# Apache + Mongrel Cluster Caching (cross server) **URL:** \ **Category:** Rails\ **Created:** [March 21, 2007, 10:05pm UTC](https://www.ruby-forum.com/t/apache-mongrel-cluster-caching-cross-server/89652 "2007-03-21T22:05:49Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![justin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/3ab097/32.png) [@justin](https://www.ruby-forum.com/u/justin)\ **Post date:** [March 21, 2007, 10:05pm UTC](https://www.ruby-forum.com/t/apache-mongrel-cluster-caching-cross-server/89652/1 "2007-03-21T22:05:49Z")
Has anyone here successfully setup a system to take advantage of rails page/action caching when using a mongrel cluster that spans multiple servers? If so, could you shed some light on how you handled expiring cache across multiple mongrel servers (physically different machines)? ---
**Author:** ![justin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/3ab097/32.png) [@justin](https://www.ruby-forum.com/u/justin)\ **Post date:** [March 21, 2007, 10:52pm UTC](https://www.ruby-forum.com/t/apache-mongrel-cluster-caching-cross-server/89652/2 "2007-03-21T22:52:52Z")
I’m working on this now. I have two approaches: 1. (Implemented) - If you control the URLs, put the timestamp of the resource in the URL linking to it. eg url\_for(:product =\> product, :timestamp =\> product.modified\_at.to\_i) 2. Instead of using page caching, have Apache cache, use mod\_cache. Then, set the expires header very short - Apache will ask Rails for the resource. But don’t return it if it’s still okay - see [Client HTTP Caching in Rails - igvita.com](http://www.igvita.com/blog/2007/03/07/client-http-caching-in-rails/) (I have the headers in #2 working but have not turned on mod\_cache yet) Let me know how your experience goes. ---
**Author:** ![justin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/3ab097/32.png) [@justin](https://www.ruby-forum.com/u/justin)\ **Post date:** [March 22, 2007, 4:26am UTC](https://www.ruby-forum.com/t/apache-mongrel-cluster-caching-cross-server/89652/3 "2007-03-22T04:26:21Z")
Action caching can be configured to use a shared fragment store - DRb or Memcache fragment stores are supplied. Expiry from any server will expiry the action for all servers, and, with Memcache, the store can be distributed over a set of servers for redundancy. Page caching will need some form of sharing of the cache directory across machines - NFS would be the obvious choice, but I don’t know how reliable this is, or how Rails or Apache behave when there are network problems. ---
**Author:** ![justin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/3ab097/32.png) [@justin](https://www.ruby-forum.com/u/justin)\ **Post date:** [March 28, 2007, 12:55am UTC](https://www.ruby-forum.com/t/apache-mongrel-cluster-caching-cross-server/89652/4 "2007-03-28T00:55:27Z")
On 3/21/07, S. Robert J. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > 1. (Implemented) - If you control the URLs, put the timestamp of the > resource in the URL linking to it. eg url\_for(:product =\> > product, :timestamp =\> product.modified\_at.to\_i) > 1. Instead of using page caching, have Apache cache, use mod\_cache. > Then, set the expires header very short - Apache will ask Rails for > the resource. But don’t return it if it’s still okay - see > [Client HTTP Caching in Rails - igvita.com](http://www.igvita.com/blog/2007/03/07/client-http-caching-in-rails/) 1. Use a SAN. J. ---
**Author:** ![justin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/3ab097/32.png) [@justin](https://www.ruby-forum.com/u/justin)\ **Post date:** [March 28, 2007, 3:32am UTC](https://www.ruby-forum.com/t/apache-mongrel-cluster-caching-cross-server/89652/5 "2007-03-28T03:32:43Z")
I have it implemented and working for a long time using NFS mounts for the public directory. But you don’t really need NFS specifically. Anything you can mount and share across servers will work. Bye, Guy. On 3/21/07, Justin [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > – Family management on rails: [http://www.famundo.com](http://www.famundo.com) My development related blog: [http://devblog.famundo.com](http://devblog.famundo.com)