/**
* NOTE: This method only throws exceptions if it is in an illegal state to be scheduled, or if
* the tasks needs to be scheduled immediately and no resource is available. If the task is
* accepted by the schedule, any error sets the vertex state to failed and triggers the recovery
* logic.
*
* @param scheduler The scheduler to use to schedule this execution attempt.
* @param queued Flag to indicate whether the scheduler may queue this task if it cannot
* immediately deploy it.
* @throws IllegalStateException Thrown, if the vertex is not in CREATED state, which is the only
* state that permits scheduling.
* @throws NoResourceAvailableException Thrown is no queued scheduling is allowed and no resources
* are currently available.
*/
public boolean scheduleForExecution(Scheduler scheduler, boolean queued)
throws NoResourceAvailableException {
if (scheduler == null) {
throw new IllegalArgumentException("Cannot send null Scheduler when scheduling execution.");
}
final SlotSharingGroup sharingGroup = vertex.getJobVertex().getSlotSharingGroup();
final CoLocationConstraint locationConstraint = vertex.getLocationConstraint();
// sanity check
if (locationConstraint != null && sharingGroup == null) {
throw new RuntimeException(
"Trying to schedule with co-location constraint but without slot sharing allowed.");
}
if (transitionState(CREATED, SCHEDULED)) {
ScheduledUnit toSchedule =
locationConstraint == null
? new ScheduledUnit(this, sharingGroup)
: new ScheduledUnit(this, sharingGroup, locationConstraint);
// IMPORTANT: To prevent leaks of cluster resources, we need to make sure that slots are
// returned
// in all cases where the deployment failed. we use many try {} finally {} clauses to
// assure that
if (queued) {
SlotAllocationFuture future = scheduler.scheduleQueued(toSchedule);
future.setFutureAction(
new SlotAllocationFutureAction() {
@Override
public void slotAllocated(SimpleSlot slot) {
try {
deployToSlot(slot);
} catch (Throwable t) {
try {
slot.releaseSlot();
} finally {
markFailed(t);
}
}
}
});
} else {
SimpleSlot slot = scheduler.scheduleImmediately(toSchedule);
try {
deployToSlot(slot);
} catch (Throwable t) {
try {
slot.releaseSlot();
} finally {
markFailed(t);
}
}
}
return true;
} else {
// call race, already deployed, or already done
return false;
}
}
