Actually, that is exactly how it is done. Here at http://www.guidestar.org we have 6 2xproc dell servers each running a webserver. If one drops out the cisco load balancer sees this and directs traffic to the other 5. We use a database table and a custom jdbc session manager to provide for session persistance. This session manager allows not to worry about session affinity. Every webserver can get at every session at anytime. When we update code we have an ant script that downs the service, replaces the code from a central server, starts the service and then repeats this process for each machine in turn. On the backend we have 4 DB servers 2 clustered active/passive as read only for our heavy read only usage and 2 clustered active/passive as read write for editing and data loading. There is a nightly job that refreshes the R/O from the R/W right after the backups run. The actual DB data is stored on an EMC drive box (I have no idea what TLA (Three Letter Acronym) is running on this thing). I will say that being a tech NPO is a GREAT thing, we get lots of cool toys cheap! --Angus
> -----Original Message----- > From: Raffi [mailto:[EMAIL PROTECTED] > Sent: Tuesday, August 05, 2003 9:17 AM > To: 'Tomcat Users List' > Subject: RE: how to suppor 30000 concurrent users > > > I always wondered about how high-profile sites like Ebay and Amazon > updated their systems because they never seem to place > messages at their > sites regarding system downtime for routine maintainance. In > a clustered > app server environment, I'm assuming that each node is downed and > updated individually while the other nodes support user requests, or > perhaps it's done differently. Can you explain, thanks! > > Raffi > > -----Original Message----- > From: Angus Mezick [mailto:[EMAIL PROTECTED] > Sent: Tuesday, August 05, 2003 9:07 AM > To: Tomcat Users List > Subject: RE: how to suppor 30000 concurrent users > > > With that many users you are going to HAVE to cluster if for no other > reason than to provide backup for system maintanence. As to how many, > the answer is it depends on the hardware you are going to use and the > types of load your webapp puts on the system. When you say 30k > concurrent users do you mean 30k people clicking a link at > the same time > or 30k active sessions at a time? If you are going to have this many > people clicking on the same time you should have the cash to do proper > load testing to see how many people one of your servers can > take, divide > 30k by that number for the number of servers you have, multiply by 1.1 > AT LEAST and round up to get 110% capacity so you should be > able to swap > out one server. This is BARE minimum. Don't forget about > the wonderful > world of DB backends and routers and all the fun stuff :) --Angus > > > -----Original Message----- > > From: Heart Prince [mailto:[EMAIL PROTECTED] > > Sent: Tuesday, August 05, 2003 8:57 AM > > To: [EMAIL PROTECTED] > > Subject: how to suppor 30000 concurrent users > > > > > > howmany concurrent users does tomcat support? if i want to > > design a web > > application for 30,000 concurrent users, what is the step? > > clustering is > > related to this? how many servers i need if i am clustering > > > > _________________________________________________________________ > > Latest movie trailers. On your mobile. > > http://server1.msn.co.in/sp03/gprs/howcani_movie.asp With GPRS. > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
