On Tue, Mar 16, 2010 at 11:06 AM, Manuel Vacelet
<manuel.vace...@gmail.com> wrote:
> 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 ?I think I have an answer to this question: In some cases, the apache process (I'm running prefork) doesn't use mod_ldap cache. I made a test: In parallel of a very slow checkout, I ran another one. The second checkout was running as normal rate. A couple of strace on the server later, it appears that, the apache process that server the second checkout never talk to the ldap server So the new question is: Why 2 apache processes forked from the same root could behave so differently ? 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-unsubscr...@httpd.apache.org " from the digest: users-digest-unsubscr...@httpd.apache.org For additional commands, e-mail: users-h...@httpd.apache.org
