Table of Contents
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.
The Trigger Service has been rewritten and restructured for the most recent 4.2.0 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.
- Not applicable
- 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.
- 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.
The following problems and limitations are known to exist for WS MDS Trigger at the time of the 4.2.0 release:
The Trigger Service depends on the following GT components:
The Trigger Service depends on the following 3rd party software:
Tested Platforms for WS MDS Trigger Service
- Linux on i386
Tested containers for WS MDS Trigger Service:
- Java WS Core container
The Trigger Service interfaces and underlying protocols have changed since the GT 4.0.x version. The Trigger Service will not interoperate with GT 4.0.x servers or clients; however, trigger action programs written for previous versions of the Trigger Service should continue to work with this one.
- WS-ResourceProperties (WSRF-RP)
- WS-ResourceLifetime (WSRF-RL)
- WS-ServiceGroup (WSRF-SG)
- WS-BaseFaults (WSRF-BF)
See Trigger Service for more information about this component.