The OGSA-DAI activity framework contains an infrastructure for monitoring requests currently being executed by OGSA-DAI. This includes when activities are created, start processing, throw errrors and complete and when data flows flows through inter-activity pipes.
By default we provide
This adds all events into a
java.util.Map, indexed by request ID,
where each entry is a
java.util.List of all events
associated with the request.
|The example request monitor is a proof-of-concept only. It stores all the events it receives but there is no means of flushing these so it will gradually consume memory. To avoid this you may want to regularly restart your server - or customise the request monitor!|
If you wish to use our monitoring framework implementation or provide your own you will need to specify this implementation to OGSA-DAI.
To declare the monitoring framework, you simply have to uncomment the following XML fragment within the OGSA-DAI context configuration file.The server's context configuration file is located in:
The XML is as follows:
<bean id="uk.org.ogsadai.MONITORING_FRAMEWORK" class="uk.org.ogsadai.monitoring.example.EventListMonitoringFramework\"/>
An instance of the request monitor will be available in the OGSA-DAI context on the server, and so accessible to all OGSA-DAI components, when OGSA-DAI starts up.
You can then use it as follows:
First visit the OGSA-DAI JSP index page in a browser (this was already deployed when you deploy OGSA-DAI) e.g:
Visit the OGSA-DAI request monitor JSP page in a browser (this was already deployed when you deploy OGSA-DAI) e.g:
If you want to use your own implementation of a request monitor,
or a customisation of ours then all you have to do is
with the class name of your implementation in the foregoing deployment
You must ensure that your class implements
and that the class is available on the server.