Mailing-List: contact users-help@httpd.apache.org; run by ezmlm
Precedence: bulk
Reply-To: users@httpd.apache.org
Received-SPF: pass (athena.apache.org: domain of manuel.vacelet@gmail.com
 designates 209.85.218.222 as permitted sender)
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=mime-version:date:message-id:subject:from:to:content-type;
        b=ZSk75hmzB0nva/uSCQ63mCOVYkzSQj8sSSEUhMqLg+bKkbTWBoVVcyY5BqaPOpKdqI
         +4hfYkiptjYnMaP9b7lJZk7l0XpfpvXKQSGu12Dk+ZE1VT7aaB4gXGZVePviuc580pAs
         ukjmVorqX8i5wGVpZczxqU/SJrQZ3IVD0Z9Jc=
MIME-Version: 1.0
Date: Tue, 16 Mar 2010 11:06:42 +0100
Message-ID: <cde570731003160306t19a46498qf02eb5972bc860e2@mail.gmail.com>
From: Manuel Vacelet <manuel.vacelet@gmail.com>
To: users@httpd.apache.org
Content-Type: text/plain; charset=ISO-8859-1
Subject: [users@httpd] mod_ldap cache and strace doesn't tell the same story

Hi all,

I'm facing a strange issue.
I have a major performance penalty on some apache related operations
(svn checkout that used to take 5mn but that suddenly takes more than
7 hours).

I'm running a standard RHEL5.3 with apache 2.2.3 (fyi the server runs
mod_php, mod_auth_mysql and some other modules too).

Thanks to strace, I identified that the httpd process that is "very
long" (the httpd process that discuss with svn client that takes hour
to complete).
The process makes a lot of operation on a file descriptor attached to
my ldap server and is regulary blocking with following syscall:
poll([{fd=3, events=POLLIN|POLLPRI|POLLERR|POLLHUP}], 1, -1 <unfinished ...>

fd3 is a socket (/proc/<pid>/fd/3) and the inode of this socket is
used to communicate with the ldap server (shown by netstat)

This is where I no longer understand what happens:
- I'm using mod_ldap so there should be a cache of all ldap info.
- ldap-status confirm that the credentials used for the svn operation
are in cache.
- The cache is far from full (2%)
- The hit ratio is close to 100%

=> Why there is an activity between my httpd process and the ldap server ?

Any help appreciate,
Cheers,
Manuel

---------------------------------------------------------------------
The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:http://httpd.apache.org/userslist.html> for more info.
To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
   "   from the digest: users-digest-unsubscribe@httpd.apache.org
For additional commands, e-mail: users-help@httpd.apache.org