GT Information Services: Monitoring & Discovery System (MDS)

The Monitoring and Discovery System (MDS) is the information services component of the Globus Toolkit and provides information about the available resources on the Grid and their status.

MDS in GT4

MDS4 is a WSRF implementation of information services released with Globus Toolkit 4.0.

MDS in GT 4.0

This version of MDS includes WSRF implementations of the Index Service, a Trigger Service, WebMDS (formerly known as the Web Service Data Browser) and the underyling framework, the Aggregator Framework.

To support existing deployments, the GT 4.0 distribution also includes MDS2 (also referred to as Pre-Web Services MDS).

MDS in GT3

Developed with Globus Toolkit 3.x, MDS3 is an OGSI implementation of information services and is available in Globus Toolkit 3.0 and 3.2. Includes the Index Service and Service Data Providers (corresponds to the Information Providers of MDS2) with three Provider interfaces. MDS3 is compatible with the Web Service Data Browser tool (which is the OGSI implementation of WebMDS).

To support existing deployments, GT3 distributions also include MDS2 (also referred to as Pre-Web Services MDS).

MDS in GT 3.2

MDS in GT 3.0

Note: GT 3.0 is no longer supported.

MDS in GT2

Developed with Globus Toolkit 2.x, MDS2 is an LDAP-based implementation of information services. This component is also available in later versions of the Globus Toolkit (3.0, 3.2 and 4.0) to support existing deployments. It is based on OpenLDAP and fully implements referral with a combined GRIS and GIIS listening on port 2135 and answering queries based on the ``Mds-VO-name'' string. Mds-VO-Name=local refers to the GRIS and anything else refers to a GIIS if it exists with that name.

Includes: GRIS, GIIS and information providers.

Note: GT 2.x is no longer supported.

Security Notice for MDS 2.4 in the Globus Toolkit 4.0 Release

Please note that in the GT4 pre-WS build, MDS2 is not installed by default. This is because of security concerns with two third-party libraries, Open LDAP v.2.0.22 and Cyrus SASL (v. 1.5.27). That version of OpenLDAP has security vulnerabilities that are no longer being patched due to the age of the version (the current version is 2.2.25). This means that anyone who runs MDS2 on their server has a chance of being affected by this, although we have no reported cases of this occurring. A similar situation exists for the version of Cyrus SASL we are using although this can be avoided by not using MDS2 in secure-mode.

An unsupported, minimally-tested version of MDS2 based on more recent, more secure versions of OpenLDAP and Cyrus SASL is available for download here; however, we strongly recommend that any MDS2 users upgrade their system to use the new WSRF-based MDS4, and we will be happy to work with you to make this possible for your project. Please note that in GT4, MDS2 is a depreciated component, which means that it will not be included in the GT4.2 release, nor supported once GT4.4 exists.

MDS in GT 2.4

  • Documentation (this documentation is also compatible with the MDS2 components in later versions of the Globus Toolkit )
  • Related software
    Note: some of these links were pointing to the deprecated GTR (and have been disabled) and some are linking to the current site of the mdsweb and are only DRAFTS.
    • MDS2 Viz Scripts - A set of flexible PHP scripts to show basic MDS2 information.
    • Simple Ganglia MDS Information Provider - Connects to a ganglia monitoring daemon (gmond) or a ganglia Meta-daemon (gmetad).
    • Teragrid Service Status Information Provider - Interfaces to a set of scripts to describe the status of some basic services. As part of the TeraGrid project, Jim Basney has created a series of scripts to describe the status of several resource services, which this IP interacts with.
    • Certificate Publishing Information Provider - Advertises information about what user certificates are accepted at a site.
    • GridFTP Server Information Provider - Advertises the state of the GridFTP server installation, and works with any MDS2 installation.
    • Software Information Provider - Uses a small configuration file to report path and versioning information for software packages that are running on your machines.