How to customize JVM options on Azure Functions - Azure/azure-functions-java-worker GitHub Wiki

Customize JVM options on Azure Functions

• Dedicated and Premium Functions: Create an app setting named JAVA_OPTS with a value of your customizing parameters for example “-Dexample=true”. If you already have the JAVA_OPTS app setting set, just append “-Dexample=true” to the existing value.

• Consumption Functions: Create an app setting named languageWorkers__java__arguments with a value of “-Dexample=true”.

More examples can be find here: https://github.com/Azure/azure-functions-java-worker/issues/474

Case - Update JVM heap size

Dedicate plan (P1V2)

• default (without setting JAVA_OPTS): heap size is 711589888 bytes

• set JAVA_OPTS to -Xmx2g: heap size is 2075918336 bytes

The sample apply to appsetting languageWorkers__java__arguments on consumption plan.