yahoo-eng-team team mailing list archive

[OpenStack Infra <1993181@xxxxxxxxxxxxxxxxxx>]

Reviewed:  https://review.opendev.org/c/openstack/neutron/+/861649
Committed: https://opendev.org/openstack/neutron/commit/f43891bf866b65ceef0e51633afbbf57ee2a6be8
Submitter: "Zuul (22348)"
Branch:    master

commit f43891bf866b65ceef0e51633afbbf57ee2a6be8
Author: Rodolfo Alonso Hernandez <ralonsoh@xxxxxxxxxx>
Date:   Wed Oct 5 13:22:29 2022 +0200

    [OVN] Allow to execute ``MetadataProxyHandler`` in a local thread
    
    If configuration option "metadata_workers=0", the OVN metadata agent
    will try to spawn the ``MetadataProxyHandler`` instance inside a local
    thread, instead of creating a new process. In this case, the method
    ``MetadataProxyHandler.post_fork_initialize`` is never called and the
    SB IDL is never created.
    
    This patch passes the OVN metadata agent SB IDL instance to the proxy
    handler instance. This also reduces the number of OVN database active
    connections.
    
    Closes-Bug: #1993181
    Change-Id: If9d827228002de7e3a55be660da266b60b0dfb79


** Changed in: neutron
       Status: In Progress => Fix Released

-- 
You received this bug notification because you are a member of Yahoo!
Engineering Team, which is subscribed to neutron.
https://bugs.launchpad.net/bugs/1993181

Title:
  [OVN] OVN metadata "MetadataProxyHandler" not working if workers=0

Status in neutron:
  Fix Released

Bug description:
  The OVN metadata service can spawn several "MetadataProxyHandler"
  instances in separate processes. The number of workers
  ("metadata_workers") will define how many processes will be created.

  If this configuration variable is set to zero, the parent process (in
  the case the OVN metadata agent) won't create a new process but start
  the service. The "wsgi.Server" instance will be started instead; that
  means the "wsgi.Server" instance will use the thread pool "self.pool =
  eventlet.GreenPool(1)" to execute the application. The server
  application is an instance of
  "neutron.agent.ovn.metadata.server.MetadataProxyHandler".

  This instance of "MetadataProxyHandler" has a SB IDL connection. This
  IDL connection is initialized in the "post_fork_initialize" call, that
  is executed when the event (resources.PROCESS, events.AFTER_INIT) is
  received. The problem is that when the "MetadataProxyHandler" instance
  is called inside a thread, not a process, this method is not called
  and the IDL connection is not initialized.

  In order to solve this issue and at the same time save OVN DB
  connections, the proposal is to resuse the OVN metadata IDL connection
  with the Proxy thread.

To manage notifications about this bug go to:
https://bugs.launchpad.net/neutron/+bug/1993181/+subscriptions