I'm going to say the same thing as bug 1801733 - this is super nifty and interesting, but realistically is not a concern and will most likely never get addressed.
** Changed in: nova Status: New => Won't Fix -- 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/1800204 Title: n-cpu.service consuming 100% of CPU indeterminately Status in OpenStack Compute (nova): Won't Fix Bug description: Description ============== I used fault injection to assess the robustness of the nova-conductor, and by injecting a specific sequence of failures I saw a failure that can threaten the robustness of the system. The resulting of applying these faults in the interface of nova-conductor prevent the nova-compute provisioning new instances. Steps to reproduce ===================== I reproduced this bug 100% from 10 attempts. I used devstack/queens. The workload I used is of the following steps: 1) First, create a VM with the following flavor: 64MB RAM, 1 VCPU, 0 DISK; and the reference image 'cirros.0.3.4' for instance; all other settings can be the defaults of admin account; 2) Rebuild with an alternative image: for instance, 'cirros 0.4.0'; 3) Rebuild with the reference image again; 4) Shelve the instance; 5) Delete the instance; Below, I describe the faultload. For each time a fault is injected, the workload is executed from its begin. The steps are: 1) Intercept the first RPC message (i.e. AMQP) that calls for 'schedule_and_build_instances'; 2) Inject the 'fault' in 'schedule_and_build_instances.args.build_requests->'nova_object.data'.instance.'nova_object.data'.flavor.'nova_object.data'.vcpus' The pseudo-algorithm: 1. execute workload 2. for each fault in ['2', '-10000000000000000000001', '10000000000000000000000'] 2.1. execute workload in parallel with faultload(fault) 3. see the CPU activity for the process n-cpu.service of devstack Expected result ================== nova-compute handles the faults not impacting in future requests. Actual result ================ nova-compute consumes 100% of CPU and new instances is set to 'error' state without any clue about the issue, so it is not possible to create new instances without restarting n-cpu.service Environment ============== Devstack/Queens in Single Machine with defaults. Logs & Configs ================= Logs attached. To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1800204/+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