ZeroMQ Context should be created once per driver instance

https://blueprints.launchpad.net/oslo.messaging/+spec/zmq-context-per-driver-instance

ZeroMQ context object has singleton nature, so producing it more than once per driver is inefficient consuming of resources.

Now it is created per socket.

Proposed change

oslo-messaging

Move creation of zmq context from ZmqSocket constructor ZmqSocket.__init__()

# oslo_messaging/_drivers/impl_zmq.py

class ZmqSocket(object):

   def __init__(self, addr, zmq_type, bind=True, subscribe=None):
      self.ctxt = zmq.Context(CONF.rpc_zmq_contexts)
      self.sock = self.ctxt.socket(zmq_type)

to ZmqDriver constructor ZmqDriver.__init__()

# oslo_messaging/_drivers/impl_zmq.py

class ZmqDriver(base.BaseDriver):

    def __init__(self, conf, url, default_exchange=None,
                 allowed_remote_exmods=None):
    self.ctxt = zmq.Context(CONF.rpc_zmq_contexts)

Update ZmqSocket.__init__() to pass zmq context as an argument

# oslo_messaging/_drivers/impl_zmq.py

class ZmqSocket(object):
   ...
   def __init__(self, zmq_ctx, addr, zmq_type, bind=True, subscribe=None):
      self.ctxt = zmq_ctx
      self.sock = self.ctxt.socket(zmq_type)

Alternatives

None

Impact on Existing APIs

None

Security impact

None

Performance Impact

None

Configuration Impact

None

Developer Impact

None

Implementation

Assignee(s)

Primary assignee:

Oleksii Zamiatin (ozamiatin@mirantis.com)

Other contributors:

None

Milestones

next-kilo

Work Items

1. Perform the code movements

2. Update all places in impl_zmq where socket used

Incubation

N/A

Adoption

N/A

Library

oslo.messaging

Documentation Impact

N/A

Dependencies

None

References

Note

Check neutron https://bugs.launchpad.net/neutron/+bug/1364814