multiple-backends configured hit the storwize ssh limitation

[TaoBai]

The storwize has a limitation that within 1 second can't burst more than 3 ssh connection to avoid hacker attack.
If configure more than 3 backends(pools) from the same storwize, each backend will start a new cinder-volume service and create new ssh connection. Then it will hit the storwize limiation.

I know is a feature in progress may solve this problem.
https://etherpad.openstack.org/p/cinder-pool-impl-comparison

I create this to see what we can do before this feature be finished

[Huang Zhiteng (zhiteng-huang)]

This doesn't seem like a Cinder bug. I'd call it a Storwize bug/issue/limitation instead.

[Jakub Pavlik (pavlk-jakub)]

Is there posibillity how to start each ssh session into storwize with 1 sec delay?

[Jay Bryant (jsbryant)]

Tao,

Wasn't that a workaround that had been tried was to put a 1 second sleep in? I think that it taking that approach for now is acceptable. Shouldn't be a notable performance impact.

[TaoBai (baitao2020)]

Hi Jay
Thanks for your comments, that's also what I thought. I will do it.

[Jason Ni (jason-ni-py)]

As it's a workaround, I think it would be good to expose a switch in conf file that enable users to have the choice.

[TaoBai (baitao2020)]

Hi ZhiTeng
After consideration, I will change the status from In progress to new. Because I will use this ticket to follow storwize driver change. let me know, if you still can't agree. You are also welcome to review the code change
Thanks.

[TaoBai (baitao2020)]

Hi Jason

I don't think we need change the cinder.conf. It affect every storwize driver user when setup more than 3 backend. And the change will only influence storwize driver

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/104137

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/104137
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=776c94a8a3f49370a519e4ca92fb3071fc86e262
Submitter: Jenkins
Branch: master

commit 776c94a8a3f49370a519e4ca92fb3071fc86e262
Author: Tao Bai <email address hidden>
Date: Wed Jul 2 03:17:50 2014 -0700

    Slow down Storwize driver initialization

    Storwize has the limitation that can not burst more than
    3 new ssh connection within 1 second.So slow down storwize
    driver initialization.

    Closes-Bug: #1335722
    Change-Id: Id442cd6421ef23b953a3cb45a5f6dd6969064a6e

[OpenStack Infra (hudson-openstack)]

Change abandoned by Mike Perez (<email address hidden>) on branch: master
Review: https://review.openstack.org/134147
Reason: No activity for over a month.