Bug #84090 mysql 5.6.24 got signal 11 and restarted
Submitted: 7 Dec 2016 10:08 Modified: 30 Dec 2016 8:44
Reporter: victor zheng Email Updates:
Status: Duplicate Impact on me:
Category:MySQL Server: Federated storage engine Severity:S3 (Non-critical)
Version:mysql 5.6.24 OS:Debian
Assigned to: CPU Architecture:Any

[7 Dec 2016 10:08] victor zheng
one day,mysql 5.6.24 restarted.And I find the error log in mysql error log as belows.

machine information:

free -g
total       used       free     shared    buffers     cached
Mem:            94         94          0          0          0         34
-/+ buffers/cache:         58         35
Swap:            3          0          3

mysql error log:

10:35:05 UTC - 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_threads = 135407054 K  bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x2ad200b4e3a0
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 = 2ad195e2d0b8 thread_stack 0x40000

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (2ad264cd0580): flush tables
Connection ID (thread ID): 107052

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.
161202 18:35:09 mysqld_safe Number of processes running now: 0
161202 18:35:09 mysqld_safe mysqld restarted

How to repeat:
I cann't repeat the bug now.
[7 Dec 2016 10:45] MySQL Verification Team
We need a repeatable test case to check a bug and with the latest released version, please test 5.6.34 version and re-open this bug report if the issue persists. Thanks.
[30 Dec 2016 8:44] MySQL Verification Team

This is a known bug with FEDERATED tables in the table cache.
For reference it is fixed:

Noted in 5.5.49, 5.6.30, 5.7.12, 5.8.0 changelogs.

Concurrent selecting and flushing of a FEDERATED table while killing
connections accessing it could result in a server exit.