Other Cluster Monitoring Facilities

3.5. Other Cluster Monitoring Facilities

3.5.1. The Proc Filesystem

The next link leads to a standard Apache filesystem view of the Linux /proc filesystem. These files and directories do not reside on disk, but are instead dynamically generated by the Linux kernel upon request. They are used to convey dynamic information about resource usage and running processes on the machine. Due to their ethereal nature, the information provided by the /proc files is extremely fresh, and in fact represent the current state of the operating system at the time the file was requested.

However, data contained in these files may reveal information useful to hackers and other malicious parties. In addition to user names and program parameters, this area contains data about local network interfaces and firewalls. Therefore, by default this link is subject to the same "private network only" restriction as the database web interface.

3.5.2. Cluster Distribution

This link displays a filesystem view of the /home/install/ directory tree on the frontend node. This area holds the repositories of RPM packages used to construct nodes in the cluster, along with the XML kickstart graph that defines the various node types. The distribution used to build the cluster may be examined here.

Knowledge of the software versions present on the cluster is considered sensitive since it may give hackers insight to available security holes. By default, access to this link is restricted to the private network as well.

3.5.3. Kickstart Graph

This link will return an image of the current kickstart graph used to choose software for appliance types. Rocks automatically generates kickstart files based on the nodes and edges in this graph. Rolls can add or alter the graph, and new appliance types may be created. Currently Rocks differentiates appliances only by their starting node in this graph however more complex definitions are possible.

The GIF image returned by this link is generated on the fly, and so is current. It is made by the "dot" application that is part of the GraphVIZ project.

3.5.4. Cluster Labels

The "Make Labels" link generates a PDF document containing labels for each node in the cluster. By saving this document to disk and printing it on standard Avery 5260 address stock, you can easily label the nodes of your cluster.

3.5.5. Rocks Users Guide

The final link on the Table of Contents page leads to the Rocks Users Guide. This is simply a local version of the guide present on the official Rocks website http://www.rocksclusters.org/. In it you will find instructions for addding nodes to your cluster, as well as FAQs which may prove invaluable during troubleshooting. You may have already read much of the guide, as this page resides in it.

These links represent the monitoring tools available on a standard Rocks cluster. With them you may edit the database, view the state of the cluster's resources and the parallel job queue, and examine the software package repository. These tools are actively being developed extended, and additional pages may be added in the future.