The first step for deprecating innodb_autoinc_lock_mode(see MDEV-27844) is:
- to switch statement binlog format to ROW if binlog format is MIXED and
the statement changes autoincremented fields
- issue warnings if innodb_autoinc_lock_mode == 2 and binlog format is
STATEMENT
The warning out of OPTIMIZE
Statement is unsafe because it uses a system function
was indeed counterfactual and was resulted by checking an
insufficiently strict property of lex' sql_command_flags.
Fixed with deploying an additional checking of weather
the current sql command that modifes a share->non_determinstic_insert
table is capable of generating ROW format events.
The extra check rules out the unsafety to OPTIMIZE et al, while the
existing check continues to do so to CREATE TABLE (which is
perculiarly tagged as ROW-event generative sql command).
As a side effect sql_sequence.binlog test gets corrected and
binlog_stm_unsafe_warning.test is reinforced to add up
an unsafe CREATE..SELECT test.
The assert was caused by an error of XA transaction that had
BINLOG 'base64_string' statement.
The statement failed because of lack of checking whether the encoded
replication event was handled by the slave applier thread.
If it's not the slave applier no error should be generated, but it was
in this case, see a test added.
Fixed along with the idea borrowed the upstream to introduce a check
of which applier executes the replication event and do not
report any error if the applier is a regular server client.
CREATE-OR-REPLACE SEQUENCE is not logged with Gtid event DDL flag
which affects its slave parallel execution.
Unlike other DDL:s it can occur in concurrent execution with following transactions
which can lead to various errors, including asserts like
(mdl_request->type != MDL_INTENTION_EXCLUSIVE && mdl_request->type != MDL_EXCLUSIVE) || !(get_thd()->rgi_slave && get_thd()->rgi_slave->is_parallel_exec && lock->check_if_conflicting_replication_locks(this)
in MDL_context::acquire_lock.
Fixed to wrap internal statement level commit with save-
and-restore of TRANS_THD::m_unsafe_rollback_flags.
failed in Diagnostics_area::set_ok_status in my_ok from
mysql_sql_stmt_prepare
Analysis: Before PREPARE is executed, binlog_format is STATEMENT.
This PREPARE had SET STATEMENT which sets binlog_format to ROW. Now after
PREPARE is done we reset the binlog_format (back to STATEMENT). But we have
temporary table, it doesn't let changing binlog_format=ROW to
binlog_format=STATEMENT and gives error which goes unreported. This
unreported error eventually causes assertion failure.
Fix: Change return type for LEX::restore_set_statement_var() to bool and
make it return error state.
Problem:
=======
There are two issues that are addressed in this patch:
1) SHOW BINARY LOGS uses caching to store the binary logs that exist
in the log directory; however, if new events are written to the logs,
the caching strategy is unaware. This is okay for users, as it is
okay for SHOW to return slightly old data. The test, however, can
result in inconsistent data. It runs two connections concurrently,
where one shows the logs, and the other adds a new file. The output
of SHOW BINARY LOGS then depends on when the cache is built, with
respect to the time that the second connection rotates the logs.
2) There is a race condition between RESET MASTER and SHOW BINARY
LOGS. More specifically, where they both need the binary log lock to
begin, SHOW BINARY LOGS only needs the lock to build its cache. If
RESET MASTER is issued after SHOW BINARY LOGS has built its cache and
before it has returned the results, the presented data may be
incorrect.
Solution:
========
1) As it is okay for users to see stale data, to make the test
consistent, use DEBUG_SYNC to force the race condition (problem 2) to
make SHOW BINARY LOGS build a cache before RESET MASTER is called.
Then, use additional logic from the next part of the solution to
rebuild the cache.
2) Use an Atomic_counter to keep track of the number of times RESET
MASTER has been called. If the value of the counter changes after
building the cache, the cache should be rebuilt and the analysis
should be restarted.
Reviewed By:
============
Andrei Elkin: <andrei.elkin@mariadb.com>
Problem:
========
Aborting OPTIMIZE TABLE still logs in binary logs and replicates to the
Slave server. "Optimize table" command under execution, is killed by using
"Ctrl-C" as shown below.
MariaDB [test]> optimize table t2;
^CCtrl-C -- query killed. Continuing normally.
In spite of query execution being interrupted the query gets written to
binary log.
Analysis:
========
Admin command execution logic is not handling KILL command, hence it
ignores the KILL command and completes its execution.
Fix:
===
Check for thread killed notification, during admin command execution and
handle it. If thread kill occurs prior to any table modification the query
will not be written to binary log. If kill happens after at least one table
is modified then the query will be written to binary log. Ex: command in
execution is 'OPTIMIZE TABLE t1,t2' and the thread kill happens after t1
table is modified then 'OPTIMIZE TABLE t1,t2' will be written to binary log
as admin commands will not make the slave to diverge from master.
There was race between a committing transaction and the following in binlog
order FLUSH LOGS that could create a 2nd Binlog checkpoint (BCP) event
in the new file *before* the first logged-in-old-binlog transaction gets committed in
Innodb. That would cause the transaction loss at recovery, should
the server stop right after the BCP.
The race is tackled by enforcing the necessary set of mutexes to be acquired
by FLUSH-LOGS handler in the correct order (of the group commit leader
pattern).
Note, there remain two cases where a similar race is still possible:
- the above race as it is when the server is run with ("unlikely")
non-default `--binlog-optimize-thread-scheduling=0` (MDEV-24530), and
- at unlikely event of bin-logging of Incident event (MDEV-24531) that
also triggers binlog rotation,
in both cases though with lesser chances after the current fixes.
The assert fired falsely having not captured two more not apparent
possiblities in its condition.
They are masked out hton error out of REPLACE execution (so at later xa-prepare
that engine is still present as read-write) and a prepare-capable engine
which also may not be an actual participant in the xa transation. That
engine, such as SEQUENCE, though does create its own event block.
