For a basic installation, the Index Service itself does not need any configuration changes from default; a default Index Service is available and automatically "registers" with the following GT web services based resources to allow monitoring and discovery: [CAS], [RFT], and [GRAM4] (click the links for information about what data is sent and how to change it).

	Note
	Auto-registration is turned on by default in GT 4.2.0. See the per service links above for information about configuring this capability.

In order for information to appear in the Index Service, the source of that information must be registered to the Index Service. Information sources are registered using tools like mds-servicegroup-add(1). Each registration has a limited lifetime; mds-servicegroup-add should be left running in the background so that it can continue to refresh registrations. Depending on administration preference, it may be run on the same host as the index, on the same host as a member resource, or on any other host(s).

The Index Service is built on Aggregator Framework and can use any Aggregator Sources Reference to collect information. In the most common case, the index service uses the QueryAggregatorSource to gather resource property values from the registered resource using one of the three WS-Resource Properties operations to poll for information; the polling method used depends on the configuration element supplied in the registration content.

Two other aggregator sources are supplied with the distribution: the SubscriptionAggregatorSource, which gathers resource property values through subscription/notification, and the ExecutionAggregatorSource, which executes an external program to gather information.

The aggregation sources used to collect data can be changed from default by editing the aggregatorSources parameter in the JNDI service configuration. See $GLOBUS_LOCATION/etc/globus_wsrf_mds_index/jndi-config.xml:

<resource name="configuration"
             type="org.globus.mds.aggregator.impl.AggregatorConfiguration">
  <resourceParams>
    <parameter>
      <name> factory</name>
      <value>org.globus.wsrf.jndi.BeanFactory</value>
    </parameter>
    <parameter>
      <name>aggregatorSource</name>
      <value>org.globus.mds.aggregator.impl.QueryAggregatorSource 
             org.globus.mds.aggregator.impl.SubscriptionAggregatorSource 
             org.globus.mds.aggregator.impl.ExecutionAggregatorSource
      </value>
    </parameter>
</resourceParams>

This parameter specifies one or more Java classes that may be used to collect data for the Index. By default it is set to use the QueryAggregatorSource, SubscriptionAggregatorSource, and ExecutionAggregatorSource. Details of these standard sources are in the Aggregator Sources Reference.