MySQL Bugs: #41662: corruption of relay logs

Bug #41662	corruption of relay logs
Submitted:	21 Dec 2008 4:15	Modified:	22 Dec 2008 9:45
Reporter:	Gerald Nowitzky	Email Updates:
Status:	Not a Bug	Impact on me:	None
Category:	MySQL Server: Replication	Severity:	S1 (Critical)
Version:	5.0.72	OS:	Linux (gentoo )
Assigned to:		CPU Architecture:	Any

Description:
As I can't reopen a bug, I open a new one. bug #26489 doesn't seem to be fixed. I still see the slave stopping with the same symptoms in the mysqld log:

081220  2:40:05 [ERROR] Error reading packet from server: Lost connection to MySQL server during query ( server_errno=2013)
081220  2:40:05 [Note] Slave I/O thread: Failed reading log event, reconnecting to retry, log 'mysqld-db1n-bin.000951' position 994185738
081220  2:40:05 [Note] Slave: connected to master 'repli@db1n:3306',replication resumed in log 'mysqld-db1n-bin.000951' at position 994185738

and then:

081220  3:04:55 [ERROR] Slave: Error 'You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '5' at line 3' on query. ---
081220  3:04:55 [ERROR] Error running query, slave SQL thread aborted. Fix the problem, and restart the slave SQL thread with "SLAVE START". We stopped at log 'mysqld-db1n-bin.000951' position 994184266

The occurence of this bug in my case doesn't have anything to do with network outages. I see it on a Server at a time where this server has very high load (cpu and IO) due to a multi-threaded java-process.

How to repeat:
run replication under heavy IO/CPU load on the slave

Suggested fix:
rework patch on bug #26489

Thank you for the report.

Did you upgrade both master and slave?

Only the slave is updated to 5.0.72. The master is 5.0.51. However, the master logs are intact, as only one slave fails at a time and can be repaired with set_master_log_pos=xxxx.

Thank you for the feedback.

Fix for bug #26489 is in the part of replication that runs on the master. So you must upgrade master to get fix of this bug.

I set this report as "Not a Bug" because so, feel free to reopen it if you meet same problem after upgrading master.