InnoDB Testing, Discussion Results

[Max Kanat-Alexander]

	I did some performance testing of InnoDB vs. MyISAM on Bugzilla, using
my load-testing script from bug 347520.

	As far as I can tell, under heavy load there's little difference
between the speed of MyISAM and the speed of InnoDB. This is probably
because we still use whole-table locks in the Bugzilla code.

	Looking into it (using MySQL's slow query log), I did find that under
high numbers of simultaneous users, certain buglist searches do spend a
lot of time waiting for WRITE locks on the database to release. That is,
every time somebody uses process_bug or post_bug, it's going to slow
down queries. If we were under transactions, this would end. So InnoDB
probably is a big plus in that area.

	I've read very good things about the stability of InnoDB, and for our
uses its speed seems entirely comparable to the speed of MyISAM.
Overall, I see more benefit in moving to InnoDB than I see problems.

	From our discussion I've learned some valuable things, and I'm sure
that many of them would be of interest to our users, and should be
mentioned in the Release Notes. And it's true that we will have certain
hurdles to jump in making our InnoDB support perfect, but we always have
hurdles to jump when making improvements.

	Also, for those interested, here's the bug with the patch that actually
changes Bugzilla to use InnoDB:

	https://bugzilla.mozilla.org/show_bug.cgi?id=347475

	I'm going to wait a day or two, and then probably commit it, unless the
approvers object, or unless somebody explains a very definite reason
that moving to InnoDB would cause more harm than good for the majority
of our users.

	-Max
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