Uploaded image for project: 'Hive'
  1. Hive
  2. HIVE-17481

LLAP workload management

Log workAgile BoardRank to TopRank to BottomBulk Copy AttachmentsBulk Move AttachmentsVotersWatch issueWatchersCreate sub-taskMoveLinkCloneLabelsUpdate Comment AuthorReplace String in CommentUpdate Comment VisibilityDelete Comments
    XMLWordPrintableJSON

Details

    • New Feature
    • Status: Closed
    • Major
    • Resolution: Fixed
    • None
    • 3.0.0
    • None
    • None

    Description

      This effort is intended to improve various aspects of cluster sharing for LLAP. Some of these are applicable to non-LLAP queries and may later be extended to all queries. Administrators will be able to specify and apply policies for workload management ("resource plans") that apply to the entire cluster, with only one resource plan being active at a time. The policies will be created and modified using new Hive DDL statements.
      The policies will cover:

      • Dividing the cluster into a set of (optionally, nested) query pools that are each allocated a fraction of the cluster, a set query parallelism, resource sharing policy between queries, and potentially others like priority, etc.
      • Mapping the incoming queries into pools based on the query user, groups, explicit configuration, etc.
      • Specifying rules that perform actions on queries based on counter values (e.g. killing or moving queries).
        One would also be able to switch policies on a live cluster without (usually) affecting running queries, including e.g. to change policies for daytime and nighttime usage patterns, and other similar scenarios. The switches would be safe and atomic; versioning may eventually be supported.

      Some implementation details:

      • WM will only be supported in HS2 (for obvious reasons).
      • All LLAP query AMs will run in "interactive" YARN queue and will be fungible between Hive pools.
      • We will use the concept of "guaranteed tasks" (also known as ducks) to enforce cluster allocation without a central scheduler and without compromising throughput. Guaranteed tasks preempt other (speculative) tasks and are distributed from HS2 to AMs, and from AMs to tasks, in accordance with percentage allocations in the policy. Each "duck" corresponds to a CPU resource on the cluster. The implementation will be isolated so as to allow different ones later.
      • In future, we may consider improved task placement and late binding, similar to the ones described in Sparrow paper, to work around potential hotspots/etc. that are not avoided with the decentralized scheme.
      • Only one HS2 will initially be supported to avoid split-brain workload management. We will also implement (in a tangential set of work items) active-passive HS2 recovery. Eventually, we intend to switch to full active-active HS2 configuration with shared WM and Tez session pool (unlike the current case with 2 separate session pools).

      Attachments

        1. Workload management design doc.pdf
          214 kB
          Sergey Shelukhin

        Issue Links

        There are no Sub-Tasks for this issue.

        Activity

          This comment will be Viewable by All Users Viewable by All Users
          Cancel

          People

            sershe Sergey Shelukhin Assign to me
            sershe Sergey Shelukhin
            Votes:
            0 Vote for this issue
            Watchers:
            10 Start watching this issue

            Dates

              Created:
              Updated:
              Resolved:

              Slack

                Issue deployment