Hi all,I am using Apache 2.2.9 (built from source) on Debian Lenny to run a fairly large community LAMP (Perl, MySQL) site. I use the proxy and cache of Apache to improve site performance - I have a front end proxy build and a back-end mod_perl build. I have been using this setup for years successfully, but most of that time was using Apache 1.3, with mod_access and mod_deflate from Igor Sysoev. Since moving to Apache 2.2, I am using the stock caching.
I am finding that the cache directories that mod_cache builds are very large, and take a long time to traverse under ext2. There is currently about 10 GB under the cache according to du, and it took 162 minutes just to tell me that. I'm using three levels of directory. Htcacheclean also takes a long time to process this if I run it from cron nightly, during which time I see a huge spike in iowait on the server. If I run htcacheclean in daemon mode, using the -n (nice) option, then it doesn't seem to be able to keep up, the cache just creeps up in size.
So what I'm observing is that at least part of the problem appears to be that the directory structure is just very, very big and takes a long time to traverse, even for basic system functions like du.
This leads to my main question, which is this: Would a different filesystem, perhaps reiserfs, be better for the cache? I have never used reiser before, but from reputation it seems to be designed for handling many small files efficiently. I wonder if it would be any easier for my system to traverse the directory and maintain the cache if it was under reiser rather than ext.
Has anybody any experience that would confirm or deny this theory? Anybody have any advice for making cache management a little more, well, manageable?
I have a quad core server (AMD Opteron 265), with four 10k SCSI drives set up in RAID0 (yeah I know it's risky, but everything is backed up immediately via mysql replication, and I need the space and performance).
Thanks! Neil --------------------------------------------------------------------- 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@xxxxxxxxxxxxxxxx " from the digest: users-digest-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx
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