VDP as Windows service with large memory heap configurations

Goal

This document describes how to configure the VDP Windows service when using large memory heap configurations.

Content

The Windows service wrapper, the application that launches VDP as a windows service, has an activity checker to verify that the VDP Server is alive. By default, the check is performed every 30 seconds and it will wait up to 150 seconds for a response from the VDP Server. If there is no response after 150 seconds, the Windows service wrapper will send a kill message to the VDP Server.

When using large memory heap configurations, the execution of the Java Virtual Machine (JVM) Garbage Collector (GC) could last a long time. In some cases the GC execution makes a “Stop-the-World” pause, so all application threads are stopped until the garbage collection operations end.

Due to this, sometimes the VDP server JVM is paused for longer than 150 seconds. In this case, with the default configuration, the VDP Server is killed by the Windows service wrapper.

The solution to this is to increase the timeout in the VDP Server activity checker used by the Windows service to verify that the server is alive.

The following properties:

• wrapper.ping.interval=30
• wrapper.ping.timeout=150

Need to be modified to higher values in the following files:

• <DENODO_HOME>/conf/vdp/service.conf

The timeout value will depend on the particular scenario. Using the Resources Monitor of the Diagnostic & Monitoring Tool it is possible to review the Garbage Collector usage.

In addition, the properties:

• service.wrapper.WRAPPER_PING_INTERVAL=30
• service.wrapper.WRAPPER_PING_TIMEOUT=150

Need to be modified in the same manner in the file:

• <DENODO_HOME>/conf/vdp/VDBConfiguration.properties

This is because when the file is automatically updated after a change in the JVM settings using the Denodo Control Center or calling the regenerateFiles script the values are pulled from these properties.

For Denodo 7.0 and newer versions only: Change the configuration for the Solution Manager in the following files:

•  <SOLUTION_MANAGER_HOME>/conf/vdp/service.conf
• <SOLUTION_MANAGER_HOME>/conf/vdp/VDBConfiguration.properties

Once these properties are added, the Windows service must be restarted so the changes take effect.

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