[Pkg-openldap-devel] Bug#660917: fileno ulimit regression: slapd rejects connections approaching 1024 simultaneous connections

[Steve Langasek]

On Wed, Feb 22, 2012 at 12:48:15PM -0800, Chris Hiestand wrote:

> I believe in previous versions of slapd there was a line in
> /etc/init.d/slapd setting the ulimit -n higher.  However this is not
> present in the current version.

No, there never was such a line.  Bug #378261 refers to a locally-modified
/etc/init.d/slapd with a raised ulimit.

> The original bug was reported in #378261. I am re-using the perl script in
> that bug report to reproduce the problem.

That script tries to open 4096 connections to the server.  Well, of course
if the server has the default ulimit of 1024, and you try to open 4096
simultaneous connections, it's going to fail; but I don't think there's any
bug in slapd here.  4096 is just as arbitrary a cut-off point as 1024 is,
1024 is more than enough for most slapd servers, and I don't think there's
any good reason to diverge from the system default for slapd in particular.
Users who require a higher connection limit can continue to tweak this in
the init script.

> A vanilla squeeze install of slapd (amd64) will max out before 1024
> connections, and the nofiles limit is 1024 (verified in /proc/$pid/limits)

Yes, that's to be expected.  This is the limit of all files the process has
open, not the limit of connections.

-- 
Steve Langasek                   Give me a lever long enough and a Free OS
Debian Developer                   to set it on, and I can move the world.
Ubuntu Developer                                    http://www.debian.org/
slangasek at ubuntu.com                                     vorlon at debian.org
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