Hi All,

I have been asked to look into some performance and scalability issues with a legacy J2EE application that is not scaling inline with expectations. The application is about 2-3 years old and is liked by the users but is not handling additional users well as the application user base expands.

The app is JSP, EJB 1.1 (SLSB and BMP Entity Beans). No JMS, basic standard stuff although it is very poorly coded and has no architecture, layering or separation of concerns to speak of.

One of the characteristics of the application is that it has a very large number of JSPs some of which are very large. Does anyone out there have any experience of similarly large numbers of JSPs on Weblogic 8.1 and did it cause a problem. One of our theories at the moment is that the App Server just can't handle the number and size of the JSPs but we have been unable to derive any proof of this. This application is run on a single server with an Oracle 9i backend.

Number of JSPs > 1300 (One Thousand Three Hundred)

Average size of JSPs around 100K going up to 900K max

This seems like a very large number of very big JSPs to me. Can anyone give any insight into similar sized systems.

Regards,



Gerard.

Worked on an install that had 300+ jsp's on JBoss/Tomcat, no problems at all. All JSP's were precompiled.

Didn't seem to have any issues at all. The only problems we saw were around massive amount of short-lived garbage being created (50+ page returns per second, almost 200MB of garbage was being created within a few seconds)- check out the OSCache tag for caching static content and reducing overhead of GC.

Thanks for that, I have also worked on systems that are around 300 JSPs with no problem. This system is over 1300 JSPs (and rising as the system expands). I was hoping to get feed back on similar sized systems.

Regards,


Ged Roberts.

get couple of thread dumps during peak and check, what they are doing

if it does not help you will have to go for a profiling

I do not think you have a problem with JSPs, but more with some SW error in your code; 1 wrong line in your JSP/Servlet can kill your scalability

this can give you a general background, how to tune the J2EE apps: http://docs.sun.com/app/docs/doc/817-2180

"I do not think you have a problem with JSPs"

I am not saying you are wrong, but why do you say thay? Do you have similar experience (1300+ JSPs upto a megabyte, averaging 100 KByte +) with deployments like this.

Over the past 5 years I have built many similar system but never had scalability problems like this. Sure, the code in this app is horrible; we know that and we know that it is going to be a rewrite in the long term. We just need to get past the next six months or so.

I am looking for evidence that there are similar apps out there without scalability problems so that we can decide whether it is the JSPs or just the crap code behind it.

We have profiled the app but nothing is showing up apart from shocking rendering times (because the JSPs are so big and because the JSPs do everything?). This is not a reference architecture!!!

Thanks for your input and I am interested to hear if you can validate (or not) the number/size of JSPs theory.

Regards,




Ged Roberts

Hei there.
I'm no expert, but i have some trubble issues. I think there is a memory leak in the jsp compiler while using JDK 1.3. this is said to be fixed with JDK 1.4.

Well anyway we experianced a lot of issues running on Oracle 9iAS here where i work.. Mostly related to memory and gc handling.

We upgraded to 10g (9.0.4.1) a few months back and it really made a difference =)

Hate to say it but i think there are a lot of issues with the implementaion you are running on :-S

Wish u the best of luck!

have tried any performance testing / diagnostics tools...we had 700JSP based application and we used a tool called PerformaSure....it really helped us in diagnosing performance issues

OPNET's Panorama is the only solution that will correlate changes in performance of ALL systems/tiers an application runs across to accelerate identification of the scalability limiting piece of the puzzle. http://www.opnet.com/products/panorama jwetzel at opnet dot com 760.510.1787