Instead we use LOCK_status only to protect summary of thread statistics and use a new mutex, LOCK_show_status
to protect concurrent SHOW STATUS.
sql/mysqld.cc:
Add LOCK_show_status
Don't free LOCK_status while calculating status variables.
sql/mysqld.h:
Add LOCK_show_status
sql/sql_show.cc:
Use LOCK_show_status to protect SHOW STATUS instead of LOCK_status.
Analysis: wsrep_applier_thread shutdown signaling does not always work
correctly causing a timing problem where main thread is waiting in a
condition variable a signal that all worker threads to end.
Merged lp:maria/maria-10.0-galera up to revision 3880.
Added a new functions to handler API to forcefully abort_transaction,
producing fake_trx_id, get_checkpoint and set_checkpoint for XA. These
were added for future possiblity to add more storage engines that
could use galera replication.
Merged lp:maria/maria-10.0-galera up to revision 3879.
Added a new functions to handler API to forcefully abort_transaction,
producing fake_trx_id, get_checkpoint and set_checkpoint for XA. These
were added for future possiblity to add more storage engines that
could use galera replication.
mysqldump:
- Added --log-queries to allow one to disable logging for the dump
sql/log_event.cc:
- Removed setting of enable_slow_log as it's not required anymore.
sql/sql_parse.cc:
- Set enable_slow_log to value of thd->variables.sql_log_slow as this will speed up tests if slow log is disabled.
- opt_log_slow_admin_statements can now only disable slow log, not enable it.
sql/sql_explain.cc:
- Minor cleanup
Other things:
- Added sql_log_slow to system variables.
- Changed opt_slow_log to global_system_variables.sql_log_slow in all files
- Updated tests to reflect changes
bzr merge -r4264 maria/5.5
Text conflict in sql/mysqld.cc
Text conflict in storage/xtradb/btr/btr0cur.c
Text conflict in storage/xtradb/buf/buf0buf.c
Text conflict in storage/xtradb/buf/buf0lru.c
Text conflict in storage/xtradb/handler/ha_innodb.cc
5 conflicts encountered.
We don't support changing tc_log implementation at run time.
If the first XA-capable engine is loaded with INSTALL PLUGIN - disable its
XA capabilities with a warning
Reason for the problem was that the hash of changed files in the key cache was too small (was 128). Fixed by making the hash size larger and changeable.
- Introduced key-cache-file-hash-size (default 512) for MyISAM and aria_pagecache_file_hash_size (default 512) for Aria.
- Added new status variable "Feature_delay_key_write" which counts number of tables opened that are using delay_key_write
mysql-test/r/features.result:
Added test of Feature_delay_key_write
mysql-test/r/key_cache.result:
Updated tests as the number of blocks has changed
mysql-test/r/mysqld--help.result:
Updated result
mysql-test/suite/maria/maria3.result:
Updated result
mysql-test/suite/sys_vars/r/key_cache_file_hash_size_basic.result:
Test new variable
mysql-test/suite/sys_vars/t/aria_pagecache_file_hash_size_basic.test:
Test new variable
mysql-test/suite/sys_vars/t/key_cache_file_hash_size_basic.test:
Test new variable
mysql-test/t/features.test:
Added test of Feature_delay_key_write
mysql-test/t/key_cache.test:
Updated tests as the number of blocks has changed
mysys/mf_keycache.c:
Made CHANGED_BLOCKS_HASH dynamic
sql/handler.cc:
Updated call to init_key_cache()
sql/mysqld.cc:
Added "Feature_delay_key_write"
Added support for key-cache-file-hash-size
sql/mysqld.h:
Added support for key-cache-file-hash-size
sql/sql_class.h:
Added feature_files_opened_with_delayed_keys
sql/sys_vars.cc:
Added key_cache_file_hash_size
storage/maria/ha_maria.cc:
Added pagecache_file_hash_size
Added counting of files with delay_key_write
storage/maria/ma_checkpoint.c:
Fixed compiler warning
storage/maria/ma_pagecache.c:
Made PAGECACHE_CHANGED_BLOCKS_HASH into a variable
storage/maria/ma_pagecache.h:
Made PAGECACHE_CHANGED_BLOCKS_HASH into a variable
storage/maria/ma_rt_test.c:
Updated parameters for init_pagecache()
storage/maria/ma_test1.c:
Updated parameters for init_pagecache()
storage/maria/ma_test2.c:
Updated parameters for init_pagecache()
storage/maria/ma_test3.c:
Updated parameters for init_pagecache()
storage/maria/maria_chk.c:
Updated parameters for init_pagecache()
storage/maria/maria_ftdump.c:
Updated parameters for init_pagecache()
storage/maria/maria_pack.c:
Updated parameters for init_pagecache()
storage/maria/maria_read_log.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_pagecache_consist.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_pagecache_rwconsist.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_pagecache_rwconsist2.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_pagecache_single.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_first_lsn-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_max_lsn-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_multigroup-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_multithread-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_noflush-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_nologs-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_pagecache-t.c:
Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_purge-t.c:
Updated parameters for init_pagecache()
storage/myisam/ha_myisam.cc:
Added counting of files with delay_key_write
storage/myisam/mi_check.c:
Updated call to init_key_cache()
storage/myisam/mi_test1.c:
Updated call to init_key_cache()
storage/myisam/mi_test2.c:
Updated call to init_key_cache()
storage/myisam/mi_test3.c:
Updated call to init_key_cache()
storage/myisam/mi_test_all.sh:
Fixed broken test
storage/myisam/myisam_ftdump.c:
Updated call to init_key_cache()
storage/myisam/myisamchk.c:
Updated call to init_key_cache()
storage/myisam/myisamlog.c:
Updated call to init_key_cache()
The bug was that my_real_read() called net_before_header_psi() multiple times for long packets.
Fixed by adding a flag when we are reading a header.
Did also some cleanups to interface of my_net_read() to avoid unnecessary calls if performance schema is not used.
- Added my_net_read_packet() as a replacement for my_net_read(). my_net_read() is still in the client library for old clients.
- Removed THD->m_server_idle (not needed anymore as this is now given as argument to my_net_read_packet()
- Added my_net_read_packet(), which is a new version of my_net_read() with a new parameter if we are doing a read for a new command from the server.
- Added tests for compressed protocol and big packets
include/mysql.h.pp:
Added my_net_read_packet() as a replacement for my_net_read()
include/mysql_com.h:
Added my_net_read_packet() as a replacement for my_net_read()
mysql-test/r/mysql_client_test_comp.result:
New test
mysql-test/t/mysql_client_test-master.opt:
Added max_allowed_packet to be able to test big packets and packet size overflows.
mysql-test/t/mysql_client_test_comp-master.opt:
New test
mysql-test/t/mysql_client_test_nonblock-master.opt:
Added max_allowed_packet to be able to test big packets and packet size overflows.
sql-common/client.c:
Use my_net_read_packet()
sql/mf_iocache.cc:
Use my_net_read_packet()
sql/mysqld.cc:
Removed THD->m_server_idle (not needed anymore as this is now given as argument to my_net_read_packet()
sql/net_serv.cc:
Added argument to my_real_read() to indicte if we are reading the first block of the next statement and should call performance schema.
Added 'compatibilty function' my_net_read().
Added my_net_read_packet(), which is a new version of my_net_read() with a new parameter if we are doing a read for a new command from the server.
sql/sql_class.cc:
Removed m_server_idle (not needed anymore)
sql/sql_class.h:
Removed m_server_idle (not needed anymore)
sql/sql_parse.cc:
Removed m_server_idle (not needed anymore)
tests/mysql_client_test.c:
Added tests for compressed protocol and big packets
Merge the patches into MariaDB 10.0 main.
With this patch, parallel replication will now automatically retry a
transaction that fails due to deadlock or other temporary error, same as
single-threaded replication.
We catch deadlocks with InnoDB transactions due to enforced commit order. If
T1 must commit before T2 in parallel replication and T1 ends up waiting for T2
inside InnoDB, we kill T2 and retry it later to resolve the deadlock
automatically.
After-review changes.
For this patch in 10.0, we do not introduce a new public storage engine API,
we just fix the InnoDB/XtraDB issues. In 10.1, we will make a better public
API that can be used for all storage engines (MDEV-6429).
Eliminate the background thread that did deadlock kills asynchroneously.
Instead, we ensure that the InnoDB/XtraDB code can handle doing the kill from
inside the deadlock detection code (when thd_report_wait_for() needs to kill a
later thread to resolve a deadlock).
(We preserve the part of the original patch that introduces dedicated mutex
and condition for the slave init thread, to remove the abuse of
LOCK_thread_count for start/stop synchronisation of the slave init thread).
Description:
THREAD_CONCURRENCY is deprecated and there is no
deprecation warning message while setting this variable
while starting the server.
Analysis:
This variable is specific to Solaris 8 and earlier systems
and is ignored on all other platforms. But since many
customers, who uses other than Solaris, still has this
variable in their configuration file, it is important to
have a deprecation warning.
Fix:
THREAD_CONCURRENCY deprecation warning message is added.
Description:
THREAD_CONCURRENCY is deprecated and there is no
deprecation warning message while setting this variable
while starting the server.
Analysis:
This variable is specific to Solaris 8 and earlier systems
and is ignored on all other platforms. But since many
customers, who uses other than Solaris, still has this
variable in their configuration file, it is important to
have a deprecation warning.
Fix:
THREAD_CONCURRENCY deprecation warning message is added.
Auto-generate the allowed list of values for enum/set/flagset options
in --help output. But don't do that when the help text already has them.
Also, remove lists of values from help strings of various options, where
they were simply listed without any additional information.
Adapt default_tmp_storage_engine implementation from mysql-5.6
New feature (as compared to 5.6), default_tmp_storage_engine=NULL
means that temporary tables will use default_storage_engine value.
This makes the behavior backward compatible.
Some variables weren't cleared properly so consequitive embedded server start/stop failed.
Cleanups added. Also mysql_client_test.c extended to test that (taken from Mattias Johnson's patch)
replication causing replication to fail.
In parallel replication, we run transactions from the master in parallel, but
force them to commit in the same order they did on the master. If we force T1
to commit before T2, but T2 holds eg. a row lock that is needed by T1, we get
a deadlock when T2 waits until T1 has committed.
Usually, we do not run T1 and T2 in parallel if there is a chance that they
can have conflicting locks like this, but there are certain edge cases where
it can occasionally happen (eg. MDEV-5914, MDEV-5941, MDEV-6020). The bug was
that this would cause replication to hang, eventually getting a lock timeout
and causing the slave to stop with error.
With this patch, InnoDB will report back to the upper layer whenever a
transactions T1 is about to do a lock wait on T2. If T1 and T2 are parallel
replication transactions, and T2 needs to commit later than T1, we can thus
detect the deadlock; we then kill T2, setting a flag that causes it to catch
the kill and convert it to a deadlock error; this error will then cause T2 to
roll back and release its locks (so that T1 can commit), and later T2 will be
re-tried and eventually also committed.
The kill happens asynchroneously in a slave background thread; this is
necessary, as the reporting from InnoDB about lock waits happen deep inside
the locking code, at a point where it is not possible to directly call
THD::awake() due to mutexes held.
Deadlock is assumed to be (very) rarely occuring, so this patch tries to
minimise the performance impact on the normal case where no deadlocks occur,
rather than optimise the handling of the occasional deadlock.
Also fix transaction retry due to deadlock when it happens after a transaction
already signalled to later transactions that it started to commit. In this
case we need to undo this signalling (and later redo it when we commit again
during retry), so following transactions will not start too early.
Also add a missing thd->send_kill_message() that got triggered during testing
(this corrects an incorrect fix for MySQL Bug#58933).
Decoupled wsrep thread count from connection count. By doing so,
the number of wsrep threads (applier/rollbacker) would no longer
affect the threads_connected status variable and thus maximum
allowable user connections limit would be @@max_connections.
Also introduced a new status variable 'wsrep_thread_count' to hold
the number of wsrep applier/rollbacker threads.
Added a test case.
SHOW PROCESSLIST, SHOW BINLOGS
Problem: A deadlock was occurring when 4 threads were
involved in acquiring locks in the following way
Thread 1: Dump thread ( Slave is reconnecting, so on
Master, a new dump thread is trying kill
zombie dump threads. It acquired thread's
LOCK_thd_data and it is about to acquire
mysys_var->current_mutex ( which LOCK_log)
Thread 2: Application thread is executing show binlogs and
acquired LOCK_log and it is about to acquire
LOCK_index.
Thread 3: Application thread is executing Purge binary logs
and acquired LOCK_index and it is about to
acquire LOCK_thread_count.
Thread 4: Application thread is executing show processlist
and acquired LOCK_thread_count and it is
about to acquire zombie dump thread's
LOCK_thd_data.
Deadlock Cycle:
Thread 1 -> Thread 2 -> Thread 3-> Thread 4 ->Thread 1
The same above deadlock was observed even when thread 4 is
executing 'SELECT * FROM information_schema.processlist' command and
acquired LOCK_thread_count and it is about to acquire zombie
dump thread's LOCK_thd_data.
Analysis:
There are four locks involved in the deadlock. LOCK_log,
LOCK_thread_count, LOCK_index and LOCK_thd_data.
LOCK_log, LOCK_thread_count, LOCK_index are global mutexes
where as LOCK_thd_data is local to a thread.
We can divide these four locks in two groups.
Group 1 consists of LOCK_log and LOCK_index and the order
should be LOCK_log followed by LOCK_index.
Group 2 consists of other two mutexes
LOCK_thread_count, LOCK_thd_data and the order should
be LOCK_thread_count followed by LOCK_thd_data.
Unfortunately, there is no specific predefined lock order defined
to follow in the MySQL system when it comes to locks across these
two groups. In the above problematic example,
there is no problem in the way we are acquiring the locks
if you see each thread individually.
But If you combine all 4 threads, they end up in a deadlock.
Fix:
Since everything seems to be fine in the way threads are taking locks,
In this patch We are changing the duration of the locks in Thread 4
to break the deadlock. i.e., before the patch, Thread 4
('show processlist' command) mysqld_list_processes()
function acquires LOCK_thread_count for the complete duration
of the function and it also acquires/releases
each thread's LOCK_thd_data.
LOCK_thread_count is used to protect addition and
deletion of threads in global threads list. While show
process list is looping through all the existing threads,
it will be a problem if a thread is exited but there is no problem
if a new thread is added to the system. Hence a new mutex is
introduced "LOCK_thd_remove" which will protect deletion
of a thread from global threads list. All threads which are
getting exited should acquire LOCK_thd_remove
followed by LOCK_thread_count. (It should take LOCK_thread_count
also because other places of the code still thinks that exit thread
is protected with LOCK_thread_count. In this fix, we are changing
only 'show process list' query logic )
(Eg: unlink_thd logic will be protected with
LOCK_thd_remove).
Logic of mysqld_list_processes(or file_schema_processlist)
will now be protected with 'LOCK_thd_remove' instead of
'LOCK_thread_count'.
Now the new locking order after this patch is:
LOCK_thd_remove -> LOCK_thd_data -> LOCK_log ->
LOCK_index -> LOCK_thread_count
SHOW PROCESSLIST, SHOW BINLOGS
Problem: A deadlock was occurring when 4 threads were
involved in acquiring locks in the following way
Thread 1: Dump thread ( Slave is reconnecting, so on
Master, a new dump thread is trying kill
zombie dump threads. It acquired thread's
LOCK_thd_data and it is about to acquire
mysys_var->current_mutex ( which LOCK_log)
Thread 2: Application thread is executing show binlogs and
acquired LOCK_log and it is about to acquire
LOCK_index.
Thread 3: Application thread is executing Purge binary logs
and acquired LOCK_index and it is about to
acquire LOCK_thread_count.
Thread 4: Application thread is executing show processlist
and acquired LOCK_thread_count and it is
about to acquire zombie dump thread's
LOCK_thd_data.
Deadlock Cycle:
Thread 1 -> Thread 2 -> Thread 3-> Thread 4 ->Thread 1
The same above deadlock was observed even when thread 4 is
executing 'SELECT * FROM information_schema.processlist' command and
acquired LOCK_thread_count and it is about to acquire zombie
dump thread's LOCK_thd_data.
Analysis:
There are four locks involved in the deadlock. LOCK_log,
LOCK_thread_count, LOCK_index and LOCK_thd_data.
LOCK_log, LOCK_thread_count, LOCK_index are global mutexes
where as LOCK_thd_data is local to a thread.
We can divide these four locks in two groups.
Group 1 consists of LOCK_log and LOCK_index and the order
should be LOCK_log followed by LOCK_index.
Group 2 consists of other two mutexes
LOCK_thread_count, LOCK_thd_data and the order should
be LOCK_thread_count followed by LOCK_thd_data.
Unfortunately, there is no specific predefined lock order defined
to follow in the MySQL system when it comes to locks across these
two groups. In the above problematic example,
there is no problem in the way we are acquiring the locks
if you see each thread individually.
But If you combine all 4 threads, they end up in a deadlock.
Fix:
Since everything seems to be fine in the way threads are taking locks,
In this patch We are changing the duration of the locks in Thread 4
to break the deadlock. i.e., before the patch, Thread 4
('show processlist' command) mysqld_list_processes()
function acquires LOCK_thread_count for the complete duration
of the function and it also acquires/releases
each thread's LOCK_thd_data.
LOCK_thread_count is used to protect addition and
deletion of threads in global threads list. While show
process list is looping through all the existing threads,
it will be a problem if a thread is exited but there is no problem
if a new thread is added to the system. Hence a new mutex is
introduced "LOCK_thd_remove" which will protect deletion
of a thread from global threads list. All threads which are
getting exited should acquire LOCK_thd_remove
followed by LOCK_thread_count. (It should take LOCK_thread_count
also because other places of the code still thinks that exit thread
is protected with LOCK_thread_count. In this fix, we are changing
only 'show process list' query logic )
(Eg: unlink_thd logic will be protected with
LOCK_thd_remove).
Logic of mysqld_list_processes(or file_schema_processlist)
will now be protected with 'LOCK_thd_remove' instead of
'LOCK_thread_count'.
Now the new locking order after this patch is:
LOCK_thd_remove -> LOCK_thd_data -> LOCK_log ->
LOCK_index -> LOCK_thread_count
committer: Christopher Powers <chris.powers@oracle.com>
branch nick: mysql-5.6-bug16750433
timestamp: Fri 2013-06-28 07:48:12 -0500
message:
Bug#16750433 - THE STATEMENT DIGEST DOES NOT SHOW THE SLAVE SQL
THREAD STATEMENTS
revno: 5414.1.1
committer: Marc Alff <marc.alff@oracle.com>
branch nick: mysql-5.6-bug17271055
timestamp: Thu 2013-08-29 12:29:25 +0200
message:
Bug#17271055 "STATEMENT/COM" EVENT MEANING IS UNCLEAR
(test case was merged with perfschema 5.6.17)
