With combination of --log-bin and Galera the server may crash
reporting two characteristic stacks:
/usr/sbin/mysqld(_ZN13MYSQL_BIN_LOG13mark_xid_doneEmb+0xc7)[0x7f182a8e2cb7]
/usr/sbin/mysqld(binlog_background_thread+0x2b5)[0x7f182a8e3275]
or
/usr/sbin/mysqld(_ZN13MYSQL_BIN_LOG21do_checkpoint_requestEm+0x9d)[0x7ff395b2dafd]
/usr/sbin/mysqld(_ZN13MYSQL_BIN_LOG20checkpoint_and_purgeEm+0x11)[0x7ff395b2db91]
/usr/sbin/mysqld(_ZN13MYSQL_BIN_LOG16rotate_and_purgeEb+0xc2)[0x7ff395b300b2]
The reason of the failure appears to be non-matching decrements for
`xid_count_per_binlog::xid_count`
which can occur when a transaction is executed having its connection issued
`SET @@sql_log_bin=0`. In such case the xid count is not incremented but
its decrements still runs to turn `binlog_xid_count_list` into improper state
which the following FLUSH BINARY LOGS exposes through the crash.
*Note_1*: the regression test reuses an existing galera.sql_log_bin
which does not run stably (even in its base form) by mtr with --log-bin.
*Note_2*: 10.0-galera branch is free of this issue having missed MDEV-7205
fixes.
While sql_bin_log=1(0) is meant to control binary logging for the
current session so that the updates to do(not) get logged into the
binary log to be replicated to the async MariaDB slave. The same
should not affect galera replication.
That is, the updates should always get replicated to other galera
nodes regardless of sql_bin_log's value.
Fixed by making sure that the updates are written to binlog cache
irrespective of sql_bin_log.
Added test cases.