GT 3.9.5 WS MDS Trigger Service: System Administrator's Guide

Introduction

This guide contains advanced configuration information for system administrators working with the WS MDS Trigger Service. It provides references to information on procedures typically performed by system administrators, including installation, configuring, deploying, and testing the installation.

This information is in addition to the basic installation instructions in the GT 3.9.5 System Administrator's Guide.

Building and Installing

The Trigger service is installed as part of the standard Globus Toolkit installation.

Configuring

The trigger service is an MDS aggregator service, and so inherits much of its configuration system from the aggregator framework module. The configuration instructions for the aggregator framework should be read before this section.

  • TriggerRuleType: In addition to the source parameters specified in the aggregator framework configuration guide, this trigger-specific configuration element must be added to all registrations made to the trigger service. This registration paramete contains the following options:
    • matchingRule: XPath rule to be applied against incoming data. The XPath expression will be evaluated against aggregated data, and will be regarded as matching the incoming data if it matches one or more nodes in that data.
    • actionScript: the name of a script in $GLOBUS_LOCATION/libexec/trigger/ that will be executed when the matchingRule matches (except as rate limited by the following parameters).
    • minimumFiringInterval: the action script will not be executed more than once in this number of seconds. If unspecified, there will be no minimum interval.
    • minimumMatchTime: the matchingRule must be true for this number of seconds before the actionScript will be executed. If unspecified, there is no minimum time period that the rule must match and the rule will fire immediately the matchingRule becomes true.
    • outputXSL: (UNIMPLEMENTED in GT 3.9.3). The delivered message will be transformed by the specified XSLT stylesheet and fed into the stdin of the action script. It is intended that this will be implemented in a subsequent release of the GT3.9.x series.

The rate limiting parameters behave in such a way that the rate of action script executions can be decreased by increasing the minimumFiringInterval and/or by increasing the minimumMatchTime.

Deploying

This component is deployed as part of the standard toolkit installation.

Testing

[procedures for how to test the configuration. must include examples of the tests ]

Security Considerations

The security considerations for the Aggregator Framework also apply to the Trigger Service.

Troubleshooting

[help for common problems sysadmins may experience]