[jira] [Created] (YARN-9598) Make reservation work well when multi-node enabled

["Tao Yang (JIRA)" <ji...@apache.org>]

Tao Yang created YARN-9598:
------------------------------

             Summary: Make reservation work well when multi-node enabled
                 Key: YARN-9598
                 URL: https://issues.apache.org/jira/browse/YARN-9598
             Project: Hadoop YARN
          Issue Type: Bug
          Components: capacityscheduler
            Reporter: Tao Yang
            Assignee: Tao Yang


This issue is to solve problems about reservation when multi-node enabled:
 # As discussed in YARN-9576, re-reservation proposal may be always generated on the same node and break the scheduling for this app and later apps. I think re-reservation in unnecessary and we can replace it with LOCALITY_SKIPPED to let scheduler have a chance to look up follow candidates for this app when multi-node enabled.
 # Scheduler iterates all nodes and try to allocate for reserved container in LeafQueue#allocateFromReservedContainer. Here there are two problems:
 ** The node of reserved container should be taken as candidates instead of all nodes when calling FiCaSchedulerApp#assignContainers, otherwise later scheduler may generate a reservation-fulfilled proposal on another node, which will always be rejected in FiCaScheduler#commonCheckContainerAllocation.
 ** Assignment returned by FiCaSchedulerApp#assignContainers could never be null even if it's just skipped, it will break the normal scheduling process for this leaf queue because of the if clause in LeafQueue#assignContainers: "if (null != assignment) \{ return assignment;}"
 # Nodes which have been reserved should be skipped when iterating candidates in RegularContainerAllocator#allocate, otherwise scheduler may generate allocation or reservation proposal on these node which will always be rejected in FiCaScheduler#commonCheckContainerAllocation.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: yarn-issues-unsubscribe@hadoop.apache.org
For additional commands, e-mail: yarn-issues-help@hadoop.apache.org