Fullstack neutron-server fails to start with: 'RuntimeError: Could not bind to 0.0.0.0:X after trying for 30 seconds'

[Assaf Muller]

Paste of TRACE:
http://paste.openstack.org/show/491377/

Example of failure:
http://logs.openstack.org/06/286106/3/check/gate-neutron-dsvm-fullstack/df82460/logs/TestOvsConnectivitySameNetwork.test_connectivity_VLANs,Ofctl_/neutron-server--2016-03-22--00-18-18-027088.log.txt.gz

[Jakub Libosvar (libosvar)]

Looks like the same cause as in https://bugs.launchpad.net/neutron/+bug/1551288

[Assaf Muller (amuller)]

@Jakub, I can confirm that the run I saw this failure was based on a patch whose parent was merged in February, while the fix for the bug you linked was merged in March. In other words, I saw a failure that occurred before the RNG patch (Even though the CI run itself was after the RNG patch was merged).

[Assaf Muller (amuller)]

I'm going to set to incomplete for now, if this pops up at the gate I'll restore.

[Assaf Muller (amuller)]

Back to confirmed. I noticed a failure here: http://logs.openstack.org/98/294798/1/check/gate-neutron-dsvm-fullstack/52d29e4/, on a patch that includes the RNG change (Fix for https://bugs.launchpad.net/neutron/+bug/1551288), so it looks like this can still happen.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/298056

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/298056
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=03999961ac620249950d8bca628719e9c14c4382
Submitter: Jenkins
Branch: master

commit 03999961ac620249950d8bca628719e9c14c4382
Author: Assaf Muller <email address hidden>
Date: Thu Mar 24 22:14:07 2016 -0400

    Add fullstack cross-process port/ip address fixtures

    We've had a series of bugs with resources that need
    to be unique on the system across test runner
    processes. Ports are used by neutron-server and the
    OVS agent when run in native openflow mode. The function
    that generates ports looks up random unused ports and
    starts the service. However, it is raceful: By the time the
    port is found to be unused and the service is started,
    another test runner can pick the same random port.
    With close to 65536 ports to choose from, the chance
    for collision is low, but given enough test runs, it's
    happened a non-trivial amount of times, and given that
    a voting job needs a very low false-negative rate, we
    need a more robust solution. The same applies to IP
    addresses that are used by the OVS agent in tunneling
    mode, and for the LB agent in all modes. With IP addresses,
    we don't check if the IP address is used, we simply
    pick a random address from a large pool, and again
    we've seen a non-trivial amount of test failures.

    The bugs referenced below had simple, short term solutions
    applied but the bugs remain remain. This patch is a correct,
    long term solution that doesn't rely on chance.

    This patch adds a resource allocator that uses the disk
    to persist allocations. Access to the disk is guarded
    via a file lock. IP address, networks and ports fixtures
    use an allocator internally.

    Closes-Bug: #1551288
    Closes-Bug: #1561248
    Closes-Bug: #1560277
    Change-Id: I46c0ca138b806759128462f8d44a5fab96a106d3

[Doug Hellmann (doug-hellmann)]

This issue was fixed in the openstack/neutron 9.0.0.0b1 development milestone.