On Apr 5, 1:34 am, "Rob Sanheim" <[EMAIL PROTECTED]> wrote:
> So for page caching across a cluster, or static resources in general > w/ a rails cluster, is NFS a bad idea? I've read a lot of posts where > folks talk about how unreliable NFS has been in the past, and it has > issues with locking and what not. My company has had issues as well > when servers are restarted and have issues reconnecting to the NFS > mount. > > I wouldn't mind page caching on each web server and just duplicating > data, if it weren't for the problem of expiring data across machines. > > The environment is RHEL 4, at least a couple web servers plus a DB > server and a few others. Fairly standard Mongrel/Apache22/Mysql > deployment. > > Any ideas/experiences? thanks... At Engine Yard we use a clustered filesystem, GFS, and storing the data on remote disk bank via AoE. You could choose iSCSI, but it's slower, and Fiber channel is fantastic if you can afford it. :-) This has the enormous advantage of page cache coherence, full POSIX file semantics including locking, and can be fully fault tolerant. Disk access between two nodes is identical to disk access between two processes on the same node. Performance is a lot better than NFS, particularly so when you have fast disks and big pipes to the disks, as you don't have share the network interface(s) with disk I/O. There are some potential disadvantages of a system like this. It fundamentally violates shared nothing, which means you cannot scale to infinity with this, but it can likely scale to somewhere around 95th percentile of all internet websites... Somewhere around 95th percentile, all bets are off no matter how you start, so I don't consider this a real problem. :-) -- -- Tom Mornini, CTO -- Engine Yard, Ruby on Rails Hosting -- Reliability, Ease of Use, Scalability -- (866) 518-YARD (9273) --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Deploying Rails" group. To post to this group, send email to rubyonrails-deployment@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/rubyonrails-deployment?hl=en -~----------~----~----~----~------~----~------~--~---
