configure-xml

XML Configuration

The samples in this module demonstrate how to configure a Hazelcast Jet cluster with XML configuration.

Configuration Lookup

Creating member instance with Jet.newJetInstance() looks for configuration files in multiple locations both in XML and YAML format. XML configuration takes precedence over YAML configuration in all locations resulting the following lookup order:

1. The configuration passed in hazelcast.jet.config JVM argument, either XML or YAML
2. hazelcast-jet.xml on the classpath
3. hazelcast-jet.xml in the working directory
4. hazelcast-jet.yaml on the classpath
5. hazelcast-jet.yaml in the working directory
6. default configuration hazelcast-jet-default.xml

Similarly, the (Java) client instances created with Jet.newJetClient() follows the same lookup logic and order:

1. The configuration passed in hazelcast.client.config JVM argument, either XML or YAML
2. hazelcast-client.xml on the classpath
3. hazelcast-client.xml in the working directory
4. hazelcast-client.yaml on the classpath
5. hazelcast-client.yaml in the working directory
6. default configuration hazelcast-jet-client-default.xml

The sample ConfigLookup demonstrates how the configuration files are located on the classpath and how to use the locator logic to take only YAML configuration files into account.

Loading XML Configuration Without Lookup

If it is known that the cluster will be configured with XML configuration and no need for using the location logic shown in the first sample, the following XML-specific config loader utility methods on the JetConfig class can be used:

• JetConfig.loadFromClasspath(): loads the configuration from the classpath based on the provided filename
• JetConfig.loadFromFile() : loads the configuration from the file system based on the provided filename
• JetConfig.loadXmlFromStream(): loads the configuration from the provided input stream
• JetConfig.loadXmlFromString(): loads the configuration from the provided String containing XML configuration

The sample XmlJetConfigClasspath loads the jet configuration hazelcast-jet-sample.xml from the classpath and demonstrates variable replacement in XML configuration by defining the backup count and metrics configuration in variables taken from the system properties and then from a provided Properties instance.

Full XML Configuration Example

There is a full example XML configuration in the distributed Hazelcast Jet jars, named hazelcast-jet-full-example.xml. This example file can be used for reference when writing XML configuration.