resizing cluster failed for unexpected reason

[Yanyan Hu]

When adjustment parameters are not provided in action input when resizing cluster, current desired_capacity will be used to check size parameter:

http://git.openstack.org/cgit/openstack/senlin/tree/senlin/engine/service.py#n842

This is incorrect. Consider the following case:

cluster.min_size = 1, cluster.max_size = 3, cluster.desired_capacity = 2. If cluster is resized using the following input:
params = {
    'max_size': 0,
}

The check is expected to fail here:
http://git.openstack.org/cgit/openstack/senlin/tree/senlin/common/scaleutils.py#n141

However, the parameter check will actually fail for the following reason:
http://git.openstack.org/cgit/openstack/senlin/tree/senlin/common/scaleutils.py#n113
and the exception message will be:
'The target capacity (2) is greater than the specified max_size(0)'

We should set desired to None rather than current desired_capacity in this case:
http://git.openstack.org/cgit/openstack/senlin/tree/senlin/engine/service.py#n842

[Qiming Teng (tengqim)]

It would be difficult to do size checking if we set 'desired' to None on line 842.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/273988

[Yanyan Hu (yanyanhu)]

Hi, Qiming, currently, check_size_params util function has been able to cover that case correctly. So we only need to give it correct size parameters we want to check against.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/273988
Committed: https://git.openstack.org/cgit/openstack/senlin/commit/?id=07c33fcb1b02c8dff06ea7d3c45e18847988b481
Submitter: Jenkins
Branch: master

commit 07c33fcb1b02c8dff06ea7d3c45e18847988b481
Author: yanyanhu <email address hidden>
Date: Fri Jan 29 03:36:24 2016 -0500

    Fix a bug in cluster_resize service routine

    This patch fixes a bug in cluster_resize service routine.

    Change-Id: Ib1677bcfab25a26b0d5a9a404261151f62ac2394
    Closes-Bug: #1539454

[Thierry Carrez (ttx)]

This issue was fixed in the openstack/senlin 1.0.0.0b3 development milestone.