Re: PHP web clusters and session information

["markw-4" <user=5@nabble.blu.org>]

 > Date: Thu, 15 May 2008 19:52:20 -0500 
> From: <[hidden email]> 
> Subject: Re: PHP web clusters and session information 
> To: ref <[hidden email]> 
> Cc: L-blu <[hidden email]> 
> Message-ID: <ff7a2c351635d134a265c7840e586bbd@localhost> 
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> 
> I concur with Richard that the simplest method I have found is to simply 
> change session.save_path in your php.ini file to an NFS mount.  In my own 
> benchmarks, under a moderate simulated web load with hosts mounted against 
> the NFS share this performed much better than when trying to use a rather 
> simple method of storing it in a MySQL back-end (there is of course a lot 
> of room for optimization on the later which I did not consider at the time 
> as was looking for simplicity).  This seemed to peak at around 6 
> concurrent 
> web hosts against the NFS mount point, though I only had 7 physical hosts 
> to play with and so don't have insight into the drop-off beyond 7.  I can 
> probably dig out my project paper detailing the specs under this testing 
> if 
> you think it might be of benefit to you. 
> 
> In theory if you used iSCSI on the back-end for the shared storage with a 
> clustered file system (I am thinking GFS, as I don't believe OCFS is 
> designed to perform well with the way PHP stores the session files) you 
> could scale this well beyond 6 hosts without suffering any performance 
> degradation. 
> 
> If you have the luxury of a BigIP, then you can start to do clever things 
> such as using embedded cookies to leverage sticky sessions in pinning 
> someone to a specific host in the cluster, etc.  Of course the expense of 
> such puts out of reach of most open source projects and hobbyists.