Runtime

Java runtime

You can define how StormForge applies JVM max heap size recommendations to JVM containers.

The Java max heap recommendation settings apply to workloads identified as JVM workloads that StormForge is able to collect JVM metrics for. For non-Java workloads, these settings will have no effect.

StormForge by default assumes that Java applications use the -XX:MaxRamPercentage heap size management mechanism, and that changing the container’s memory limit will therefore change the effective max heap size. StormForge will attempt to use this relationship to optimize heap size without changing any configuration for your app.

If an app does not use -XX:MaxRamPercentage, you will need to adjust the max heap patch path setting to define another way of automating the heap size.

For more information about Java recommendations, see Java heap size.

Max heap patch path

Specifies where the value for Java Max Heap should be in the StormForge patch.

Description

This setting controls how StormForge applies its recommended max heap value to workloads.

If you don’t configure a patch-path, StormForge won’t directly update a specific value for max heap anywhere in the workload. Instead, StormForge will take the JVM’s observed MaxRamPercentage as a constant and adjust the container’s memory limit in order to change the heap size.

If you configure a patch-path, StormForge will instead inject the recommended max heap value into the workload at the location you specify.

Max heap patch format

Specifies how to format the Java Max Heap recommended value in StormForge patches.

Description

The format StormForge uses when it injects a recommended value into a workload can be customized by setting a patch-format.

If you don’t configure a specific patch-format, StormForge’s default behavior is to produce a MaxRamPercentage setting (-XX:MaxRamPercentage=VALUE) if the workload has a memory limit. If the workload does not have a memory limit, it will produce a MaxHeapSize setting (-XX:MaxHeapSize=VALUE) instead.

This setting has no effect when patch-path is set to -.

Minimum and maximum bounds for max heap

Values indicate the lower bound and upper bound of the range for Java max heap.

Description

The minimum and maximum bounds for Java max heap acts a constraint on what max heap values StormForge will recommend, regardless of the observed heap usage. These bounds can be used to set a floor below which the max heap should never drop and a ceiling above which StormForge will never raise it.

When used as defaults for the cluster, max heap bounds can be used to implement default automation policies such as “never set max heap of less than 128Mi” or “never set max heap higher than 8192Gi”.