Due to how gap locks work, two transactions could group commit together on the
master, but get lock conflicts and then deadlock due to different thread
scheduling order on slave.
For now, remove these deadlocks by running the parallel slave in READ
COMMITTED mode. And let InnoDB/XtraDB allow statement-based binlogging for the
parallel slave in READ COMMITTED.
We are also investigating a different solution long-term, which is based on
relaxing the gap locks only between the transactions running in parallel for
one slave, but not against possibly external transactions.
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()
Clean up and improve the parallel implementation code, mainly related to
scheduling of work to threads and handling of stop and errors.
Fix a lot of bugs in various corner cases that could lead to crashes or
corruption.
Fix that a single replication domain could easily grab all worker threads and
stall all other domains; now a configuration variable
--slave-domain-parallel-threads allows to limit the number of
workers.
Allow next event group to start as soon as previous group begins the commit
phase (as opposed to when it ends it); this allows multiple event groups on
the slave to participate in group commit, even when no other opportunities for
parallelism are available.
Various fixes:
- Fix some races in the rpl.rpl_parallel test case.
- Fix an old incorrect assertion in Log_event iocache read.
- Fix repeated malloc/free of wait_for_commit and rpl_group_info objects.
- Simplify wait_for_commit wakeup logic.
- Fix one case in queue_for_group_commit() where killing one thread would
fail to correctly signal the error to the next, causing loss of the
transaction after slave restart.
- Fix leaking of pthreads (and their allocated stack) due to missing
PTHREAD_CREATE_DETACHED attribute.
- Fix how one batch of group-committed transactions wait for the previous
batch before starting to execute themselves. The old code had a very
complex scheduling where the first transaction was handled differently,
with subtle bugs in corner cases. Now each event group is always scheduled
for a new worker (in a round-robin fashion amongst available workers).
Keep a count of how many transactions have started to commit, and wait for
that counter to reach the appropriate value.
- Fix slave stop to wait for all workers to actually complete processing;
before, the wait was for update of last_committed_sub_id, which happens a
bit earlier, and could leave worker threads potentially accessing bits of
the replication state that is no longer valid after slave stop.
- Fix a couple of places where the test suite would kill a thread waiting
inside enter_cond() in connection with debug_sync; debug_sync + kill can
crash in rare cases due to a race with mysys_var_current_mutex in this
case.
- Fix some corner cases where we had enter_cond() but no exit_cond().
- Fix that we could get failure in wait_for_prior_commit() but forget to flag
the error with my_error().
- Fix slave stop (both for normal stop and stop due to error). Now, at stop
we pick a specific safe point (in terms of event groups executed) and make
sure that all event groups before that point are executed to completion,
and that no event group after start executing; this ensures a safe place to
restart replication, even for non-transactional stuff/DDL. In error stop,
make sure that all prior event groups are allowed to execute to completion,
and that any later event groups that have started are rolled back, if
possible. The old code could leave eg. T1 and T3 committed but T2 not, or
it could even leave half a transaction not rolled back in some random
worker, which would cause big problems when that worker was later reused
after slave restart.
- Fix the accounting of amount of events queued for one worker. Before, the
amount was reduced immediately as soon as the events were dequeued (which
happens all at once); this allowed twice the amount of events to be queued
in memory for each single worker, which is not what users would expect.
- Fix that an error set during execution of one event was sometimes not
cleared before executing the next, causing problems with the error
reporting.
- Fix incorrect handling of thd->killed in worker threads.
This is port of fix for MySQL BUG#17647863.
revno: 5572
revision-id: jon.hauglid@oracle.com-20131030232243-b0pw98oy72uka2sj
committer: Jon Olav Hauglid <jon.hauglid@oracle.com>
timestamp: Thu 2013-10-31 00:22:43 +0100
message:
Bug#17647863: MYSQL DOES NOT COMPILE ON OSX 10.9 GM
Rename test() macro to MY_TEST() to avoid conflict with libc++.
MDEV-4984: Implement MASTER_GTID_WAIT() and @@LAST_GTID.
MDEV-4726: Race in mysql-test/suite/rpl/t/rpl_gtid_stop_start.test
MDEV-5636: Deadlock in RESET MASTER
MASTER_GTID_WAIT() is similar to MASTER_POS_WAIT(), but works with a
GTID position rather than an old-style filename/offset.
@@LAST_GTID gives the GTID assigned to the last transaction written
into the binlog.
Together, the two can be used by applications to obtain the GTID of
an update on the master, and then do a MASTER_GTID_WAIT() for that
position on any read slave where it is important to get results that
are caught up with the master at least to the point of the update.
The implementation of MASTER_GTID_WAIT() is implemented in a way
that tries to minimise the performance impact on the SQL threads,
even in the presense of many waiters on single GTID positions (as
from @@LAST_GTID).
- CREATE TABLE is by default executed on the slave as CREATE OR REPLACE
- DROP TABLE is by default executed on the slave as DROP TABLE IF NOT EXISTS
This means that a slave will by default continue even if we try to create
a table that existed on the slave (the table will be deleted and re-created) or
if we try to drop a table that didn't exist on the slave.
This should be safe as instead of having the slave stop because of an inconsistency between
master and slave, it will fix the inconsistency.
Those that would prefer to get a stopped slave instead for the above cases can set slave_ddl_exec_mode to STRICT.
- Ensure that a CREATE OR REPLACE TABLE which dropped a table is replicated
- DROP TABLE that generated an error on master is handled as an identical DROP TABLE on the slave (IF NOT EXISTS is not added in this case)
- Added slave_ddl_exec_mode variable to decide how DDL's are replicated
New logic for handling BEGIN GTID ... COMMIT from the binary log:
- When we find a BEGIN GTID, we start a transaction and set OPTION_GTID_BEGIN
- When we find COMMIT, we reset OPTION_GTID_BEGIN and execute the normal COMMIT code.
- While OPTION_GTID_BEGIN is set:
- We don't generate implict commits before or after statements
- All tables are regarded as transactional tables in the binary log (to ensure things are executed exactly as on the master)
- We reset OPTION_GTID_BEGIN also on rollback
This will help ensuring that we don't get any sporadic commits (and thus new GTID's) on the slave and will help keep the GTID's between master and slave in sync.
mysql-test/extra/rpl_tests/rpl_log.test:
Added testing of mode slave_ddl_exec_mode=STRICT
mysql-test/r/mysqld--help.result:
New help messages
mysql-test/suite/rpl/r/create_or_replace_mix.result:
Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/r/create_or_replace_row.result:
Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/r/create_or_replace_statement.result:
Testing replication of create or replace
mysql-test/suite/rpl/r/rpl_gtid_startpos.result:
Test must be run in slave_ddl_exec_mode=STRICT as part of the test depends on that DROP TABLE should fail on slave.
mysql-test/suite/rpl/r/rpl_row_log.result:
Updated result
mysql-test/suite/rpl/r/rpl_row_log_innodb.result:
Updated result
mysql-test/suite/rpl/r/rpl_row_show_relaylog_events.result:
Updated result
mysql-test/suite/rpl/r/rpl_stm_log.result:
Updated result
mysql-test/suite/rpl/r/rpl_stm_mix_show_relaylog_events.result:
Updated result
mysql-test/suite/rpl/r/rpl_temp_table_mix_row.result:
Updated result
mysql-test/suite/rpl/t/create_or_replace.inc:
Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/t/create_or_replace_mix.cnf:
Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/t/create_or_replace_mix.test:
Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/t/create_or_replace_row.cnf:
Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/t/create_or_replace_row.test:
Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/t/create_or_replace_statement.cnf:
Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/t/create_or_replace_statement.test:
Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/t/rpl_gtid_startpos.test:
Test must be run in slave_ddl_exec_mode=STRICT as part of the test depends on that DROP TABLE should fail on slave.
mysql-test/suite/rpl/t/rpl_stm_log.test:
Removed some lines
mysql-test/suite/sys_vars/r/slave_ddl_exec_mode_basic.result:
Testing of slave_ddl_exec_mode
mysql-test/suite/sys_vars/t/slave_ddl_exec_mode_basic.test:
Testing of slave_ddl_exec_mode
sql/handler.cc:
Regard all tables as transactional in commit if OPTION_GTID_BEGIN is set.
This is to ensure that statments are not commited too early if non transactional tables are used.
sql/log.cc:
Regard all tables as transactional in commit if OPTION_GTID_BEGIN is set.
Also treat 'direct' log events as transactional (to get them logged as they where on the master)
sql/log_event.cc:
Ensure that the new error from DROP TABLE when trying to drop a view is treated same as the old one.
Store error code that slave expects in THD.
Set OPTION_GTID_BEGIN if we find a BEGIN.
Reset OPTION_GTID_BEGIN if we find a COMMIT.
sql/mysqld.cc:
Added slave_ddl_exec_mode_options
sql/mysqld.h:
Added slave_ddl_exec_mode_options
sql/rpl_gtid.cc:
Reset OPTION_GTID_BEGIN if we record a gtid (safety)
sql/sql_class.cc:
Regard all tables as transactional in commit if OPTION_GTID_BEGIN is set.
sql/sql_class.h:
Added to THD: log_current_statement and slave_expected_error
sql/sql_insert.cc:
Ensure that CREATE OR REPLACE is logged if table was deleted.
Don't do implicit commit for CREATE if we are under OPTION_GTID_BEGIN
sql/sql_parse.cc:
Change CREATE TABLE -> CREATE OR REPLACE TABLE for slaves
Change DROP TABLE -> DROP TABLE IF EXISTS for slaves
CREATE TABLE doesn't force implicit commit in case of OPTION_GTID_BEGIN
Don't do commits before or after any statement if OPTION_GTID_BEGIN was set.
sql/sql_priv.h:
Added OPTION_GTID_BEGIN
sql/sql_show.cc:
Enhanced store_create_info() to also be able to handle CREATE OR REPLACE
sql/sql_show.h:
Updated prototype
sql/sql_table.cc:
Ensure that CREATE OR REPLACE is logged if table was deleted.
sql/sys_vars.cc:
Added slave_ddl_exec_mode
sql/transaction.cc:
Added warning if we got a GTID under OPTION_GTID_BEGIN
on server shutdown after SELECT with CONVERT_TZ
It's wrong to return my_empty_string from val_str().
Removing my_empty_string. Using make_empty_result() instead.
Plugins get error notifications only when my_message_sql() is called.
But errors are launched with THD::raise_condition() calls in other
places. These are push_warning(), implementations of SIGNAL and
RESIGNAL commands.
So it makes sence to notify plugins there in THD::raise_condition().
Add another test case. This one for killing a query that is waiting
for a prior commit, when --log-slave-updates=0 (in this case the
wait happens in different code from --log-slave-updates=1).
Add a test case for killing a waiting query in parallel replication.
Fix several bugs found:
- We should not wakeup_subsequent_commits() in ha_rollback_trans(), since we
do not know the right wakeup_error() to give.
- When a wait_for_prior_commit() is killed, we must unregister from the
waitee so we do not race and get an extra (non-kill) wakeup.
- We need to deal with error propagation correctly in queue_for_group_commit
when one thread is killed.
- Fix one locking issue in queue_for_group_commit(), we could unlock the
waitee lock too early and this end up processing wakeup() with insufficient
locking.
- Fix Xid_log_event::do_apply_event; if commit fails it must not update the
in-memory @@gtid_slave_pos state.
- Fix and cleanup some things in the rpl_parallel.cc error handling.
- Add a missing check for killed in the slave sql driver thread, to avoid a
race.
(and valgrind warnings)
* move thd userstat initialization to the same function
that was adding thd userstat to global counters.
* initialize thd->start_bytes_received in THD::init
(when thd->userstat_running is set)
MDEV-5217: Unlock of de-allocated mutex
There was a race in the code for wait_for_commit::wakeup().
Since the waiter does a dirty read of the waiting_for_commit
flag, it was possible for the waiter to complete and deallocate
the wait_for_commit object while the waitee was still running
inside wakeup(). This would cause the waitee to access invalid
memory.
Fixed by putting an extra lock/unlock in the destructor for
wait_for_commit, to ensure that waitee has finished with the
object before it is deallocated.
The merge is still missing a few hunks related to temporary tables and
InnoDB log file size. The associated code did not seem to exist in
10.0, so the merge of that needs more work. Until this is fixed, there
are a number of test failures as a result.
Add an error code to the wait_for_commit facility.
Now, when a transaction fails, it can signal the error to
any subsequent transaction that is waiting for it to commit.
The waiting transactions then receive the error code back from
wait_for_prior_commit() and can handle the error appropriately.
Also fix one race that could cause crash if @@slave_parallel_threads
were changed several times quickly in succession.
- Made slaves temporary table multi-thread slave safe by adding mutex around save_temporary_table usage.
- rli->save_temporary_tables is the active list of all used temporary tables
- This is copied to THD->temporary_tables when temporary tables are opened and updated when temporary tables are closed
- Added THD->lock_temporary_tables() and THD->unlock_temporary_tables() to simplify this.
- Relay_log_info->sql_thd renamed to Relay_log_info->sql_driver_thd to avoid wrong usage for merged code.
- Added is_part_of_group() to mark functions that are part of the next function. This replaces setting IN_STMT when events are executed.
- Added is_begin(), is_commit() and is_rollback() functions to Query_log_event to simplify code.
- If slave_skip_counter is set run things in single threaded mode. This simplifies code for skipping events.
- Updating state of relay log (IN_STMT and IN_TRANSACTION) is moved to one single function: update_state_of_relay_log()
We can't use OPTION_BEGIN to check for the state anymore as the sql_driver and sql execution threads may be different.
Clear IN_STMT and IN_TRANSACTION in init_relay_log_pos() and Relay_log_info::cleanup_context() to ensure the flags doesn't survive slave restarts
is_in_group() is now independent of state of executed transaction.
- Reset thd->transaction.all.modified_non_trans_table() if we did set it for single table row events.
This was mainly for keeping the flag as documented.
- Changed slave_open_temp_tables to uint32 to be able to use atomic operators on it.
- Relay_log_info::sleep_lock -> rpl_group_info::sleep_lock
- Relay_log_info::sleep_cond -> rpl_group_info::sleep_cond
- Changed some functions to take rpl_group_info instead of Relay_log_info to make them multi-slave safe and to simplify usage
- do_shall_skip()
- continue_group()
- sql_slave_killed()
- next_event()
- Simplifed arguments to io_salve_killed(), check_io_slave_killed() and sql_slave_killed(); No reason to supply THD as this is part of the given structure.
- set_thd_in_use_temporary_tables() removed as in_use is set on usage
- Added information to thd_proc_info() which thread is waiting for slave mutex to exit.
- In open_table() reuse code from find_temporary_table()
Other things:
- More DBUG statements
- Fixed the rpl_incident.test can be run with --debug
- More comments
- Disabled not used function rpl_connect_master()
mysql-test/suite/perfschema/r/all_instances.result:
Moved sleep_lock and sleep_cond to rpl_group_info
mysql-test/suite/rpl/r/rpl_incident.result:
Updated result
mysql-test/suite/rpl/t/rpl_incident-master.opt:
Not needed anymore
mysql-test/suite/rpl/t/rpl_incident.test:
Fixed that test can be run with --debug
sql/handler.cc:
More DBUG_PRINT
sql/log.cc:
More comments
sql/log_event.cc:
Added DBUG statements
do_shall_skip(), continue_group() now takes rpl_group_info param
Use is_begin(), is_commit() and is_rollback() functions instead of inspecting query string
We don't have set slaves temporary tables 'in_use' as this is now done when tables are opened.
Removed IN_STMT flag setting. This is now done in update_state_of_relay_log()
Use IN_TRANSACTION flag to test state of relay log.
In rows_event_stmt_cleanup() reset thd->transaction.all.modified_non_trans_table if we had set this before.
sql/log_event.h:
do_shall_skip(), continue_group() now takes rpl_group_info param
Added is_part_of_group() to mark events that are part of the next event. This replaces setting IN_STMT when events are executed.
Added is_begin(), is_commit() and is_rollback() functions to Query_log_event to simplify code.
sql/log_event_old.cc:
Removed IN_STMT flag setting. This is now done in update_state_of_relay_log()
do_shall_skip(), continue_group() now takes rpl_group_info param
sql/log_event_old.h:
Added is_part_of_group() to mark events that are part of the next event.
do_shall_skip(), continue_group() now takes rpl_group_info param
sql/mysqld.cc:
Changed slave_open_temp_tables to uint32 to be able to use atomic operators on it.
Relay_log_info::sleep_lock -> Rpl_group_info::sleep_lock
Relay_log_info::sleep_cond -> Rpl_group_info::sleep_cond
sql/mysqld.h:
Updated types and names
sql/rpl_gtid.cc:
More DBUG
sql/rpl_parallel.cc:
Updated TODO section
Set thd for event that is execution
Use new is_begin(), is_commit() and is_rollback() functions.
More comments
sql/rpl_rli.cc:
sql_thd -> sql_driver_thd
Relay_log_info::sleep_lock -> rpl_group_info::sleep_lock
Relay_log_info::sleep_cond -> rpl_group_info::sleep_cond
Clear IN_STMT and IN_TRANSACTION in init_relay_log_pos() and Relay_log_info::cleanup_context() to ensure the flags doesn't survive slave restarts.
Reset table->in_use for temporary tables as the table may have been used by another THD.
Use IN_TRANSACTION instead of OPTION_BEGIN to check state of relay log.
Removed IN_STMT flag setting. This is now done in update_state_of_relay_log()
sql/rpl_rli.h:
Changed relay log state flags to bit masks instead of bit positions (most other code we have uses bit masks)
Added IN_TRANSACTION to mark if we are in a BEGIN ... COMMIT section.
save_temporary_tables is now thread safe
Relay_log_info::sleep_lock -> rpl_group_info::sleep_lock
Relay_log_info::sleep_cond -> rpl_group_info::sleep_cond
Relay_log_info->sql_thd renamed to Relay_log_info->sql_driver_thd to avoid wrong usage for merged code
is_in_group() is now independent of state of executed transaction.
sql/slave.cc:
Simplifed arguments to io_salve_killed(), sql_slave_killed() and check_io_slave_killed(); No reason to supply THD as this is part of the given structure.
set_thd_in_use_temporary_tables() removed as in_use is set on usage in sql_base.cc
sql_thd -> sql_driver_thd
More DBUG
Added update_state_of_relay_log() which will calculate the IN_STMT and IN_TRANSACTION state of the relay log after the current element is executed.
If slave_skip_counter is set run things in single threaded mode.
Simplifed arguments to io_salve_killed(), check_io_slave_killed() and sql_slave_killed(); No reason to supply THD as this is part of the given structure.
Added information to thd_proc_info() which thread is waiting for slave mutex to exit.
Disabled not used function rpl_connect_master()
Updated argument to next_event()
sql/sql_base.cc:
Added mutex around usage of slave's temporary tables. The active list is always kept up to date in sql->rgi_slave->save_temporary_tables.
Clear thd->temporary_tables after query (safety)
More DBUG
When using temporary table, set table->in_use to current thd as the THD may be different for slave threads.
Some code is ifdef:ed with REMOVE_AFTER_MERGE_WITH_10 as the given code in 10.0 is not yet in this tree.
In open_table() reuse code from find_temporary_table()
sql/sql_binlog.cc:
rli->sql_thd -> rli->sql_driver_thd
Remove duplicate setting of rgi->rli
sql/sql_class.cc:
Added helper functions rgi_lock_temporary_tables() and rgi_unlock_temporary_tables()
Would have been nicer to have these inline, but there was no easy way to do that
sql/sql_class.h:
Added functions to protect slaves temporary tables
sql/sql_parse.cc:
Added DBUG_PRINT
sql/transaction.cc:
Added comment
