Bug #19942 Mysql user disappeared
Submitted: 19 May 2006 13:19 Modified: 19 Jun 2006 15:52
Reporter: Gilberto Müller Email Updates:
Status: No Feedback Impact on me:
Category:MySQL Server Severity:S2 (Serious)
Version:5.0.20a-pro OS:Linux (Debian GNU/Linux)
Assigned to: MySQL Verification Team CPU Architecture:Any

[19 May 2006 13:19] Gilberto Müller
In this case.
I have a master server with 4.0.20a-pro-nt version. 
There are two slaves pointed to that master, both with 5.0.20a-pro.
Suddenly, one database user dissapeard, i looked at .err and saw a crash.
The server are working fine, but the user wich I was connected to the server are gone. (I have an application which show me the replication status of many servers). 
It's not the first time that it happens.

Here is the .err

060518 16:52:51 [ERROR] Slave I/O thread: error reconnecting to master 'USER@HOST:3306': Error: ''  errno: 0  retry-time: 10  retries: 86400
060518 16:53:43 [Note] Slave I/O thread killed during or after a reconnect done to recover from failed read
060518 16:53:43 [Note] Slave I/O thread exiting, read up to log 'login.240', position 952805
060518 16:53:43 [Note] Error reading relay log event: slave SQL thread was killed
060518 16:53:44 [Note] Slave SQL thread initialized, starting replication in log 'login.240' at position 952805, relay log '/PATHTORELAYLOG/relaylog.000645' position: 955933
060518 16:53:44 [Note] Slave I/O thread: connected to master 'USER@HOST:3306',  replication started in log 'login.240' at position 952805
mysqld got signal 11;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.
We will try our best to scrape up some info that will hopefully help diagnose
the problem, but since we have already crashed, something is definitely wrong
and this may fail.

It is possible that mysqld could use up to 
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_connections = 308847 K
bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
Cannot determine thread, fp=0xb327dacc, backtrace may not be correct.
Stack range sanity check OK, backtrace follows:
New value of fp=(nil) failed sanity check, terminating stack trace!
Please read http://dev.mysql.com/doc/mysql/en/Using_stack_trace.html and follow instructions on how to resolve the stack trace. Resolved
stack trace is much more helpful in diagnosing the problem, so please do 
resolve it
Trying to get some variables.
Some pointers may be invalid and cause the dump to abort...
thd->query at 0xb0a2153f  is invalid pointer
The manual page at http://www.mysql.com/doc/en/Crashing.html contains
information that should help you find out what is causing the crash.

Number of processes running now: 0
060518 16:54:23  mysqld restarted
060518 16:54:24  InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
060518 16:54:25  InnoDB: Starting log scan based on checkpoint at
InnoDB: log sequence number 2 4088478668.
InnoDB: Doing recovery: scanned up to log sequence number 2 4088791711
060518 16:54:25  InnoDB: Starting an apply batch of log records to the database...
InnoDB: Progress in percents: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 
InnoDB: Apply batch completed
InnoDB: In a MySQL replication slave the last master binlog file
InnoDB: position 0 2899061, file name login.240
060518 16:54:26  InnoDB: Started; log sequence number 2 4088791711
060518 16:54:27 [Note] /usr/local/mysql/bin/mysqld: ready for connections.
Version: '5.0.20a-pro'  socket: '/PATHTOSOCK/mysql.sock'  port: 3311  MySQL Pro (Commercial)
060518 16:54:27 [Note] Slave SQL thread initialized, starting replication in log 'login.240' at position 2930951, relay log '/PATHTORELAYLOG/relaylog.000646' position: 1984444
060518 16:54:29 [Note] Slave I/O thread: connected to master 'USER@HOST:3306',  replication started in log 'login.240' at position 2933432

How to repeat:
I coun't repeat. But it happened some times randomly
[19 May 2006 15:52] MySQL Verification Team
Thank you for the bug report. Could you please open this bug report
when you are able to provide a repeatable test case?

Thanks in advance.
[19 Jun 2006 23:00] Bugs System
No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
[23 Jan 2009 8:33] Ingvar Hagelund
We had a similar error a few days ago. Server went down roughly, being fenced out in a fail-over situation (ie no graceful shutdown of mysqld). When mysqld started up again, one user was gone. We did a check of all tables, without any reported errors.

As mysqld died instantly, of course, we have no error logs, nor any way to reproduce this :-(

This is Debian Etch

# /usr/sbin/mysqld --version
Ver 5.0.32-Debian_7etch8-log for pc-linux-gnu on x86_64 (Debian etch distribution)