GT 4.1.0 Release Notes: WS MDS Trigger Service

1. Component Overview

The Trigger Service collects data from resources on the grid and, if administrator defined rules match, can perform various actions. An example use is to send email when queue length on a compute resource goes over a threshold value.

2. Feature Summary

Features new in release 4.1.0

  • Multiple TriggerRules per data source aggregation is now supported. Each trigger rule will be evaluated against the incoming message in the order specified in the aggregator configuration.
  • Support for XML Namespace resolution in the TriggerRule Xpath statement. This allows namespace prefixes to be specified in the TriggerRule XPath matching rule string parameter.
  • Invalidity time ranges for action script execution. A given TriggerRule will not execute an actionScript if the current time falls within a valid InvalidyTime datetime-range pair.
  • Additional options for configuring input to action scripts. It is now possible to disable the sending of the original trigger message data as input to the action script. It is also now possible to specify that any filtered result set returned by the XPath matching rule statement should be included as input to the action script.

Other Supported Features

  • Uses the Aggregator Framework to monitor XML data for matching trigger conditions
  • When a trigger condition matches, fires a customizable action: for example, sends email to an administrator.
  • Monitored services are managed through service group-based registration API, allowing use of many of the same clients that can be used in the Index Service.

Deprecated Features

  • Not applicable

3. Changes Summary

The following changes have occurred for WS MDS Trigger Service since the last stable release, 4.0.2:

New Features:

  • Multiple TriggerRules per data source aggregation is now supported. Each trigger rule will be evaluated against the incoming message in the order specified in the aggregator configuration.
  • Support for XML Namespace resolution in the TriggerRule Xpath statement. This allows namespace prefixes to be specified in the TriggerRule XPath matching rule string parameter.
  • Invalidity time ranges for action script execution. A given TriggerRule will not execute an actionScript if the current time falls within a valid InvalidyTime datetime-range pair.
  • Additional options for configuring input to action scripts. It is now possible to disable the sending of the original trigger message data as input to the action script. It is also now possible to specify that any filtered result set returned by the XPath matching rule statement should be included as input to the action script.

Changes:

  • Format of action script input document changed slightly in order to incorporate new options.

5. Known Problems

The following problems and limitations are known to exist for WS MDS Trigger at the time of the 4.1.0 release:

5.1. Limitations

  • No known limitations exist.

6. Technology Dependencies

The Trigger Service depends on the following GT components:

The Trigger Service depends on the following 3rd party software:

  • None

7. Tested Platforms

Tested Platforms for WS-MDS Trigger Service

  • Linux on i386
  • Windows XP

Tested containers for WS-MDS Trigger Service:

  • Java WS Core container
  • Tomcat 5.0.28

8. Backward Compatibility Summary

The Trigger Service is a new component for GT 4.1.0 and so has no compatibility statement.

9. Associated Standards

Associated standards for WS MDS Trigger:

  • WS-ResourceProperties (WSRF-RP)
  • WS-ResourceLifetime (WSRF-RL)
  • WS-ServiceGroup (WSRF-SG)
  • WS-BaseFaults (WSRF-BF)
  • WS-BaseNotification
  • WS-Topics

10. For More Information

See WS MDS Trigger Service for more information about this component.