WorkflowGridAdaptor

Overview

This adaptor constructs an ExecutionPlan that can mediate to submit a job described through a JDL file using a gLite Grid UI node. After its submission the job is monitored for its status and once completed the output files are retrieved and stored in the StorageSystem. The resources that are provided and need to be moved to the Grid UI are all transfered through the StorageSystem. They are stored once the plan is constructed and are then retrieved once the execution is started. This does not include the provided user proxy which is transfered as an attachment directly to the remote node to allow secure transfer if the SSL communication option is enabled.

Plan Template

The entire execution process takes place in the gLite Grid UI node. This node is picked from the InformationSystem and is currently chosen randomly from all the available ones. Currently once the node has been picked, the execution cannot be moved to a different one even if there is a problem communicating with that node. The execution that takes place is a sequential series of steps. These steps include the following:

• Contact the remote node
• Retrieval of the data stored in the StorageSystem and these include the resources marked as Configuration, Input Data, and JDL description
• Submit the job using the provided JDL file and optionally any configuration additionally provided using the provided user proxy certificate
• Go into a loop until either the job is completed or a timeout has expired (If a timeout has been set)
  • Wait for a defined period
  • Retrieve the job status
  • Retrieve the job logging info
  • Process the results of the above two steps
• Check the reason the loop ended
• If a timeout happened, cancel the job
• Otherwise retrieve the output files of the job

Known limitations

- Only retrieve output files if completion is successful. - Handle errors and not let every exception stop the execution. - Allow for relocation of execution - If relocated cancel previous execution - Add SSL option in communication - Allow multiple JDLs and collection style submission - Delete files stored in Storage System if error in plan construction and after completion