Comments on: Some Tuning Tips For Apache Mod_Cache (mod_disk_cache) http://www.philchen.com/2009/02/09/some-tuning-tips-for-apache-mod_cache-mod_disk_cache Phil Chen Mon, 06 Sep 2010 23:24:47 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: Velocity: The Ultimate Web Performance and Operations Conference | Phil Chen http://www.philchen.com/2009/02/09/some-tuning-tips-for-apache-mod_cache-mod_disk_cache/comment-page-1#comment-2612 Velocity: The Ultimate Web Performance and Operations Conference | Phil Chen Fri, 16 Jul 2010 16:45:18 +0000 http://www.philchen.com/?p=82#comment-2612 [...] Kasindorf (dormando) and, after discussing file-system optimization, proceeded to implement some file-system tuning which, in turn, helped increase our Apache Web Servers running mod_disk_cache efficiency by 3 [...] [...] Kasindorf (dormando) and, after discussing file-system optimization, proceeded to implement some file-system tuning which, in turn, helped increase our Apache Web Servers running mod_disk_cache efficiency by 3 [...]

]]> By: Vincenzo D'Amore http://www.philchen.com/2009/02/09/some-tuning-tips-for-apache-mod_cache-mod_disk_cache/comment-page-1#comment-2412 Vincenzo D'Amore Wed, 09 Jun 2010 11:11:59 +0000 http://www.philchen.com/?p=82#comment-2412 Hello, I have mod_cache used in conjunction with mod_cband. But when we enable mod_cache mod_cband are overridden. Any idea in order to define the order of execution? Best regards, Vincenzo D'Amore Hello,

I have mod_cache used in conjunction with mod_cband.
But when we enable mod_cache mod_cband are overridden.
Any idea in order to define the order of execution?

Best regards,
Vincenzo D’Amore

]]> By: randy melder http://www.philchen.com/2009/02/09/some-tuning-tips-for-apache-mod_cache-mod_disk_cache/comment-page-1#comment-2269 randy melder Wed, 05 May 2010 17:43:52 +0000 http://www.philchen.com/?p=82#comment-2269 Nice job, Phil. Simple change with a big impact. I'm seeing lots of hits and first person accounts have proven this a valuable config change. You're the man. Nice job, Phil. Simple change with a big impact. I’m seeing lots of hits and first person accounts have proven this a valuable config change. You’re the man.

]]> By: Phil Chen http://www.philchen.com/2009/02/09/some-tuning-tips-for-apache-mod_cache-mod_disk_cache/comment-page-1#comment-2166 Phil Chen Wed, 27 Jan 2010 05:04:50 +0000 http://www.philchen.com/?p=82#comment-2166 Doug in Paia, Thanks for posting your results from your Apache ab tests. Looks like you are testing the theory on disk caching versus caching in RAM. Apache ab test is a good way to go about it however I think the variable is that of your disk speed as well as your EXT3 settings which maybe slowing your disk results up. To be honest the performance difference between disk caching and mem caching in this instance is not very large my results regarding this aspect were different by just 0.2. The big factor is the EXT3 settings I outline when using disk caching that you get the bigger bang. I chose disk caching because it allows for a lot more cache storage versus that in the maximum amount of RAM in your server. So for my situation disk allowed me a lot more cache and the steps above gave me the performance I needed. Thats just my view on it, hope that helps :) Doug in Paia,

Thanks for posting your results from your Apache ab tests. Looks like you are testing the theory on disk caching versus caching in RAM. Apache ab test is a good way to go about it however I think the variable is that of your disk speed as well as your EXT3 settings which maybe slowing your disk results up.

To be honest the performance difference between disk caching and mem caching in this instance is not very large my results regarding this aspect were different by just 0.2. The big factor is the EXT3 settings I outline when using disk caching that you get the bigger bang. I chose disk caching because it allows for a lot more cache storage versus that in the maximum amount of RAM in your server. So for my situation disk allowed me a lot more cache and the steps above gave me the performance I needed.

Thats just my view on it, hope that helps :)

]]> By: Doug in Paia http://www.philchen.com/2009/02/09/some-tuning-tips-for-apache-mod_cache-mod_disk_cache/comment-page-1#comment-2162 Doug in Paia Sat, 23 Jan 2010 23:13:15 +0000 http://www.philchen.com/?p=82#comment-2162 Hi Phil, Thanks for the great post, this really got me jump started. I am running a small site with cakePHP. We host on a couple of CentOS 5 boxes, 64 bit on both VPS and dedicated. I am running apache ab against our VPS instances and I tried your settings. As well I tried a vanilla mem cache. I came up with the results below. The summary is that I didn't get any performance boost for test on two sample pages. In the first instance, disk caching is slower by a factor of 3, memory caching is about the same. In the second test case, memory caching or not seems to be the same. Is apache ab a valid test? Any thoughts about what I might be doing wrong. Thanks, --Doug n1000c10ModCache_new-releases.html:Requests per second:2.65 n1000c10ModMemCache_new-releases.html:Requests per second:8.59 n1000c10new-releases.html:Requests per second:8.89 << no cache enabled n1000c10ModCache_moon-blue-ray.html:Requests per second:1.14 n1000c10ModCacheR1_moon-blue-ray.html:Requests per second:1.20 n1000c10ModCacheR1_moon-blue-ray_try2.html:Requests per second:1.23 n1000c10ModMemCache_moon-blue-ray.html:Requests per second:1.22 n1000c10moon-blue-ray.html:Requests per second:1.25 << no cache enabled Hi Phil, Thanks for the great post, this really got me jump started. I am running a small site with cakePHP. We host on a couple of CentOS 5 boxes, 64 bit on both VPS and dedicated. I am running apache ab against our VPS instances and I tried your settings. As well I tried a vanilla mem cache. I came up with the results below. The summary is that I didn’t get any performance boost for test on two sample pages. In the first instance, disk caching is slower by a factor of 3, memory caching is about the same. In the second test case, memory caching or not seems to be the same. Is apache ab a valid test? Any thoughts about what I might be doing wrong. Thanks, –Doug

n1000c10ModCache_new-releases.html:Requests per second:2.65
n1000c10ModMemCache_new-releases.html:Requests per second:8.59
n1000c10new-releases.html:Requests per second:8.89 << no cache enabled

n1000c10ModCache_moon-blue-ray.html:Requests per second:1.14
n1000c10ModCacheR1_moon-blue-ray.html:Requests per second:1.20
n1000c10ModCacheR1_moon-blue-ray_try2.html:Requests per second:1.23
n1000c10ModMemCache_moon-blue-ray.html:Requests per second:1.22
n1000c10moon-blue-ray.html:Requests per second:1.25 << no cache enabled

]]> By: akira http://www.philchen.com/2009/02/09/some-tuning-tips-for-apache-mod_cache-mod_disk_cache/comment-page-1#comment-2149 akira Wed, 25 Nov 2009 20:09:52 +0000 http://www.philchen.com/?p=82#comment-2149 Did you try tmpfs as disk_cache? Did you try tmpfs as disk_cache?

]]> By: Phil Chen http://www.philchen.com/2009/02/09/some-tuning-tips-for-apache-mod_cache-mod_disk_cache/comment-page-1#comment-2126 Phil Chen Sun, 09 Aug 2009 23:37:30 +0000 http://www.philchen.com/?p=82#comment-2126 Upon doing some research it looks like you are correct that noatime is a superset of nodiratime which is a subset. Thanks for the input Lamah. Upon doing some research it looks like you are correct that noatime is a superset of nodiratime which is a subset. Thanks for the input Lamah.

]]> By: Lamah http://www.philchen.com/2009/02/09/some-tuning-tips-for-apache-mod_cache-mod_disk_cache/comment-page-1#comment-2125 Lamah Sun, 09 Aug 2009 11:20:29 +0000 http://www.philchen.com/?p=82#comment-2125 Hi there, nodiratime is not actually required (it is implied as part of noatime, which applies to all files, including directories.) Hi there, nodiratime is not actually required (it is implied as part of noatime, which applies to all files, including directories.)

]]> By: Phil Chen http://www.philchen.com/2009/02/09/some-tuning-tips-for-apache-mod_cache-mod_disk_cache/comment-page-1#comment-2116 Phil Chen Wed, 01 Jul 2009 01:00:23 +0000 http://www.philchen.com/?p=82#comment-2116 Hi Frederic, I currently have Apache mod_cache using disk caching running on a cluster of 9 servers sitting behind some Foundry Load Balancers and it works fine. It more depends on your application in regards to how the Load Balancer would effect the situation. Hope that answers your question. Hi Frederic,

I currently have Apache mod_cache using disk caching running on a cluster of 9 servers sitting behind some Foundry Load Balancers and it works fine. It more depends on your application in regards to how the Load Balancer would effect the situation. Hope that answers your question.

]]> By: frederic sidler http://www.philchen.com/2009/02/09/some-tuning-tips-for-apache-mod_cache-mod_disk_cache/comment-page-1#comment-2111 frederic sidler Mon, 29 Jun 2009 13:38:11 +0000 http://www.philchen.com/?p=82#comment-2111 I have a load balancer in front of my app server. Would mod_cache, mod_disk_cache also be the solution if the load balancer balances the load to many servers behind it. I have a load balancer in front of my app server. Would mod_cache, mod_disk_cache also be the solution if the load balancer balances the load to many servers behind it.

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