Correction:  Ultra Monkey is now FREE: www.ultramonkey.org (503)754-4452 Blackberry || www.obnosis.com via USB PPP EDVO/CDMA on Dell Latitude PII - Kubuntu 7.10 --- On Thu, 7/3/08, Lisa Kachold wrote: From: Lisa Kachold Subject: Re: Server failover To: "Main PLUG discussion list" Date: Thursday, July 3, 2008, 6:30 PM WEB Server FARMS, clustering and failover: Let's use the "OSI Layer" here: Layer 5-7: If you are running Java in a single tiered model,  there are cluster based options in the Application server side.  Layer 3.5-4:  Network hardware load balancer is an excellent tool.  These also allow you do some URL rewriting (the best is a CSS switch; cheap Alteons are available for cheap used).  They balance multiple servers for incoming packets and provide failover. Layer 3: drbd or heartbeat works but not really well.  The server, not the Apache process will failover, and it not really scalable. Layer 3: Ultra Monkey no arp clustering.  This is an Alan Cox kernel hack that will allow you to cluster a great number of servers to take a HUGE amounts of hits.  If one quits it is removed from the Director.  It works well, and is easy to setup.  Ultra Monkey is the name of a product, but the application developed by Alan Cox is a kernel rebuild to route packets based on Mac address rather than IP from and to a Director script/application.  Research it and see if you can engineer your own for you distro, or just buy Ultra Monkey.  (503)754-4452 Blackberry || www.obnosis.com via USB PPP EDVO/CDMA on Dell Latitude PII - Kubuntu 7.10 --- On Thu, 7/3/08, Judd Pickell wrote: From: Judd Pickell Subject: Re: Server failover To: "Main PLUG discussion list" Cc: klsmith2020@yahoo.com Date: Thursday, July 3, 2008, 3:40 PM One of the places I worked for used this: http://bb4.com/ however it maybe too big for your needs, I am not sure. On Thu, Jul 3, 2008 at 10:04 AM, Matt Graham wrote: > From: keith smith >> I am looking for information on how I might be able to mirror one >> server onto another and set them up so if the main server dies >> the second server will take over automatically. > > heartbeat and drbd. http://linux-ha.org/ and http://drbd.org/ to > start. > >> The mirroring would require the website content itself and the >> MySql data. > > drbd works below the filesystem level, if you want to use that. You > really need a dedicated high-speed link between the 2 systems if you > want to use drbd. Unless you use one of the newer and less well > tested filesystems such as GFS, if you use drbd, you have to have the > primary machine mount the filesystem, and the secondary machine can't > mount the filesystem at all. Scripts allow the secondary machine to > become primary if/when the primary flails over. > >> Now if I had 3 servers would I be able to do this by having them >> all three working as a "farm" to serve up multiple websites? > > Not in the way described above. drbd is very much a 2-machine system. > You could have a drbd cluster with large disks acting as the main > fileserver, and 1..N machines that mount the filesystems on that > server via NFS. Then machines 1..N could serve content via apache > or apache combined with ldirectord. > >> Is it possible to do this on a small budget? > > Define "small". You need boxes, time to set it all up, and disks. > > -- > Matt G / Dances With Crows > The Crow202 Blog: http://crow202.org/wordpress/ > There is no Darkness in Eternity/But only Light too dim for us to see > > > --------------------------------------------------- > PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us > To subscribe, unsubscribe, or to change your mail settings: > http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss > --------------------------------------------------- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss --------------------------------------------------- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss