How to list compatible computing resources (Computing Elements) for a job prior to submission.
It is possible to see which Computing Element (CE) satisfies the requirements for a job by using the command
$ glite-wms-job-list-match -a [--rank] <jdl>
where <jdl> is the JDL file describing the job to be submitted. The --rank option also prints the rank of the CEs. The rank is a number expressing the adequacy of a CE (the higher, the better).
A JDL can specify the resources that it needs using the "Requirements" attribute, which is a Boolean ClassAd expression. To have a job scheduled to run on a given CE, this requirements expression must evaluate to true on the given CE. The evaluation is performed by the Workload Management System (WMS) during the match-making phase.
This is an example of a requirements expression:
Requirements = other.GlueCEInfoLRMSType == "PBS" &&
other.GlueCEInfoTotalCPUs > 2 && Member("IDL1.7",other.GlueHostApplicationSoftwareRunTimeEnvironment);
The above expression requires a CE whose local resource manager is PBS, which has at least 2 CPUs, and where the IDL software version 1.7 is installed.