_poll_shelved_instances periodic task is offloading instances even if shelved_offload_time is -1

[Abhishek Kekane]

shelved_offload_time -1 means instance will remain in the SHELVED state until user unshelves it.
Current behavior of _poll_shelved_instances periodic task is not considering shelved_offload_time is configured as -1 and offloading all the instances which are in 'SHELVED' state.

Stpes to reproduce:
1. set shelved_offload_time to -1 and restart nova-compute service.
2. create instance and shelve it using command, "nova shelve <instance_id>"
3. verify instance is in SHELVED state and instance files are present in instance path.
4. wait until _poll_shelved_instances periodic task executes (default is 3600 seconds, you can change it to 120 seconds)
5. Once _poll_shelved_instances periodic task is executed, instance state changes to SHELVED_OFFLOADED and instance files are deleted from instance path.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/201436

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/201436
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=abf20cd57023039958091c39f6cdb775c912c9ac
Submitter: Jenkins
Branch: master

commit abf20cd57023039958091c39f6cdb775c912c9ac
Author: abhishekkekane <email address hidden>
Date: Thu Jul 9 02:58:30 2015 -0700

    Execute _poll_shelved_instances only if shelved_offload_time is > 0

    shelved_offload_time -1 means never offload shelved instance. Currently,
    the periodic task "_poll_shelved_instances" changes the vm state from
    SHELVED to SHELVED_OFFLOAD even when the shelved_offload_time is set to -1.

    Added check in _poll_shelved_instances to offload instances only if
    shelved_offload_time is greater than 0.

    DocImpact
    Closes-bug: #1472946
    Change-Id: I55368e961b65a5ca73718fdcd42823680f7cbfa4

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/kilo
Review: https://review.openstack.org/205384

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/juno
Review: https://review.openstack.org/205449

[Matt Riedemann (mriedem)]

Apparently this was regressed in kilo with change https://review.openstack.org/#/c/107057/. We don't need this for stable/juno though.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Abhishek Kekane (<email address hidden>) on branch: stable/juno
Review: https://review.openstack.org/205449

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/205384
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=701c88950c8c12660bec3f06a494e52f43051f61
Submitter: Jenkins
Branch: stable/kilo

commit 701c88950c8c12660bec3f06a494e52f43051f61
Author: abhishekkekane <email address hidden>
Date: Thu Jul 9 02:58:30 2015 -0700

    Execute _poll_shelved_instances only if shelved_offload_time is > 0

    shelved_offload_time -1 means never offload shelved instance. Currently,
    the periodic task "_poll_shelved_instances" changes the vm state from
    SHELVED to SHELVED_OFFLOAD even when the shelved_offload_time is set to -1.

    Added check in _poll_shelved_instances to offload instances only if
    shelved_offload_time is greater than 0.

    DocImpact
    Closes-bug: #1472946
    Change-Id: I55368e961b65a5ca73718fdcd42823680f7cbfa4
    (cherry picked from commit abf20cd57023039958091c39f6cdb775c912c9ac)