mysql - 阿里云服务器数据库自动关闭，怎么解决

Question

网站运行一段时间，突然连不上数据库了，重启数据库，网站又正常了！请问是什么原因呢？
以下是错误日子内容：

160423 00:45:59 mysqld_safe Number of processes running now: 0
160423 00:45:59 mysqld_safe mysqld restarted
160423  0:46:10  InnoDB: Initializing buffer pool, size = 8.0M
160423  0:46:10  InnoDB: Completed initialization of buffer pool
InnoDB: Error: pthread_create returned 11
160423 00:46:11 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
160423 02:19:52 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
160423  2:19:52  InnoDB: Initializing buffer pool, size = 8.0M
160423  2:19:52  InnoDB: Completed initialization of buffer pool
InnoDB: Log scan progressed past the checkpoint lsn 0 4483638
160423  2:19:52  InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
InnoDB: Doing recovery: scanned up to log sequence number 0 4483853
160423  2:19:52  InnoDB: Starting an apply batch of log records to the database...
InnoDB: Progress in percents: 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 
InnoDB: Apply batch completed
160423  2:19:53  InnoDB: Started; log sequence number 0 4483853
160423  2:19:53 [Note] Event Scheduler: Loaded 0 events
160423  2:19:53 [Note] /usr/libexec/mysqld: ready for connections.
Version: '5.1.73'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  Source distribution
160423 22:23:09 mysqld_safe Number of processes running now: 0
160423 22:23:09 mysqld_safe mysqld restarted
160423 22:23:09  InnoDB: Initializing buffer pool, size = 8.0M
160423 22:23:09  InnoDB: Completed initialization of buffer pool
InnoDB: The log sequence number in ibdata files does not match
InnoDB: the log sequence number in the ib_logfiles!
160423 22:23:09  InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
160423 22:23:10  InnoDB: Started; log sequence number 0 4484975
160423 22:23:10 [Note] Event Scheduler: Loaded 0 events
160423 22:23:10 [Note] /usr/libexec/mysqld: ready for connections.
Version: '5.1.73'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  Source distribution
160423 22:23:20 mysqld_safe Number of processes running now: 0
160423 22:23:20 mysqld_safe mysqld restarted
160423 22:24:45 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
160423 23:39:13 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
160423 23:39:13  InnoDB: Initializing buffer pool, size = 8.0M
160423 23:39:13  InnoDB: Completed initialization of buffer pool
InnoDB: The log sequence number in ibdata files does not match
InnoDB: the log sequence number in the ib_logfiles!
160423 23:39:13  InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
160423 23:39:14  InnoDB: Started; log sequence number 0 4484975
160423 23:39:14 [Note] Event Scheduler: Loaded 0 events
160423 23:39:14 [Note] /usr/libexec/mysqld: ready for connections.
Version: '5.1.73'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  Source distribution

Answer 1

From the log, the error reported is this InnoDB: Error: pthread_create returned 11, which is stackoverflow, and the stack size limit needs to be increased.

ulimit -s Check the stack size limit. On my personal PC it is 8192 (KB), ulimit -s n sets the stack size limit, ulimit -s unlimited sets an unlimited limit (not recommended, but can be used to verify whether this is the reason).

Settings only take effect for the current session. Persistence can add settings to /etc/profile.

Answer 2

If you don’t communicate with the database for a long time, it will be automatically disconnected. Try changing the database connection to stay connected