My website (Wordpress) sometimes stopped working with message "cannot connect to Datatabse".
I checked the log file of MySQL and I found the following crash-info:
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2021-01-21 0:44:59 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2021-01-21 0:44:59 0 [Note] InnoDB: Uses event mutexes
2021-01-21 0:44:59 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
2021-01-21 0:44:59 0 [Note] InnoDB: Number of pools: 1
2021-01-21 0:45:00 0 [Note] InnoDB: Using SSE2 crc32 instructions
2021-01-21 0:45:00 0 [Note] InnoDB: Initializing buffer pool, total size = 16M, instances = 1, chunk size = 16M
2021-01-21 0:45:00 0 [Note] InnoDB: Completed initialization of buffer pool
2021-01-21 0:45:00 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2021-01-21 0:45:00 0 [Note] InnoDB: Starting crash recovery from checkpoint LSN=215993122
2021-01-21 0:45:07 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2021-01-21 0:45:07 0 [Note] InnoDB: Uses event mutexes
2021-01-21 0:45:07 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
2021-01-21 0:45:07 0 [Note] InnoDB: Number of pools: 1
2021-01-21 0:45:07 0 [Note] InnoDB: Using SSE2 crc32 instructions
2021-01-21 0:45:07 0 [Note] InnoDB: Initializing buffer pool, total size = 16M, instances = 1, chunk size = 16M
2021-01-21 0:45:07 0 [Note] InnoDB: Completed initialization of buffer pool
2021-01-21 0:45:07 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2021-01-21 0:45:07 0 [Note] InnoDB: Starting crash recovery from checkpoint LSN=215993122
2021-01-21 0:50:02 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2021-01-21 0:50:02 0 [Note] InnoDB: Uses event mutexes
2021-01-21 0:50:02 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
2021-01-21 0:50:02 0 [Note] InnoDB: Number of pools: 1
2021-01-21 0:50:02 0 [Note] InnoDB: Using SSE2 crc32 instructions
2021-01-21 0:50:02 0 [Note] InnoDB: Initializing buffer pool, total size = 16M, instances = 1, chunk size = 16M
2021-01-21 0:50:02 0 [Note] InnoDB: Completed initialization of buffer pool
2021-01-21 0:50:02 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2021-01-21 0:50:02 0 [Note] InnoDB: Starting crash recovery from checkpoint LSN=215993122
2021-01-21 0:50:02 0 [Note] InnoDB: 128 out of 128 rollback segments are active.
2021-01-21 0:50:02 0 [Note] InnoDB: Removed temporary tablespace data file: "ibtmp1"
2021-01-21 0:50:02 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2021-01-21 0:50:02 0 [Note] InnoDB: Setting file '/opt/lampp/var/mysql/ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
2021-01-21 0:50:02 0 [Note] InnoDB: File '/opt/lampp/var/mysql/ibtmp1' size is now 12 MB.
2021-01-21 0:50:02 0 [Note] InnoDB: Waiting for purge to start
2021-01-21 0:50:02 0 [Note] InnoDB: 10.4.11 started; log sequence number 215993131; transaction id 221150
2021-01-21 0:50:02 0 [Note] Plugin 'FEEDBACK' is disabled.
2021-01-21 0:50:02 0 [Note] InnoDB: Loading buffer pool(s) from /opt/lampp/var/mysql/ib_buffer_pool
2021-01-21 0:50:02 0 [Note] Server socket created on IP: '::'.
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I restarted MySQL and my website worked well. The version of my MySQL is: Distrib 10.4.11-MariaDB, for Linux (x86_64) Ubuntu version 20.
This situation appeared a few times in the last month.
I searched the solution in some posts before.
I've already tried this configuration:
max_connections = 100
key_buffer = 50M
max_allowed_packet = 10M
thread_stack = 128K
table_cache = 50
but it still downed.
This is one source I've already found about my problem: MySQL keeps crashing
Does anyone encountered the same issue, and knows a fix?
I solved this question at
https://serverfault.com/questions/1051060/my-mysql-crashed-many-times-in-a-month/1051369#1051369
And I will close this question, many thanks to support me !