Explanation on how to handle the problem that mysql innodb fails to start and cannot be restarted

The computer crashed during use. After restarting, it was found that mysql did not start successfully. Checking the error log found that there was a problem with innodb that caused mysql to fail to start.

Error log

$ mysql.server start
Starting MySQL
. ERROR! The server quit without updating PID file (/usr/local/var/mysql/fdipzonedeMacBook-Air.local.pid).22:08:37 mysqld_safe Starting mysqld daemon with databases from /usr/local/var/mysql2016-04-23 22:08:38 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).2016-04-23 22:08:38 0 [Note] /usr/local/Cellar/mysql/5.6.24/bin/mysqld (mysqld 5.6.24) starting as process 3604 ...2016-04-23 22:08:38 3604 [Warning] Setting lower_case_table_names=2 because file system for /usr/local/var/mysql/ is case insensitive2016-04-23 22:08:38 3604 [Note] Plugin 'FEDERATED' is disabled.2016-04-23 22:08:38 3604 [Note] InnoDB: Using atomics to ref count buffer pool pages2016-04-23 22:08:38 3604 [Note] InnoDB: The InnoDB memory heap is disabled2016-04-23 22:08:38 3604 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins2016-04-23 22:08:38 3604 [Note] InnoDB: Memory barrier is not used2016-04-23 22:08:38 3604 [Note] InnoDB: Compressed tables use zlib 1.2.32016-04-23 22:08:38 3604 [Note] InnoDB: Using CPU crc32 instructions2016-04-23 22:08:38 3604 [Note] InnoDB: Initializing buffer pool, size = 128.0M2016-04-23 22:08:38 3604 [Note] InnoDB: Completed initialization of buffer pool2016-04-23 22:08:38 3604 [Note] InnoDB: Highest supported file format is Barracuda.2016-04-23 22:08:38 3604 [Note] InnoDB: Log scan progressed past the checkpoint lsn 689299334402016-04-23 22:08:38 3604 [Note] InnoDB: Database was not shutdown normally!2016-04-23 22:08:38 3604 [Note] InnoDB: Starting crash recovery.2016-04-23 22:08:38 3604 [Note] InnoDB: Reading tablespace information from the .ibd files...2016-04-23 22:08:38 3604 [ERROR] InnoDB: checksum mismatch in tablespace ./test_user/user_recommend_code#P#pmax.ibd (table test_user/user_recommend_code#P#pmax)2016-04-23 22:08:38 3604 [Note] InnoDB: Page size:1024 Pages to analyze:642016-04-23 22:08:38 3604 [Note] InnoDB: Page size: 1024, Possible space_id count:02016-04-23 22:08:38 3604 [Note] InnoDB: Page size:2048 Pages to analyze:482016-04-23 22:08:38 3604 [Note] InnoDB: Page size: 2048, Possible space_id count:02016-04-23 22:08:38 3604 [Note] InnoDB: Page size:4096 Pages to analyze:242016-04-23 22:08:38 3604 [Note] InnoDB: Page size: 4096, Possible space_id count:02016-04-23 22:08:38 3604 [Note] InnoDB: Page size:8192 Pages to analyze:122016-04-23 22:08:38 3604 [Note] InnoDB: Page size: 8192, Possible space_id count:02016-04-23 22:08:38 3604 [Note] InnoDB: Page size:16384 Pages to analyze:62016-04-23 22:08:38 3604 [Note] InnoDB: VALID: space:2947354 page_no:3 page_size:163842016-04-23 22:08:38 3604 [Note] InnoDB: Page size: 16384, Possible space_id count:12016-04-23 22:08:38 3604 [Note] InnoDB: space_id:2947354, Number of pages matched: 1/1 (16384)2016-04-23 22:08:38 3604 [Note] InnoDB: Chosen space:29473542016-04-23 22:08:38 3604 [Note] InnoDB: Restoring page 0 of tablespace 29473542016-04-23 22:08:38 3604 [Warning] InnoDB: Doublewrite does not have page_no=0 of space: 29473542016-04-23 22:08:38 7fff79b9e300  InnoDB: Operating system error number 2 in a file operation.
InnoDB: The error means the system cannot find the path specified.
InnoDB: If you are installing InnoDB, remember that you must create
InnoDB: directories yourself, InnoDB does not create them.
InnoDB: Error: could not open single-table tablespace file ./test_user/user_recommend_code#P#pmax.ibdInnoDB: We do not continue the crash recovery, because the table may become
InnoDB: corrupt if we cannot apply the log records in the InnoDB log to it.
InnoDB: To fix the problem and start mysqld:
InnoDB: 1) If there is a permission problem in the file and mysqld cannot
InnoDB: open the file, you should modify the permissions.
InnoDB: 2) If the table is not needed, or you can restore it from a backup,
InnoDB: then you can remove the .ibd file, and InnoDB will do a normal
InnoDB: crash recovery and ignore that table.
InnoDB: 3) If the file system or the disk is broken, and you cannot remove
InnoDB: the .ibd file, you can set innodb_force_recovery > 0 in my.cnf
InnoDB: and force InnoDB to continue crash recovery here.

Solution

1. If the data is not important or already has a backup, you only need to restore mysql startup

Enter the mysql directory, generally Is: /usr/local/var/mysql/
Delete ib_logfile*
Delete ibdata*
Delete all database physical directories (for example, if the database is test_db, execute rm -rf test_db)
Restart mysql
Rebuild the database or use backup coverage

2. If the data is very important and there is no backup

You can use the innodb_force_recovery parameter to make mysqld skip the recovery step and start mysqld, export the data and rebuild the database.

innodb_force_recovery Can be set to 1-6, the larger number includes the impact of all previous numbers

1. (SRV_FORCE_IGNORE_CORRUPT): Ignore the detected corruption Page.

2. (SRV_FORCE_NO_BACKGROUND): Prevent the main thread from running. If the main thread needs to perform a full purge operation, it will cause a crash.

3. (SRV_FORCE_NO_TRX_UNDO): Do not perform transaction rollback operation.

4. (SRV_FORCE_NO_IBUF_MERGE): Do not perform the merge operation of the insert buffer.

5. (SRV_FORCE_NO_UNDO_LOG_SCAN): Without checking the redo log, the InnoDB storage engine will treat uncommitted transactions as committed.

6. (SRV_FORCE_NO_LOG_REDO): Do not perform rollforward operation.

Add
innodb_force_recovery = 6
innodb_purge_thread = 0

Restart in my.cnf (windows is my.ini) mysql

At this time, you can only perform select, create, drop operations, but you cannot perform insert, update, delete operations
Perform logical export. After completion, it will innodb_force_recovery=0, innodb_purge_threads=1, then rebuild the database, and finally re-import the exported data

This article explains how to handle the failure of mysql innodb to restart and more related content Please pay attention to php Chinese website.

Related recommendations:

Explain how PHP obtains relevant content on a specified date

Detailed explanation of how PHP generates a unique RequestID class

How to check the database table capacity through MySQL

The above is the detailed content of Explanation on how to handle the problem that mysql innodb fails to start and cannot be restarted. For more information, please follow other related articles on the PHP Chinese website!