Reviewed: https://review.openstack.org/593131 Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=c3a77f80b1863e114109af9c32ea01b205c1a735 Submitter: Zuul Branch: master
commit c3a77f80b1863e114109af9c32ea01b205c1a735 Author: Dan Smith <[email protected]> Date: Fri Aug 17 07:56:05 2018 -0700 Make instance_list perform per-cell batching This makes the instance_list module support batching across cells with a couple of different strategies, and with room to add more in the future. Before this change, an instance list with limit 1000 to a deployment with 10 cells would generate a query to each cell database with the same limit. Thus, that API request could end up processing up to 10,000 instance records despite only returning 1000 to the user (because of the limit). This uses the batch functionality in the base code added in Iaa4759822e70b39bd735104d03d4deec988d35a1 by providing a couple of strategies by which the batch size per cell can be determined. These should provide a lot of gain in the short term, and we can extend them with other strategies as we identify some with additional benefits. Closes-Bug: #1787977 Change-Id: Ie3a5f5dc49f8d9a4b96f1e97f8a6ea0b5738b768 ** Changed in: nova Status: In Progress => Fix Released -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to OpenStack Compute (nova). https://bugs.launchpad.net/bugs/1787977 Title: Inefficient multi-cell instance list Status in OpenStack Compute (nova): Fix Released Status in OpenStack Compute (nova) queens series: New Status in OpenStack Compute (nova) rocky series: New Bug description: This is based on some performance and scale testing done by Huawei, reported in this dev ML thread: http://lists.openstack.org/pipermail/openstack- dev/2018-August/133363.html In that scenario, they have 10 cells with 10000 instances in each cell. They then run through a few GET /servers/detail scenarios with multiple cells and varying limits. The thread discussion pointed out that they were wasting time pulling 1000 records (the default [api]/max_limit) from all 10 cells and then throwing away 9000 of those results, so the DB query time per cell was small, but the sqla/ORM/python was chewing up the time. Dan Smith has a series of changes here: https://review.openstack.org/#/q/topic:batched-inst- list+(status:open+OR+status:merged) Which allow us to batch the DB queries per cell which, when distributed across the 10 cells, e.g. 1000 / 10 = 100 batch size per cell, ends up cutting the time spent in about half (around 11 sec to around 6 sec). This is clearly a performance issue which we have a fix, and we arguably should backport the fix. Note this is less of an issue for deployments that leverage the [api]/instance_list_per_project_cells option (like CERN): https://docs.openstack.org/nova/latest/configuration/config.html#api.instance_list_per_project_cells To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1787977/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : [email protected] Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp
