Goal

This document describes how to configure the Virtual DataPort (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 issue 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 increased to higher values, in the following file:

• <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
  

have 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.

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

Solution Manager

Change the same parameters for the following Solution Manager configuration 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.

Related links

Configure Windows Services — Installation Guide (denodo.com)

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