Upgrading the JRE used by Coldfusion

Recently I was investigating some performance issues on a Coldfusion 8 box. During the course of my investigations I discovered that JRun was using the default release of java 1.6.0_4 which it ships with. This was one of the first issues I tackled.

Issues with Java 1.6.0_4

When Coldfusion 8 was release Adobe pushed the envelope by using the then new 1.6.0_4 edition of Java. This was supposed to bring enhanced speed and performance. However it was quickly discovered that there was a bug in the Java class loader which actually caused performance issues. This was particularly bad in applications that used frameworks or made extensive use of components.

The Solution

At the time the solution was to downgrade the JRE to 1.5.x. Fortunately the problem was addressed with the java 1.6.0_10 release (08 Aug 2008). Anyone still running the default version of java should update to the current release. At the time of writing this was 1.6.0_21.

Step 1: Confirm your current jre

To confirm the current jre log into the Coldfusion Admin and click the information icon the white "i" on a blue background. Look for the Java Version listed.

Step 2: Download the JDK

Once you have confirmed if you need to update your jre the next step is to download the current J2SE JDK (Java Development Kit). Note: Coldfusion needs the 'Hot-Spot JVM' which does not ship with the standard JRE. Install this to your machine. On my system I ended up with an install path of:

c:\program files\java\jdk1.6.0_21\