On Thu, 20 May 2004 15:48, David Wilk <[EMAIL PROTECTED]> wrote: > The cluster is comprised of a load-balancer, several web servers > connected to a redundant pair of NFS servers and a redundant pair of > MySQL servers. The current bottle-neck is, of course, the NFS servers. > However, the entire thing needs an increase in capacity by several > times.
The first thing I would do in such a situation is remove the redundant NFS servers. I have found the NFS client code in Linux to be quite fragile and wouldn't be surprised if a cluster fail-over killed all the NFS clients (a problem I often had in Solaris 2.6). > However, for alot less money, one could simply do away with the file > server entirely. Since this is static content, one could keep these > files locally on the webservers and push the content out from a central > server via rsync. I figure a pair of redundant internal web server > 'staging servers' could be used for content update. Once tested, the > update could be pushed to the production servers with a script using > rsync and ssh. Each server, would of course, require fast and redundant > disk subsystems. Yes, that's a good option. I designed something similar for an ISP I used to work for, never got around to implementing it though. My idea was to have a cron job watch the FTP logs to launch rsync. That way rsync would only try to copy the files that were most recently updated. There would be a daily rsync cron job to cover for any problems in launching rsync from ftpd. With local disks you get much more bandwidth (even a Gig-E link can't compare with a local disk), better reliability, and you can use the kernel-httpd if you need even better performance for static content. Finally such a design allows you to have a virtually unlimited number of web servers. -- http://www.coker.com.au/selinux/ My NSA Security Enhanced Linux packages http://www.coker.com.au/bonnie++/ Bonnie++ hard drive benchmark http://www.coker.com.au/postal/ Postal SMTP/POP benchmark http://www.coker.com.au/~russell/ My home page
