Note that before starting mysqld with the general query log enabled, you should check all your tables with myisamchk. See Chapter 5, MySQL Server Administration.
If mysqld dies or hangs, you should start mysqld with the general query log enabled. See Section 5.4.3, “The General Query Log”. When mysqld dies again, you can examine the end of the log file for the query that killed mysqld.
If you use the default general query log file, the log is stored
in the database directory as
most cases it is the last query in the log file that killed
mysqld, but if possible you should verify
this by restarting mysqld and executing the
found query from the mysql command-line
tools. If this works, you should also test all complicated
queries that did not complete.
You can also try the command
EXPLAIN on all
SELECT statements that takes a
long time to ensure that mysqld is using
indexes properly. See Section 13.8.2, “EXPLAIN Statement”.
You can find the queries that take a long time to execute by starting mysqld with the slow query log enabled. See Section 5.4.5, “The Slow Query Log”.
If you find the text
mysqld restarted in the
error log (normally a file named
you probably have found a query that causes
mysqld to fail. If this happens, you should
check all your tables with myisamchk (see
Chapter 5, MySQL Server Administration), and test the queries
in the MySQL log files to see whether one fails. If you find
such a query, try first upgrading to the newest MySQL version.
If this does not help, report a bug, see
Section 1.5, “How to Report Bugs or Problems”.
If you have started mysqld with the
variable set, MySQL automatically checks and tries to repair
MyISAM tables if they are marked as 'not
closed properly' or 'crashed'. If this happens, MySQL writes an
entry in the
'Warning: Checking table ...' which is
Warning: Repairing table if the
table needs to be repaired. If you get a lot of these errors,
without mysqld having died unexpectedly just
before, then something is wrong and needs to be investigated
further. See Section 5.1.7, “Server Command Options”.
When the server detects
corruption, it writes additional information to the error log,
such as the name and line number of the source file, and the
list of threads accessing the table. Example:
error from thread_id=1, mi_dynrec.c:368. This is
useful information to include in bug reports.
It is not a good sign if mysqld did die
unexpectedly, but in this case, you should not investigate the
Checking table... messages, but instead try
to find out why mysqld died.