MySQL Bugs: #33332: assert at the end of mysql_binlog

Bug #33332	assert at the end of mysql_binlog_send
Submitted:	18 Dec 2007 14:06	Modified:	16 Feb 2008 11:37
Reporter:	Andrei Elkin	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Replication	Severity:	S3 (Non-critical)
Version:		OS:	Any
Assigned to:	Andrei Elkin	CPU Architecture:	Any
Tags:	heartbeat

Description:
Core dumps left after some tests with mysql-5.1-telco-6.3 shows the stack

#5  0x00002af2ef377660 in abort () from /lib/libc.so.6
#6  0x00002af2ef36f436 in __assert_fail () from /lib/libc.so.6
#7  0x0000000000694c84 in Diagnostics_area::set_eof_status (this=0x1f05670, d=0x1f04268) at sql_class.cc:418
#8  0x00000000005ce1e2 in send_eof (thd=0x1f04268) at sql_class.h:2116
#9  0x0000000000858707 in mysql_binlog_send

How to repeat:
It's necessary to have at least two tests

./mysql-test-run.pl --mtr=113 --vardir=/dev/shm/var rpl_ndb.rpl_ndb_UUID rpl_ndb.rpl_ndb_add_column 

Suggested fix:
Check net_flush return value before to generate the return value of
send_heartbeat_event().

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/40137

ChangeSet@1.2804, 2007-12-18 16:10:51+02:00, aelkin@koti.dsl.inet.fi +1 -0
  Bug #33332 assert at the end of mysql_binlog_send
  
  The heartbeat code did not check possible error in net_flush which
  kept the dump thread hanging in heartbeating loop even though
  the slave has disappeared.
  When eventaully the dump thread was killed its cleanup did not use the error
  path and that led to an assert.
  
  Fixed with adding the check of net_flush return value. If one happens
  send_heartbeat_event() returns the error which forces the dump thread
  to exit along the error path.

Patch was queued to mysql-5.1-telco-6.3

Patch was queued to mysql-5.1-telco-6.3

Pushed into 6.0.5-alpha

Documented bugfix in the 5.1.23-ndb-6.3.8 and 6.0.5 changelogs as follows:

        The code implementing heartbeats did not check for possible
        errors in some circumstances; this kept the dump thread hanging
        while waiting for heartbeats loop even though the slave was no
        longer connected.