A No Brainer Performance Optimization

Friday, June 17, 2005

Some performance optimizations are a no brainer and should always be set, here we discuss one of them.

Recently I was helping a client with performance tuning of an application that had much higher CPU utilization then expected. They were moving from another product to WebLogic Express and were surprised that the CPU utilization under WebLogic Express was orders of magnitude higher then the product they had been previously using.

We drew up a list of performance tuning parameters, in order of priority, to try to rectify the problem and at the top of the list were what I call the no brainer parameters. These are parameters that you know should be set to a particular value for maximum value and have no potential negative impact. The two first parameters were the pageCheckSeconds and servlet-reload-check-secs parameters. By default these are set to 1, which means that WebLogic checks for a newer version of JSP pages and servlets every second for every JSP and servlet. This is a good setting for development, but in production this can lead to a significant amount of overhead if your system has a large number of JSP pages and servlets.

If your production system never updates JSP pages or servlets on the fly, then this should be set to -1 which indicates to WebLogic to never check for newer pages. Alternatively, if you need changes to JSP pages and servlets to be picked up, try setting this to a larger number such as 180 to reduce the effect checking for newer versions has on the system.

Setting these parameters to -1 for the client's application cut the CPU utilization in half, a pretty significant benefit for the minimal effort involved in changing the parameters.

Posted by Gerald Nunn at 10:09 AM | Categories: | | | Permalink