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Postby josh » Sat Nov 01, 2003 8:41 pm

Do any of you have much experience with mysql? We're running v 3.23 -- this was part of the standard buildout of the ISP who set up the server, and I'm thinking they believe it to be stable.

I'm seeing the big tables get corrupted more and more -- I have to run the myisamchk repair tool to fix them. So far they've been recoverable, but it is worrisome, and occasionally causes a crash (btw, spameater now dies with a TEMPFAIL error code for sendmail, so it's treated as a temporary failure).

The "big" tables aren't that big -- Emails has about 390k records, and Users has about 43k records. They do get positively slammed with updates though.

Any tips on stabilizing this? Upgrading? Switching (PostGres?)?
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I am researching that

Postby SysKoll » Sun Nov 02, 2003 3:59 am

I am researching that. I wasn't aware of a MySQL table corruption issue. That's bad. Short of switching to DB2, there must be a way to get a stable DB that can withstand massive updates. PostGreSQL looks like a possibility.
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Test case procedure for MySQL

Postby SysKoll » Sun Nov 02, 2003 9:02 pm

Josh,

The MySQL developers have a nice little doc outlining how to create a test case and report a bug. It requires making a copy of the tables. Since you need to stop mysqld to run the myisamchk program, maybe you can use that opportunity to make a copy of the corrupt table and run that problem isolation procedure? (You do stop the mysqld daemon when you run the repair utility, right?)

http://www.mysql.com/doc/en/Reproduceable_test_case.html
Last edited by SysKoll on Sun Nov 02, 2003 9:31 pm, edited 3 times in total.
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What error does myisamchk give you?

Postby SysKoll » Sun Nov 02, 2003 9:06 pm

Josh,

I forgot to ask the most obvious question: When you run myisamchk, what messages do you see? What kind of error do you get?

Please let us know where the running code is on the server so we can take a look at it.
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Postby josh » Wed Nov 05, 2003 2:12 am

Sorry about the dead air recently -- slammed at the day job again.

I didn't record the myisamchk output last time, but I do have this from the log:

read_const: Got error 127 when reading table ./XXXXX/Users

(where XXXXX is the name of the database). Not real specific, I know.
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Postby maratheamit » Fri Feb 20, 2004 4:15 pm

Josh, how is mysql holding up these days? Do you still see table corruption on a regular basis?
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Postby josh » Fri Feb 20, 2004 5:28 pm

no - I haven't seen the problem for awhile...

I'm wondering: awhile back I had tried to set up a test version of the website using Apache::Registry with persistent database connections. I *think* I probably compiled the apached mod against the wrong set of mysql libs. I know that whenever I accessed the site, the test database went to hell. Maybe that was what behind the problems we saw earlier? Don't know.
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