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MySQL 5.7 Reference Manual  /  The InnoDB Storage Engine  /  InnoDB Troubleshooting

14.18 InnoDB Troubleshooting

The following general guidelines apply to troubleshooting InnoDB problems:

  • When an operation fails or you suspect a bug, look at the MySQL server error log (see Section 5.2.2, “The Error Log”).

  • If the failure is related to a deadlock, run with the innodb_print_all_deadlocks option enabled so that details about each InnoDB deadlock are printed to the MySQL server error log.

  • Issues relating to the InnoDB data dictionary include failed CREATE TABLE statements (orphaned table files), inability to open .InnoDB files, and system cannot find the path specified errors. For information about these sorts of problems and errors, see Section 14.18.3, “Troubleshooting InnoDB Data Dictionary Operations”.

  • When troubleshooting, it is usually best to run the MySQL server from the command prompt, rather than through mysqld_safe or as a Windows service. You can then see what mysqld prints to the console, and so have a better grasp of what is going on. On Windows, start mysqld with the --console option to direct the output to the console window.

  • Enable the InnoDB Monitors to obtain information about a problem (see Section 14.14, “InnoDB Monitors”). If the problem is performance-related, or your server appears to be hung, you should enable the standard Monitor to print information about the internal state of InnoDB. If the problem is with locks, enable the Lock Monitor. If the problem is in creation of tables or other data dictionary operations, enable the Table Monitor to print the contents of the InnoDB internal data dictionary. To see tablespace information enable the Tablespace Monitor.

    InnoDB temporarily enables standard InnoDB Monitor output under the following conditions:

    • A long semaphore wait

    • InnoDB cannot find free blocks in the buffer pool

    • Over 67% of the buffer pool is occupied by lock heaps or the adaptive hash index

  • If you suspect that a table is corrupt, run CHECK TABLE on that table.

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User Comments
  Posted by Chris Murphy on July 14, 2014
If you are getting:
InnoDB: Error: Table "mysql"."innodb_table_stats" not found.
in the .err file for five tables (innodb_table_stats plus another four) then read and run the .sql mentioned at this link:
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