Globus Toolkit 3.9.2 Development Release Notes: WS MDS (MDS4)
The WS Globus Monitoring and Discovery System, MDS4, is a WSRF-based Grid-level
monitor used primarily for resource discovery and resource management selection
decisions. This component provides a wide range of information about basic
resources
and queues, and can interface to cluster monitoring systems such as Ganglia
for local
cluster data. Each WSRF-based service provides a range of monitoring information
about
itself, thereby allowing WS MDS to make use of this data as well.
Like any Grid monitoring system, MDS4 provides an index service where data
is
collected and cached. In addition, MDS4 has an associated archiver that stores
data in a
Xindice XML-based database, and a web-based interface for easy viewing of collected
data.
This release will aggregate Resource Properties from registered resources and publish in service group form.This release does not contain clients for registering or accessing indexes. You can find example code that demonstrates use of the index in the index package at:
src/org/globus/mds/index/impl/test1.java
The present version of the index will only index a single named Resource Property per installation, set in the etc/jndi-config.xml parameter 'indexedRP' on the IndexService. By default, this RP is the 'foo' resource property as published through the sample Widget service.
Ganglia
The Ganglia module publishes data from the Ganglia cluster monitoring system into a resource property, using the XML mapping of the GLUE schema as used in MDS3.
It is intended that this code will eventually publish a resource property through GRAM, but for the 3.9.2 release, it is included as a standalone service instead.
This module is intended to replace and/or supplement the traditional hostinfo scripts which have been present in earlier releases of MDS, by providing cluster information rather than information on the job submission host.
Run the service on a host which has ganglia running on port 8649 (the default). Data from the service can be seen by executing the command:
wsrf-query -s http://localhost:8080/wsrf/services/GangliaService /
Data is published in the GLUE schema, although at time of writing, only a small amount of information per host is published.
The translation from Ganglia to GLUE schemas is performed using an XSLT stylesheet,
in $GLOBUS_LOCATION/ganglia_to_glue.xslt which can be modified to add additional
fields to the published data.