# mysqld got signal 11 **URL:** \ **Category:** Percona Server for MySQL 5.6\ **Created:** [November 7, 2014, 1:34pm UTC](https://forums.percona.com/t/mysqld-got-signal-11/3863 "2014-11-07T13:34:30Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![michaelcaplan](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/michaelcaplan/32/830_2.png) [@michaelcaplan](https://forums.percona.com/u/michaelcaplan)\ **Post date:** [November 7, 2014, 1:34pm UTC](https://forums.percona.com/t/mysqld-got-signal-11/3863/1 "2014-11-07T13:34:30Z")
HI, My last apt-get upgrade to percona-server-server 5.6.21-70.0-688.utopic from what I thought was an earlier release in the 5.6 series, maybe 5.6.19 is causing mysql to crash. I can’t put my finger on what is making mysql crash. What seems clear is that is range of different SQL and DML operations cause a crash, and they are all repeatable. For example, this DML statement causes a signal 11: CREATE TABLE IF NOT EXISTS sessions ( id varchar(64) character set utf8 NOT NULL, access int(10) unsigned default NULL, data text character set utf8, user\_id int(10) unsigned default NULL, start INT(10) UNSIGNED NOT NULL, secure TINYINT(1) UNSIGNED NOT NULL DEFAULT 0, PRIMARY KEY (id), KEY user\_id (user\_id), [B] INDEX start (start ASC), CONSTRAINT sessions\_ibfk\_1 FOREIGN KEY (user\_id) REFERENCES users (id) ON DELETE CASCADE ON UPDATE CASCADE ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8\_general\_ci; I can’t run this statement in an existing schema or new one. The crash looks like this: [/B] 18:41:38 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. Please help us make Percona Server better by reporting any bugs at [url][System Dashboard - Percona JIRA](http://bugs.percona.com/%5B/url%5D) key\_buffer\_size=16777216 read\_buffer\_size=131072 max\_used\_connections=1 max\_threads=153 thread\_count=1 connection\_count=1 It is possible that mysqld could use up to key\_buffer\_size + (read\_buffer\_size + sort\_buffer\_size)\*max\_threads = 77372 K bytes of memory Hope that’s ok; if not, decrease some variables in the equation. Thread pointer: 0x3a87780 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 = 7f071bf60e60 thread\_stack 0x30000 /usr/sbin/mysqld(my\_print\_stacktrace+0x3b)[0x8fff2b] /usr/sbin/mysqld(handle\_fatal\_signal+0x369)[0x651369] /lib/x86\_64-linux-gnu/libpthread.so.0(+0xfc90)[0x7f0763c34c90] /usr/sbin/mysqld[0xabd1bd] /usr/sbin/mysqld[0xab06a7] /usr/sbin/mysqld[0xab1475] /usr/sbin/mysqld[0xabe03e] /usr/sbin/mysqld[0xa421d0] /usr/sbin/mysqld[0xa42f07] /usr/sbin/mysqld[0xa43544] /usr/sbin/mysqld[0xa2a2c0] /usr/sbin/mysqld[0xa5146d] /usr/sbin/mysqld[0x9b5cf2] /usr/sbin/mysqld(\_Z15ha\_create\_tableP3THDPKcS2\_S2\_P24st\_ha\_create\_informationbb+0x225)[0x58cf85] /usr/sbin/mysqld(\_Z17mysql\_alter\_tableP3THDPcS1\_P24st\_ha\_create\_informationP10TABLE\_LISTP10Alter\_infojP8st\_orderb+0x2938)[0x738b08] /usr/sbin/mysqld(\_ZN19Sql\_cmd\_alter\_table7executeEP3THD+0x44b)[0x82724b] /usr/sbin/mysqld(\_Z21mysql\_execute\_commandP3THD+0x2381)[0x6dd531] /usr/sbin/mysqld(\_Z11mysql\_parseP3THDPcjP12Parser\_state+0x640)[0x6e2680] /usr/sbin/mysqld(\_Z16dispatch\_command19enum\_server\_commandP3THDPcj+0x21e5)[0x6e4ea5] /usr/sbin/mysqld(\_Z24do\_handle\_one\_connectionP3THD+0x245)[0x6aa855] /usr/sbin/mysqld(handle\_one\_connection+0x39)[0x6aa8a9] /usr/sbin/mysqld(pfs\_spawn\_thread+0x140)[0x944e80] /lib/x86\_64-linux-gnu/libpthread.so.0(+0x80a5)[0x7f0763c2d0a5] /lib/x86\_64-linux-gnu/libc.so.6(clone+0x6d)[0x7f076334584d] Trying to get some variables. Some pointers may be invalid and cause the dump to abort. Query (7f06fc004f70): is an invalid pointer Connection ID (thread ID): 1 Status: NOT\_KILLED You may download the Percona Server operations manual by visiting [url][http://www.percona.com/software/percona-server/[/url]](http://www.percona.com/software/percona-server/%5B/url%5D). You may find information in the manual which will help you identify the cause of the crash. 141107 14:41:39 mysqld\_safe Number of processes running now: 0 141107 14:41:39 mysqld\_safe mysqld restarted 2014-11-07 14:41:39 0 [Warning] Using unique option prefix key\_buffer instead of key\_buffer\_size is deprecated and will be removed in a future release. Please use the full name instead. 2014-11-07 14:41:39 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit\_defaults\_for\_timestamp server option (see documentation for more details). 2014-11-07 14:41:39 19883 [Warning] Using unique option prefix myisam-recover instead of myisam-recover-options is deprecated and will be removed in a future release. Please use the full name instead. 2014-11-07 14:41:39 19883 [Note] Plugin ‘FEDERATED’ is disabled. 2014-11-07 14:41:39 7f862c14f780 InnoDB: Warning: Using innodb\_additional\_mem\_pool\_size is DEPRECATED. This option may be removed in future releases, together with the option innodb\_use\_sys\_malloc and with the InnoDB’s internal memory allocator. 2014-11-07 14:41:39 19883 [Note] InnoDB: Using atomics to ref count buffer pool pages 2014-11-07 14:41:39 19883 [Note] InnoDB: The InnoDB memory heap is disabled 2014-11-07 14:41:39 19883 [Note] InnoDB: Mutexes and rw\_locks use GCC atomic builtins 2014-11-07 14:41:39 19883 [Note] InnoDB: Memory barrier is not used 2014-11-07 14:41:39 19883 [Note] InnoDB: Compressed tables use zlib 1.2.8 2014-11-07 14:41:39 19883 [Note] InnoDB: Using Linux native AIO 2014-11-07 14:41:39 19883 [Note] InnoDB: Using CPU crc32 instructions 2014-11-07 14:41:39 19883 [Note] InnoDB: Initializing buffer pool, size = 500.0M 2014-11-07 14:41:39 19883 [Note] InnoDB: Completed initialization of buffer pool 2014-11-07 14:41:39 19883 [Note] InnoDB: Highest supported file format is Barracuda. 2014-11-07 14:41:39 19883 [Note] InnoDB: The log sequence numbers 3677334509 and 3677334509 in ibdata files do not match the log sequence number 3677335208 in the ib\_logfiles! 2014-11-07 14:41:39 19883 [Note] InnoDB: Database was not shutdown normally! 2014-11-07 14:41:39 19883 [Note] InnoDB: Starting crash recovery. 2014-11-07 14:41:39 19883 [Note] InnoDB: Reading tablespace information from the .ibd files… 2014-11-07 14:41:40 19883 [Note] InnoDB: Restoring possible half-written data pages 2014-11-07 14:41:40 19883 [Note] InnoDB: from the doublewrite buffer… InnoDB: Last MySQL binlog file position 0 4738636, file name ./mysql-bin.001446 2014-11-07 14:41:40 19883 [Note] InnoDB: 128 rollback segment(s) are active. 2014-11-07 14:41:40 19883 [Note] InnoDB: Waiting for purge to start 2014-11-07 14:41:40 19883 [Note] InnoDB: Percona XtraDB ([http://www.percona.com](http://www.percona.com)) 5.6.21-70.0 started; log sequence number 3677335208 2014-11-07 14:41:40 19883 [Note] RSA private key file not found: /var/lib/mysql//private\_key.pem. Some authentication plugins will not work. 2014-11-07 14:41:40 19883 [Note] RSA public key file not found: /var/lib/mysql//public\_key.pem. Some authentication plugins will not work. 2014-11-07 14:41:40 19883 [Note] Server hostname (bind-address): ‘127.0.0.1’; port: 3306 2014-11-07 14:41:40 19883 [Note] - ‘127.0.0.1’ resolves to ‘127.0.0.1’; 2014-11-07 14:41:40 19883 [Note] Server socket created on IP: ‘127.0.0.1’. 2014-11-07 14:41:40 19883 [Warning] ‘user’ entry ‘root@goldman’ ignored in --skip-name-resolve mode. 2014-11-07 14:41:40 19883 [Warning] ‘proxies\_priv’ entry ‘@ root@goldman’ ignored in --skip-name-resolve mode. 2014-11-07 14:41:40 19883 [Note] Event Scheduler: Loaded 0 events 2014-11-07 14:41:40 19883 [Note] /usr/sbin/mysqld: ready for connections. Anyone else experiencing this? Thanks for the feedback, Mike ---
**Author:** ![michaelcaplan](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/michaelcaplan/32/830_2.png) [@michaelcaplan](https://forums.percona.com/u/michaelcaplan)\ **Post date:** [November 9, 2014, 8:11pm UTC](https://forums.percona.com/t/mysqld-got-signal-11/3863/2 "2014-11-09T20:11:14Z")
FYI, For the time being I downgraded to the bundled version of ubuntu utopic mysql-server 5.6.19. I’ll give percona 5.6 a go again with the next release Mike