ComputingElement

The Computing Element class is a base class for all the various types CEs. It serves several purposes:

  • collects general CE related parameters to generate CE description for the job matching

  • provides logic for evaluation of the number of available CPU slots

  • provides logic for the proxy renewal while executing jobs

The CE parameters are collected from the following sources, in hierarchy descending order:

  • parameters provided through setParameters() method of the class

  • parameters in /LocalSite configuration section

  • parameters in /LocalSite/<ceName>/ResourceDict configuration section

  • parameters in /LocalSite/ResourceDict configuration section

  • parameters in /LocalSite/<ceName> configuration section

  • parameters in /Resources/Computing/<ceName> configuration section

  • parameters in /Resources/Computing/CEDefaults configuration section

The ComputingElement objects are usually instantiated with the help of ComputingElementFactory.

class DIRAC.Resources.Computing.ComputingElement.ComputingElement(ceName)

Bases: object

ComputingElement base class

__init__(ceName)

Standard constructor

available(jobIDList=None)

This method returns the number of available slots in the target CE. The CE instance polls for waiting and running jobs and compares to the limits in the CE parameters.

Parameters

jobIDList (list) – list of already existing job IDs to be checked against

getCEStatus()

Method to get dynamic job information, can be overridden in sub-class.

getDescription()

Get CE description as a dictionary.

This is called by the JobAgent for the case of “inner” CEs.

initializeParameters()

Initialize the CE parameters after they are collected from various sources

isProxyValid(valid=1000)

Check if the stored proxy is valid

isValid()

Check the sanity of the Computing Element definition

loadBatchSystem(batchSystemName)

Instantiate object representing the backend batch system

Parameters

batchSystemName (str) – name of the batch system

loadParallelLibrary(parallelLibraryName, workingDirectory='.')

Instantiate object representing the parallel library that will generate a script to wrap the executable

Parameters

parallelLibraryName (str) – name of the parallel library

sendOutput(stdid, line)

Callback function such that the results from the CE may be returned.

setCPUTimeLeft(cpuTimeLeft=None)

Update the CPUTime parameter of the CE classAd, necessary for running in filling mode

setParameters(ceOptions)

Add parameters from the given dictionary overriding the previous values

Parameters

ceOptions (dict) – CE parameters dictionary to update already defined ones

setProxy(proxy, valid=0)

Set proxy for this instance

shutdown()

Optional method to shutdown the (Inner) Computing Element

submitJob(executableFile, proxy, **kwargs)

Method to submit job, should be overridden in sub-class.

writeProxyToFile(proxy)

CE helper function to write a CE proxy string to a file.

DIRAC.Resources.Computing.ComputingElement.getCEConfigDict(ceName)

Look into LocalSite for configuration Parameters for this CE