Public bug reported: Description ===========
When using soft-affinity to schedule instances on the same host, the weight is unexpectedly low if a server was previously scheduled to any server-group with more members on a host. Steps to reproduce ================== Do not restart nova-scheduler in the process or the bug doesn't appear. * Create a server-group with soft-affinity (let's call it A) * Create 6 servers in server-group A, one after the other so they end up on the same host. * Create another server-group with soft-affinity (B) * Create 1 server in server-group B * Create 1 server in server-group B and look at the scheduler's weights assigned to the hosts by the ServerGroupSoftAffinityWeigher. Expected result =============== The weight assigned to the host by the ServerGroupSoftAffinityWeigher should be 1, as the maximum number of instances for server-group B is on that host (the one we created there before). Actual result ============= The weight assigned to the host by the ServerGroupSoftAffinityWeigher is 0.2, as the maximum number of instances ever encountered on a host is 5. Environment =========== We noticed this on a queens version of nova a year ago. Can't give the exact commit anymore, but the code still looks broken in current master. I've opened a review-request for fixing this bug here: https://review.opendev.org/#/c/713863/ ** Affects: nova Importance: Undecided Assignee: Johannes Kulik (jkulik) Status: In Progress -- 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/1870096 Title: soft-affinity weight not normalized base on server group's maximum Status in OpenStack Compute (nova): In Progress Bug description: Description =========== When using soft-affinity to schedule instances on the same host, the weight is unexpectedly low if a server was previously scheduled to any server-group with more members on a host. Steps to reproduce ================== Do not restart nova-scheduler in the process or the bug doesn't appear. * Create a server-group with soft-affinity (let's call it A) * Create 6 servers in server-group A, one after the other so they end up on the same host. * Create another server-group with soft-affinity (B) * Create 1 server in server-group B * Create 1 server in server-group B and look at the scheduler's weights assigned to the hosts by the ServerGroupSoftAffinityWeigher. Expected result =============== The weight assigned to the host by the ServerGroupSoftAffinityWeigher should be 1, as the maximum number of instances for server-group B is on that host (the one we created there before). Actual result ============= The weight assigned to the host by the ServerGroupSoftAffinityWeigher is 0.2, as the maximum number of instances ever encountered on a host is 5. Environment =========== We noticed this on a queens version of nova a year ago. Can't give the exact commit anymore, but the code still looks broken in current master. I've opened a review-request for fixing this bug here: https://review.opendev.org/#/c/713863/ To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1870096/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : yahoo-eng-team@lists.launchpad.net Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp