Hi all,


I am quite a jboss newbie, dealing with a commercial website made of :

1 f5 load balancer
2 apache with mod_jk 1.2.26 ( with load balancer set as busyness )
4 application servers ( all of them lbfactor of 1 ) 12gb ram, 8cpu, java 1.6.0.11 and jboss-eap-4.3.0.GA_CP06 ( -Xms6144m -Xmx6144m -XX:MaxPermSize=1024m )
2 oracle boxes set up with RAC by dba on the backend


They are running fine and the website is looking good. Course sometimes they swap but nothing to worry about.

I have been told that in a couple of weeks we are gonna have an increment in the accesses on the website.

I do have cacti to monitor apaches and jboss servers ( httpd threads, processes, memory, cpu, load, network et similia ).

Apache is just fine, I cannot see any bottleneck in it at the time being. What I am concerned about is the app servers. By having a look at cpu, load, memory, network they look fine, but what I need to find out in time is whether or not they will be coping with the growing traffic.


Is there anything particular I should be looking at ? I need to make some assumptions before we get the increase of traffic, just to be safe.




Thanks in advance.

without knowing the hotpoints of the system, it's nigh on impossible to point at anything. The only common gotcha is resource allocation in terms of things like database connection pools and the likes. Assume things will scale linearly, and ensure that if you have a 10 connection db pool that you're currently using less than half if the the incoming traffic is expected to double.

You also didn't mention anything about the F5. F5 is a company, not a product, so do you mean LTM? With Ramcache? Without? With WebAccelerator? these things can often almost negate the load on the real servers with static and dynamic object caching. I would also suggest never ever load balancing apache to tomcat with software if you've an LTM sitting there infront. why not use that and get performance benefits there in the mid tier as well as the front? I'd also hope to a fictional god that you're using proper load balancing to even out spikes and the likes than just sticking the servers on a round robin or a least connections algorithm.

I'd assume that you don't *need* new servers, but if you do hit problems and are unable to work out what the root cause is, and address it, more servers is often a next resort which may well be justifiable given their cost and the time to investigate issues more extensively.