The execution aggregation source provides a way to aggregate data (arbitrary XML information) about a registered resource using an arbitrary local executable (such as an external script). The executable will be passed registration information as parameters and is expected to output the gathered data, as detailed below.

A basic example of the use of this API is described in the ping test example for the aggregator execution source

The execution aggregation source will periodically execute an identified executable. The identity of the executable and the frequency with which it is to run are specified in the registration message.

To register resources:

The file consists of an optional defaultServiceGroupEPR, an optional defaultRegistrantEPR, and then one or more ServiceGroupRegistrationParameters blocks, each of which represents one registration.

The general syntax of the configuration file is:

<?xml version="1.0" encoding="UTF-8" ?>
<ServiceGroupRegistrations
  xmlns="http://mds.globus.org/servicegroup/client">

  // An optional default service group EPR.
  <defaultServiceGroupEPR>
    // Default service group EPR
  </defaultServiceGroupEPR>

  // An optional default registrant EPR.
  <defaultRegistrantEPR>
    // Default registrant EPR
  </defaultRegistrantEPR>

  // An optional default security descriptor file.
  <defaultSecurityDescriptorFile>
    // Path name of default security descriptor file
  </defaultSecurityDescriptorFile>

  // One or more service group registration blocks:

  <ServiceGroupRegistrationParameters>
    <ServiceGroupEPR>
      // EPR of the service group to register to
    </ServiceGroupEPR>
    <RegistrantEPR>
      // EPR of the entity to be monitored.
    </RegistrantEPR>
    <InitialTerminationTime>
      // Initial termination time
    </InitialTerminationTime>
    <RefreshIntervalSecs>
      // Refresh interval, in seconds
    </RefreshIntervalSecs>
    <Content type="agg:AggregatorContent">
      // Aggregator-source-specific configuration parameters
    </Content>
  </ServiceGroupRegistrationParameters>

</ServiceGroupRegistrations>

The following table describes the different blocks of the file and any parameters:

The configuration block for ExecutionAggregatorSource (inside the Content block) looks like this:

<Content xsi:type="agg:AggregatorContent"
   xmlns:agg="http://mds.globus.org/aggregator/types">
  <agg:AggregatorConfig xsi:type="agg:AggregatorConfig">
    <agg:ExecutionPollType>
      <agg:PollIntervalMillis>interval_in_ms</agg:PollIntervalMillis>
      <agg:ProbeName>dummy_namespace:probe_name</agg:ProbeName>
    </agg:ExecutionPollType>
  </agg:AggregatorConfig>
  <agg:AggregatorData/>
 </Content>
    

where:

If you've properly configured and registered your script for execution but are getting errors from the container because it cannot find the specified script, there are two likely causes.

First, make sure that your script/program is executable and is located in the $GLOBUS_LOCATION/libexec/aggrexec directory. When it's specified in the configuration mentioned above, only specify the name of the script/program, without any qualification or path. For example, using the ProbeName as test-script will be specifying the file $GLOBUS_LOCATION/libexec/aggrexec/test-script script.

Next, make sure that you have correctly created an executableMappings definition in the appropriate jndi-config.xml file.

The following links provide information for configuring the three types of aggregator sources provided by the Globus Toolkit:

An aggregator sink may require sink-specific configuration (the MDS Trigger service requires sink-specific configuration; the MDS Index service does not). See the documentation for the specific aggregator service being used for details on sink-specific documentation.