I think it depends mostly on the following factors - amount of cpu/memory usage in your application - amount of cpu/memory usage on the database - amount of cpu/memory usage of tomcat - amount of cpu/memory usage of apache - the amount of network traffic between your application and the database - the amount of network traffic between tomcat and the webserver
All of this figures are dependend on your application, and the database design. So there is no general answer. I think you have to test that. On single processor machines our expierience shows that it is better to put the servlet engine (it wasn't tomcat but mod_jserv+gnujsp) on the webserver than on the database server. (Apart from the fact that our sysadmin is a strict advocate for the separation of concerns, so he wouldn't like a servlet engine on the database server anyway) BTW: Why would you like to run two instances of tomcat on one server ? If it is mainly for performance reasons, I think that you are better off with one tomcat. As tomcat/java is multithreaded it will take advantage of the additional processors anyway. With the loadbalancer you introduce more complexity in the setup, more overhead for each request, more memory consumption and it can make your application more sophisticated. (Load balancing isn't transparent to all kind of applications. If you use information that has more than session scope you have to take care of that) > -----Urspr�ngliche Nachricht----- > Von: Robert Parker [mailto:RParker@;membersequity.com.au] > Gesendet: Mittwoch, 23. Oktober 2002 13:32 > An: 'Tomcat Users List' > Betreff: Tomcat(s) on web server or database server > > I have a configuration which comprises two physical machines, > a dual proc webserver and a quad proc database server. I am > planning on running two tomcat instances using the JK load > balancer. > My question - for performance, should I run the two tomcats > on the webserver or both on the database server? -- To unsubscribe, e-mail: <mailto:tomcat-user-unsubscribe@;jakarta.apache.org> For additional commands, e-mail: <mailto:tomcat-user-help@;jakarta.apache.org>
