Tech note: Adjusting Tomcat memory for Matillion ETL upgrades

This tech note outlines the required procedure for adjusting the Java Virtual Machine (JVM) memory allocation for the Tomcat service after upgrading Matillion ETL.

Applies To

This procedure is mandatory for any Matillion ETL instance that has been upgraded from a version below 1.78.0 to version 1.78.0 or higher. Failing to apply this change can lead to performance degradation and "Out of Memory" errors.

Procedure

Follow these steps to increase the memory available to the Tomcat service. This process requires root access to the Matillion ETL instance's command line.

Connect to the instance. Use SSH to establish a connection to your Matillion ETL instance.
Switch to the root user. Elevate your privileges to root to ensure you have the necessary permissions to edit system files:
```
sudo -i
```
Edit the configuration file. Open the Tomcat environment settings file using a text editor like vi or nano:
```
vi /usr/share/tomcat/bin/setenv.sh
```
Set the memory allocation. Add the following line to the file. This command instructs Tomcat to use a maximum of 50% of the instance's total RAM for its heap space:
```
export CATALINA_OPTS="$CATALINA_OPTS -XX:MaxRAMPercentage=50"
```
Save your changes to the setenv.sh file and exit the text editor.
Restart the Tomcat service for the new memory settings to take effect:
```
systemctl restart tomcat
```

The instance is now correctly configured.