For a while now our MySQL has been crashing daily, sometimes multiple times even. I've troubleshot a lot but nothing seems to help, it's also a live server so I have to be careful with tests/experiments. I even tried cloning the entire server to test more thoroughly, but I'm unable to reproduce the errors on there. So I'm fairly certain it requires at least a certain pressure on the server.
We're on CentOS 6.8 x86_64, running MySQL 5.6.29 (we're unable to upgrade either due to circumstances). It has 8 GB of RAM, usually about 4 GB is "cached" memory with a few 100 MBs that are actually unallocated. All databases run on the built-in version of InnoDB as far as I can tell.
The DB and
.ibd file in the first line are different every time so it's not that that particular DB/table is corrupt. If it were, the test server would've crashed too.
2017-02-10 02:39:47 24223 [ERROR] InnoDB: Unable to lock ./mydb/field_revision_field_tel_nr_.ibd, error: 37 2017-02-10 02:39:47 2ab04c081700 InnoDB: Assertion failure in thread 46936678209280 in file fil0fil.cc line 875 InnoDB: Failing assertion: ret InnoDB: We intentionally generate a memory trap. InnoDB: Submit a detailed bug report to http://bugs.mysql.com. InnoDB: If you get repeated assertion failures or crashes, even InnoDB: immediately after the mysqld startup, there may be InnoDB: corruption in the InnoDB tablespace. Please refer to InnoDB: http://dev.mysql.com/doc/refman/5.6/en/forcing-innodb-recovery.html InnoDB: about forcing recovery. 01:39:47 UTC - 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=131072 max_used_connections=18 max_threads=300 thread_count=6 connection_count=5 It is possible that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 151807 K bytes of memory Hope that's ok; if not, decrease some variables in the equation. Thread pointer: 0xf906670 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 = 2ab04c080e10 thread_stack 0x40000 /usr/sbin/mysqld(my_print_stacktrace+0x35)[0x91f1d5] /usr/sbin/mysqld(handle_fatal_signal+0x3d8)[0x678e78] /lib64/libpthread.so.0(+0xf7e0)[0x2aaf7aff57e0] /lib64/libc.so.6(gsignal+0x35)[0x2aaf7c21c5e5] /lib64/libc.so.6(abort+0x175)[0x2aaf7c21ddc5] /usr/sbin/mysqld[0xa8645b] /usr/sbin/mysqld[0xa8670e] /usr/sbin/mysqld[0xa8d119] /usr/sbin/mysqld[0xa57a3b] /usr/sbin/mysqld[0xa580ab] /usr/sbin/mysqld[0xa45b1a] /usr/sbin/mysqld[0xa98716] /usr/sbin/mysqld[0x940e8a] /usr/sbin/mysqld[0x72cd36] /usr/sbin/mysqld[0x73c1fd] /usr/sbin/mysqld(_Z14get_all_tablesP3THDP10TABLE_LISTP4Item+0x665)[0x73c975] /usr/sbin/mysqld(_Z24get_schema_tables_resultP4JOIN23enum_schema_table_state+0x2cd)[0x72942d] /usr/sbin/mysqld(_ZN4JOIN14prepare_resultEPP4ListI4ItemE+0x6d)[0x71c2ad] /usr/sbin/mysqld(_ZN4JOIN4execEv+0xfd)[0x6d727d] /usr/sbin/mysqld[0x71ee39] /usr/sbin/mysqld(_Z12mysql_selectP3THDP10TABLE_LISTjR4ListI4ItemEPS4_P10SQL_I_ListI8st_orderESB_S7_yP13select_resultP18st_select_lex_unitP13st_select_lex+0xbc)[0x71f8fc] /usr/sbin/mysqld(_Z13handle_selectP3THDP13select_resultm+0x175)[0x71fb05] /usr/sbin/mysqld[0x6f9929] /usr/sbin/mysqld(_Z21mysql_execute_commandP3THD+0x34ae)[0x6fe01e] /usr/sbin/mysqld(_Z11mysql_parseP3THDPcjP12Parser_state+0x338)[0x701d48] /usr/sbin/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0x1231)[0x703761] /usr/sbin/mysqld(_Z10do_commandP3THD+0xd7)[0x705037] /usr/sbin/mysqld(_Z24do_handle_one_connectionP3THD+0x116)[0x6cb956] /usr/sbin/mysqld(handle_one_connection+0x45)[0x6cba35] /usr/sbin/mysqld(pfs_spawn_thread+0x126)[0xaf56f6] /lib64/libpthread.so.0(+0x7aa1)[0x2aaf7afedaa1] /lib64/libc.so.6(clone+0x6d)[0x2aaf7c2d2aad] Trying to get some variables. Some pointers may be invalid and cause the dump to abort. Query (2ab054008b90): is an invalid pointer Connection ID (thread ID): 1435 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. 170210 02:39:48 mysqld_safe Number of processes running now: 0 170210 02:39:48 mysqld_safe mysqld restarted 2017-02-10 02:39:49 0 [Note] /usr/sbin/mysqld (mysqld 5.6.29) starting as process 5207 ... 2017-02-10 02:39:50 5207 [Note] Plugin 'FEDERATED' is disabled. 2017-02-10 02:39:50 5207 [Note] InnoDB: Using atomics to ref count buffer pool pages 2017-02-10 02:39:50 5207 [Note] InnoDB: The InnoDB memory heap is disabled 2017-02-10 02:39:50 5207 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins 2017-02-10 02:39:50 5207 [Note] InnoDB: Memory barrier is not used 2017-02-10 02:39:50 5207 [Note] InnoDB: Compressed tables use zlib 1.2.3 2017-02-10 02:39:50 5207 [Note] InnoDB: Using Linux native AIO 2017-02-10 02:39:50 5207 [Note] InnoDB: Using CPU crc32 instructions 2017-02-10 02:39:50 5207 [Note] InnoDB: Initializing buffer pool, size = 128.0M 2017-02-10 02:39:50 5207 [Note] InnoDB: Completed initialization of buffer pool 2017-02-10 02:39:50 5207 [Note] InnoDB: Highest supported file format is Barracuda. 2017-02-10 02:39:50 5207 [Note] InnoDB: The log sequence numbers 98028365051 and 98028365051 in ibdata files do not match the log sequence number 101119859781 in the ib_logfiles! 2017-02-10 02:39:50 5207 [Note] InnoDB: Database was not shutdown normally! 2017-02-10 02:39:50 5207 [Note] InnoDB: Starting crash recovery. 2017-02-10 02:39:50 5207 [Note] InnoDB: Reading tablespace information from the .ibd files... 2017-02-10 02:40:35 5207 [Note] InnoDB: Restoring possible half-written data pages 2017-02-10 02:40:36 5207 [Note] InnoDB: 128 rollback segment(s) are active. 2017-02-10 02:40:36 5207 [Note] InnoDB: Waiting for purge to start 2017-02-10 02:40:36 5207 [Note] InnoDB: 5.6.29 started; log sequence number 101119859781 2017-02-10 02:40:36 5207 [Note] Server hostname (bind-address): '*'; port: 3306 2017-02-10 02:40:36 5207 [Note] IPv6 is available. 2017-02-10 02:40:36 5207 [Note] - '::' resolves to '::'; 2017-02-10 02:40:36 5207 [Note] Server socket created on IP: '::'. 2017-02-10 02:40:37 5207 [Note] Event Scheduler: Loaded 1 event 2017-02-10 02:40:37 5207 [Note] /usr/sbin/mysqld: ready for connections. Version: '5.6.29' socket: '/var/lib/mysql/mysql.sock' port: 3306 MySQL Community Server (GPL) 2017-02-10 02:40:37 5207 [Note] Event Scheduler: scheduler thread started with id 1
I ran the Percona Config Wizard to generate most of the configuration file. Not entirely sure why it contains both
innodb-file-per-table but I've left it for now.
[mysqld] event_scheduler=on local-infile=0 innodb_file_per_table = 1 max_allowed_packet = 256M explicit_defaults_for_timestamp # PERCONA WIZARD START # key-buffer-size = 32M # Caches/limits tmp-table-size = 32M max-heap-table-size = 32M query-cache-type = 0 query-cache-size = 0 max-connections = 300 thread-cache-size = 50 open-files-limit = 65535 table-definition-cache = 4096 table-open-cache = 10240 innodb-flush-method = O_DIRECT innodb-log-files-in-group = 2 innodb-log-file-size = 64M innodb-flush-log-at-trx-commit = 1 innodb-file-per-table = 1 innodb-buffer-pool-size = 128M # PERCONA WIZARD END #
Also, down below's the rule for
security/limits.conf. The number is higher than
open-files-limit to give it some headroom, just in case.
mysql - nofile 81920
Any ideas on how to resolve this?