======Dispatch manager Scheduler 5.4======

In order to decouple the scheduling process, GridWay uses a Scheduler module to schedule jobs.

The format to send a scheduling request to the Scheduler, through its standard input, is:<file>SCHEDULE - - -</file>On the other side, the format to receive a response from the Scheduler, through its standard output, is:<file>OPERATION JID RESULT INFO</file>Where:
  * OPERATION: Is the operation requested to the Dispatch Manager. The Dispatch Manager only supports the SCHEDULE_JOB operation.
  * JID: It is a job identifier.
  * RESULT: It is the result of the operation. Could be SUCCESS or FAILURE.
  * INFO: If RESULT is FAILURE, it contains the cause of failure. Otherwise, if OPERATION is SCHEDULE_JOB it contains a resource specification in the form HID:QNAME:RANK, where:
    * HID: It is the host identifier, as provided by **gwhost** command.
    * QNAME: It is the queue name.
    * RANK: It is the rank of the host.

GridWay 5 includes a scheduler template ("gw_scheduler_skel.c") to develop custom schedulers. As an example a Round-Robin/Flooding scheduler can be found in the GridWay distribution ("gw_flood_scheduler.c", in "$GW_LOCATION/src/sched/"). This is a very simple scheduling algorithm, which maximizes the number of jobs submitted to the Grid.