- Fixed typos
- Added --core-on-failure to mysql-test-run
- More DBUG_PRINT in viosocket.c
- Don't forget CLIENT_REMEMBER_OPTIONS for compressed slave protocol
- Removed not used stage variables
(like DROP TABLE) has been scheduled before conflicting DDL's (like INSERT)
are commited.
What makes these bugs hard to detect is that in most cases any wrong
schduling are caught by MDL locks. It's only when there are timing issues
that the bugs (usually deadlocks) are noticed.
This patch adds a DBUG_ASSERT() that detects, in parallel replication,
if a DDL is scheduled before any depending DML'S are commited.
It does this be checking if there are any conflicting replication locks
when the DDL is about to wait for getting it's MDL lock.
I also did some minor code cleanups in sql_base.cc to make this code
similar to other related code.
The main.merge test case was failing when tested using row based
binlog format.
While analyzing the issue it was found the following issues:
a) The server is calling binlog related code even when a statement will
not be binlogged;
b) The child table list was not present into table structure by the time
to generate the create table statement;
c) The tables in the child table list will not be opened yet when
generating table create info using row based replication;
d) CREATE TABLE LIKE TEMP_TABLE does not preserve original table storage
engine when using row based replication;
This patch addressed all above issues.
@ sql/sql_class.h
Added a function to determine if the binary log is disabled to
the current session. This is related with issue (a) above.
@ sql/sql_table.cc
Added code to skip binary logging related code if the statement
will not be binlogged. This is related with issue (a) above.
Added code to add the children to the query list of the table that
will have its CREATE TABLE generated. This is related with issue (b)
above.
Added code to force the storage engine to be generated into the
CREATE TABLE. This is related with issue (d) above.
@ storage/myisammrg/ha_myisammrg.cc
Added a test to skip a table getting info about a child table if the
child table is not opened. This is related to issue (c) above.
- Added testing if connection is killed to shortcut reading of connection data
This will allow us later in 10.2 to do a cleaner shutdown of slaves (less errors in the log)
- Add new status variables: Slaves_connected, Slaves_running and Slave_connections.
- Use MYSQL_SLAVE_NOT_RUN instead of 0 with slave_running.
- Don't print obvious extra warnings to the error log when slave is shut down normally.
Problem:
At the end of first execution select_lex->prep_where is pointing to
a runtime created object (temporary table field). As a result
server exits trying to access a invalid pointer during second
execution.
Analysis:
While optimizing the join conditions for the query, after the
permanent transformation, optimizer makes a copy of the new
where conditions in select_lex->prep_where. "prep_where" is what
is used as the "where condition" for the query at the start of execution.
W.r.t the query in question, "where" condition is actually pointing
to a field in the temporary table. As a result, for the second
execution the pointer is no more valid resulting in server exit.
Fix:
At the end of the first execution, select_lex->where will have the
original item of the where condition.
Make prep_where the new place where the original item of select->where
has to be rolled back.
Fixed in 5.7 with the wl#7082 - Move permanent transformations from
JOIN::optimize to JOIN::prepare
Patch for 5.5 includes the following backports from 5.6:
Bugfix for Bug12603141 - This makes the first execute statement in the testcase
pass in 5.5
However it was noted later in in Bug16163596 that the above bugfix needed to
be modified. Although Bug16163596 is reproducible only with changes done for
Bug12582849, we have decided include the fix.
Considering that Bug12582849 is related to Bug12603141, the fix is
also included here. However this results in Bug16317817, Bug16317685,
Bug16739050. So fix for the above three bugs is also part of this patch.
The old code used pthread_setspecific() to store temporary data used by the thread.
This is not safe when used with thread pool, as the thread may change for the transaction.
The fix is to save the data in THD, which is guaranteed to be properly freed.
I also fixed the code so that we don't do a malloc() for every transaction.
including the big commit
commit 305130361bf72726de220f3d2b2787395e10be61
Author: Marc Alff <marc.alff@oracle.com>
Date: Tue Feb 10 11:31:32 2015 +0100
WL#8354 BACKPORT DIGEST IMPROVEMENTS TO MYSQL 5.6
(with the following commits) and related changes in sql/
if we clear the error status (in THD::clear_error())
make sure to clear the thd->killed == KILL_BAD_DATA too,
because it was caused by the error that we're clearing.
The hangs occur when the group_commit_orderer object is freed before the last
mark_start_commit() call on it - this loses the wakeup to other waiting worker
threads, causing them to hang until killed manually.
The object was freed because wakeup_subsequent_commits() was called two early
in two places. For MDEV-7888, during ANALYZE TABLE, and for MDEV-7929 during
record_gtid() after processing a DDL event. The group_commit_orderer object
can be freed when its last transaction has called wait_for_prior_commit().
Fix by implementing a suspend/resume mechanism for wakeup_subsequent_commits()
that can be used in places where a transaction is committed without this being
the commit of the actual replication event group.
Also add a protection mechanism (that asserts in debug builds) which can
prevent the too-early free and hang if other similar bugs should remain in
other parts of the code.
Parallel replication (in 10.0 / "conservative" mode) relies on binlog group
commits to group transactions that can be safely run in parallel on the
slave. The --binlog-commit-wait-count and --binlog-commit-wait-usec options
exist to increase the number of commits per group. But in case of conflicts
between transactions, this can cause unnecessary delay and reduced througput,
especially on a slave where commit order is fixed.
This patch adds a heuristics to reduce this problem. When transaction T1 goes
to commit, it will first wait for N transactions to queue up for a group
commit. However, if we detect that another transaction T2 is waiting for a row
lock held by T1, then we will skip the wait and let T1 commit immediately,
releasing locks and let T2 continue.
On a slave, this avoids the unfortunate situation where T1 is waiting for T2
to join the group commit, but T2 is waiting for T1 to release locks, causing
no work to be done for the duration of the --binlog-commit-wait-usec timeout.
(The heuristic seems reasonable on the master as well, so it is enabled for
all transactions, not just replication transactions).
The code in binlog group commit around wait_for_commit that controls commit
order, did the wakeup of subsequent commits early, as soon as a following
transaction is put into the group commit queue, but before any such commit has
actually taken place. This causes problems with too early wakeup of
transactions that need to wait for prior to commit, but do not take part in
the binlog group commit for one reason or the other.
This patch solves the problem, by moving the wakeup to happen only after the
binlog group commit is completed.
This requires a new solution to ensure that transactions that arrive later
than the leader are still able to participate in group commit. This patch
introduces a flag wait_for_commit::commit_started. When this is set, a waiter
can queue up itself in the group commit queue.
This way, effectively the wait_for_prior_commit() is skipped only for
transactions that participate in group commit, so that skipping the wait is
safe. Other transactions still wait as needed for correctness.
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).
replication causing replication to fail.
Remove the temporary fix for MDEV-5914, which used READ COMMITTED for parallel
replication worker threads. Replace it with a better, more selective solution.
The issue is with certain edge cases of InnoDB gap locks, for example between
INSERT and ranged DELETE. It is possible for the gap lock set by the DELETE to
block the INSERT, if the DELETE runs first, while the record lock set by
INSERT does not block the DELETE, if the INSERT runs first. This can cause a
conflict between the two in parallel replication on the slave even though they
ran without conflicts on the master.
With this patch, InnoDB will ask the server layer about the two involved
transactions before blocking on a gap lock. If the server layer tells InnoDB
that the transactions are already fixed wrt. commit order, as they are in
parallel replication, InnoDB will ignore the gap lock and allow the two
transactions to proceed in parallel, avoiding the conflict.
Improve the fix for MDEV-6020. When InnoDB itself detects a deadlock, it now
asks the server layer for any preferences about which transaction to roll
back. In case of parallel replication with two transactions T1 and T2 fixed to
commit T1 before T2, the server layer will ask InnoDB to roll back T2 as the
deadlock victim, not T1. This helps in some cases to avoid excessive deadlock
rollback, as T2 will in any case need to wait for T1 to complete before it can
itself commit.
Also some misc. fixes found during development and testing:
- Remove thd_rpl_is_parallel(), it is not used or needed.
- Use KILL_CONNECTION instead of KILL_QUERY when a parallel replication
worker thread is killed to resolve a deadlock with fixed commit
ordering. There are some cases, eg. in sql/sql_parse.cc, where a KILL_QUERY
can be ignored if the query otherwise completed successfully, and this
could cause the deadlock kill to be lost, so that the deadlock was not
correctly resolved.
- Fix random test failure due to missing wait_for_binlog_checkpoint.inc.
- Make sure that deadlock or other temporary errors during parallel
replication are not printed to the the error log; there were some places
around the replication code with extra error logging. These conditions can
occur occasionally and are handled automatically without breaking
replication, so they should not pollute the error log.
- Fix handling of rgi->gtid_sub_id. We need to be able to access this also at
the end of a transaction, to be able to detect and resolve deadlocks due to
commit ordering. But this value was also used as a flag to mark whether
record_gtid() had been called, by being set to zero, losing the value. Now,
introduce a separate flag rgi->gtid_pending, so rgi->gtid_sub_id remains
valid for the entire duration of the transaction.
- Fix one place where the code to handle ignored errors called reset_killed()
unconditionally, even if no error was caught that should be ignored. This
could cause loss of a deadlock kill signal, breaking deadlock detection and
resolution.
- Fix a couple of missing mysql_reset_thd_for_next_command(). This could
cause a prior error condition to remain for the next event executed,
causing assertions about errors already being set and possibly giving
incorrect error handling for following event executions.
- Fix code that cleared thd->rgi_slave in the parallel replication worker
threads after each event execution; this caused the deadlock detection and
handling code to not be able to correctly process the associated
transactions as belonging to replication worker threads.
- Remove useless error code in slave_background_kill_request().
- Fix bug where wfc->wakeup_error was not cleared at
wait_for_commit::unregister_wait_for_prior_commit(). This could cause the
error condition to wrongly propagate to a later wait_for_prior_commit(),
causing spurious ER_PRIOR_COMMIT_FAILED errors.
- Do not put the binlog background thread into the processlist. It causes
too many result differences in mtr, but also it probably is not useful
for users to pollute the process list with a system thread that does not
really perform any user-visible tasks...
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).
The previous patch for this bug was unfortunately completely wrong.
The purpose of cached_charset is to remember which character set we
have installed currently in the THD, so that in the common case where
charset does not change between queries, we do not need to update it
in the THD. Thus, it is important that the cached_charset field is
tightly coupled to the THD for which it handles caching.
Thus the right place to put cached_charset seems to be in the THD.
This patch introduces a field THD:system_thread_info where such info
in general can be placed without further inflating the THD with unused
data for other threads (THD is already far too big as it is). It then
moves the cached_charset into this slot for the SQL driver thread and
for the parallel replication worker threads.
The THD::rpl_filter field is also moved inside system_thread_info, to
keep the size of THD unchanged. Moving further fields in to reduce the
size of THD is a separate task, filed as MDEV-6164.
Reason for the bug was an optimization for higher connect speed where we moved when global status was updated,
but forgot to update states when slave thread dies.
Fixed by adding thd->add_status_to_global() before deleting slave thread's thd.
mysys/my_delete.c:
Added missing newline
sql/mysqld.cc:
Use add_status_to_global()
sql/slave.cc:
Added missing add_status_to_global()
sql/sql_class.cc:
Use add_status_to_global()
sql/sql_class.h:
Simplify adding local status to global by adding add_status_to_global()
mysql-test/r/create_or_replace.result:
Added test of releasing of metadata locks
mysql-test/t/create_or_replace.test:
Added test of releasing of metadata locks
sql/handler.h:
Added marker if table was deleted as part of CREATE OR REPLACE
sql/sql_base.cc:
Added Locked_tables_list::unlock_locked_table()
sql/sql_class.h:
New prototypes
sql/sql_insert.cc:
Unlock metadata locks for deleted table in case of error. Also do unlock tables if this was the only locked table.
sql/sql_table.cc:
Unlock metadata locks for deleted table in case of error. Also do unlock tables if this was the only locked table.
