On 11/03/2015 11:45 PM, John Griffith wrote:
On Tue, Nov 3, 2015 at 3:20 PM, Boris Pavlovic <bo...@pavlovic.me <mailto:bo...@pavlovic.me>> wrote: Hi stackers, Usually such projects like Heat, Tempest, Rally, Scalar, and other tool that works with OpenStack are working with resources (e.g. VM, Volumes, Images, ..) in the next way: >>> resource = api.resouce_do_some_stuff() >>> while api.resource_get(resource["uuid"]) != expected_status >>> sleep(a_bit) For each async operation they are polling and call many times resource_get() which creates significant load on API and DB layers due the nature of this request. (Usually getting full information about resources produces SQL requests that contains multiple JOINs, e,g for nova vm it's 6 joins). What if we add new API method that will just resturn resource status by UUID? Or even just extend get request with the new argument that returns only status?
Hey Boris, As I asked in IRC, I'm kinda curious what the difference is here in terms of API and DB calls. I very well might be missing an idea here, but currently we do a get by ID in that loop that you mention, the only difference I see in what you're suggesting is a reduced payload maybe? A response that only includes the status? I may be missing an important idea here, but it seems to me that you would still have the same number of API calls and DB request, just possibly a slightly smaller payload. Let me know if I'm missing the idea here.
I think the idea is that we would only retrieve resource status rather than the full information about the resource. In doing so we would:
1) Reduce the load on the DB due to doing fewer JOINs and retrieving less data. 2) Reduce the message payload. I suspect that the first one is more important. Chris __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
