Nicira plugin: concurrent instance creation leads to timeouts

[Salvatore Orlando]

When instance are spawned from nova concurrently, either by concurrently submitting requests to nova, or by specifying num_instance > 1 on a create server request, the nicira plugin might fail in creating a port for the instance because of a NVP timeout in create_port

The root cause for this timeout depends on the fact that the NVP request is executed within a SQL transaction, and is executed spawning an eventlet, thus manifesting a behaviour similar to the one observed in bug 1086173.

This issue can be solved by moving the NVP operation outside of the sql transaction and ensuring orphaned resources, both in the database and NVP, are properly removed.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/36570

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/36570
Committed: http://github.com/openstack/neutron/commit/270fd80391ea1dd8f3be13d38df81be71ae751ee
Submitter: Jenkins
Branch: master

commit 270fd80391ea1dd8f3be13d38df81be71ae751ee
Author: Salvatore Orlando <email address hidden>
Date: Wed Jul 10 14:44:12 2013 +0200

    Separate NVP create lport operation and neutron db transaction

    Bug 1200001

    This patch removes the NVP call for creating a logical port from
    the SQL transaction context used for creating the Neutron port.
    It also ensures orphaned data are properly removed from both
    the Neutron DB and the NVP backend.

    Change-Id: I028a1493ecf732f2422e0eaa2020bac4ebdbb457