Note: If you have not done so already, we recommend reading the GT4 Primer before continuing. Also keep in mind that in this documentation, the concepts of MDS are written for the latest version, WS MDS (also known as MDS4). The GT 4.1.3 release has deprecated the Pre-WS component, MDS2.

The Monitoring and Discovery System (MDS) is a suite of web services to monitor and discover resources and services on Grids. This system allows users to discover what resources are considered part of a Virtual Organization (VO) and to monitor those resources. MDS services provide query and subscription interfaces to arbitrarily detailed resource data and a trigger interface that can be configured to take action when pre-configured trouble conditions are met. The services included in MDS4 acquire their information through an extensible interface which can be used to:

query WSRF services for resource property information,
execute a program to acquire data, or
interface with third-party monitoring systems.

Grid computing resources and services can advertise a large amount of data for many different use cases. MDS4 was specifically designed to address the needs of a Grid monitoring system – one that publishes data that is available to multiple people at multiple sites. As such, it is not an event handling system, like NetLogger, or a cluster monitor on its own, but can interface to more detailed monitoring systems and archives, and can publish summary data using standard interfaces.

Table of Contents

MDS4 Services
MDS4 Information Interfaces and Providers
Putting it all together
Glossary

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