Managing the Composer Query Engine

The query engine is a stand-alone microservice within the Composer environment that processes visual queries. If you install or upgrade Composer using the supplied installation script, the query engine microservice is started automatically. If you install or upgrade Composer manually, you must manually enable and start the query engine microservice.

Configuring the Query Engine

In your environment, the query engine is called zoomdata-query-engine. To configure and manage the microservices that the query engine executes and runs, you need to make changes to the query-engine.properties file. It contains properties that are specific to how the query engine operates within your environment.

The query engine also has a query-engine.env file and a query-engine.jvm file. You can edit these files to configure the following:

  • To define the environment variables that are visible for the microservice, edit the query-engine.env file.
  • To configure the JVM options that are used to start up Composer microservices, edit the query-engine.jvm file.

The default memory configurations give the query engine up to 6 GB of heap memory. During microservice startup, the query engine consumes at least 1 GB of memory. You can alter this using the following parameters in the query-engine.jvm file:

-Xms1g
-Xmx6g

For information on editing configuration files, see Editing a Composer Configuration File. For information about query engine properties, see Query Engine Properties.