Bug#224495: libc6: Regex Performance Kills OpenLDAP
Package: libc6
Version: 2.3.2.ds1-10
Severity: normal
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.
Thanks in advance!
Tony Awtrey
-- System Information:
Debian Release: testing/unstable
Architecture: i386
Kernel: Linux laptop03 2.4.22 #1 Fri Oct 17 16:25:04 EDT 2003 i686
Locale: LANG=C, LC_CTYPE=C
Versions of packages libc6 depends on:
ii libdb1-compat 2.1.3-7 The Berkeley database routines [gl
-- no debconf information
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