Setting the Java Virtual Machine (JVM) in Cognos
There are a few settings in Cognos BI that can dramatically improve performance in Cognos BI when using TM1 as a data source. The first of these is to stop Cognos from using the old Bluenose method of querying TM1 and force it to use the native TM1 engine. The next setting that we need to configure is the Java Virtual Machine, or JVM.
Wikipedia defines a Java Virtual Machine as an abstract computing machine that enables a computer to run a Java program. Cognos BI runs inside a Java Virtual Machine and the JVM needs to be set large enough to satisfy the requirements of Cognos.
How to Set the JVM in Cognos BI
These settings are written for Cognos 10.2.2 where Dynamic Cubes are not deployed.
- In Cognos BI, open Cognos Administration
- Go to the Configuration tab
- Scroll down to the Query Service and click Properties
- Select the Settings tab
- Scroll down to find the two Java Virtual Machine settings.
- Change the “Initial JVM heap size for the query service” to at least 4096 (megabytes)
- Change the “JVM heap size limit for the query service” to at least 8192 (megabytes)
This information was sourced from our experience and referenced in this page from IBM.
Click here for more information on tuning Cognos and TM1 to work together.