Bug #11820 Relay log filled with unnecessary rotate events
Submitted: 8 Jul 2005 16:40 Modified: 2 Oct 2007 7:47
Reporter: Dean Ellis Email Updates:
Status: Duplicate Impact on me:
None 
Category:MySQL Server: Replication Severity:S3 (Non-critical)
Version:4.1.13 OS:Any
Assigned to: Assigned Account CPU Architecture:Any

[8 Jul 2005 16:40] Dean Ellis
Description:
The relay log is recording a ROTATE event apparently every 5 seconds even though master binlog log/position has not advanced.

Ex:

# at 21722
#691231 18:00:00 server id 411  log_pos 0       Rotate to nif-bin.000004  pos: 13198
# at 21768
#691231 18:00:00 server id 411  log_pos 0       Rotate to nif-bin.000004  pos: 13198
# at 21814
#691231 18:00:00 server id 411  log_pos 0       Rotate to nif-bin.000004  pos: 13198
# at 21860
#691231 18:00:00 server id 411  log_pos 0       Rotate to nif-bin.000004  pos: 13198

-rw-rw----  1 mysql mysql 24666 Jul  8 11:33 niflheim-relay-bin.000002
-rw-rw----  1 mysql mysql 24712 Jul  8 11:34 niflheim-relay-bin.000002
-rw-rw----  1 mysql mysql 24758 Jul  8 11:34 niflheim-relay-bin.000002
-rw-rw----  1 mysql mysql 24804 Jul  8 11:34 niflheim-relay-bin.000002

How to repeat:
Configure replication; watch relay log.

Suggested fix:
n/a
[28 Jul 2005 16:53] Jeremy Tinley
This happens in 4.0.24 too.

Corresponding .err log entries are:

050728 11:47:57 Slave: received 0 length packet from server, apparent master shutdown:
050728 11:47:57 Slave I/O thread: Failed reading log event, reconnecting to retry, log 'master.004' position 4
050728 11:47:57 Slave: connected to master 'replication@hostname:3306',replication resumed in log 'master.004' at position 4
[22 Nov 2006 7:12] Andrei Elkin
Looks to relate to bug #20435
[2 Oct 2007 7:47] Andrei Elkin
Certainly, it is a duplicate of bug#20435, which is under reviewing at this time.
Rotating is a consequence of reconnecting by slave to the idling master after
slave_net_timeout.