Comment 10 for bug 1489548

Reviewed: https://review.openstack.org/226135
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=5576ffd249e251abab87fc954f778e2f9b003cfe
Submitter: Jenkins
Branch: master

commit 5576ffd249e251abab87fc954f778e2f9b003cfe
Author: Steve Baker <email address hidden>
Date: Tue Sep 22 10:50:23 2015 +1200

    Use root_stack_id for stack_count_total_resources

    The current implementation of stack_count_total_resources
    scales very poorly for stacks with many nested stacks.

    This change replaces the implementation with a single count
    query filtering on the resource.root_stack_id column.

    The following template was used for performance testing:

    heat_template_version: 2015-04-30
    description: >
      Stress test, create many stacks in a RG
    parameters:
      count:
        type: number
        default: 4
    resources:
      dummies:
        type: OS::Heat::ResourceGroup
        properties:
          count: {get_param: count}
          resource_def:
            type: dummy_node.yaml

     # dummy_node.yaml
    heat_template_version: 2015-04-30
    parameters:
    resources:
      random:
        type: OS::Heat::RandomString
      randoms:
        type: OS::Heat::ResourceGroup
        properties:
          count: 1
          resource_def:
            type: OS::Heat::RandomString

    This template was used to time the stack creation with
    count=40 and count=80 against heat-master, the previous
    change I2b00285514235834131222012408d2b5b2b37d30
    and this change. Here are the results:

     Stack heat-master-40 CREATE_COMPLETE
    real 1m9.103s

     Stack root-stack-id-40 CREATE_COMPLETE
    real 0m59.233s

     Stack count-total-resources-40 CREATE_COMPLETE
    real 0m43.308s

     Stack heat-master-80 CREATE_COMPLETE
    real 2m47.190s

     Stack root-stack-id-80 CREATE_COMPLETE
    real 2m16.743s

     Stack count-total-resources-80 CREATE_COMPLETE
    real 1m15.288s

    Also, the test template in bug #1489548 took 3 minutes
    to create (vs the originally reported 13 minutes).

    Change-Id: Iab3eaaba3ece16e14db3231f1c725bca3c8985c2
    Closes-Bug: 1489548