MySQL Manual
E Porting to Other Systems
- E.1 Debugging a MySQL server
- E.1.1 Compiling MYSQL for Debugging
- E.1.2 Creating Trace Files
- E.1.3 Debugging mysqld under gdb
- E.1.4 Using a Stack Trace
- E.1.5 Using Log Files to Find Cause of Errors in mysqld
- E.1.6 Making a Test Case If You Experience Table Corruption
E.1.6 Making a Test Case If You Experience Table Corruption
If you get corrupted tables or if mysqld always fails after some
update commands, you can test if this bug is reproducible by doing the
following:
-
Take down the MySQL daemon (with
mysqladmin shutdown). - Make a backup of the tables (to guard against the very unlikely case that the repair will do something bad).
-
Check all tables with
myisamchk -s database/*.MYI. Repair any wrong tables withmyisamchk -r database/table.MYI. - Make a second backup of the tables.
- Remove (or move away) any old log files from the MySQL data directory if you need more space.
-
Start
mysqldwith--log-bin. See section 4.9.4 The Binary Log. If you want to find a query that crashesmysqld, you should use--log --log-bin. -
When you have gotten a crashed table, stop the
mysqld server. - Restore the backup.
-
Restart the
mysqldserver without--log-bin -
Re-execute the commands with
mysqlbinlog update-log-file | mysql. The update log is saved in the MySQL database directory with the namehostname-bin.#. -
If the tables are corrupted again or you can get
mysqldto die with the above command, you have found reproducible bug that should be easy to fix! FTP the tables and the binary log to ftp://support.mysql.com/pub/mysql/secret/ and enter it into our bugs system at http://bugs.mysql.com/. If you are a support customer), you can also support@mysql.com to alert the MySQL team about the problem and have it fixed as soon as possible.
You can also use the script mysql_find_rows to just execute some of the
update statements if you want to narrow down the problem.
