MySQL Bugs: #64241: Got signal 6

Bug #64241	Got signal 6
Submitted:	6 Feb 2012 15:02	Modified:	20 Apr 2012 17:52
Reporter:	Wojciech Pospiech	Email Updates:
Status:	No Feedback	Impact on me:	None
Category:	MySQL Server	Severity:	S3 (Non-critical)
Version:	5.5.20	OS:	Other (centos)
Assigned to:		CPU Architecture:	Any

Description:
 mysqld got signal 6 ;
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.

key_buffer_size=33554432
read_buffer_size=2097152
max_used_connections=14
max_threads=100
thread_count=7
connection_count=7
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 1057906 K  bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x7fd53c0c4ea0
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...
stack_bottom = 40d780b8 thread_stack 0x30000
/usr/libexec/mysqld(my_print_stacktrace+0x2e)[0x7abd7e]
/usr/libexec/mysqld(handle_fatal_signal+0x3e2)[0x677d32]
/lib64/libpthread.so.0[0x3de2a0eb70]
/lib64/libc.so.6(gsignal+0x35)[0x3de2230265]
/lib64/libc.so.6(abort+0x110)[0x3de2231d10]
/lib64/libc.so.6[0x3de226a99b]
/lib64/libc.so.6[0x3de227245f]
/lib64/libc.so.6(cfree+0x4b)[0x3de22728bb]
/usr/libexec/mysqld(_ZN11MDL_context27release_locks_stored_beforeE17enum_mdl_durationP10MDL_ticket+0x49)[0x613239]
/usr/libexec/mysqld(_Z21mysql_execute_commandP3THD+0x4bd)[0x571dcd]
/usr/libexec/mysqld(_Z11mysql_parseP3THDPcjP12Parser_state+0x10a)[0x57799a]
/usr/libexec/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0x14e9)[0x579679]
/usr/libexec/mysqld(_Z10do_commandP3THD+0xc2)[0x5799d2]
/usr/libexec/mysqld(_Z24do_handle_one_connectionP3THD+0xf2)[0x60b082]
/usr/libexec/mysqld(handle_one_connection+0x53)[0x60b173]
/lib64/libpthread.so.0[0x3de2a0673d]
/lib64/libc.so.6(clone+0x6d)[0x3de22d44bd]

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (1a8adf40): SELECT p.`id`, p.`odbiorca`, p.`data`, p.`tytul`, p.`read`, u.`id` FROM `poczta` p LEFT JOIN `users` u ON u.`login` = p.`odbiorca` WHERE p.`nadawca`='Boroda' ORDER BY `data` DESC LIMIT 30
Connection ID (thread ID): 8147
Status: NOT_KILLED

The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains
information that should help you find out what is causing the crash.

How to repeat:
Don't know it came from nowhere

The server crashes if you execute again the involved query?.

SELECT p.`id`, p.`odbiorca`, p.`data`, p.`tytul`, p.`read`, u.`id` FROM
`poczta` p LEFT JOIN `users` u ON u.`login` = p.`odbiorca` WHERE p.`nadawca`='Boroda'
ORDER BY `data` DESC LIMIT 30

Thanks.

No, it's random

Please, upload the entire error log (compressed if it's big). I wonder if there is any assertion failure info before signal 6.

Mysqld logs

Attachment: mysqld.log (application/octet-stream, text), 350.13 KiB.

Your log is full of memory corruption messages and signal 6 for every other statement in different contexts... 

Please, send the output of:

uname -a
free

Linux commands and send your my.cnf file content.

# uname -a
Linux ns224595.ovh.net 2.6.38.2-grsec-xxxx-grs-ipv6-64 #2 SMP Thu Aug 25 16:40:22 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

# free
             total       used       free     shared    buffers     cached
Mem:      24726100   22267468    2458632          0     303784   14936192
-/+ buffers/cache:    7027492   17698608
Swap:      1046520      13748    1032772

my.cnf

Attachment: my.cnf (application/octet-stream, text), 19.37 KiB.

Thank you for the feedback.

All crashes happened when MDL locks were released.

Please check your RAM modules and if they are OK turn on InnoDB monitor and lock monitor, then send us full error log file when crash happens next time (InnoDB monitors do not show MDL locks, but they will show what is going on in crash time).

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".