keith wrote: > Hi all, > > I'm wondering if anyone knows what are the advantages of running the > same web application in multiple instances of Tomcat on the same machine > (with a dual duo-core Intel processor). > > Do having multiple instances affect performance positively or negatively > taking in to account that the machine has multiple processors? I doubt there's a performance gain as you could also increase the default settings of just one Tomcat. Of course, each JVM adds memory overhead. Depending on how many webapps you deploy this might not be the issue compared to your webappss' memory consumption however.
Pro: 1) However in case you have more memory in your machine than a JVM can possible use with Windows/Linux you might want to start multiple Tomcats/JVMs and distribute webapps or even the same webapp to distribute the memory consumption of one app's sessions and loadbalance. 2) You might want two Tomcat instances with loadbalancing in front in order to do maintainance work. Of course, you could just have one hot-standby instead of using both. So probably only a good idea if combined with #2. 3) If you don't trust your VM you might hope if one crashes you still got one ;-) However OOMs might be difficult to detect properly by a loadbalancer and that Tomcat might still hang around, but not stable. 4) you prefer to distribute webapps, need a complex vhost setup, <add what you like>, but dislike configuring just one Tomcat. Instead you want one Tomcat per "special" setup. Cons: 1) keeping config in sync 2) webapps installed multiple times (or symlinked /webapp with other effects...). Tomcat updates shouldn't be more effort as long as you stick just to patch versions as you'll still only have on binary installation CATALINA_HOME vs. multiple CATALINA_BASE configs. 3) more complex, might want session clustering to get session replications Cheers, Michael > --------------------------------------------------------------------- > 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]
