Re: mysql process 99.9 percent

[Greg 'groggy' Lehey]

On Monday, 26 September 2005 at  9:29:32 +0200, mark carson wrote:
> Joeffrey Betita wrote:
>> hi
>>  do you have any idea why the mysql process is 99.9 percent? when i click
>> one hyperlink it takes more than 1 minute to load the page. thank you very
>> much.
>
> Most readers in this list expect OS and MySQL server information etc
> before responding.
>
> In our experience this is usually caused by poor SQL query construction
> e.g. large result set e.g. x million rows and/or index choice, database
> table design and/or MySQL server setup.
>
> Turn-on logging, rerun selected queries with and without the explain
> syntax, look at the MySQL administrator process list to see which query
> is the problem whilst the CPU is 99.9 %.

FWIW, we have at least one case where the server gets itself into a
loop for no obvious reason.  See http://bugs.mysql.com/bug.php?id=414
and http://bugs.mysql.com/bug.php?id=12061 for more details.  If the
problem at hand is related to this bug, I'd be very interested in
hearing from you, especially if you can reproduce the problem easily.

Note that the submitter of the second-mentioned bug report has done a
very good job of describing his problem.  Only reports of similar
quality would be of much help.

If this isn't your (Joeffrey's) problem, it might give you an idea of
the kind of information we're looking for.

Greg
--
Greg Lehey, Senior Software Engineer
MySQL AB, http://www.mysql.com/
Echunga, South Australia
See complete headers for address and phone numbers.

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