// Last_SQL_Error
protocol->store(mi->rli.last_error().message, &my_charset_bin);
// Replicate_Ignore_Server_Ids
{
char buff[FN_REFLEN];
ulong i, cur_len;
for (i= 0, buff[0]= 0, cur_len= 0;
i < mi->ignore_server_ids.elements; i++)
{
ulong s_id, slen;
char sbuff[FN_REFLEN];
get_dynamic(&mi->ignore_server_ids, (uchar*) &s_id, i);
slen= sprintf(sbuff, (i==0? "%lu" : ", %lu"), s_id);
if (cur_len + slen + 4 > FN_REFLEN)
{
/*
break the loop whenever remained space could not fit
ellipses on the next cycle
*/
sprintf(buff + cur_len, "...");
break;
}
cur_len += sprintf(buff + cur_len, "%s", sbuff);
}
protocol->store(buff, &my_charset_bin);
}
// Master_Server_id
protocol->store((uint32) mi->master_id);
mysql_mutex_unlock(&mi->rli.err_lock);
mysql_mutex_unlock(&mi->err_lock);
mysql_mutex_unlock(&mi->rli.data_lock);
mysql_mutex_unlock(&mi->data_lock);
if (my_net_write(&thd->net, (uchar*) thd->packet.ptr(), packet->length()))
DBUG_RETURN(TRUE);
}
my_eof(thd);
DBUG_RETURN(FALSE);
}
void set_slave_thread_options(THD* thd)
{
DBUG_ENTER("set_slave_thread_options");
/*
It's nonsense to constrain the slave threads with max_join_size; if a
query succeeded on master, we HAVE to execute it. So set
OPTION_BIG_SELECTS. Setting max_join_size to HA_POS_ERROR is not enough
(and it's not needed if we have OPTION_BIG_SELECTS) because an INSERT
SELECT examining more than 4 billion rows would still fail (yes, because
when max_join_size is 4G, OPTION_BIG_SELECTS is automatically set, but
only for client threads.
*/
ulonglong options= thd->variables.option_bits | OPTION_BIG_SELECTS;
if (opt_log_slave_updates)
options|= OPTION_BIN_LOG;
else
options&= ~OPTION_BIN_LOG;
thd->variables.option_bits= options;
thd->variables.completion_type= 0;
DBUG_VOID_RETURN;
}
void set_slave_thread_default_charset(THD* thd, Relay_log_info const *rli)
{
DBUG_ENTER("set_slave_thread_default_charset");
thd->variables.character_set_client=
global_system_variables.character_set_client;
thd->variables.collation_connection=
global_system_variables.collation_connection;
thd->variables.collation_server=
global_system_variables.collation_server;
thd->update_charset();
/*
We use a const cast here since the conceptual (and externally
visible) behavior of the function is to set the default charset of
the thread. That the cache has to be invalidated is a secondary
effect.
*/
const_cast<Relay_log_info*>(rli)->cached_charset_invalidate();
DBUG_VOID_RETURN;
}
/*
init_slave_thread()
*/
static int init_slave_thread(THD* thd, SLAVE_THD_TYPE thd_type)
{
DBUG_ENTER("init_slave_thread");
#if !defined(DBUG_OFF)
int simulate_error= 0;
#endif
thd->system_thread = (thd_type == SLAVE_THD_SQL) ?
SYSTEM_THREAD_SLAVE_SQL : SYSTEM_THREAD_SLAVE_IO;
thd->security_ctx->skip_grants();
my_net_init(&thd->net, 0);
/*
Adding MAX_LOG_EVENT_HEADER_LEN to the max_allowed_packet on all
slave threads, since a replication event can become this much larger
than the corresponding packet (query) sent from client to master.
*/
thd->variables.max_allowed_packet= global_system_variables.max_allowed_packet
+ MAX_LOG_EVENT_HEADER; /* note, incr over the global not session var */
thd->slave_thread = 1;
thd->enable_slow_log= opt_log_slow_slave_statements;
set_slave_thread_options(thd);
thd->client_capabilities = CLIENT_LOCAL_FILES;
mysql_mutex_lock(&LOCK_thread_count);
thd->thread_id= thd->variables.pseudo_thread_id= thread_id++;
mysql_mutex_unlock(&LOCK_thread_count);
DBUG_EXECUTE_IF("simulate_io_slave_error_on_init",
simulate_error|= (1 << SLAVE_THD_IO););
DBUG_EXECUTE_IF("simulate_sql_slave_error_on_init",
simulate_error|= (1 << SLAVE_THD_SQL););
#if !defined(DBUG_OFF)
if (init_thr_lock() || thd->store_globals() || simulate_error & (1<< thd_type))
#else
if (init_thr_lock() || thd->store_globals())
#endif
{
thd->cleanup();
DBUG_RETURN(-1);
}
if (thd_type == SLAVE_THD_SQL)
thd_proc_info(thd, "Waiting for the next event in relay log");
else
thd_proc_info(thd, "Waiting for master update");
thd->set_time();
/* Do not use user-supplied timeout value for system threads. */
thd->variables.lock_wait_timeout= LONG_TIMEOUT;
DBUG_RETURN(0);
}
static int safe_sleep(THD* thd, int sec, CHECK_KILLED_FUNC thread_killed,
void* thread_killed_arg)
{
int nap_time;
thr_alarm_t alarmed;
DBUG_ENTER("safe_sleep");
thr_alarm_init(&alarmed);
time_t start_time= my_time(0);
time_t end_time= start_time+sec;
while ((nap_time= (int) (end_time - start_time)) > 0)
{
ALARM alarm_buff;
/*
The only reason we are asking for alarm is so that
we will be woken up in case of murder, so if we do not get killed,
set the alarm so it goes off after we wake up naturally
*/
thr_alarm(&alarmed, 2 * nap_time, &alarm_buff);
sleep(nap_time);
thr_end_alarm(&alarmed);
if ((*thread_killed)(thd,thread_killed_arg))
DBUG_RETURN(1);
start_time= my_time(0);
}
DBUG_RETURN(0);
}
static int request_dump(THD *thd, MYSQL* mysql, Master_info* mi,
bool *suppress_warnings)
{
uchar buf[FN_REFLEN + 10];
int len;
ushort binlog_flags = 0; // for now
char* logname = mi->master_log_name;
DBUG_ENTER("request_dump");
*suppress_warnings= FALSE;
if (RUN_HOOK(binlog_relay_io,
before_request_transmit,
(thd, mi, binlog_flags)))
DBUG_RETURN(1);
// TODO if big log files: Change next to int8store()
int4store(buf, (ulong) mi->master_log_pos);
int2store(buf + 4, binlog_flags);
int4store(buf + 6, server_id);
len = (uint) strlen(logname);
memcpy(buf + 10, logname,len);
if (simple_command(mysql, COM_BINLOG_DUMP, buf, len + 10, 1))
{
/*
Something went wrong, so we will just reconnect and retry later
in the future, we should do a better error analysis, but for
now we just fill up the error log :-)
*/
if (mysql_errno(mysql) == ER_NET_READ_INTERRUPTED)
*suppress_warnings= TRUE; // Suppress reconnect warning
else
sql_print_error("Error on COM_BINLOG_DUMP: %d %s, will retry in %d secs",
mysql_errno(mysql), mysql_error(mysql),
mi->connect_retry);
DBUG_RETURN(1);
}
DBUG_RETURN(0);
}
/*
Read one event from the master
SYNOPSIS
read_event()
mysql MySQL connection
mi Master connection information
suppress_warnings TRUE when a normal net read timeout has caused us to
try a reconnect. We do not want to print anything to
the error log in this case because this a anormal
event in an idle server.
RETURN VALUES
'packet_error' Error
number Length of packet
*/
static ulong read_event(MYSQL* mysql, Master_info *mi, bool* suppress_warnings)
{
ulong len;
DBUG_ENTER("read_event");
*suppress_warnings= FALSE;
/*
my_real_read() will time us out
We check if we were told to die, and if not, try reading again
*/
#ifndef DBUG_OFF
if (disconnect_slave_event_count && !(mi->events_till_disconnect--))
DBUG_RETURN(packet_error);
#endif
len = cli_safe_read(mysql);
if (len == packet_error || (long) len < 1)
{
if (mysql_errno(mysql) == ER_NET_READ_INTERRUPTED)
{
/*
We are trying a normal reconnect after a read timeout;
we suppress prints to .err file as long as the reconnect
happens without problems
*/
*suppress_warnings= TRUE;
}
else
sql_print_error("Error reading packet from server: %s ( server_errno=%d)",
mysql_error(mysql), mysql_errno(mysql));
DBUG_RETURN(packet_error);
}
/* Check if eof packet */
if (len < 8 && mysql->net.read_pos[0] == 254)
{
sql_print_information("Slave: received end packet from server, apparent "
"master shutdown: %s",
mysql_error(mysql));
DBUG_RETURN(packet_error);
}
DBUG_PRINT("exit", ("len: %lu net->read_pos[4]: %d",
len, mysql->net.read_pos[4]));
DBUG_RETURN(len - 1);
}
/*
Check if the current error is of temporary nature of not.
Some errors are temporary in nature, such as
ER_LOCK_DEADLOCK and ER_LOCK_WAIT_TIMEOUT. Ndb also signals
that the error is temporary by pushing a warning with the error code
ER_GET_TEMPORARY_ERRMSG, if the originating error is temporary.
*/
static int has_temporary_error(THD *thd)
{
DBUG_ENTER("has_temporary_error");
DBUG_EXECUTE_IF("all_errors_are_temporary_errors",
if (thd->stmt_da->is_error())
{
thd->clear_error();
my_error(ER_LOCK_DEADLOCK, MYF(0));
});
/*
If there is no message in THD, we can't say if it's a temporary
error or not. This is currently the case for Incident_log_event,
which sets no message. Return FALSE.
*/
if (!thd->is_error())
DBUG_RETURN(0);
/*
Temporary error codes:
currently, InnoDB deadlock detected by InnoDB or lock
wait timeout (innodb_lock_wait_timeout exceeded
*/
if (thd->stmt_da->sql_errno() == ER_LOCK_DEADLOCK ||
thd->stmt_da->sql_errno() == ER_LOCK_WAIT_TIMEOUT)
DBUG_RETURN(1);
#ifdef HAVE_NDB_BINLOG
/*
currently temporary error set in ndbcluster
*/
List_iterator_fast<MYSQL_ERROR> it(thd->warning_info->warn_list());
MYSQL_ERROR *err;
while ((err= it++))
{
DBUG_PRINT("info", ("has condition %d %s", err->get_sql_errno(),
err->get_message_text()));
switch (err->get_sql_errno())
{
case ER_GET_TEMPORARY_ERRMSG:
DBUG_RETURN(1);
default:
break;
}
}
#endif
DBUG_RETURN(0);
}
/**
Applies the given event and advances the relay log position.
In essence, this function does:
@code
ev->apply_event(rli);
ev->update_pos(rli);
@endcode
But it also does some maintainance, such as skipping events if
needed and reporting errors.
If the @c skip flag is set, then it is tested whether the event
should be skipped, by looking at the slave_skip_counter and the
server id. The skip flag should be set when calling this from a
replication thread but not set when executing an explicit BINLOG
statement.
@retval 0 OK.
@retval 1 Error calling ev->apply_event().
@retval 2 No error calling ev->apply_event(), but error calling
ev->update_pos().
*/
int apply_event_and_update_pos(Log_event* ev, THD* thd, Relay_log_info* rli)
{
int exec_res= 0;
DBUG_ENTER("apply_event_and_update_pos");
DBUG_PRINT("exec_event",("%s(type_code: %d; server_id: %d)",
ev->get_type_str(), ev->get_type_code(),
ev->server_id));
DBUG_PRINT("info", ("thd->options: %s%s; rli->last_event_start_time: %lu",
FLAGSTR(thd->variables.option_bits, OPTION_NOT_AUTOCOMMIT),
FLAGSTR(thd->variables.option_bits, OPTION_BEGIN),
(ulong) rli->last_event_start_time));
/*
Execute the event to change the database and update the binary
log coordinates, but first we set some data that is needed for
the thread.
The event will be executed unless it is supposed to be skipped.
Queries originating from this server must be skipped. Low-level
events (Format_description_log_event, Rotate_log_event,
Stop_log_event) from this server must also be skipped. But for
those we don't want to modify 'group_master_log_pos', because
these events did not exist on the master.
Format_description_log_event is not completely skipped.
Skip queries specified by the user in 'slave_skip_counter'. We
can't however skip events that has something to do with the log
files themselves.
Filtering on own server id is extremely important, to ignore
execution of events created by the creation/rotation of the relay
log (remember that now the relay log starts with its Format_desc,
has a Rotate etc).
*/
thd->server_id = ev->server_id; // use the original server id for logging
thd->set_time(); // time the query
thd->lex->current_select= 0;
if (!ev->when)
ev->when= my_time(0);
ev->thd = thd; // because up to this point, ev->thd == 0
int reason= ev->shall_skip(rli);
if (reason == Log_event::EVENT_SKIP_COUNT)
sql_slave_skip_counter= --rli->slave_skip_counter;
mysql_mutex_unlock(&rli->data_lock);
if (reason == Log_event::EVENT_SKIP_NOT)
exec_res= ev->apply_event(rli);
#ifndef DBUG_OFF
/*
This only prints information to the debug trace.
TODO: Print an informational message to the error log?
*/
static const char *const explain[] = {
// EVENT_SKIP_NOT,
"not skipped",
// EVENT_SKIP_IGNORE,
"skipped because event should be ignored",
// EVENT_SKIP_COUNT
"skipped because event skip counter was non-zero"
};
DBUG_PRINT("info", ("OPTION_BEGIN: %d; IN_STMT: %d",
test(thd->variables.option_bits & OPTION_BEGIN),
rli->get_flag(Relay_log_info::IN_STMT)));
DBUG_PRINT("skip_event", ("%s event was %s",
ev->get_type_str(), explain[reason]));
#endif
DBUG_PRINT("info", ("apply_event error = %d", exec_res));
if (exec_res == 0)
{
int error= ev->update_pos(rli);
#ifdef HAVE_purify
if (!rli->is_fake)
#endif
{
#ifndef DBUG_OFF
char buf[22];
#endif
DBUG_PRINT("info", ("update_pos error = %d", error));
DBUG_PRINT("info", ("group %s %s",
llstr(rli->group_relay_log_pos, buf),
rli->group_relay_log_name));
DBUG_PRINT("info", ("event %s %s",
llstr(rli->event_relay_log_pos, buf),
rli->event_relay_log_name));
}
/*
The update should not fail, so print an error message and
return an error code.
TODO: Replace this with a decent error message when merged
with BUG#24954 (which adds several new error message).
*/
if (error)
{
char buf[22];
rli->report(ERROR_LEVEL, ER_UNKNOWN_ERROR,
"It was not possible to update the positions"
" of the relay log information: the slave may"
" be in an inconsistent state."
" Stopped in %s position %s",
rli->group_relay_log_name,
llstr(rli->group_relay_log_pos, buf));
DBUG_RETURN(2);
}
}
DBUG_RETURN(exec_res ? 1 : 0);
}
/**
Top-level function for executing the next event from the relay log.
This function reads the event from the relay log, executes it, and
advances the relay log position. It also handles errors, etc.
This function may fail to apply the event for the following reasons:
- The position specfied by the UNTIL condition of the START SLAVE
command is reached.
- It was not possible to read the event from the log.
- The slave is killed.
- An error occurred when applying the event, and the event has been
tried slave_trans_retries times. If the event has been retried
fewer times, 0 is returned.
- init_master_info or init_relay_log_pos failed. (These are called
if a failure occurs when applying the event.)
- An error occurred when updating the binlog position.
@retval 0 The event was applied.
@retval 1 The event was not applied.
*/
static int exec_relay_log_event(THD* thd, Relay_log_info* rli)
{
DBUG_ENTER("exec_relay_log_event");
/*
We acquire this mutex since we need it for all operations except
event execution. But we will release it in places where we will
wait for something for example inside of next_event().
*/
mysql_mutex_lock(&rli->data_lock);
Log_event * ev = next_event(rli);
DBUG_ASSERT(rli->sql_thd==thd);
if (sql_slave_killed(thd,rli))
{
mysql_mutex_unlock(&rli->data_lock);
delete ev;
DBUG_RETURN(1);
}
if (ev)
{
int exec_res;
/*
This tests if the position of the beginning of the current event
hits the UNTIL barrier.
*/
if (rli->until_condition != Relay_log_info::UNTIL_NONE &&
rli->is_until_satisfied(thd, ev))
{
char buf[22];
sql_print_information("Slave SQL thread stopped because it reached its"
" UNTIL position %s", llstr(rli->until_pos(), buf));
/*
Setting abort_slave flag because we do not want additional message about
error in query execution to be printed.
*/
rli->abort_slave= 1;
mysql_mutex_unlock(&rli->data_lock);
delete ev;
DBUG_RETURN(1);
}
{ /**
The following failure injecion works in cooperation with tests
setting @@global.debug= 'd,incomplete_group_in_relay_log'.
Xid or Commit events are not executed to force the slave sql
read hanging if the realy log does not have any more events.
*/
DBUG_EXECUTE_IF("incomplete_group_in_relay_log",
if ((ev->get_type_code() == XID_EVENT) ||
((ev->get_type_code() == QUERY_EVENT) &&
strcmp("COMMIT", ((Query_log_event *) ev)->query) == 0))
{
DBUG_ASSERT(thd->transaction.all.modified_non_trans_table);
rli->abort_slave= 1;
mysql_mutex_unlock(&rli->data_lock);
delete ev;
rli->inc_event_relay_log_pos();
DBUG_RETURN(0);
};);
}
exec_res= apply_event_and_update_pos(ev, thd, rli);
/*
Format_description_log_event should not be deleted because it will be
used to read info about the relay log's format; it will be deleted when
the SQL thread does not need it, i.e. when this thread terminates.
*/
if (ev->get_type_code() != FORMAT_DESCRIPTION_EVENT)
{
DBUG_PRINT("info", ("Deleting the event after it has been executed"));
delete ev;
}
/*
update_log_pos failed: this should not happen, so we don't
retry.
*/
if (exec_res == 2)
DBUG_RETURN(1);
if (slave_trans_retries)
{
int temp_err;
if (exec_res && (temp_err= has_temporary_error(thd)))
{
const char *errmsg;
/*
We were in a transaction which has been rolled back because of a
temporary error;
let's seek back to BEGIN log event and retry it all again.
Note, if lock wait timeout (innodb_lock_wait_timeout exceeded)
there is no rollback since 5.0.13 (ref: manual).
We have to not only seek but also
a) init_master_info(), to seek back to hot relay log's start for later
(for when we will come back to this hot log after re-processing the
possibly existing old logs where BEGIN is: check_binlog_magic() will
then need the cache to be at position 0 (see comments at beginning of
init_master_info()).
b) init_relay_log_pos(), because the BEGIN may be an older relay log.
*/
if (rli->trans_retries < slave_trans_retries)
{
if (init_master_info(rli->mi, 0, 0, 0, SLAVE_SQL))
sql_print_error("Failed to initialize the master info structure");
else if (init_relay_log_pos(rli,
rli->group_relay_log_name,
rli->group_relay_log_pos,
1, &errmsg, 1))
sql_print_error("Error initializing relay log position: %s",
errmsg);
else
{
exec_res= 0;
rli->cleanup_context(thd, 1);
/* chance for concurrent connection to get more locks */
safe_sleep(thd, min(rli->trans_retries, MAX_SLAVE_RETRY_PAUSE),
(CHECK_KILLED_FUNC)sql_slave_killed, (void*)rli);
mysql_mutex_lock(&rli->data_lock); // because of SHOW STATUS
rli->trans_retries++;
rli->retried_trans++;
mysql_mutex_unlock(&rli->data_lock);
DBUG_PRINT("info", ("Slave retries transaction "
"rli->trans_retries: %lu", rli->trans_retries));
}
}
else
sql_print_error("Slave SQL thread retried transaction %lu time(s) "
"in vain, giving up. Consider raising the value of "
"the slave_transaction_retries variable.",
slave_trans_retries);
}
else if ((exec_res && !temp_err) ||
(opt_using_transactions &&
rli->group_relay_log_pos == rli->event_relay_log_pos))
{
/*
Only reset the retry counter if the entire group succeeded
or failed with a non-transient error. On a successful
event, the execution will proceed as usual; in the case of a
non-transient error, the slave will stop with an error.
*/
rli->trans_retries= 0; // restart from fresh
DBUG_PRINT("info", ("Resetting retry counter, rli->trans_retries: %lu",
rli->trans_retries));
}
}
DBUG_RETURN(exec_res);
}
mysql_mutex_unlock(&rli->data_lock);
rli->report(ERROR_LEVEL, ER_SLAVE_RELAY_LOG_READ_FAILURE,
ER(ER_SLAVE_RELAY_LOG_READ_FAILURE), "\
Could not parse relay log event entry. The possible reasons are: the master's \
binary log is corrupted (you can check this by running 'mysqlbinlog' on the \
binary log), the slave's relay log is corrupted (you can check this by running \
'mysqlbinlog' on the relay log), a network problem, or a bug in the master's \
or slave's MySQL code. If you want to check the master's binary log or slave's \
relay log, you will be able to know their names by issuing 'SHOW SLAVE STATUS' \
on this slave.\
");
DBUG_RETURN(1);
}
static bool check_io_slave_killed(THD *thd, Master_info *mi, const char *info)
{
if (io_slave_killed(thd, mi))
{
if (info && global_system_variables.log_warnings)
sql_print_information("%s", info);
return TRUE;
}
return FALSE;
}
/**
@brief Try to reconnect slave IO thread.
@details Terminates current connection to master, sleeps for
@c mi->connect_retry msecs and initiates new connection with
@c safe_reconnect(). Variable pointed by @c retry_count is increased -
if it exceeds @c master_retry_count then connection is not re-established
and function signals error.
Unless @c suppres_warnings is TRUE, a warning is put in the server error log
when reconnecting. The warning message and messages used to report errors
are taken from @c messages array. In case @c master_retry_count is exceeded,
no messages are added to the log.
@param[in] thd Thread context.
@param[in] mysql MySQL connection.
@param[in] mi Master connection information.
@param[in,out] retry_count Number of attempts to reconnect.
@param[in] suppress_warnings TRUE when a normal net read timeout
has caused to reconnecting.
@param[in] messages Messages to print/log, see
reconnect_messages[] array.
@retval 0 OK.
@retval 1 There was an error.
*/
static int try_to_reconnect(THD *thd, MYSQL *mysql, Master_info *mi,
uint *retry_count, bool suppress_warnings,
const char *messages[SLAVE_RECON_MSG_MAX])
{
mi->slave_running= MYSQL_SLAVE_RUN_NOT_CONNECT;
thd->proc_info= messages[SLAVE_RECON_MSG_WAIT];
#ifdef SIGNAL_WITH_VIO_CLOSE
thd->clear_active_vio();
#endif
end_server(mysql);
if ((*retry_count)++)
{
if (*retry_count > master_retry_count)
return 1; // Don't retry forever
safe_sleep(thd, mi->connect_retry, (CHECK_KILLED_FUNC) io_slave_killed,
(void *) mi);
}
if (check_io_slave_killed(thd, mi, messages[SLAVE_RECON_MSG_KILLED_WAITING]))
return 1;
thd->proc_info = messages[SLAVE_RECON_MSG_AFTER];
if (!suppress_warnings)
{
char buf[256], llbuff[22];
my_snprintf(buf, sizeof(buf), messages[SLAVE_RECON_MSG_FAILED],
IO_RPL_LOG_NAME, llstr(mi->master_log_pos, llbuff));
/*
Raise a warining during registering on master/requesting dump.
Log a message reading event.
*/
if (messages[SLAVE_RECON_MSG_COMMAND][0])
{
mi->report(WARNING_LEVEL, ER_SLAVE_MASTER_COM_FAILURE,
ER(ER_SLAVE_MASTER_COM_FAILURE),
messages[SLAVE_RECON_MSG_COMMAND], buf);
}
else
{
sql_print_information("%s", buf);
}
}
if (safe_reconnect(thd, mysql, mi, 1) || io_slave_killed(thd, mi))
{
if (global_system_variables.log_warnings)
sql_print_information("%s", messages[SLAVE_RECON_MSG_KILLED_AFTER]);
return 1;
}
return 0;
}
/**
Slave IO thread entry point.
@param arg Pointer to Master_info struct that holds information for
the IO thread.
@return Always 0.
*/
pthread_handler_t handle_slave_io(void *arg)
{
THD *thd; // needs to be first for thread_stack
MYSQL *mysql;
Master_info *mi = (Master_info*)arg;
Relay_log_info *rli= &mi->rli;
char llbuff[22];
uint retry_count;
bool suppress_warnings;
int ret;
#ifndef DBUG_OFF
uint retry_count_reg= 0, retry_count_dump= 0, retry_count_event= 0;
#endif
// needs to call my_thread_init(), otherwise we get a coredump in DBUG_ stuff
my_thread_init();
DBUG_ENTER("handle_slave_io");
DBUG_ASSERT(mi->inited);
mysql= NULL ;
retry_count= 0;
mysql_mutex_lock(&mi->run_lock);
/* Inform waiting threads that slave has started */
mi->slave_run_id++;
#ifndef DBUG_OFF
mi->events_till_disconnect = disconnect_slave_event_count;
#endif
thd= new THD; // note that contructor of THD uses DBUG_ !
THD_CHECK_SENTRY(thd);
mi->io_thd = thd;
pthread_detach_this_thread();
thd->thread_stack= (char*) &thd; // remember where our stack is
mi->clear_error();
if (init_slave_thread(thd, SLAVE_THD_IO))
{
mysql_cond_broadcast(&mi->start_cond);
mysql_mutex_unlock(&mi->run_lock);
sql_print_error("Failed during slave I/O thread initialization");
goto err;
}
mysql_mutex_lock(&LOCK_thread_count);
threads.append(thd);
mysql_mutex_unlock(&LOCK_thread_count);
mi->slave_running = 1;
mi->abort_slave = 0;
mysql_mutex_unlock(&mi->run_lock);
mysql_cond_broadcast(&mi->start_cond);
DBUG_PRINT("master_info",("log_file_name: '%s' position: %s",
mi->master_log_name,
llstr(mi->master_log_pos,llbuff)));
/* This must be called before run any binlog_relay_io hooks */
my_pthread_setspecific_ptr(RPL_MASTER_INFO, mi);
if (RUN_HOOK(binlog_relay_io, thread_start, (thd, mi)))
{
mi->report(ERROR_LEVEL, ER_SLAVE_FATAL_ERROR,
ER(ER_SLAVE_FATAL_ERROR), "Failed to run 'thread_start' hook");
goto err;
}
if (!(mi->mysql = mysql = mysql_init(NULL)))
{
mi->report(ERROR_LEVEL, ER_SLAVE_FATAL_ERROR,
ER(ER_SLAVE_FATAL_ERROR), "error in mysql_init()");
goto err;
}
thd_proc_info(thd, "Connecting to master");
// we can get killed during safe_connect
if (!safe_connect(thd, mysql, mi))
{
sql_print_information("Slave I/O thread: connected to master '%s@%s:%d',"
"replication started in log '%s' at position %s",
mi->user, mi->host, mi->port,
IO_RPL_LOG_NAME,
llstr(mi->master_log_pos,llbuff));
/*
Adding MAX_LOG_EVENT_HEADER_LEN to the max_packet_size on the I/O
thread, since a replication event can become this much larger than
the corresponding packet (query) sent from client to master.
*/
mysql->net.max_packet_size= thd->net.max_packet_size+= MAX_LOG_EVENT_HEADER;
}
else
{
sql_print_information("Slave I/O thread killed while connecting to master");
goto err;
}
connected:
DBUG_EXECUTE_IF("dbug.before_get_running_status_yes",
{
const char act[]=
"now "
"wait_for signal.io_thread_let_running";
DBUG_ASSERT(opt_debug_sync_timeout > 0);
DBUG_ASSERT(!debug_sync_set_action(thd,
STRING_WITH_LEN(act)));
};);
// TODO: the assignment below should be under mutex (5.0)
mi->slave_running= MYSQL_SLAVE_RUN_CONNECT;
thd->slave_net = &mysql->net;
thd_proc_info(thd, "Checking master version");
ret= get_master_version_and_clock(mysql, mi);
if (ret == 1)
/* Fatal error */
goto err;
if (ret == 2)
{
if (check_io_slave_killed(mi->io_thd, mi, "Slave I/O thread killed"
"while calling get_master_version_and_clock(...)"))
goto err;
suppress_warnings= FALSE;
/* Try to reconnect because the error was caused by a transient network problem */
if (try_to_reconnect(thd, mysql, mi, &retry_count, suppress_warnings,
reconnect_messages[SLAVE_RECON_ACT_REG]))
goto err;
goto connected;
}
if (mi->rli.relay_log.description_event_for_queue->binlog_version > 1)
{
/*
Register ourselves with the master.
*/
thd_proc_info(thd, "Registering slave on master");
if (register_slave_on_master(mysql, mi, &suppress_warnings))
{
if (!check_io_slave_killed(thd, mi, "Slave I/O thread killed "
"while registering slave on master"))
{
sql_print_error("Slave I/O thread couldn't register on master");
if (try_to_reconnect(thd, mysql, mi, &retry_count, suppress_warnings,
reconnect_messages[SLAVE_RECON_ACT_REG]))
goto err;
}
else
goto err;
goto connected;
}
DBUG_EXECUTE_IF("FORCE_SLAVE_TO_RECONNECT_REG",
if (!retry_count_reg)
{
retry_count_reg++;
sql_print_information("Forcing to reconnect slave I/O thread");
if (try_to_reconnect(thd, mysql, mi, &retry_count, suppress_warnings,
reconnect_messages[SLAVE_RECON_ACT_REG]))
goto err;
goto connected;
});
}
DBUG_PRINT("info",("Starting reading binary log from master"));
while (!io_slave_killed(thd,mi))
{
thd_proc_info(thd, "Requesting binlog dump");
if (request_dump(thd, mysql, mi, &suppress_warnings))
{
sql_print_error("Failed on request_dump()");
if (check_io_slave_killed(thd, mi, "Slave I/O thread killed while \
requesting master dump") ||
try_to_reconnect(thd, mysql, mi, &retry_count, suppress_warnings,
reconnect_messages[SLAVE_RECON_ACT_DUMP]))
goto err;
goto connected;
}
DBUG_EXECUTE_IF("FORCE_SLAVE_TO_RECONNECT_DUMP",
if (!retry_count_dump)
{
retry_count_dump++;
sql_print_information("Forcing to reconnect slave I/O thread");
if (try_to_reconnect(thd, mysql, mi, &retry_count, suppress_warnings,
reconnect_messages[SLAVE_RECON_ACT_DUMP]))
goto err;
goto connected;
});
const char *event_buf;
DBUG_ASSERT(mi->last_error().number == 0);
while (!io_slave_killed(thd,mi))
{
ulong event_len;
/*
We say "waiting" because read_event() will wait if there's nothing to
read. But if there's something to read, it will not wait. The
important thing is to not confuse users by saying "reading" whereas
we're in fact receiving nothing.
*/
thd_proc_info(thd, "Waiting for master to send event");
event_len= read_event(mysql, mi, &suppress_warnings);
if (check_io_slave_killed(thd, mi, "Slave I/O thread killed while \
reading event"))
goto err;
DBUG_EXECUTE_IF("FORCE_SLAVE_TO_RECONNECT_EVENT",
if (!retry_count_event)
{
retry_count_event++;
sql_print_information("Forcing to reconnect slave I/O thread");
if (try_to_reconnect(thd, mysql, mi, &retry_count, suppress_warnings,
reconnect_messages[SLAVE_RECON_ACT_EVENT]))
goto err;
goto connected;
});
if (event_len == packet_error)
{
uint mysql_error_number= mysql_errno(mysql);
switch (mysql_error_number) {
case CR_NET_PACKET_TOO_LARGE:
sql_print_error("\
Log entry on master is longer than max_allowed_packet (%ld) on \
slave. If the entry is correct, restart the server with a higher value of \
max_allowed_packet",
thd->variables.max_allowed_packet);
mi->report(ERROR_LEVEL, ER_NET_PACKET_TOO_LARGE,
"%s", ER(ER_NET_PACKET_TOO_LARGE));
goto err;
case ER_MASTER_FATAL_ERROR_READING_BINLOG:
mi->report(ERROR_LEVEL, ER_MASTER_FATAL_ERROR_READING_BINLOG,
ER(ER_MASTER_FATAL_ERROR_READING_BINLOG),
mysql_error_number, mysql_error(mysql));
goto err;
case ER_OUT_OF_RESOURCES:
sql_print_error("\
Stopping slave I/O thread due to out-of-memory error from master");
mi->report(ERROR_LEVEL, ER_OUT_OF_RESOURCES,
"%s", ER(ER_OUT_OF_RESOURCES));
goto err;
}
if (try_to_reconnect(thd, mysql, mi, &retry_count, suppress_warnings,
reconnect_messages[SLAVE_RECON_ACT_EVENT]))
goto err;
goto connected;
} // if (event_len == packet_error)
retry_count=0; // ok event, reset retry counter
thd_proc_info(thd, "Queueing master event to the relay log");
event_buf= (const char*)mysql->net.read_pos + 1;
if (RUN_HOOK(binlog_relay_io, after_read_event,
(thd, mi,(const char*)mysql->net.read_pos + 1,
event_len, &event_buf, &event_len)))
{
mi->report(ERROR_LEVEL, ER_SLAVE_FATAL_ERROR,
ER(ER_SLAVE_FATAL_ERROR),
"Failed to run 'after_read_event' hook");
goto err;
}
/* XXX: 'synced' should be updated by queue_event to indicate
whether event has been synced to disk */
bool synced= 0;
if (queue_event(mi, event_buf, event_len))
{
mi->report(ERROR_LEVEL, ER_SLAVE_RELAY_LOG_WRITE_FAILURE,
ER(ER_SLAVE_RELAY_LOG_WRITE_FAILURE),
"could not queue event from master");
goto err;
}
if (RUN_HOOK(binlog_relay_io, after_queue_event,
(thd, mi, event_buf, event_len, synced)))
{
mi->report(ERROR_LEVEL, ER_SLAVE_FATAL_ERROR,
ER(ER_SLAVE_FATAL_ERROR),
"Failed to run 'after_queue_event' hook");
goto err;
}
if (flush_master_info(mi, TRUE, TRUE))
{
sql_print_error("Failed to flush master info file");
goto err;
}
/*
See if the relay logs take too much space.
We don't lock mi->rli.log_space_lock here; this dirty read saves time
and does not introduce any problem:
- if mi->rli.ignore_log_space_limit is 1 but becomes 0 just after (so
the clean value is 0), then we are reading only one more event as we
should, and we'll block only at the next event. No big deal.
- if mi->rli.ignore_log_space_limit is 0 but becomes 1 just after (so
the clean value is 1), then we are going into wait_for_relay_log_space()
for no reason, but this function will do a clean read, notice the clean
value and exit immediately.
*/
#ifndef DBUG_OFF
{
char llbuf1[22], llbuf2[22];
DBUG_PRINT("info", ("log_space_limit=%s log_space_total=%s \
ignore_log_space_limit=%d",
llstr(rli->log_space_limit,llbuf1),
llstr(rli->log_space_total,llbuf2),
(int) rli->ignore_log_space_limit));
}
#endif
if (rli->log_space_limit && rli->log_space_limit <
rli->log_space_total &&
!rli->ignore_log_space_limit)
if (wait_for_relay_log_space(rli))
{
sql_print_error("Slave I/O thread aborted while waiting for relay \
log space");
goto err;
}
}
}
// error = 0;
err:
// print the current replication position
sql_print_information("Slave I/O thread exiting, read up to log '%s', position %s",
IO_RPL_LOG_NAME, llstr(mi->master_log_pos,llbuff));
RUN_HOOK(binlog_relay_io, thread_stop, (thd, mi));
thd->set_query(NULL, 0);
thd->reset_db(NULL, 0);
if (mysql)
{
/*
Here we need to clear the active VIO before closing the
connection with the master. The reason is that THD::awake()
might be called from terminate_slave_thread() because somebody
issued a STOP SLAVE. If that happends, the close_active_vio()
can be called in the middle of closing the VIO associated with
the 'mysql' object, causing a crash.
*/
#ifdef SIGNAL_WITH_VIO_CLOSE
thd->clear_active_vio();
#endif
mysql_close(mysql);
mi->mysql=0;
}
write_ignored_events_info_to_relay_log(thd, mi);
thd_proc_info(thd, "Waiting for slave mutex on exit");
mysql_mutex_lock(&mi->run_lock);
/* Forget the relay log's format */
delete mi->rli.relay_log.description_event_for_queue;
mi->rli.relay_log.description_event_for_queue= 0;
// TODO: make rpl_status part of Master_info
change_rpl_status(RPL_ACTIVE_SLAVE,RPL_IDLE_SLAVE);
DBUG_ASSERT(thd->net.buff != 0);
net_end(&thd->net); // destructor will not free it, because net.vio is 0
mysql_mutex_lock(&LOCK_thread_count);
THD_CHECK_SENTRY(thd);
delete thd;
mysql_mutex_unlock(&LOCK_thread_count);
mi->abort_slave= 0;
mi->slave_running= 0;
mi->io_thd= 0;
/*
Note: the order of the two following calls (first broadcast, then unlock)
is important. Otherwise a killer_thread can execute between the calls and
delete the mi structure leading to a crash! (see BUG#25306 for details)
*/
mysql_cond_broadcast(&mi->stop_cond); // tell the world we are done
DBUG_EXECUTE_IF("simulate_slave_delay_at_terminate_bug38694", sleep(5););
mysql_mutex_unlock(&mi->run_lock);
DBUG_LEAVE; // Must match DBUG_ENTER()
my_thread_end();
pthread_exit(0);
return 0; // Avoid compiler warnings
}
/*
Check the temporary directory used by commands like
LOAD DATA INFILE.
*/
static
int check_temp_dir(char* tmp_file)
{
int fd;
MY_DIR *dirp;
char tmp_dir[FN_REFLEN];
size_t tmp_dir_size;
DBUG_ENTER("check_temp_dir");
/*
Get the directory from the temporary file.
*/
dirname_part(tmp_dir, tmp_file, &tmp_dir_size);
/*
Check if the directory exists.
*/
if (!(dirp=my_dir(tmp_dir,MYF(MY_WME))))
DBUG_RETURN(1);
my_dirend(dirp);
/*
Check permissions to create a file.
*/
if ((fd= mysql_file_create(key_file_misc,
tmp_file, CREATE_MODE,
O_WRONLY | O_BINARY | O_EXCL | O_NOFOLLOW,
MYF(MY_WME))) < 0)
DBUG_RETURN(1);
/*
Clean up.
*/
mysql_file_close(fd, MYF(0));
mysql_file_delete(key_file_misc, tmp_file, MYF(0));
DBUG_RETURN(0);
}
/**
Slave SQL thread entry point.
@param arg Pointer to Relay_log_info object that holds information
for the SQL thread.
@return Always 0.
*/
pthread_handler_t handle_slave_sql(void *arg)
{
THD *thd; /* needs to be first for thread_stack */
char llbuff[22],llbuff1[22];
char saved_log_name[FN_REFLEN];
char saved_master_log_name[FN_REFLEN];
my_off_t UNINIT_VAR(saved_log_pos);
my_off_t UNINIT_VAR(saved_master_log_pos);
my_off_t saved_skip= 0;
Relay_log_info* rli = &((Master_info*)arg)->rli;
const char *errmsg;
// needs to call my_thread_init(), otherwise we get a coredump in DBUG_ stuff
my_thread_init();
DBUG_ENTER("handle_slave_sql");
DBUG_ASSERT(rli->inited);
mysql_mutex_lock(&rli->run_lock);
DBUG_ASSERT(!rli->slave_running);
errmsg= 0;
#ifndef DBUG_OFF
rli->events_till_abort = abort_slave_event_count;
#endif
thd = new THD; // note that contructor of THD uses DBUG_ !
thd->thread_stack = (char*)&thd; // remember where our stack is
rli->sql_thd= thd;
/* Inform waiting threads that slave has started */
rli->slave_run_id++;
rli->slave_running = 1;
pthread_detach_this_thread();
if (init_slave_thread(thd, SLAVE_THD_SQL))
{
/*
TODO: this is currently broken - slave start and change master
will be stuck if we fail here
*/
mysql_cond_broadcast(&rli->start_cond);
mysql_mutex_unlock(&rli->run_lock);
rli->report(ERROR_LEVEL, ER_SLAVE_FATAL_ERROR,
"Failed during slave thread initialization");
goto err;
}
thd->init_for_queries();
thd->temporary_tables = rli->save_temporary_tables; // restore temp tables
set_thd_in_use_temporary_tables(rli); // (re)set sql_thd in use for saved temp tables
mysql_mutex_lock(&LOCK_thread_count);
threads.append(thd);
mysql_mutex_unlock(&LOCK_thread_count);
/*
We are going to set slave_running to 1. Assuming slave I/O thread is
alive and connected, this is going to make Seconds_Behind_Master be 0
i.e. "caught up". Even if we're just at start of thread. Well it's ok, at
the moment we start we can think we are caught up, and the next second we
start receiving data so we realize we are not caught up and
Seconds_Behind_Master grows. No big deal.
*/
rli->abort_slave = 0;
mysql_mutex_unlock(&rli->run_lock);
mysql_cond_broadcast(&rli->start_cond);
/*
Reset errors for a clean start (otherwise, if the master is idle, the SQL
thread may execute no Query_log_event, so the error will remain even
though there's no problem anymore). Do not reset the master timestamp
(imagine the slave has caught everything, the STOP SLAVE and START SLAVE:
as we are not sure that we are going to receive a query, we want to
remember the last master timestamp (to say how many seconds behind we are
now.
But the master timestamp is reset by RESET SLAVE & CHANGE MASTER.
*/
rli->clear_error();
//tell the I/O thread to take relay_log_space_limit into account from now on
mysql_mutex_lock(&rli->log_space_lock);
rli->ignore_log_space_limit= 0;
mysql_mutex_unlock(&rli->log_space_lock);
rli->trans_retries= 0; // start from "no error"
DBUG_PRINT("info", ("rli->trans_retries: %lu", rli->trans_retries));
if (init_relay_log_pos(rli,
rli->group_relay_log_name,
rli->group_relay_log_pos,
1 /*need data lock*/, &errmsg,
1 /*look for a description_event*/))
{
rli->report(ERROR_LEVEL, ER_SLAVE_FATAL_ERROR,
"Error initializing relay log position: %s", errmsg);
goto err;
}
THD_CHECK_SENTRY(thd);
#ifndef DBUG_OFF
{
char llbuf1[22], llbuf2[22];
DBUG_PRINT("info", ("my_b_tell(rli->cur_log)=%s rli->event_relay_log_pos=%s",
llstr(my_b_tell(rli->cur_log),llbuf1),
llstr(rli->event_relay_log_pos,llbuf2)));
DBUG_ASSERT(rli->event_relay_log_pos >= BIN_LOG_HEADER_SIZE);
/*
Wonder if this is correct. I (Guilhem) wonder if my_b_tell() returns the
correct position when it's called just after my_b_seek() (the questionable
stuff is those "seek is done on next read" comments in the my_b_seek()
source code).
The crude reality is that this assertion randomly fails whereas
replication seems to work fine. And there is no easy explanation why it
fails (as we my_b_seek(rli->event_relay_log_pos) at the very end of
init_relay_log_pos() called above). Maybe the assertion would be
meaningful if we held rli->data_lock between the my_b_seek() and the
DBUG_ASSERT().
*/
#ifdef SHOULD_BE_CHECKED
DBUG_ASSERT(my_b_tell(rli->cur_log) == rli->event_relay_log_pos);
#endif
}
#endif
DBUG_ASSERT(rli->sql_thd == thd);
DBUG_PRINT("master_info",("log_file_name: %s position: %s",
rli->group_master_log_name,
llstr(rli->group_master_log_pos,llbuff)));
if (global_system_variables.log_warnings)
sql_print_information("Slave SQL thread initialized, starting replication in \
log '%s' at position %s, relay log '%s' position: %s", RPL_LOG_NAME,
llstr(rli->group_master_log_pos,llbuff),rli->group_relay_log_name,
llstr(rli->group_relay_log_pos,llbuff1));
if (check_temp_dir(rli->slave_patternload_file))
{
rli->report(ERROR_LEVEL, thd->stmt_da->sql_errno(),
"Unable to use slave's temporary directory %s - %s",
slave_load_tmpdir, thd->stmt_da->message());
goto err;
}
/* execute init_slave variable */
if (opt_init_slave.length)
{
execute_init_command(thd, &opt_init_slave, &LOCK_sys_init_slave);
if (thd->is_slave_error)
{
rli->report(ERROR_LEVEL, thd->stmt_da->sql_errno(),
"Slave SQL thread aborted. Can't execute init_slave query");
goto err;
}
}
/*
First check until condition - probably there is nothing to execute. We
do not want to wait for next event in this case.
*/
mysql_mutex_lock(&rli->data_lock);
if (rli->slave_skip_counter)
{
strmake(saved_log_name, rli->group_relay_log_name, FN_REFLEN - 1);
strmake(saved_master_log_name, rli->group_master_log_name, FN_REFLEN - 1);
saved_log_pos= rli->group_relay_log_pos;
saved_master_log_pos= rli->group_master_log_pos;
saved_skip= rli->slave_skip_counter;
}
if (rli->until_condition != Relay_log_info::UNTIL_NONE &&
rli->is_until_satisfied(thd, NULL))
{
char buf[22];
sql_print_information("Slave SQL thread stopped because it reached its"
" UNTIL position %s", llstr(rli->until_pos(), buf));
mysql_mutex_unlock(&rli->data_lock);
goto err;
}
mysql_mutex_unlock(&rli->data_lock);
/* Read queries from the IO/THREAD until this thread is killed */
while (!sql_slave_killed(thd,rli))
{
thd_proc_info(thd, "Reading event from the relay log");
DBUG_ASSERT(rli->sql_thd == thd);
THD_CHECK_SENTRY(thd);
if (saved_skip && rli->slave_skip_counter == 0)
{
sql_print_information("'SQL_SLAVE_SKIP_COUNTER=%ld' executed at "
"relay_log_file='%s', relay_log_pos='%ld', master_log_name='%s', "
"master_log_pos='%ld' and new position at "
"relay_log_file='%s', relay_log_pos='%ld', master_log_name='%s', "
"master_log_pos='%ld' ",
(ulong) saved_skip, saved_log_name, (ulong) saved_log_pos,
saved_master_log_name, (ulong) saved_master_log_pos,
rli->group_relay_log_name, (ulong) rli->group_relay_log_pos,
rli->group_master_log_name, (ulong) rli->group_master_log_pos);
saved_skip= 0;
}
if (exec_relay_log_event(thd,rli))
{
DBUG_PRINT("info", ("exec_relay_log_event() failed"));
// do not scare the user if SQL thread was simply killed or stopped
if (!sql_slave_killed(thd,rli))
{
/*
retrieve as much info as possible from the thd and, error
codes and warnings and print this to the error log as to
allow the user to locate the error
*/
uint32 const last_errno= rli->last_error().number;
if (thd->is_error())
{
char const *const errmsg= thd->stmt_da->message();
DBUG_PRINT("info",
("thd->stmt_da->sql_errno()=%d; rli->last_error.number=%d",
thd->stmt_da->sql_errno(), last_errno));
if (last_errno == 0)
{
/*
This function is reporting an error which was not reported
while executing exec_relay_log_event().
*/
rli->report(ERROR_LEVEL, thd->stmt_da->sql_errno(), "%s", errmsg);
}
else if (last_errno != thd->stmt_da->sql_errno())
{
/*
* An error was reported while executing exec_relay_log_event()
* however the error code differs from what is in the thread.
* This function prints out more information to help finding
* what caused the problem.
*/
sql_print_error("Slave (additional info): %s Error_code: %d",
errmsg, thd->stmt_da->sql_errno());
}
}
/* Print any warnings issued */
List_iterator_fast<MYSQL_ERROR> it(thd->warning_info->warn_list());
MYSQL_ERROR *err;
/*
Added controlled slave thread cancel for replication
of user-defined variables.
*/
bool udf_error = false;
while ((err= it++))
{
if (err->get_sql_errno() == ER_CANT_OPEN_LIBRARY)
udf_error = true;
sql_print_warning("Slave: %s Error_code: %d", err->get_message_text(), err->get_sql_errno());
}
if (udf_error)
sql_print_error("Error loading user-defined library, slave SQL "
"thread aborted. Install the missing library, and restart the "
"slave SQL thread with \"SLAVE START\". We stopped at log '%s' "
"position %s", RPL_LOG_NAME, llstr(rli->group_master_log_pos,
llbuff));
else
sql_print_error("\
Error running query, slave SQL thread aborted. Fix the problem, and restart \
the slave SQL thread with \"SLAVE START\". We stopped at log \
'%s' position %s", RPL_LOG_NAME, llstr(rli->group_master_log_pos, llbuff));
}
goto err;
}
}
/* Thread stopped. Print the current replication position to the log */
sql_print_information("Slave SQL thread exiting, replication stopped in log "
"'%s' at position %s",
RPL_LOG_NAME, llstr(rli->group_master_log_pos,llbuff));
err:
/*
Some events set some playgrounds, which won't be cleared because thread
stops. Stopping of this thread may not be known to these events ("stop"
request is detected only by the present function, not by events), so we
must "proactively" clear playgrounds:
*/
thd->clear_error();
rli->cleanup_context(thd, 1);
/*
Some extra safety, which should not been needed (normally, event deletion
should already have done these assignments (each event which sets these
variables is supposed to set them to 0 before terminating)).
*/
thd->catalog= 0;
thd->set_query(NULL, 0);
thd->reset_db(NULL, 0);
thd_proc_info(thd, "Waiting for slave mutex on exit");
mysql_mutex_lock(&rli->run_lock);
/* We need data_lock, at least to wake up any waiting master_pos_wait() */
mysql_mutex_lock(&rli->data_lock);
DBUG_ASSERT(rli->slave_running == 1); // tracking buffer overrun
/* When master_pos_wait() wakes up it will check this and terminate */
rli->slave_running= 0;
/* Forget the relay log's format */
delete rli->relay_log.description_event_for_exec;
rli->relay_log.description_event_for_exec= 0;
/* Wake up master_pos_wait() */
mysql_mutex_unlock(&rli->data_lock);
DBUG_PRINT("info",("Signaling possibly waiting master_pos_wait() functions"));
mysql_cond_broadcast(&rli->data_cond);
rli->ignore_log_space_limit= 0; /* don't need any lock */
/* we die so won't remember charset - re-update them on next thread start */
rli->cached_charset_invalidate();
rli->save_temporary_tables = thd->temporary_tables;
/*
TODO: see if we can do this conditionally in next_event() instead
to avoid unneeded position re-init
*/
thd->temporary_tables = 0; // remove tempation from destructor to close them
DBUG_ASSERT(thd->net.buff != 0);
net_end(&thd->net); // destructor will not free it, because we are weird
DBUG_ASSERT(rli->sql_thd == thd);
THD_CHECK_SENTRY(thd);
rli->sql_thd= 0;
set_thd_in_use_temporary_tables(rli); // (re)set sql_thd in use for saved temp tables
mysql_mutex_lock(&LOCK_thread_count);
THD_CHECK_SENTRY(thd);
delete thd;
mysql_mutex_unlock(&LOCK_thread_count);
/*
Note: the order of the broadcast and unlock calls below (first broadcast, then unlock)
is important. Otherwise a killer_thread can execute between the calls and
delete the mi structure leading to a crash! (see BUG#25306 for details)
*/
mysql_cond_broadcast(&rli->stop_cond);
DBUG_EXECUTE_IF("simulate_slave_delay_at_terminate_bug38694", sleep(5););
mysql_mutex_unlock(&rli->run_lock); // tell the world we are done
DBUG_LEAVE; // Must match DBUG_ENTER()
my_thread_end();
pthread_exit(0);
return 0; // Avoid compiler warnings
}
/*
process_io_create_file()
*/
static int process_io_create_file(Master_info* mi, Create_file_log_event* cev)
{
int error = 1;
ulong num_bytes;
bool cev_not_written;
THD *thd = mi->io_thd;
NET *net = &mi->mysql->net;
DBUG_ENTER("process_io_create_file");
if (unlikely(!cev->is_valid()))
DBUG_RETURN(1);
if (!rpl_filter->db_ok(cev->db))
{
skip_load_data_infile(net);
DBUG_RETURN(0);
}
DBUG_ASSERT(cev->inited_from_old);
thd->file_id = cev->file_id = mi->file_id++;
thd->server_id = cev->server_id;
cev_not_written = 1;
if (unlikely(net_request_file(net,cev->fname)))
{
sql_print_error("Slave I/O: failed requesting download of '%s'",
cev->fname);
goto err;
}
/*
This dummy block is so we could instantiate Append_block_log_event
once and then modify it slightly instead of doing it multiple times
in the loop
*/
{
Append_block_log_event aev(thd,0,0,0,0);
for (;;)
{
if (unlikely((num_bytes=my_net_read(net)) == packet_error))
{
sql_print_error("Network read error downloading '%s' from master",
cev->fname);
goto err;
}
if (unlikely(!num_bytes)) /* eof */
{
/* 3.23 master wants it */
net_write_command(net, 0, (uchar*) "", 0, (uchar*) "", 0);
/*
If we wrote Create_file_log_event, then we need to write
Execute_load_log_event. If we did not write Create_file_log_event,
then this is an empty file and we can just do as if the LOAD DATA
INFILE had not existed, i.e. write nothing.
*/
if (unlikely(cev_not_written))
break;
Execute_load_log_event xev(thd,0,0);
xev.log_pos = cev->log_pos;
if (unlikely(mi->rli.relay_log.append(&xev)))
{
mi->report(ERROR_LEVEL, ER_SLAVE_RELAY_LOG_WRITE_FAILURE,
ER(ER_SLAVE_RELAY_LOG_WRITE_FAILURE),
"error writing Exec_load event to relay log");
goto err;
}
mi->rli.relay_log.harvest_bytes_written(&mi->rli.log_space_total);
break;
}
if (unlikely(cev_not_written))
{
cev->block = net->read_pos;
cev->block_len = num_bytes;
if (unlikely(mi->rli.relay_log.append(cev)))
{
mi->report(ERROR_LEVEL, ER_SLAVE_RELAY_LOG_WRITE_FAILURE,
ER(ER_SLAVE_RELAY_LOG_WRITE_FAILURE),
"error writing Create_file event to relay log");
goto err;
}
cev_not_written=0;
mi->rli.relay_log.harvest_bytes_written(&mi->rli.log_space_total);
}
else
{
aev.block = net->read_pos;
aev.block_len = num_bytes;
aev.log_pos = cev->log_pos;
if (unlikely(mi->rli.relay_log.append(&aev)))
{
mi->report(ERROR_LEVEL, ER_SLAVE_RELAY_LOG_WRITE_FAILURE,
ER(ER_SLAVE_RELAY_LOG_WRITE_FAILURE),
"error writing Append_block event to relay log");
goto err;
}
mi->rli.relay_log.harvest_bytes_written(&mi->rli.log_space_total) ;
}
}
}
error=0;
err:
DBUG_RETURN(error);
}
/*
Start using a new binary log on the master
SYNOPSIS
process_io_rotate()
mi master_info for the slave
rev The rotate log event read from the binary log
DESCRIPTION
Updates the master info with the place in the next binary
log where we should start reading.
Rotate the relay log to avoid mixed-format relay logs.
NOTES
We assume we already locked mi->data_lock
RETURN VALUES
0 ok
1 Log event is illegal
*/
static int process_io_rotate(Master_info *mi, Rotate_log_event *rev)
{
DBUG_ENTER("process_io_rotate");
mysql_mutex_assert_owner(&mi->data_lock);
if (unlikely(!rev->is_valid()))
DBUG_RETURN(1);
/* Safe copy as 'rev' has been "sanitized" in Rotate_log_event's ctor */
memcpy(mi->master_log_name, rev->new_log_ident, rev->ident_len+1);
mi->master_log_pos= rev->pos;
DBUG_PRINT("info", ("master_log_pos: '%s' %lu",
mi->master_log_name, (ulong) mi->master_log_pos));
#ifndef DBUG_OFF
/*
If we do not do this, we will be getting the first
rotate event forever, so we need to not disconnect after one.
*/
if (disconnect_slave_event_count)
mi->events_till_disconnect++;
#endif
/*
If description_event_for_queue is format <4, there is conversion in the
relay log to the slave's format (4). And Rotate can mean upgrade or
nothing. If upgrade, it's to 5.0 or newer, so we will get a Format_desc, so
no need to reset description_event_for_queue now. And if it's nothing (same
master version as before), no need (still using the slave's format).
*/
if (mi->rli.relay_log.description_event_for_queue->binlog_version >= 4)
{
delete mi->rli.relay_log.description_event_for_queue;
/* start from format 3 (MySQL 4.0) again */
mi->rli.relay_log.description_event_for_queue= new
Format_description_log_event(3);
}
/*
Rotate the relay log makes binlog format detection easier (at next slave
start or mysqlbinlog)
*/
rotate_relay_log(mi); /* will take the right mutexes */
DBUG_RETURN(0);
}
/*
Reads a 3.23 event and converts it to the slave's format. This code was
copied from MySQL 4.0.
*/
static int queue_binlog_ver_1_event(Master_info *mi, const char *buf,
ulong event_len)
{
const char *errmsg = 0;
ulong inc_pos;
bool ignore_event= 0;
char *tmp_buf = 0;
Relay_log_info *rli= &mi->rli;
DBUG_ENTER("queue_binlog_ver_1_event");
/*
If we get Load event, we need to pass a non-reusable buffer
to read_log_event, so we do a trick
*/
if (buf[EVENT_TYPE_OFFSET] == LOAD_EVENT)
{
if (unlikely(!(tmp_buf=(char*)my_malloc(event_len+1,MYF(MY_WME)))))
{
mi->report(ERROR_LEVEL, ER_SLAVE_FATAL_ERROR,
ER(ER_SLAVE_FATAL_ERROR), "Memory allocation failed");
DBUG_RETURN(1);
}
memcpy(tmp_buf,buf,event_len);
/*
Create_file constructor wants a 0 as last char of buffer, this 0 will
serve as the string-termination char for the file's name (which is at the
end of the buffer)
We must increment event_len, otherwise the event constructor will not see
this end 0, which leads to segfault.
*/
tmp_buf[event_len++]=0;
int4store(tmp_buf+EVENT_LEN_OFFSET, event_len);
buf = (const char*)tmp_buf;
}
/*
This will transform LOAD_EVENT into CREATE_FILE_EVENT, ask the master to
send the loaded file, and write it to the relay log in the form of
Append_block/Exec_load (the SQL thread needs the data, as that thread is not
connected to the master).
*/
Log_event *ev = Log_event::read_log_event(buf,event_len, &errmsg,
mi->rli.relay_log.description_event_for_queue);
if (unlikely(!ev))
{
sql_print_error("Read invalid event from master: '%s',\
master could be corrupt but a more likely cause of this is a bug",
errmsg);
my_free(tmp_buf);
DBUG_RETURN(1);
}
mysql_mutex_lock(&mi->data_lock);
ev->log_pos= mi->master_log_pos; /* 3.23 events don't contain log_pos */
switch (ev->get_type_code()) {
case STOP_EVENT:
ignore_event= 1;
inc_pos= event_len;
break;
case ROTATE_EVENT:
if (unlikely(process_io_rotate(mi,(Rotate_log_event*)ev)))
{
delete ev;
mysql_mutex_unlock(&mi->data_lock);
DBUG_RETURN(1);
}
inc_pos= 0;
break;
case CREATE_FILE_EVENT:
/*
Yes it's possible to have CREATE_FILE_EVENT here, even if we're in
queue_old_event() which is for 3.23 events which don't comprise
CREATE_FILE_EVENT. This is because read_log_event() above has just
transformed LOAD_EVENT into CREATE_FILE_EVENT.
*/
{
/* We come here when and only when tmp_buf != 0 */
DBUG_ASSERT(tmp_buf != 0);
inc_pos=event_len;
ev->log_pos+= inc_pos;
int error = process_io_create_file(mi,(Create_file_log_event*)ev);
delete ev;
mi->master_log_pos += inc_pos;
DBUG_PRINT("info", ("master_log_pos: %lu", (ulong) mi->master_log_pos));
mysql_mutex_unlock(&mi->data_lock);
my_free(tmp_buf);
DBUG_RETURN(error);
}
default:
inc_pos= event_len;
break;
}
if (likely(!ignore_event))
{
if (ev->log_pos)
/*
Don't do it for fake Rotate events (see comment in
Log_event::Log_event(const char* buf...) in log_event.cc).
*/
ev->log_pos+= event_len; /* make log_pos be the pos of the end of the event */
if (unlikely(rli->relay_log.append(ev)))
{
delete ev;
mysql_mutex_unlock(&mi->data_lock);
DBUG_RETURN(1);
}
rli->relay_log.harvest_bytes_written(&rli->log_space_total);
}
delete ev;
mi->master_log_pos+= inc_pos;
DBUG_PRINT("info", ("master_log_pos: %lu", (ulong) mi->master_log_pos));
mysql_mutex_unlock(&mi->data_lock);
DBUG_RETURN(0);
}
/*
Reads a 4.0 event and converts it to the slave's format. This code was copied
from queue_binlog_ver_1_event(), with some affordable simplifications.
*/
static int queue_binlog_ver_3_event(Master_info *mi, const char *buf,
ulong event_len)
{
const char *errmsg = 0;
ulong inc_pos;
char *tmp_buf = 0;
Relay_log_info *rli= &mi->rli;
DBUG_ENTER("queue_binlog_ver_3_event");
/* read_log_event() will adjust log_pos to be end_log_pos */
Log_event *ev = Log_event::read_log_event(buf,event_len, &errmsg,
mi->rli.relay_log.description_event_for_queue);
if (unlikely(!ev))
{
sql_print_error("Read invalid event from master: '%s',\
master could be corrupt but a more likely cause of this is a bug",
errmsg);
my_free(tmp_buf);
DBUG_RETURN(1);
}
mysql_mutex_lock(&mi->data_lock);
switch (ev->get_type_code()) {
case STOP_EVENT:
goto err;
case ROTATE_EVENT:
if (unlikely(process_io_rotate(mi,(Rotate_log_event*)ev)))
{
delete ev;
mysql_mutex_unlock(&mi->data_lock);
DBUG_RETURN(1);
}
inc_pos= 0;
break;
default:
inc_pos= event_len;
break;
}
if (unlikely(rli->relay_log.append(ev)))
{
delete ev;
mysql_mutex_unlock(&mi->data_lock);
DBUG_RETURN(1);
}
rli->relay_log.harvest_bytes_written(&rli->log_space_total);
delete ev;
mi->master_log_pos+= inc_pos;
err:
DBUG_PRINT("info", ("master_log_pos: %lu", (ulong) mi->master_log_pos));
mysql_mutex_unlock(&mi->data_lock);
DBUG_RETURN(0);
}
/*
queue_old_event()
Writes a 3.23 or 4.0 event to the relay log, after converting it to the 5.0
(exactly, slave's) format. To do the conversion, we create a 5.0 event from
the 3.23/4.0 bytes, then write this event to the relay log.
TODO:
Test this code before release - it has to be tested on a separate
setup with 3.23 master or 4.0 master
*/
static int queue_old_event(Master_info *mi, const char *buf,
ulong event_len)
{
DBUG_ENTER("queue_old_event");
switch (mi->rli.relay_log.description_event_for_queue->binlog_version)
{
case 1:
DBUG_RETURN(queue_binlog_ver_1_event(mi,buf,event_len));
case 3:
DBUG_RETURN(queue_binlog_ver_3_event(mi,buf,event_len));
default: /* unsupported format; eg version 2 */
DBUG_PRINT("info",("unsupported binlog format %d in queue_old_event()",
mi->rli.relay_log.description_event_for_queue->binlog_version));
DBUG_RETURN(1);
}
}
/*
queue_event()
If the event is 3.23/4.0, passes it to queue_old_event() which will convert
it. Otherwise, writes a 5.0 (or newer) event to the relay log. Then there is
no format conversion, it's pure read/write of bytes.
So a 5.0.0 slave's relay log can contain events in the slave's format or in
any >=5.0.0 format.
*/
static int queue_event(Master_info* mi,const char* buf, ulong event_len)
{
int error= 0;
String error_msg;
ulong inc_pos;
Relay_log_info *rli= &mi->rli;
mysql_mutex_t *log_lock= rli->relay_log.get_log_lock();
ulong s_id;
DBUG_ENTER("queue_event");
LINT_INIT(inc_pos);
if (mi->rli.relay_log.description_event_for_queue->binlog_version<4 &&
buf[EVENT_TYPE_OFFSET] != FORMAT_DESCRIPTION_EVENT /* a way to escape */)
DBUG_RETURN(queue_old_event(mi,buf,event_len));
LINT_INIT(inc_pos);
mysql_mutex_lock(&mi->data_lock);
switch (buf[EVENT_TYPE_OFFSET]) {
case STOP_EVENT:
/*
We needn't write this event to the relay log. Indeed, it just indicates a
master server shutdown. The only thing this does is cleaning. But
cleaning is already done on a per-master-thread basis (as the master
server is shutting down cleanly, it has written all DROP TEMPORARY TABLE
prepared statements' deletion are TODO only when we binlog prep stmts).
We don't even increment mi->master_log_pos, because we may be just after
a Rotate event. Btw, in a few milliseconds we are going to have a Start
event from the next binlog (unless the master is presently running
without --log-bin).
*/
goto err;
case ROTATE_EVENT:
{
Rotate_log_event rev(buf,event_len,mi->rli.relay_log.description_event_for_queue);
if (unlikely(process_io_rotate(mi,&rev)))
{
error= ER_SLAVE_RELAY_LOG_WRITE_FAILURE;
goto err;
}
/*
Now the I/O thread has just changed its mi->master_log_name, so
incrementing mi->master_log_pos is nonsense.
*/
inc_pos= 0;
break;
}
case FORMAT_DESCRIPTION_EVENT:
{
/*
Create an event, and save it (when we rotate the relay log, we will have
to write this event again).
*/
/*
We are the only thread which reads/writes description_event_for_queue.
The relay_log struct does not move (though some members of it can
change), so we needn't any lock (no rli->data_lock, no log lock).
*/
Format_description_log_event* tmp;
const char* errmsg;
if (!(tmp= (Format_description_log_event*)
Log_event::read_log_event(buf, event_len, &errmsg,
mi->rli.relay_log.description_event_for_queue)))
{
error= ER_SLAVE_RELAY_LOG_WRITE_FAILURE;
goto err;
}
delete mi->rli.relay_log.description_event_for_queue;
mi->rli.relay_log.description_event_for_queue= tmp;
/*
Though this does some conversion to the slave's format, this will
preserve the master's binlog format version, and number of event types.
*/
/*
If the event was not requested by the slave (the slave did not ask for
it), i.e. has end_log_pos=0, we do not increment mi->master_log_pos
*/
inc_pos= uint4korr(buf+LOG_POS_OFFSET) ? event_len : 0;
DBUG_PRINT("info",("binlog format is now %d",
mi->rli.relay_log.description_event_for_queue->binlog_version));
}
break;
case HEARTBEAT_LOG_EVENT:
{
/*
HB (heartbeat) cannot come before RL (Relay)
*/
char llbuf[22];
Heartbeat_log_event hb(buf, event_len, mi->rli.relay_log.description_event_for_queue);
if (!hb.is_valid())
{
error= ER_SLAVE_HEARTBEAT_FAILURE;
error_msg.append(STRING_WITH_LEN("inconsistent heartbeat event content;"));
error_msg.append(STRING_WITH_LEN("the event's data: log_file_name "));
error_msg.append(hb.get_log_ident(), (uint) strlen(hb.get_log_ident()));
error_msg.append(STRING_WITH_LEN(" log_pos "));
llstr(hb.log_pos, llbuf);
error_msg.append(llbuf, strlen(llbuf));
goto err;
}
mi->received_heartbeats++;
/*
compare local and event's versions of log_file, log_pos.
Heartbeat is sent only after an event corresponding to the corrdinates
the heartbeat carries.
Slave can not have a difference in coordinates except in the only
special case when mi->master_log_name, master_log_pos have never
been updated by Rotate event i.e when slave does not have any history
with the master (and thereafter mi->master_log_pos is NULL).
TODO: handling `when' for SHOW SLAVE STATUS' snds behind
*/
if ((memcmp(mi->master_log_name, hb.get_log_ident(), hb.get_ident_len())
&& mi->master_log_name != NULL)
|| mi->master_log_pos != hb.log_pos)
{
/* missed events of heartbeat from the past */
error= ER_SLAVE_HEARTBEAT_FAILURE;
error_msg.append(STRING_WITH_LEN("heartbeat is not compatible with local info;"));
error_msg.append(STRING_WITH_LEN("the event's data: log_file_name "));
error_msg.append(hb.get_log_ident(), (uint) strlen(hb.get_log_ident()));
error_msg.append(STRING_WITH_LEN(" log_pos "));
llstr(hb.log_pos, llbuf);
error_msg.append(llbuf, strlen(llbuf));
goto err;
}
goto skip_relay_logging;
}
break;
default:
inc_pos= event_len;
break;
}
/*
If this event is originating from this server, don't queue it.
We don't check this for 3.23 events because it's simpler like this; 3.23
will be filtered anyway by the SQL slave thread which also tests the
server id (we must also keep this test in the SQL thread, in case somebody
upgrades a 4.0 slave which has a not-filtered relay log).
ANY event coming from ourselves can be ignored: it is obvious for queries;
for STOP_EVENT/ROTATE_EVENT/START_EVENT: these cannot come from ourselves
(--log-slave-updates would not log that) unless this slave is also its
direct master (an unsupported, useless setup!).
*/
mysql_mutex_lock(log_lock);
s_id= uint4korr(buf + SERVER_ID_OFFSET);
if ((s_id == ::server_id && !mi->rli.replicate_same_server_id) ||
/*
the following conjunction deals with IGNORE_SERVER_IDS, if set
If the master is on the ignore list, execution of
format description log events and rotate events is necessary.
*/
(mi->ignore_server_ids.elements > 0 &&
mi->shall_ignore_server_id(s_id) &&
/* everything is filtered out from non-master */
(s_id != mi->master_id ||
/* for the master meta information is necessary */
(buf[EVENT_TYPE_OFFSET] != FORMAT_DESCRIPTION_EVENT &&
buf[EVENT_TYPE_OFFSET] != ROTATE_EVENT))))
{
/*
Do not write it to the relay log.
a) We still want to increment mi->master_log_pos, so that we won't
re-read this event from the master if the slave IO thread is now
stopped/restarted (more efficient if the events we are ignoring are big
LOAD DATA INFILE).
b) We want to record that we are skipping events, for the information of
the slave SQL thread, otherwise that thread may let
rli->group_relay_log_pos stay too small if the last binlog's event is
ignored.
But events which were generated by this slave and which do not exist in
the master's binlog (i.e. Format_desc, Rotate & Stop) should not increment
mi->master_log_pos.
If the event is originated remotely and is being filtered out by
IGNORE_SERVER_IDS it increments mi->master_log_pos
as well as rli->group_relay_log_pos.
*/
if (!(s_id == ::server_id && !mi->rli.replicate_same_server_id) ||
(buf[EVENT_TYPE_OFFSET] != FORMAT_DESCRIPTION_EVENT &&
buf[EVENT_TYPE_OFFSET] != ROTATE_EVENT &&
buf[EVENT_TYPE_OFFSET] != STOP_EVENT))
{
mi->master_log_pos+= inc_pos;
memcpy(rli->ign_master_log_name_end, mi->master_log_name, FN_REFLEN);
DBUG_ASSERT(rli->ign_master_log_name_end[0]);
rli->ign_master_log_pos_end= mi->master_log_pos;
}
rli->relay_log.signal_update(); // the slave SQL thread needs to re-check
DBUG_PRINT("info", ("master_log_pos: %lu, event originating from %u server, ignored",
(ulong) mi->master_log_pos, uint4korr(buf + SERVER_ID_OFFSET)));
}
else
{
/* write the event to the relay log */
if (likely(!(rli->relay_log.appendv(buf,event_len,0))))
{
mi->master_log_pos+= inc_pos;
DBUG_PRINT("info", ("master_log_pos: %lu", (ulong) mi->master_log_pos));
rli->relay_log.harvest_bytes_written(&rli->log_space_total);
}
else
{
error= ER_SLAVE_RELAY_LOG_WRITE_FAILURE;
}
rli->ign_master_log_name_end[0]= 0; // last event is not ignored
}
mysql_mutex_unlock(log_lock);
skip_relay_logging:
err:
mysql_mutex_unlock(&mi->data_lock);
DBUG_PRINT("info", ("error: %d", error));
if (error)
mi->report(ERROR_LEVEL, error, ER(error),
(error == ER_SLAVE_RELAY_LOG_WRITE_FAILURE)?
"could not queue event from master" :
error_msg.ptr());
DBUG_RETURN(error);
}
void end_relay_log_info(Relay_log_info* rli)
{
DBUG_ENTER("end_relay_log_info");
if (!rli->inited)
DBUG_VOID_RETURN;
if (rli->info_fd >= 0)
{
end_io_cache(&rli->info_file);
mysql_file_close(rli->info_fd, MYF(MY_WME));
rli->info_fd = -1;
}
if (rli->cur_log_fd >= 0)
{
end_io_cache(&rli->cache_buf);
mysql_file_close(rli->cur_log_fd, MYF(MY_WME));
rli->cur_log_fd = -1;
}
rli->inited = 0;
rli->relay_log.close(LOG_CLOSE_INDEX | LOG_CLOSE_STOP_EVENT);
rli->relay_log.harvest_bytes_written(&rli->log_space_total);
/*
Delete the slave's temporary tables from memory.
In the future there will be other actions than this, to ensure persistance
of slave's temp tables after shutdown.
*/
rli->close_temporary_tables();
DBUG_VOID_RETURN;
}
/**
Hook to detach the active VIO before closing a connection handle.
The client API might close the connection (and associated data)
in case it encounters a unrecoverable (network) error. This hook
is called from the client code before the VIO handle is deleted
allows the thread to detach the active vio so it does not point
to freed memory.
Other calls to THD::clear_active_vio throughout this module are
redundant due to the hook but are left in place for illustrative
purposes.
*/
extern "C" void slave_io_thread_detach_vio()
{
#ifdef SIGNAL_WITH_VIO_CLOSE
THD *thd= current_thd;
if (thd && thd->slave_thread)
thd->clear_active_vio();
#endif
}
/*
Try to connect until successful or slave killed
SYNPOSIS
safe_connect()
thd Thread handler for slave
mysql MySQL connection handle
mi Replication handle
RETURN
0 ok
# Error
*/
static int safe_connect(THD* thd, MYSQL* mysql, Master_info* mi)
{
DBUG_ENTER("safe_connect");
DBUG_RETURN(connect_to_master(thd, mysql, mi, 0, 0));
}
/*
SYNPOSIS
connect_to_master()
IMPLEMENTATION
Try to connect until successful or slave killed or we have retried
master_retry_count times
*/
static int connect_to_master(THD* thd, MYSQL* mysql, Master_info* mi,
bool reconnect, bool suppress_warnings)
{
int slave_was_killed;
int last_errno= -2; // impossible error
ulong err_count=0;
char llbuff[22];
DBUG_ENTER("connect_to_master");
#ifndef DBUG_OFF
mi->events_till_disconnect = disconnect_slave_event_count;
#endif
ulong client_flag= CLIENT_REMEMBER_OPTIONS;
if (opt_slave_compressed_protocol)
client_flag=CLIENT_COMPRESS; /* We will use compression */
mysql_options(mysql, MYSQL_OPT_CONNECT_TIMEOUT, (char *) &slave_net_timeout);
mysql_options(mysql, MYSQL_OPT_READ_TIMEOUT, (char *) &slave_net_timeout);
#ifdef HAVE_OPENSSL
if (mi->ssl)
{
mysql_ssl_set(mysql,
mi->ssl_key[0]?mi->ssl_key:0,
mi->ssl_cert[0]?mi->ssl_cert:0,
mi->ssl_ca[0]?mi->ssl_ca:0,
mi->ssl_capath[0]?mi->ssl_capath:0,
mi->ssl_cipher[0]?mi->ssl_cipher:0);
mysql_options(mysql, MYSQL_OPT_SSL_VERIFY_SERVER_CERT,
&mi->ssl_verify_server_cert);
}
#endif
mysql_options(mysql, MYSQL_SET_CHARSET_NAME, default_charset_info->csname);
/* This one is not strictly needed but we have it here for completeness */
mysql_options(mysql, MYSQL_SET_CHARSET_DIR, (char *) charsets_dir);
while (!(slave_was_killed = io_slave_killed(thd,mi)) &&
(reconnect ? mysql_reconnect(mysql) != 0 :
mysql_real_connect(mysql, mi->host, mi->user, mi->password, 0,
mi->port, 0, client_flag) == 0))
{
/* Don't repeat last error */
if ((int)mysql_errno(mysql) != last_errno)
{
last_errno=mysql_errno(mysql);
suppress_warnings= 0;
mi->report(ERROR_LEVEL, last_errno,
"error %s to master '%s@%s:%d'"
" - retry-time: %d retries: %lu",
(reconnect ? "reconnecting" : "connecting"),
mi->user, mi->host, mi->port,
mi->connect_retry, master_retry_count);
}
/*
By default we try forever. The reason is that failure will trigger
master election, so if the user did not set master_retry_count we
do not want to have election triggered on the first failure to
connect
*/
if (++err_count == master_retry_count)
{
slave_was_killed=1;
if (reconnect)
change_rpl_status(RPL_ACTIVE_SLAVE,RPL_LOST_SOLDIER);
break;
}
safe_sleep(thd,mi->connect_retry,(CHECK_KILLED_FUNC)io_slave_killed,
(void*)mi);
}
if (!slave_was_killed)
{
mi->clear_error(); // clear possible left over reconnect error
if (reconnect)
{
if (!suppress_warnings && global_system_variables.log_warnings)
sql_print_information("Slave: connected to master '%s@%s:%d',\
replication resumed in log '%s' at position %s", mi->user,
mi->host, mi->port,
IO_RPL_LOG_NAME,
llstr(mi->master_log_pos,llbuff));
}
else
{
change_rpl_status(RPL_IDLE_SLAVE,RPL_ACTIVE_SLAVE);
general_log_print(thd, COM_CONNECT_OUT, "%s@%s:%d",
mi->user, mi->host, mi->port);
}
#ifdef SIGNAL_WITH_VIO_CLOSE
thd->set_active_vio(mysql->net.vio);
#endif
}
mysql->reconnect= 1;
DBUG_PRINT("exit",("slave_was_killed: %d", slave_was_killed));
DBUG_RETURN(slave_was_killed);
}
/*
safe_reconnect()
IMPLEMENTATION
Try to connect until successful or slave killed or we have retried
master_retry_count times
*/
static int safe_reconnect(THD* thd, MYSQL* mysql, Master_info* mi,
bool suppress_warnings)
{
DBUG_ENTER("safe_reconnect");
DBUG_RETURN(connect_to_master(thd, mysql, mi, 1, suppress_warnings));
}
MYSQL *rpl_connect_master(MYSQL *mysql)
{
THD *thd= current_thd;
Master_info *mi= my_pthread_getspecific_ptr(Master_info*, RPL_MASTER_INFO);
if (!mi)
{
sql_print_error("'rpl_connect_master' must be called in slave I/O thread context.");
return NULL;
}
bool allocated= false;
if (!mysql)
{
if(!(mysql= mysql_init(NULL)))
{
sql_print_error("rpl_connect_master: failed in mysql_init()");
return NULL;
}
allocated= true;
}
/*
XXX: copied from connect_to_master, this function should not
change the slave status, so we cannot use connect_to_master
directly
TODO: make this part a seperate function to eliminate duplication
*/
mysql_options(mysql, MYSQL_OPT_CONNECT_TIMEOUT, (char *) &slave_net_timeout);
mysql_options(mysql, MYSQL_OPT_READ_TIMEOUT, (char *) &slave_net_timeout);
#ifdef HAVE_OPENSSL
if (mi->ssl)
{
mysql_ssl_set(mysql,
mi->ssl_key[0]?mi->ssl_key:0,
mi->ssl_cert[0]?mi->ssl_cert:0,
mi->ssl_ca[0]?mi->ssl_ca:0,
mi->ssl_capath[0]?mi->ssl_capath:0,
mi->ssl_cipher[0]?mi->ssl_cipher:0);
mysql_options(mysql, MYSQL_OPT_SSL_VERIFY_SERVER_CERT,
&mi->ssl_verify_server_cert);
}
#endif
mysql_options(mysql, MYSQL_SET_CHARSET_NAME, default_charset_info->csname);
/* This one is not strictly needed but we have it here for completeness */
mysql_options(mysql, MYSQL_SET_CHARSET_DIR, (char *) charsets_dir);
if (io_slave_killed(thd, mi)
|| !mysql_real_connect(mysql, mi->host, mi->user, mi->password, 0,
mi->port, 0, 0))
{
if (!io_slave_killed(thd, mi))
sql_print_error("rpl_connect_master: error connecting to master: %s (server_error: %d)",
mysql_error(mysql), mysql_errno(mysql));
if (allocated)
mysql_close(mysql); // this will free the object
return NULL;
}
return mysql;
}
/*
Store the file and position where the execute-slave thread are in the
relay log.
SYNOPSIS
flush_relay_log_info()
rli Relay log information
NOTES
- As this is only called by the slave thread or on STOP SLAVE, with the
log_lock grabbed and the slave thread stopped, we don't need to have
a lock here.
- If there is an active transaction, then we don't update the position
in the relay log. This is to ensure that we re-execute statements
if we die in the middle of an transaction that was rolled back.
- As a transaction never spans binary logs, we don't have to handle the
case where we do a relay-log-rotation in the middle of the transaction.
If this would not be the case, we would have to ensure that we
don't delete the relay log file where the transaction started when
we switch to a new relay log file.
TODO
- Change the log file information to a binary format to avoid calling
longlong2str.
RETURN VALUES
0 ok
1 write error
*/
bool flush_relay_log_info(Relay_log_info* rli)
{
bool error=0;
DBUG_ENTER("flush_relay_log_info");
if (unlikely(rli->no_storage))
DBUG_RETURN(0);
IO_CACHE *file = &rli->info_file;
char buff[FN_REFLEN*2+22*2+4], *pos;
my_b_seek(file, 0L);
pos=strmov(buff, rli->group_relay_log_name);
*pos++='\n';
pos=longlong2str(rli->group_relay_log_pos, pos, 10);
*pos++='\n';
pos=strmov(pos, rli->group_master_log_name);
*pos++='\n';
pos=longlong2str(rli->group_master_log_pos, pos, 10);
*pos='\n';
if (my_b_write(file, (uchar*) buff, (size_t) (pos-buff)+1))
error=1;
if (flush_io_cache(file))
error=1;
if (sync_relayloginfo_period &&
!error &&
++(rli->sync_counter) >= sync_relayloginfo_period)
{
if (my_sync(rli->info_fd, MYF(MY_WME)))
error=1;
rli->sync_counter= 0;
}
/*
Flushing the relay log is done by the slave I/O thread
or by the user on STOP SLAVE.
*/
DBUG_RETURN(error);
}
/*
Called when we notice that the current "hot" log got rotated under our feet.
*/
static IO_CACHE *reopen_relay_log(Relay_log_info *rli, const char **errmsg)
{
DBUG_ENTER("reopen_relay_log");
DBUG_ASSERT(rli->cur_log != &rli->cache_buf);
DBUG_ASSERT(rli->cur_log_fd == -1);
IO_CACHE *cur_log = rli->cur_log=&rli->cache_buf;
if ((rli->cur_log_fd=open_binlog(cur_log,rli->event_relay_log_name,
errmsg)) <0)
DBUG_RETURN(0);
/*
We want to start exactly where we was before:
relay_log_pos Current log pos
pending Number of bytes already processed from the event
*/
rli->event_relay_log_pos= max(rli->event_relay_log_pos, BIN_LOG_HEADER_SIZE);
my_b_seek(cur_log,rli->event_relay_log_pos);
DBUG_RETURN(cur_log);
}
/**
Reads next event from the relay log. Should be called from the
slave IO thread.
@param rli Relay_log_info structure for the slave IO thread.
@return The event read, or NULL on error. If an error occurs, the
error is reported through the sql_print_information() or
sql_print_error() functions.
*/
static Log_event* next_event(Relay_log_info* rli)
{
Log_event* ev;
IO_CACHE* cur_log = rli->cur_log;
mysql_mutex_t *log_lock = rli->relay_log.get_log_lock();
const char* errmsg=0;
THD* thd = rli->sql_thd;
DBUG_ENTER("next_event");
DBUG_ASSERT(thd != 0);
#ifndef DBUG_OFF
if (abort_slave_event_count && !rli->events_till_abort--)
DBUG_RETURN(0);
#endif
/*
For most operations we need to protect rli members with data_lock,
so we assume calling function acquired this mutex for us and we will
hold it for the most of the loop below However, we will release it
whenever it is worth the hassle, and in the cases when we go into a
mysql_cond_wait() with the non-data_lock mutex
*/
mysql_mutex_assert_owner(&rli->data_lock);
while (!sql_slave_killed(thd,rli))
{
/*
We can have two kinds of log reading:
hot_log:
rli->cur_log points at the IO_CACHE of relay_log, which
is actively being updated by the I/O thread. We need to be careful
in this case and make sure that we are not looking at a stale log that
has already been rotated. If it has been, we reopen the log.
The other case is much simpler:
We just have a read only log that nobody else will be updating.
*/
bool hot_log;
if ((hot_log = (cur_log != &rli->cache_buf)))
{
DBUG_ASSERT(rli->cur_log_fd == -1); // foreign descriptor
mysql_mutex_lock(log_lock);
/*
Reading xxx_file_id is safe because the log will only
be rotated when we hold relay_log.LOCK_log
*/
if (rli->relay_log.get_open_count() != rli->cur_log_old_open_count)
{
// The master has switched to a new log file; Reopen the old log file
cur_log=reopen_relay_log(rli, &errmsg);
mysql_mutex_unlock(log_lock);
if (!cur_log) // No more log files
goto err;
hot_log=0; // Using old binary log
}
}
/*
As there is no guarantee that the relay is open (for example, an I/O
error during a write by the slave I/O thread may have closed it), we
have to test it.
*/
if (!my_b_inited(cur_log))
goto err;
#ifndef DBUG_OFF
{
/* This is an assertion which sometimes fails, let's try to track it */
char llbuf1[22], llbuf2[22];
DBUG_PRINT("info", ("my_b_tell(cur_log)=%s rli->event_relay_log_pos=%s",
llstr(my_b_tell(cur_log),llbuf1),
llstr(rli->event_relay_log_pos,llbuf2)));
DBUG_ASSERT(my_b_tell(cur_log) >= BIN_LOG_HEADER_SIZE);
DBUG_ASSERT(my_b_tell(cur_log) == rli->event_relay_log_pos);
}
#endif
/*
Relay log is always in new format - if the master is 3.23, the
I/O thread will convert the format for us.
A problem: the description event may be in a previous relay log. So if
the slave has been shutdown meanwhile, we would have to look in old relay
logs, which may even have been deleted. So we need to write this
description event at the beginning of the relay log.
When the relay log is created when the I/O thread starts, easy: the
master will send the description event and we will queue it.
But if the relay log is created by new_file(): then the solution is:
MYSQL_BIN_LOG::open() will write the buffered description event.
*/
if ((ev=Log_event::read_log_event(cur_log,0,
rli->relay_log.description_event_for_exec)))
{
DBUG_ASSERT(thd==rli->sql_thd);
/*
read it while we have a lock, to avoid a mutex lock in
inc_event_relay_log_pos()
*/
rli->future_event_relay_log_pos= my_b_tell(cur_log);
if (hot_log)
mysql_mutex_unlock(log_lock);
DBUG_RETURN(ev);
}
DBUG_ASSERT(thd==rli->sql_thd);
if (opt_reckless_slave) // For mysql-test
cur_log->error = 0;
if (cur_log->error < 0)
{
errmsg = "slave SQL thread aborted because of I/O error";
if (hot_log)
mysql_mutex_unlock(log_lock);
goto err;
}
if (!cur_log->error) /* EOF */
{
/*
On a hot log, EOF means that there are no more updates to
process and we must block until I/O thread adds some and
signals us to continue
*/
if (hot_log)
{
/*
We say in Seconds_Behind_Master that we have "caught up". Note that
for example if network link is broken but I/O slave thread hasn't
noticed it (slave_net_timeout not elapsed), then we'll say "caught
up" whereas we're not really caught up. Fixing that would require
internally cutting timeout in smaller pieces in network read, no
thanks. Another example: SQL has caught up on I/O, now I/O has read
a new event and is queuing it; the false "0" will exist until SQL
finishes executing the new event; it will be look abnormal only if
the events have old timestamps (then you get "many", 0, "many").
Transient phases like this can be fixed with implemeting
Heartbeat event which provides the slave the status of the
master at time the master does not have any new update to send.
Seconds_Behind_Master would be zero only when master has no
more updates in binlog for slave. The heartbeat can be sent
in a (small) fraction of slave_net_timeout. Until it's done
rli->last_master_timestamp is temporarely (for time of
waiting for the following event) reset whenever EOF is
reached.
*/
time_t save_timestamp= rli->last_master_timestamp;
rli->last_master_timestamp= 0;
DBUG_ASSERT(rli->relay_log.get_open_count() ==
rli->cur_log_old_open_count);
if (rli->ign_master_log_name_end[0])
{
/* We generate and return a Rotate, to make our positions advance */
DBUG_PRINT("info",("seeing an ignored end segment"));
ev= new Rotate_log_event(rli->ign_master_log_name_end,
0, rli->ign_master_log_pos_end,
Rotate_log_event::DUP_NAME);
rli->ign_master_log_name_end[0]= 0;
mysql_mutex_unlock(log_lock);
if (unlikely(!ev))
{
errmsg= "Slave SQL thread failed to create a Rotate event "
"(out of memory?), SHOW SLAVE STATUS may be inaccurate";
goto err;
}
ev->server_id= 0; // don't be ignored by slave SQL thread
DBUG_RETURN(ev);
}
/*
We can, and should release data_lock while we are waiting for
update. If we do not, show slave status will block
*/
mysql_mutex_unlock(&rli->data_lock);
/*
Possible deadlock :
- the I/O thread has reached log_space_limit
- the SQL thread has read all relay logs, but cannot purge for some
reason:
* it has already purged all logs except the current one
* there are other logs than the current one but they're involved in
a transaction that finishes in the current one (or is not finished)
Solution :
Wake up the possibly waiting I/O thread, and set a boolean asking
the I/O thread to temporarily ignore the log_space_limit
constraint, because we do not want the I/O thread to block because of
space (it's ok if it blocks for any other reason (e.g. because the
master does not send anything). Then the I/O thread stops waiting
and reads more events.
The SQL thread decides when the I/O thread should take log_space_limit
into account again : ignore_log_space_limit is reset to 0
in purge_first_log (when the SQL thread purges the just-read relay
log), and also when the SQL thread starts. We should also reset
ignore_log_space_limit to 0 when the user does RESET SLAVE, but in
fact, no need as RESET SLAVE requires that the slave
be stopped, and the SQL thread sets ignore_log_space_limit to 0 when
it stops.
*/
mysql_mutex_lock(&rli->log_space_lock);
// prevent the I/O thread from blocking next times
rli->ignore_log_space_limit= 1;
/*
If the I/O thread is blocked, unblock it. Ok to broadcast
after unlock, because the mutex is only destroyed in
~Relay_log_info(), i.e. when rli is destroyed, and rli will
not be destroyed before we exit the present function.
*/
mysql_mutex_unlock(&rli->log_space_lock);
mysql_cond_broadcast(&rli->log_space_cond);
// Note that wait_for_update_relay_log unlocks lock_log !
rli->relay_log.wait_for_update_relay_log(rli->sql_thd);
// re-acquire data lock since we released it earlier
mysql_mutex_lock(&rli->data_lock);
rli->last_master_timestamp= save_timestamp;
continue;
}
/*
If the log was not hot, we need to move to the next log in
sequence. The next log could be hot or cold, we deal with both
cases separately after doing some common initialization
*/
end_io_cache(cur_log);
DBUG_ASSERT(rli->cur_log_fd >= 0);
mysql_file_close(rli->cur_log_fd, MYF(MY_WME));
rli->cur_log_fd = -1;
if (relay_log_purge)
{
/*
purge_first_log will properly set up relay log coordinates in rli.
If the group's coordinates are equal to the event's coordinates
(i.e. the relay log was not rotated in the middle of a group),
we can purge this relay log too.
We do ulonglong and string comparisons, this may be slow but
- purging the last relay log is nice (it can save 1GB of disk), so we
like to detect the case where we can do it, and given this,
- I see no better detection method
- purge_first_log is not called that often
*/
if (rli->relay_log.purge_first_log
(rli,
rli->group_relay_log_pos == rli->event_relay_log_pos
&& !strcmp(rli->group_relay_log_name,rli->event_relay_log_name)))
{
errmsg = "Error purging processed logs";
goto err;
}
}
else
{
/*
If hot_log is set, then we already have a lock on
LOCK_log. If not, we have to get the lock.
According to Sasha, the only time this code will ever be executed
is if we are recovering from a bug.
*/
if (rli->relay_log.find_next_log(&rli->linfo, !hot_log))
{
errmsg = "error switching to the next log";
goto err;
}
rli->event_relay_log_pos = BIN_LOG_HEADER_SIZE;
strmake(rli->event_relay_log_name,rli->linfo.log_file_name,
sizeof(rli->event_relay_log_name)-1);
flush_relay_log_info(rli);
}
/*
Now we want to open this next log. To know if it's a hot log (the one
being written by the I/O thread now) or a cold log, we can use
is_active(); if it is hot, we use the I/O cache; if it's cold we open
the file normally. But if is_active() reports that the log is hot, this
may change between the test and the consequence of the test. So we may
open the I/O cache whereas the log is now cold, which is nonsense.
To guard against this, we need to have LOCK_log.
*/
DBUG_PRINT("info",("hot_log: %d",hot_log));
if (!hot_log) /* if hot_log, we already have this mutex */
mysql_mutex_lock(log_lock);
if (rli->relay_log.is_active(rli->linfo.log_file_name))
{
#ifdef EXTRA_DEBUG
if (global_system_variables.log_warnings)
sql_print_information("next log '%s' is currently active",
rli->linfo.log_file_name);
#endif
rli->cur_log= cur_log= rli->relay_log.get_log_file();
rli->cur_log_old_open_count= rli->relay_log.get_open_count();
DBUG_ASSERT(rli->cur_log_fd == -1);
/*
When the SQL thread is [stopped and] (re)started the
following may happen:
1. Log was hot at stop time and remains hot at restart
SQL thread reads again from hot_log (SQL thread was
reading from the active log when it was stopped and the
very same log is still active on SQL thread restart).
In this case, my_b_seek is performed on cur_log, while
cur_log points to relay_log.get_log_file();
2. Log was hot at stop time but got cold before restart
The log was hot when SQL thread stopped, but it is not
anymore when the SQL thread restarts.
In this case, the SQL thread reopens the log, using
cache_buf, ie, cur_log points to &cache_buf, and thence
its coordinates are reset.
3. Log was already cold at stop time
The log was not hot when the SQL thread stopped, and, of
course, it will not be hot when it restarts.
In this case, the SQL thread opens the cold log again,
using cache_buf, ie, cur_log points to &cache_buf, and
thence its coordinates are reset.
4. Log was hot at stop time, DBA changes to previous cold
log and restarts SQL thread
The log was hot when the SQL thread was stopped, but the
user changed the coordinates of the SQL thread to
restart from a previous cold log.
In this case, at start time, cur_log points to a cold
log, opened using &cache_buf as cache, and coordinates
are reset. However, as it moves on to the next logs, it
will eventually reach the hot log. If the hot log is the
same at the time the SQL thread was stopped, then
coordinates were not reset - the cur_log will point to
relay_log.get_log_file(), and not a freshly opened
IO_CACHE through cache_buf. For this reason we need to
deploy a my_b_seek before calling check_binlog_magic at
this point of the code (see: BUG#55263 for more
details).
NOTES:
- We must keep the LOCK_log to read the 4 first bytes, as
this is a hot log (same as when we call read_log_event()
above: for a hot log we take the mutex).
- Because of scenario #4 above, we need to have a
my_b_seek here. Otherwise, we might hit the assertion
inside check_binlog_magic.
*/
my_b_seek(cur_log, (my_off_t) 0);
if (check_binlog_magic(cur_log,&errmsg))
{
if (!hot_log)
mysql_mutex_unlock(log_lock);
goto err;
}
if (!hot_log)
mysql_mutex_unlock(log_lock);
continue;
}
if (!hot_log)
mysql_mutex_unlock(log_lock);
/*
if we get here, the log was not hot, so we will have to open it
ourselves. We are sure that the log is still not hot now (a log can get
from hot to cold, but not from cold to hot). No need for LOCK_log.
*/
#ifdef EXTRA_DEBUG
if (global_system_variables.log_warnings)
sql_print_information("next log '%s' is not active",
rli->linfo.log_file_name);
#endif
// open_binlog() will check the magic header
if ((rli->cur_log_fd=open_binlog(cur_log,rli->linfo.log_file_name,
&errmsg)) <0)
goto err;
}
else
{
/*
Read failed with a non-EOF error.
TODO: come up with something better to handle this error
*/
if (hot_log)
mysql_mutex_unlock(log_lock);
sql_print_error("Slave SQL thread: I/O error reading \
event(errno: %d cur_log->error: %d)",
my_errno,cur_log->error);
// set read position to the beginning of the event
my_b_seek(cur_log,rli->event_relay_log_pos);
/* otherwise, we have had a partial read */
errmsg = "Aborting slave SQL thread because of partial event read";
break; // To end of function
}
}
if (!errmsg && global_system_variables.log_warnings)
{
sql_print_information("Error reading relay log event: %s",
"slave SQL thread was killed");
DBUG_RETURN(0);
}
err:
if (errmsg)
sql_print_error("Error reading relay log event: %s", errmsg);
DBUG_RETURN(0);
}
/*
Rotate a relay log (this is used only by FLUSH LOGS; the automatic rotation
because of size is simpler because when we do it we already have all relevant
locks; here we don't, so this function is mainly taking locks).
Returns nothing as we cannot catch any error (MYSQL_BIN_LOG::new_file()
is void).
*/
void rotate_relay_log(Master_info* mi)
{
DBUG_ENTER("rotate_relay_log");
Relay_log_info* rli= &mi->rli;
DBUG_EXECUTE_IF("crash_before_rotate_relaylog", abort(););
/*
We need to test inited because otherwise, new_file() will attempt to lock
LOCK_log, which may not be inited (if we're not a slave).
*/
if (!rli->inited)
{
DBUG_PRINT("info", ("rli->inited == 0"));
goto end;
}
/* If the relay log is closed, new_file() will do nothing. */
rli->relay_log.new_file();
/*
We harvest now, because otherwise BIN_LOG_HEADER_SIZE will not immediately
be counted, so imagine a succession of FLUSH LOGS and assume the slave
threads are started:
relay_log_space decreases by the size of the deleted relay log, but does
not increase, so flush-after-flush we may become negative, which is wrong.
Even if this will be corrected as soon as a query is replicated on the
slave (because the I/O thread will then call harvest_bytes_written() which
will harvest all these BIN_LOG_HEADER_SIZE we forgot), it may give strange
output in SHOW SLAVE STATUS meanwhile. So we harvest now.
If the log is closed, then this will just harvest the last writes, probably
0 as they probably have been harvested.
*/
rli->relay_log.harvest_bytes_written(&rli->log_space_total);
end:
DBUG_VOID_RETURN;
}
/**
Detects, based on master's version (as found in the relay log), if master
has a certain bug.
@param rli Relay_log_info which tells the master's version
@param bug_id Number of the bug as found in bugs.mysql.com
@param report bool report error message, default TRUE
@param pred Predicate function that will be called with @c param to
check for the bug. If the function return @c true, the bug is present,
otherwise, it is not.
@param param State passed to @c pred function.
@return TRUE if master has the bug, FALSE if it does not.
*/
bool rpl_master_has_bug(const Relay_log_info *rli, uint bug_id, bool report,
bool (*pred)(const void *), const void *param)
{
struct st_version_range_for_one_bug {
uint bug_id;
const uchar introduced_in[3]; // first version with bug
const uchar fixed_in[3]; // first version with fix
};
static struct st_version_range_for_one_bug versions_for_all_bugs[]=
{
{24432, { 5, 0, 24 }, { 5, 0, 38 } },
{24432, { 5, 1, 12 }, { 5, 1, 17 } },
{33029, { 5, 0, 0 }, { 5, 0, 58 } },
{33029, { 5, 1, 0 }, { 5, 1, 12 } },
{37426, { 5, 1, 0 }, { 5, 1, 26 } },
};
const uchar *master_ver=
rli->relay_log.description_event_for_exec->server_version_split;
DBUG_ASSERT(sizeof(rli->relay_log.description_event_for_exec->server_version_split) == 3);
for (uint i= 0;
i < sizeof(versions_for_all_bugs)/sizeof(*versions_for_all_bugs);i++)
{
const uchar *introduced_in= versions_for_all_bugs[i].introduced_in,
*fixed_in= versions_for_all_bugs[i].fixed_in;
if ((versions_for_all_bugs[i].bug_id == bug_id) &&
(memcmp(introduced_in, master_ver, 3) <= 0) &&
(memcmp(fixed_in, master_ver, 3) > 0) &&
(pred == NULL || (*pred)(param)))
{
if (!report)
return TRUE;
// a short message for SHOW SLAVE STATUS (message length constraints)
my_printf_error(ER_UNKNOWN_ERROR, "master may suffer from"
" http://bugs.mysql.com/bug.php?id=%u"
" so slave stops; check error log on slave"
" for more info", MYF(0), bug_id);
// a verbose message for the error log
rli->report(ERROR_LEVEL, ER_UNKNOWN_ERROR,
"According to the master's version ('%s'),"
" it is probable that master suffers from this bug:"
" http://bugs.mysql.com/bug.php?id=%u"
" and thus replicating the current binary log event"
" may make the slave's data become different from the"
" master's data."
" To take no risk, slave refuses to replicate"
" this event and stops."
" We recommend that all updates be stopped on the"
" master and slave, that the data of both be"
" manually synchronized,"
" that master's binary logs be deleted,"
" that master be upgraded to a version at least"
" equal to '%d.%d.%d'. Then replication can be"
" restarted.",
rli->relay_log.description_event_for_exec->server_version,
bug_id,
fixed_in[0], fixed_in[1], fixed_in[2]);
return TRUE;
}
}
return FALSE;
}
/**
BUG#33029, For all 5.0 up to 5.0.58 exclusive, and 5.1 up to 5.1.12
exclusive, if one statement in a SP generated AUTO_INCREMENT value
by the top statement, all statements after it would be considered
generated AUTO_INCREMENT value by the top statement, and a
erroneous INSERT_ID value might be associated with these statement,
which could cause duplicate entry error and stop the slave.
Detect buggy master to work around.
*/
bool rpl_master_erroneous_autoinc(THD *thd)
{
if (active_mi && active_mi->rli.sql_thd == thd)
{
Relay_log_info *rli= &active_mi->rli;
DBUG_EXECUTE_IF("simulate_bug33029", return TRUE;);
return rpl_master_has_bug(rli, 33029, FALSE, NULL, NULL);
}
return FALSE;
}
#ifdef HAVE_EXPLICIT_TEMPLATE_INSTANTIATION
template class I_List_iterator<i_string>;
template class I_List_iterator<i_string_pair>;
#endif
/**
@} (end of group Replication)
*/
#endif /* HAVE_REPLICATION */
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