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MDEV-25114 Crash: WSREP: invalid state ROLLED_BACK (FATAL)

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This patch is the plan D variant for fixing potetial mutex locking
order exercised by BF aborting and KILL command execution.

In this approach, KILL command is replicated as TOI operation.
This guarantees total isolation for the KILL command execution
in the first node: there is no concurrent replication applying
and no concurrent DDL executing. Therefore there is no risk of
BF aborting to happen in parallel with KILL command execution
either. Potential mutex deadlocks between the different mutex
access paths with KILL command execution and BF aborting cannot
therefore happen.

TOI replication is used, in this approach,  purely as means
to provide isolated KILL command execution in the first node.
KILL command should not (and must not) be applied in secondary
nodes. In this patch, we make this sure by skipping KILL
execution in secondary nodes, in applying phase, where we
bail out if applier thread is trying to execute KILL command.
This is effective, but skipping the applying of KILL command
could happen much earlier as well.

This patch also fixes mutex locking order and unprotected
THD member accesses on bf aborting case. We try to hold
THD::LOCK_thd_data during bf aborting. Only case where it
is not possible is at wsrep_abort_transaction before
call wsrep_innobase_kill_one_trx where we take InnoDB
mutexes first and then THD::LOCK_thd_data.

This will also fix possible race condition during
close_connection and while wsrep is disconnecting
connections.

Added wsrep_bf_kill_debug test case

Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>
This commit is contained in:
sjaakola
2021-09-15 09:16:44 +03:00
committed by Jan Lindström
parent 9d97f92feb
commit 88a4be75a5
18 changed files with 724 additions and 150 deletions
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9
sql/sql_class.h
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@ -3231,8 +3231,13 @@ public:
void awake(killed_state state_to_set);
/** Disconnect the associated communication endpoint. */
void disconnect();
inline void disconnect()
{
mysql_mutex_lock(&LOCK_thd_data);
disconnect_mutexed();
mysql_mutex_unlock(&LOCK_thd_data);
}
void disconnect_mutexed();
/*
Allows this thread to serve as a target for others to schedule Async