@Override
public Optional<ImmutableSet<PreemptionVictim>> filterPreemptionVictims(
ITaskConfig pendingTask,
Iterable<PreemptionVictim> possibleVictims,
AttributeAggregate jobState,
Optional<HostOffer> offer,
StoreProvider storeProvider) {
// This enforces the precondition that all of the resources are from the same host. We need to
// get the host for the schedulingFilter.
Set<String> hosts =
ImmutableSet.<String>builder()
.addAll(Iterables.transform(possibleVictims, VICTIM_TO_HOST))
.addAll(Iterables.transform(offer.asSet(), OFFER_TO_HOST))
.build();
ResourceSlot slackResources = sum(Iterables.transform(offer.asSet(), OFFER_TO_RESOURCE_SLOT));
FluentIterable<PreemptionVictim> preemptableTasks =
FluentIterable.from(possibleVictims).filter(preemptionFilter(pendingTask));
if (preemptableTasks.isEmpty()) {
return Optional.absent();
}
Set<PreemptionVictim> toPreemptTasks = Sets.newHashSet();
Iterable<PreemptionVictim> sortedVictims =
resourceOrder.immutableSortedCopy(preemptableTasks);
Optional<IHostAttributes> attributes =
storeProvider.getAttributeStore().getHostAttributes(Iterables.getOnlyElement(hosts));
if (!attributes.isPresent()) {
metrics.recordMissingAttributes();
return Optional.absent();
}
for (PreemptionVictim victim : sortedVictims) {
toPreemptTasks.add(victim);
ResourceSlot totalResource =
sum(Iterables.transform(toPreemptTasks, victimToResources)).add(slackResources);
Set<Veto> vetoes =
schedulingFilter.filter(
new UnusedResource(totalResource, attributes.get()),
new ResourceRequest(pendingTask, jobState));
if (vetoes.isEmpty()) {
return Optional.of(ImmutableSet.copyOf(toPreemptTasks));
}
}
return Optional.absent();
}
