- FLUSH GLOBAL STATUS now resets most global_status_vars.
At this stage, this is mainly to be used for testing.
- FLUSH SESSION STATUS added as an alias for FLUSH STATUS.
- FLUSH STATUS does not require any privilege (before required RELOAD).
- FLUSH GLOBAL STATUS requires RELOAD privilege.
- All global status reset moved to FLUSH GLOBAL STATUS.
- Replication semisync status variables are now reset by
FLUSH GLOBAL STATUS.
- In test cases, the only changes are:
- Replace FLUSH STATUS with FLUSH GLOBAL STATUS
- Replace FLUSH STATUS with FLUSH STATUS; FLUSH GLOBAL STATUS.
This was only done in a few tests where the test was using SHOW STATUS
for both local and global variables.
- Uptime_since_flush_status is now always provided, independent if
ENABLED_PROFILING is enabled when compiling MariaDB.
- @@global.Uptime_since_flush_status is reset on FLUSH GLOBAL STATUS
and @@session.Uptime_since_flush_status is reset on FLUSH SESSION STATUS.
- When connected, @@session.Uptime_since_flush_status is set to 0.
Added SHOW_LONGLONG_NOFLUSH to mark the variables that should not be
flushed.
New variables cleared as part of SHOW STATUS:
- Rpl_semi_sync_master_request_ack
- Rpl_semi_sync_master_get_ac
- Rpl_semi_sync_slave_send_ack
- Slave_skipped_error
Remove alter_algorithm but keep the variable as no-op (with a warning).
The reasons for removing alter_algorithm are:
- alter_algorithm was introduced as a replacement for the
old_alter_table that was used to force the usage of the original
alter table algorithm (copy) in the cases where the new alter
algorithm did not work. The new option was added as a way to force
the usage of a specific algorithm when it should instead have made
it possible to disable algorithms that would not work for some
reason.
- alter_algorithm introduced some cases where ALTER TABLE would not
work without specifying the ALGORITHM=XXX option together with
ALTER TABLE.
- Having different values of alter_algorithm on master and slave could
cause slave to stop unexpectedly.
- ALTER TABLE FORCE, as used by mariadb-upgrade, would not always work
if alter_algorithm was set for the server.
- As part of the MDEV-33449 "improving repair of tables" it become
clear that alter- algorithm made it harder to provide a better and
more consistent ALTER TABLE FORCE and REPAIR TABLE and it would be
better to remove it.
This patch extends the timestamp from
2038-01-19 03:14:07.999999 to 2106-02-07 06:28:15.999999
for 64 bit hardware and OS where 'long' is 64 bits.
This is true for 64 bit Linux but not for Windows.
This is done by treating the 32 bit stored int as unsigned instead of
signed. This is safe as MariaDB has never accepted dates before the epoch
(1970).
The benefit of this approach that for normal timestamp the storage is
compatible with earlier version.
However for tables using system versioning we before stored a
timestamp with the year 2038 as the 'max timestamp', which is used to
detect current values. This patch stores the new 2106 year max value
as the max timestamp. This means that old tables using system
versioning needs to be updated with mariadb-upgrade when moving them
to 11.4. That will be done in a separate commit.
Various help message improvements:
* MySQL->MariaDB, mysqld->mariadbd, "mysqld daemon" -> "mariadbd process"
* typos
* don't specify defaults directly in the help message
* don't say that an option is deprecated, mark is as such
* missing spaces in the middle of the text
etc
* use new deprecated printer for all deprecated server options
* restore alphabetic option sorting order
* move deprecated printer from mysqld.cc to my_getopt.c
* in --help print deprecation message at the end of the option help
* move 'ALL' help text where it belongs - to other SET options, and
with a correct indentation.
* consistently end all or none command-line option help strings
with a dot - my_print_help() needs that.
It's about 50/50 now, so let's do none, less line wraps in --help
* remove trailing spaces from command-line option help strings
Currently there are mechanism to mark a system variable as
deprecated, but they are only used to print warning messages
when a deprecated variable is set.
Leverage the existing mechanisms in order to make the
deprecation information available at the --help output of mysqld by:
* Moving the deprecation information (i.e `deprecation_substitute`
attribute) from the `sys_var` class into the `my_option` struct.
As every `sys_var` contains its own `my_option` struct, the access
to the deprecation information remains available to `sys_var`
objects. `my_getotp` functions, which works directly with
`my_option` structs, gain access to this information while building
the --help output.
* For plugin variables, leverages the `PLUGIN_VAR_DEPRECATED` flag
and set the `deprecation_substitute` attribute accordingly when
building the `my_option` objects.
* Change the `option_cmp` function to use the `deprecation_substitute`
attribute instead of the name when sorting the options. This way
deprecated options and the substitutes will be grouped together.
All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer
Amazon Web Services, Inc.
Improve detection for DES support in OpenSSL, to allow compilation
against system OpenSSL without DES.
Note that MariaDB needs to be compiled against OpenSSL-like library
that itself has DES support which cmake detected. Positive detection
is indicated with CMake variable HAVE_des 1.
Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@surgut.co.uk>
The problem was that the signal thread was not killed when using
unireg_abort().
The bug was introduced by:
MDEV-30260: Slave crashed:reload_acl_and_cache during shutdown
Other things fixed:
- Don't produce memory leaks with safemalloc if all threads was not
ended properly (not useful)
This patch also fixes:
MDEV-33050 Build-in schemas like oracle_schema are accent insensitive
MDEV-33084 LASTVAL(t1) and LASTVAL(T1) do not work well with lower-case-table-names=0
MDEV-33085 Tables T1 and t1 do not work well with ENGINE=CSV and lower-case-table-names=0
MDEV-33086 SHOW OPEN TABLES IN DB1 -- is case insensitive with lower-case-table-names=0
MDEV-33088 Cannot create triggers in the database `MYSQL`
MDEV-33103 LOCK TABLE t1 AS t2 -- alias is not case sensitive with lower-case-table-names=0
MDEV-33109 DROP DATABASE MYSQL -- does not drop SP with lower-case-table-names=0
MDEV-33110 HANDLER commands are case insensitive with lower-case-table-names=0
MDEV-33119 User is case insensitive in INFORMATION_SCHEMA.VIEWS
MDEV-33120 System log table names are case insensitive with lower-cast-table-names=0
- Removing the virtual function strnncoll() from MY_COLLATION_HANDLER
- Adding a wrapper function CHARSET_INFO::streq(), to compare
two strings for equality. For now it calls strnncoll() internally.
In the future it will turn into a virtual function.
- Adding new accent sensitive case insensitive collations:
- utf8mb4_general1400_as_ci
- utf8mb3_general1400_as_ci
They implement accent sensitive case insensitive comparison.
The weight of a character is equal to the code point of its
upper case variant. These collations use Unicode-14.0.0 casefolding data.
The result of
my_charset_utf8mb3_general1400_as_ci.strcoll()
is very close to the former
my_charset_utf8mb3_general_ci.strcasecmp()
There is only a difference in a couple dozen rare characters, because:
- the switch from "tolower" to "toupper" comparison, to make
utf8mb3_general1400_as_ci closer to utf8mb3_general_ci
- the switch from Unicode-3.0.0 to Unicode-14.0.0
This difference should be tolarable. See the list of affected
characters in the MDEV description.
Note, utf8mb4_general1400_as_ci correctly handles non-BMP characters!
Unlike utf8mb4_general_ci, it does not treat all BMP characters
as equal.
- Adding classes representing names of the file based database objects:
Lex_ident_db
Lex_ident_table
Lex_ident_trigger
Their comparison collation depends on the underlying
file system case sensitivity and on --lower-case-table-names
and can be either my_charset_bin or my_charset_utf8mb3_general1400_as_ci.
- Adding classes representing names of other database objects,
whose names have case insensitive comparison style,
using my_charset_utf8mb3_general1400_as_ci:
Lex_ident_column
Lex_ident_sys_var
Lex_ident_user_var
Lex_ident_sp_var
Lex_ident_ps
Lex_ident_i_s_table
Lex_ident_window
Lex_ident_func
Lex_ident_partition
Lex_ident_with_element
Lex_ident_rpl_filter
Lex_ident_master_info
Lex_ident_host
Lex_ident_locale
Lex_ident_plugin
Lex_ident_engine
Lex_ident_server
Lex_ident_savepoint
Lex_ident_charset
engine_option_value::Name
- All the mentioned Lex_ident_xxx classes implement a method streq():
if (ident1.streq(ident2))
do_equal();
This method works as a wrapper for CHARSET_INFO::streq().
- Changing a lot of "LEX_CSTRING name" to "Lex_ident_xxx name"
in class members and in function/method parameters.
- Replacing all calls like
system_charset_info->coll->strcasecmp(ident1, ident2)
to
ident1.streq(ident2)
- Taking advantage of the c++11 user defined literal operator
for LEX_CSTRING (see m_strings.h) and Lex_ident_xxx (see lex_ident.h)
data types. Use example:
const Lex_ident_column primary_key_name= "PRIMARY"_Lex_ident_column;
is now a shorter version of:
const Lex_ident_column primary_key_name=
Lex_ident_column({STRING_WITH_LEN("PRIMARY")});
- Add additional MTRs for more coverage on invalid options
- Updating a few error messages to be more informative
- Use the exit code from handle_options() when there is an error processing
user options
All new code of the whole pull request, including one or several files that are
either new files or modified ones, are contributed under the BSD-new license. I
am contributing on behalf of my employer Amazon Web Services, Inc.
Fixed that internal temporary tables are not waiting for freed disk space.
Other things:
- 'kill id' will now kill a query waiting for free disk space instantly.
Before it could take up to 60 seconds for the kill would be noticed.
- Fixed that sorting one index is not using MY_WAIT_IF_FULL for temp files.
- Fixed bug where share->write_flag set MY_WAIT_IF_FULL for temp files.
It is quite hard to do a test case for this. Instead I tested all
combinations interactively.
The signal handler thread can use various different runtime
resources when processing a SIGHUP (e.g. master-info information)
due to calling into reload_acl_and_cache(). Currently, the shutdown
process waits for the termination of the signal thread after
performing cleanup. However, this could cause resources actively
used by the signal handler to be freed while reload_acl_and_cache()
is processing.
The specific resource that caused MDEV-30260 is a race condition for
the hostname_cache, such that mysqld would delete it in
clean_up()::hostname_cache_free(), before the signal handler would
use it in reload_acl_and_cache()::hostname_cache_refresh().
Another similar resource is the active_mi/master_info_index. There
was a race between its deletion by the main thread in end_slave(),
and their usage by the Signal Handler as a part of
Master_info_index::flush_all_relay_logs.read(active_mi) in
reload_acl_and_cache().
This patch fixes these race conditions by relocating where server
shutdown waits for the signal handler to die until after
server-level threads have been killed (i.e., as a last step of
close_connections()). With respect to the hostname_cache, active_mi
and master_info_cache, this ensures that they cannot be destroyed
while the signal handler is still active, and potentially using
them.
Additionally:
1) This requires that Events memory is still in place for SIGHUP
handling's mysql_print_status(). So event deinitialization is moved
into clean_up(), but the event scheduler still needs to be stopped
in close_connections() at the same spot.
2) The function kill_server_thread is no longer used, so it is
deleted
3) The timeout to wait for the death of the signal thread was not
consistent with the comment. The comment mentioned up to 10 seconds,
whereas it was actually 0.01s. The code has been fixed to wait up to
10 seconds.
4) A warning has been added if the signal handler thread fails to
exit in time.
5) Added pthread_join() to end of wait_for_signal_thread_to_end()
if it hadn't ended in 10s with a warning. Note this also removes
the pthread_detached attribute from the signal_thread to allow
for the pthread_join().
Reviewed By:
===========
Vladislav Vaintroub <wlad@mariadb.com>
Andrei Elkin <andrei.elkin@mariadb.com>
MDEV-26473 fixed a segmentation fault at startup between the handle
manager thread and the binlog background thread, such that the
binlog background thread could be started and submit a job to the
handle manager, before it had initialized. Where MDEV-26473 made it
so the handle manager would initialize before the main thread
started the normal binary logs, it did not account for the recovery
case. That is, there is still a possibility of a segmentation fault
when a server is recovering using the binary logs such that it can
open the binary logs, start the binlog background thread, and submit
a job to the handle manager before it is initialized.
This patch fixes this by moving the initialization of the mysql
handler manager to happen prior to recovery.
Reviewed By:
============
Andrei Elkin <andrei.elkin@mariadb.com>
Some fixes related to commit f838b2d799 and
Rows_log_event::do_apply_event() and Update_rows_log_event::do_exec_row()
for system-versioned tables were provided by Nikita Malyavin.
This was required by test versioning.rpl,trx_id,row.
When using semi-sync replication with
rpl_semi_sync_master_wait_point=AFTER_COMMIT, the performance of the
primary can significantly reduce compared to AFTER_SYNC's
performance for workloads with many concurrent users executing
transactions. This is because all connections on the primary share
the same cond_wait variable/mutex pair, so any time an ACK is
received from a replica, all waiting connections are awoken to check
if the ACK was for itself, which is done in mutual exclusion.
This patch changes this such that the waiting THD will use its own
local condition variable, and the ACK receiver thread only signals
connections which have been ACKed for wakeup. That is, the
THD::LOCK_wakeup_ready condition variable is re-used for this
purpose, and the Active_tranx queue nodes are extended to hold the
waiting thread, so it can be signalled once ACKed.
Additionally:
1) Removed part of MDEV-11853 additions, which allowed suspended
connection threads awaiting their semi-sync ACKs to live until their
ACKs had been received. This part, however, wasn't needed. That is,
all that was needed was for the Ack_thread to survive. So now the
connection threads are killed during phase 1. Thereby
THD::is_awaiting_semisync_ack, and all its related code was removed.
2) COND_binlog_send is repurposed to signal on the condition when
Active_tranx is emptied during clear_active_tranx_nodes.
3) At master shutdown (when waiting for slaves), instead of the
main loop individually waiting for each ACK, await_slave_reply()
(renamed await_all_slave_replies()) just waits once for the
repurposed COND_binlog_send to signal it is empty.
4) Test rpl_semi_sync_shutdown_await_ack is updates as following:
4.1) Added test case (adapted from Kristian Nielsen) to ensure
that if a thread awaiting its ACK is killed while SHUTDOWN WAIT FOR
ALL SLAVES is issued, the primary will still wait for the ACK from
the killed thread.
4.2) As connections which by-passed phase 1 of thread killing no
longer are delayed for kill until phase 2, we can no longer query
yes/no tx after receiving an ACK/timeout. The check for these
variables is removed.
4.3) Comment descriptions are updated which mention that the
connection is alive; and adjusted to be the Ack_thread.
Reviewed By:
============
Kristian Nielsen <knielsen@knielsen-hq.org>
signal_hand(): Remove the cmake -DWITH_DBUG_TRACE=ON instrumentation.
It can cause a crash on shutdown when the only other thread is
waiting in wait_for_signal_thread_to_end().
This removes the error:
"Failed to load slave replication state from table mysql.gtid_slave_pos:
1017: Can't find file: './mysql/' (errno: 2 "No such file or directory")
my_malloc_size_cb_func() can be called from contexts where it is not safe to
wait for LOCK_thd_kill, for example while holding LOCK_plugin. This could
lead to (probably very unlikely) deadlock of the server.
Fix by skipping the enforcement of --max-session-mem-used in the rare cases
when LOCK_thd_kill cannot be obtained. The limit will instead be enforced on
the following memory allocation. This does not significantly degrade the
behaviour of --max-session-mem-used; that limit is in any case only enforced
"softly", not taking effect until the next point at which the thread does a
check_killed().
Reviewed-by: Monty <monty@mariadb.org>
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
binlog_space_limit is a variable in Percona server used to limit the total
size of all binary logs.
This implementation is based on code from Percona server 5.7.
In MariaDB we decided to call the variable max-binlog-total-size to be
similar to max-binlog-size. This makes it easier to find in the output
from 'mariadbd --help --verbose'). MariaDB will also support
binlog_space_limit for compatibility with Percona.
Some internal notes to explain implementation notes:
- When running MariaDB does not delete binary logs that are either
used by slaves or have active xid that are not yet committed.
Some implementation notes:
- max-binlog-total-size is by default 0 (no limit).
- max-binlog-total-size can be changed without server restart.
- Binlog file sizes are checked on startup, or if
max-binlog-total-size is set to a value > 0, not for every log write.
The total size of all binary logs is cached and dynamically updated
when updating the binary log on binary log rotation.
- max-binlog-total-size is checked against existing log files during
serverstart, binlog rotation, FLUSH LOGS, when writing to binary log
or when max-binlog-total-size changes value.
- Option --slave-connections-needed-for-purge with 1 as default added.
This allows one to ensure that we do not delete binary logs if there
is less than 'slave-connections-needed-for-purge' connected.
Without this option max-binlog-total-size would potentially delete
binlogs needed by slaves on server startup or when a slave disconnects
as there are then no connected slaves to protect active binlogs.
- PURGE BINARY LOGS TO ... will be executed as if
slave-connectitons-needed-for-purge would be zero. In other words
it will do the purge even if there is no slaves connected. If there
are connected slaves working on the logs, these will be protected.
- If binary log is on and max-binlog-total_size <> 0 then the status
variable 'Binlog_disk_use' shows the current size of all old binary
logs + the state of the current one.
- Removed test of strcmp(log_file_name, log_info.log_file_name) in
purge_logs_before_date() as this is tested in can_purge_logs()
- To avoid expensive calls of log_in_use() we cache the result for the
last log that is in use by a slave. Future calls to can_purge_logs()
for this binary log will be quickly detected and false will be returned
until a slave starts working on a new log.
- Note that after a binary log rotation caused by max_binlog_size,
the last log will not be purged directly as it is still in use
internally. The next binary log write will purge binlogs if needed.
Reviewer:Kristian Nielsen <knielsen@knielsen-hq.org>
