Monitoring the Coldfusion JVM

In a previous post I talked about creating per instance jvm.config files for coldfusion for tuning the jvm and configuring monitoring of ColdFusion. Today I am going to discuss how to hook up a jvm monitor, but first lets discuss why we would want to do that.

ColdFusions Builtin Monitoring

The monitoring tools available in Coldfusion are extremely powerfull. They can give you detailed information on slow running requests, queries and application memory usage. They should always be your first point of call when you are seeing poor performance from your application. However the builtin monitoring has two flaws.

Corrupts the results

By turning on the different levels of monitoring you further increase the load on that instance of ColdFusion, this both slows the application (not good if you only have a single production machine to work with) and because it adds loads to the server this can confuse the data.

Not Deep Enough

In cases where you are seeing memory leaks where memory is being taken up and not being released even when nobody is using the application then the built in monitoring is probably not going to be enough. Yes you can see in you have extremely large sessions etc. but sometimes you need to look closer.

External Monitoring Tools

There are several external monitoring tools on the market. Some are free and some you have to pay for. One product I have used which is very powerful is FusionReactor. Its simple to use, detailed and external to ColdFusion so it has less impact on the results. However before paying out there are two very powerful free tools you can use to monitor Coldfusions jvm.

JConsole

JConsole is one of the monitoring tools that comes packaged with the latest JDK from sun/oracle. It does not come with Coldfusion so you need to download and install it. The executable is located in {JDK_HOME}/bin folder.

JVisualvm

JVisualVM is another good monitoring tool and like JConsole is also packaged in the latest JDK.