Bug#224495: libc6: Regex Performance Kills OpenLDAP
tags 224495 fixed-upstream
thanks
At Fri, 19 Dec 2003 08:54:40 -0500,
Anthony L. Awtrey <tony@idealcorp.com> wrote:
> I've got a repeatable problem with OpenLDAP search performance which
> appears to be related to the version of glibc under Debian. I posted
> to the OpenLDAP list and got a response from Masato Taruishi indicating
> that the problem we found is related to changes in the multibyte regex
> function. (See list OpenLDAP-Software thread "OpenLDAP performance and
> Glibc under Debian")
>
> My company is preparing for the eventual release of the new Debian
> stable and we are doing some preliminary testing of our key
> infrastructure on the testing/unstable release which includes OpenLDAP.
> One of our tests noted that a substring search of our shared contact
> list which used to take just under a second, now takes over 10 seconds
> to complete.
>
> If you build a pinned Debian box you can switch back and forth between
> the different versions of libc6 easily enough to test the issue. I wrote
> an automated LDIF data generator to populate an LDAP repository with
> fake contact data to demonstrate our issue. The tar ball with the files
> and more detailed problem description is available here:
>
> ftp://ftp.idealcorp.com/pub/ldap-test.tgz
>
> Logs from slapd during the OpenLDAP search running on the two different
> libc6 versions are available here:
>
> ftp://ftp.idealcorp.com/pub/libc-2.2.5.log.gz
> ftp://ftp.idealcorp.com/pub/libc-2.3.2.log.gz
>
> The tarball includes slapd configs and our schemas for both OpenLDAP 2.0
> and 2.1 as well as an automated contact list LDIF generator that can be
> used to build data to test the performance against. There is also a timed
> search script script that can be used to create the same kind of search
> we use in our web-based contact application that first identified the
> problem.
>
> I just want to make it easy to see the problem so it can be fixed.
Regex function in the latest glibc speeds up. However,
unfortunatelly, it's something large modification, so it's hardly
changed until sarge will be released. If we update regex function
(glibc 2.3.3 and so on), please retest it.
Regards,
-- gotom
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