What is Grid Engine?
Grid Engine is a cluster management software which manages access, reports usage and enforce business policies for a compute cluster. Without such a cluster management software the usage of the compute hosts is more or less chaotic because some hosts are often overloaded while others remain unused. All user have to know about any hosts and their resources, and especially parallel programs which spans over multiple computers can cause problems. It is hard to collect information about the resources users used or to limit the usage of certain resources of the clusters.
Grid Engine simplifies application runs for the users and cluster resources configurations and policy configurations for the administrators. Users have just to submit their application start script or binary with the qsub command line tool, the rest is up to Grid Engine. It dispatches this job to an appropriate compute host and starts it. During run-time the user can view the status of the job (consumed resources etc.) with the qstat command. The user has full control over the job, i.e. a job can be stopped, re-scheduled etc. An administrator can for example add users into projects and give the projects different weights, depending on their priority. The Grid Engine scheduler then respects those priorities and rules in its decisions.