if (null == anyRequest) {
continue;
}
// Required resource
Resource required = anyRequest.getCapability();
// Do we need containers at this 'priority'?
if (!needContainers(application, priority, required)) {
continue;
}
// Compute user-limit & set headroom
// Note: We compute both user-limit & headroom with the highest
// priority request as the target.
// This works since we never assign lower priority requests
// before all higher priority ones are serviced.
Resource userLimit =
computeUserLimitAndSetHeadroom(application, clusterResource,
required);
// Check queue max-capacity limit
if (!assignToQueue(clusterResource, required)) {
return NULL_ASSIGNMENT;
}
// Check user limit
if (!assignToUser(
clusterResource, application.getUser(), userLimit)) {
break;
}
// Inform the application it is about to get a scheduling opportunity
application.addSchedulingOpportunity(priority);
// Try to schedule
CSAssignment assignment =
assignContainersOnNode(clusterResource, node, application, priority,
null);
// Did the application skip this node?
if (assignment.getSkipped()) {
// Don't count 'skipped nodes' as a scheduling opportunity!
application.subtractSchedulingOpportunity(priority);
continue;
}
// Did we schedule or reserve a container?
Resource assigned = assignment.getResource();
if (Resources.greaterThan(
resourceCalculator, clusterResource, assigned, Resources.none())) {
// Book-keeping
// Note: Update headroom to account for current allocation too...