GT 4.1.3 Release Notes: MDS4 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

The Trigger Service has been rewritten and restructured for the most recent 4.1.3 version to allow for a number of improvements including the following new features:

  • Individual triggers may be created without restarting the container.
  • Once created, triggers can be enabled/activated or disabled/deactivated without restarting the container.
  • The parameters which define the trigger can be edited individually, in real-time, without restarting the container.

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 MDS4 Trigger Service since the last stable release, 4.0.5:

New Features:

  • Multiple triggers per data source aggregation is now supported. Each trigger's Matching Rule will be evaluated against the incoming message.
  • Support for XML Namespace resolution in the Matching Rule Xpath statement. This allows namespace prefixes to be specified in the TriggerRule XPath matching rule string parameter.

Changes:

  • Triggers are now created/configured in a completely different manner from previous versions. They are created dynamically, as needed.
  • Some parameter names have been changed, added, or removed.

4. Bug Fixes

  • Not applicable.

5. Known Problems

The following problems and limitations are known to exist for MDS4 Trigger at the time of the 4.1.3 release:

5.1. Limitations

  • Due to the recency of the current release, it is still in a developmental state.

    Some of the previously implemented features have not yet been reimplemented in the current version, most notably: minimum firing interval, minimum match time, start/end/invalidity time functionality, action script input/output

5.2. Known Bugs

  • Not applicable.

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 MDS4 Trigger Service

  • Linux on i386

Tested containers for MDS4 Trigger Service:

  • Java WS Core container

8. Backward Compatibility Summary

The Trigger Service is a new component for GT 4.1.3 and so has no compatibility statement.

9. Associated Standards

Associated standards for MDS4 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 Trigger Service for more information about this component.