AKA rpl.rpl_parallel, binlog_encryption.rpl_parallel fails in
buildbot with timeout in include
A replication parallel worker thread can deadlock with another
connection running SHOW SLAVE STATUS. That is, if the replication
worker thread is in do_gco_wait() and is killed, it will already
hold the LOCK_parallel_entry, and during error reporting, try to
grab the err_lock. SHOW SLAVE STATUS, however, grabs these locks in
reverse order. It will initially grab the err_lock, and then try to
grab LOCK_parallel_entry. This leads to a deadlock when both threads
have grabbed their first lock without the second.
This patch implements the MDEV-31894 proposed fix to optimize the
workers_idle() check to compare the last in-use relay log’s
queued_count==dequeued_count for idleness. This removes the need for
workers_idle() to grab LOCK_parallel_entry, as these values are
atomically updated.
Huge thanks to Kristian Nielsen for diagnosing the problem!
Reviewed By:
============
Kristian Nielsen <knielsen@knielsen-hq.org>
Andrei Elkin <andrei.elkin@mariadb.com>
Add a test case that demonstrates a working setup as described in MDEV-26632.
This requires --gtid-ignore-duplicates=1 and --gtid-strict-mode=0.
In A->B->C, B filters some (but not all) events from A. C is promoted to
create A->C->B, and the current GTID position in B contains a GTID from A that
is not present in C (due to filtering). Demonstrate that B can still connect
with GTID to C, starting at the "hole" in the binlog stream on C originating
from A.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Make sure the old binlog dump thread is not still running when manipulating
binlog files; otherwise there is a small chance it will see an invalid
partial file and report an I/O error.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Fix some random test failures following MDEV-32168 push.
Don't blindly set $rpl_only_running_threads in many places. Instead explicit
stop only the IO or SQL thread, as appropriate. Setting it interfered with
rpl_end.inc in some cases. Rather than clearing it afterwards, better to
not set it at all when it is not needed, removing ambiguity in the test
about the state of the replication threads.
Don't fail the test if include/stop_slave_io.inc finds an error in the IO
thread after stop. Such errors can be simply because slave stop happened in
the middle of the IO thread's initial communication with the master.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Wait for the disconnect of the other connection to complete, before running
SHOW BINLOG EVENTS. Otherwise the DROP TEMPORARY TABLE that is binlogged
during disconnect may not have appeared yet depending on thread scheduling.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Fix wrong change to rpl.rpl_shutdown_wait_slaves. After shutting down the
master, slaves may or may not succeed in reconnecting depending on the timing
on their reconnect relative to master restart. So don't assume all IO threads
will be running, just restart any slave that needs it.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Fix sporadic test failure in rpl.rpl_ssl1. The test incorrectly did a STOP
SLAVE too early, which could race with the expected 'Access denied' error.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Fix sporadic test failures in rpl.rpl_set_statement_default_master and
rpl.rpl_slave_load_tmpdir_not_exist. A race between START and STOP
SLAVE could leave an error condition that causes test failure after
MDEV-32168.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Test rpl.show_status_stop_slave_race-7126 now fails sporadically
because it is expected to sometimes (but not always) leave an error
condition after slave stop. Fix by explicitly allowing the error
condition in this case.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Fix a start/stop race that causes occasional test failure after more the more
strict error check of MDEV-32168.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
The reason was that Event e11 was re-executed before
"ALTER EVENT e11 DISABLE" had been executed.
Fixed by increasing re-schedule time
Other things:
- Removed double accounting of 'execution_count'. It was incremented in
top->mark_last_executed(thd) that was executed a few lines earlier.
The MTR test rpl.rpl_semi_sync_slave_compressed_protocol scans the
log file to ensure there is no magic number error. It attempts to
only scan the log files of the current test; however, the variable
which controls this, , is initialized incorrectly,
and it thereby scans the entire log file, which includes output from
prior tests. This causes it to fail if a test which expects this
error runs previously on the same worker.
This patch fixes the assert_only_after so the test only scans
through its own log contents.
The test rpl.rpl_sql_thd_start_errno_cleared can lose a debug_sync
signal, as there is a RESET immediately following a SIGNAL. When the
signal is lost, the sql_thread is stuck in a WAIT_FOR clause until
it times out, resulting in long test times (albeit still
successful).
This patch extends the test to ensure the debug_sync signal was
received before issuing the RESET
This commit fixes several bugs in error handling around disk full when
writing the statement/transaction binlog caches:
1. If the error occurs during a non-transactional statement, the code
attempts to binlog the partially executed statement (as it cannot roll
back). The stmt_cache->error was still set from the disk full error. This
caused MYSQL_BIN_LOG::write_cache() to get an error while trying to read the
cache to copy it to the binlog. This was then wrongly interpreted as a disk
full error writing to the binlog file. As a result, a partial event group
containing just a GTID event (no query or commit) was binlogged. Fixed by
checking if an error is set in the statement cache, and if so binlog an
INCIDENT event instead of a corrupt event group, as for other errors.
2. For LOAD DATA LOCAL INFILE, if a disk full error occured while writing to
the statement cache, the code would attempt to abort and read-and-discard
any remaining data sent by the client. The discard code would however
continue trying to write data to the statement cache, and wrongly interpret
another disk full error as end-of-file from the client. This left the client
connection with extra data which corrupts the communication for the next
command, as well as again causing an corrupt/incomplete event to be
binlogged. Fixed by restoring the default read function before reading any
remaining data from the client connection.
Reviewed-by: Andrei Elkin <andrei.elkin@mariadb.com>
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Semisync ack (master side) receiver thread is made to report
details of faced errors.
In case of 'magic byte' error, a hexdump of the received packet
is always (level) NOTEd into the error log.
In other cases an exact server level error is print out
as a warning (as it may not be critical) under log_warnings > 2.
An MTR test added for the magic byte error. For others existing mtr
tests cover that, provided log_warnings > 2 is set.
If a replica is actively delaying a transaction when restarted (STOP
SLAVE/START SLAVE), when the sql thread is back up,
Seconds_Behind_Master will present as 0 until the configured
MASTER_DELAY has passed. That is, before the restart,
last_master_timestamp is updated to the timestamp of the delayed
event. Then after the restart, the negation of sql_thread_caught_up
is skipped because the timestamp of the event has already been used
for the last_master_timestamp, and their update is grouped together
in the same conditional block.
This patch fixes this by separating the negation of
sql_thread_caught_up out of the timestamp-dependent block, so it is
called any time an idle parallel slave queues an event to a worker.
Note that sql_thread_caught_up is still left in the check for internal
events, as SBM should remain idle in such case to not "magically" begin
incrementing.
Reviewed By:
============
Andrei Elkin <andrei.elkin@mariadb.com>
The assert's reason was in missed FL_DDL flagging of CREATE-or-REPLACE
Query event.
MDEV-27365 fixes covered only the non-pre-existing table execution branch so
did not see a possibility of implicit commit in
the middle of execution in a rollback branch when the being CREATEd
sequence table is actually replaced.
The pre-existing table branch cleared the DDL modification
flag so the query lost FL_DDL in binlog and its parallel execution
on slave may have ended up with the assert to indicate the query
is raced by a following in binlog order event.
Fixed with applying the MDEV-27365 pattern.
An mtr test is added to cover the rollback situation.
The description test [ pass ] with a generous number of mtr parallel
reties.
The crash inside my_vsnprintf_utf32() happened correctly,
because the caller methods:
Field_string::sql_rpl_type()
Field_varstring::sql_rpl_type()
mis-used the charset library and sent pure ASCII data to the
virtual function snprintf() of a utf32 CHARSET_INFO.
It was wrong to use Field::charset() in sql_rpl_type().
We're printing the metadata (the data type) here, not the column data.
The string contraining the data type of a CHAR/VARCHAR column
is a pure ASCII string.
Fixing to use res->charset() to print, like all virtual implementations
of sql_type() do.
Review was done by Andrei Elkin.
Thanks to Andrei for proposing MTR test improvents.
- `default_client` is included already in rpl_1slave_base.cnf`, so
remove it from `my.cnf`
- Remove option group for `mysqld` server as and add comment how to
override specific settings for specific server
- Reviewer: <brandon.nesterenko@mariadb.com>
The SQL thread and a user connection executing SHOW SLAVE STATUS
have a race condition on Last_SQL_Errno, such that a slave which
previously errored and stopped, on its next start, SHOW SLAVE STATUS
can show that the SQL Thread is running while the previous error is
also showing.
The fix is to move when the last error is cleared when the SQL
thread starts to occur before setting the status of
Slave_SQL_Running.
Thanks to Kristian Nielson for his work diagnosing the problem!
Reviewed By:
============
Andrei Elkin <andrei.elkin@mariadb.com>
Kristian Nielson <knielsen@knielsen-hq.org>
- Removed commented out and unused lines.
- Updated test to reference true failure of timeout
rather than deadlock
- Switched save variables from MTR to user
- Forced relay-log purge to not potentially re-execute
an already prepared transaction
Remove the exception that InnoDB does not report auto-increment locks waits
to the parallel replication.
There was an assumption that these waits could not cause conflicts with
in-order parallel replication and thus need not be reported. However, this
assumption is wrong and it is possible to get conflicts that lead to hangs
for the duration of --innodb-lock-wait-timeout. This can be seen with three
transactions:
1. T1 is waiting for T3 on an autoinc lock
2. T2 is waiting for T1 to commit
3. T3 is waiting on a normal row lock held by T2
Here, T3 needs to be deadlock killed on the wait by T1.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Restore code to make InnoDB choose the second transaction as a deadlock
victim if two transactions deadlock that need to commit in-order for
parallel replication. This code was erroneously removed when VATS was
implemented in InnoDB.
Also add a test case for InnoDB choosing the right deadlock victim.
Also fixes this bug, with testcase that reliably reproduces:
MDEV-28776: rpl.rpl_mark_optimize_tbl_ddl fails with timeout on sync_with_master
Reviewed-by: Marko Mäkelä <marko.makela@mariadb.com>
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Restore code to make InnoDB choose the second transaction as a deadlock
victim if two transactions deadlock that need to commit in-order for
parallel replication. This code was erroneously removed when VATS was
implemented in InnoDB.
Also add a test case for InnoDB choosing the right deadlock victim.
Also fixes this bug, with testcase that reliably reproduces:
MDEV-28776: rpl.rpl_mark_optimize_tbl_ddl fails with timeout on sync_with_master
Note: This should be null-merged to 10.6, as a different fix is needed
there due to InnoDB locking code changes.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Remove the exception that InnoDB does not report auto-increment locks waits
to the parallel replication.
There was an assumption that these waits could not cause conflicts with
in-order parallel replication and thus need not be reported. However, this
assumption is wrong and it is possible to get conflicts that lead to hangs
for the duration of --innodb-lock-wait-timeout. This can be seen with three
transactions:
1. T1 is waiting for T3 on an autoinc lock
2. T2 is waiting for T1 to commit
3. T3 is waiting on a normal row lock held by T2
Here, T3 needs to be deadlock killed on the wait by T1.
Note: This should be null-merged to 10.6, as a different fix is needed
there due to InnoDB lock code changes.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
The test case accessed slave-relay-bin.000003 without waiting for the IO
thread to write it first. If the IO thread was slow, this could fail.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
