Hi, It was the problem with the Apache::DBI.
We were loading this Apache::DBI module along with other Perl modules (used for the global variables). These Perl modules access the database. So when the apache starts the parent daemon, it already has connections to the database(created by these perlmodules). And we used httpd2-prefork, when apache creates forked processes these connections (from Apache::DBI Connections) are also forked. And in this way the same database connections are shared between the forked processes and they are trying to access the session data (at the same time) creating deadlocks. We removed the preloading of modules in the apache parent daemon (from httpd.conf) and it solved the problem. So now I guess the Database connection pool (Apache::DBI) is created for each forked process of the Apache. Thanks, Vijaya. >-----Original Message----- >From: Gerald Richter [mailto:[EMAIL PROTECTED] >Sent: Saturday, November 15, 2003 2:59 PM >To: Vijaya Dasari; [EMAIL PROTECTED] >Subject: Re: Locks on sessions database > >Vijaya Dasari wrote: >> Hi, >> >> We have problem with locking of rows in the session database. We are >> using postgres as the Store. >> > >How does your Embperl session configuration look like? > >Gerald > > >> Configuration of the system is Apache 2.0.47 + Embperl 2.0b9 + >> mod_perl 1.99_09 >> >> I tried using MySQL as Store, but still the same problem. >> >>> 40 | sessions | localhost | sessions | Query | 313 | User lock | >> SELECT GET_LOCK('Apache-Session-30fac6623276e16798300d56c8de3989', >> 3600) >>> >>> 41 | sessions | localhost | sessions | Query | 266 | User lock | >> SELECT GET_LOCK('Apache-Session-30fac6623276e16798300d56c8de3989', >> 3600) >>> >> >> Two processes are trying to acquire a lock ( seems simultaneously ) on >> the same session id (row). >> We did not had this problem with Apache 1.3 >> >> I tried to use Semaphore combinations, but has the same problem. >> >> Thanks in advance, >> Vijaya. >> >> >> ------------------------------------------- >> Vijaya Krishna Dasari >> Heinz Nixdorf Zentrum fuer Informationsmanagement in der >> Max-Planck-Gesellschaft (ZIM) >> Phone: +49-89-3299-1557 >> Fax: +49-89-3299-1555 >> E-Mail: [EMAIL PROTECTED] >> http: www.zim.mpg.de >> Boltzmannstrasse 2/ITER Gebaeude >> D- 85748 Garching >> GERMANY >> ------------------------------------------- >> >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: [EMAIL PROTECTED] >> For additional commands, e-mail: [EMAIL PROTECTED] > >-------------------------------------------------------------- >Gerald Richter ecos electronic communication services gmbh >IT-Securityl�sungen * dynamische Webapplikationen * Consulting > >Post: Tulpenstrasse 5 D-55276 Dienheim b. Mainz >E-Mail: [EMAIL PROTECTED] Voice: +49 6133 939-122 >WWW: http://www.ecos.de/ Fax: +49 6133 939-333 >-------------------------------------------------------------- >| >| ECOS BB-5000 Firewall- und IT-Security Appliance: www.bb-5000.info >| >+------------------------------------------------------------- --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
