neutron_lib.rpc module

class neutron_lib.rpc.BackingOffClient(transport, target, timeout=None, version_cap=None, serializer=None, retry=None, call_monitor_timeout=None, transport_options=None, _manual_load=True)

Bases: RPCClient

An oslo messaging RPC Client that implements a timeout backoff.

This has all of the same interfaces as oslo_messaging.RPCClient but if the timeout parameter is not specified, the _BackingOffContextWrapper returned will track when call timeout exceptions occur and exponentially increase the timeout for the given call method.

prepare(*args, **kwargs)

Prepare a method invocation context.

Use this method to override client properties for an individual method invocation. For example:

def test(self, ctxt, arg):
    cctxt = self.prepare(version='2.5')
    return cctxt.call(ctxt, 'test', arg=arg)
Parameters:

  • exchange (str) – see Target.exchange

  • topic (str) – see Target.topic

  • namespace (str) – see Target.namespace

  • version (str) – requirement the server must support, see Target.version

  • server (str) – send to a specific server, see Target.server

  • fanout (bool) – send to all servers on topic, see Target.fanout

  • timeout (int or float) – an optional default timeout (in seconds) for call()s

  • version_cap (str) – raise a RPCVersionCapError version exceeds this cap

  • retry (int) – an optional connection retries configuration: None or -1 means to retry forever. 0 means no retry is attempted. N means attempt at most N retries.

  • transport_options (dictionary) – additional parameters to configure the driver for example to send parameters as “mandatory” flag in RabbitMQ

  • call_monitor_timeout (int) – an optional timeout (in seconds) for active call heartbeating. If specified, requires the server to heartbeat long-running calls at this interval (less than the overall timeout parameter).

static set_max_timeout(max_timeout)

Set RPC timeout ceiling for all backing-off RPC clients.

class neutron_lib.rpc.Connection

Bases: object

A utility class that manages a collection of RPC servers.

close()
consume_in_threads()
create_consumer(topic, endpoints, fanout=False)
class neutron_lib.rpc.RequestContextSerializer(base=None)

Bases: Serializer

Convert RPC common context into Neutron Context.

deserialize_context(ctxt)

Deserialize a dictionary into a request context.

Parameters:

ctxt – Request context dictionary

Returns:

Deserialized form of entity

deserialize_entity(ctxt, entity)

Deserialize something from primitive form.

Parameters:

  • ctxt – Request context, in deserialized form

  • entity – Primitive to be deserialized

Returns:

Deserialized form of entity

serialize_context(ctxt)

Serialize a request context into a dictionary.

Parameters:

ctxt – Request context

Returns:

Serialized form of context

serialize_entity(ctxt, entity)

Serialize something to primitive form.

Parameters:

  • ctxt – Request context, in deserialized form

  • entity – Entity to be serialized

Returns:

Serialized form of entity

class neutron_lib.rpc.Service(host, topic, manager=None, serializer=None)

Bases: Service

Service object for binaries running on hosts.

A service enables rpc by listening to queues based on topic and host.

reset()

Reset a service in case it received a SIGHUP.

start()

Start a service.

stop()

Stop a service.

Parameters:

graceful – indicates whether to wait for all threads to finish or terminate them instantly

wait()

Wait for a service to shut down.

neutron_lib.rpc.cleanup()

Deactivate and cleanup the global RPC objects.

Returns:

None.

neutron_lib.rpc.get_client(target, version_cap=None, serializer=None)

Get an RPC client for the said target.

The init() function must be called prior to calling this. :param target: The RPC target for the client. :param version_cap: The optional version cap for the RPC client. :param serializer: The optional serializer to use for the RPC client. :returns: A new RPC client.

neutron_lib.rpc.get_notifier(service=None, host=None, publisher_id=None)

Get a new notifier reference.

Parameters:

  • service – The optional service for the notifier. If not given, None is used as the service name (deprecated since 2025.1).

  • host – The optional host for the notifier. If not given, the host will be taken from the global CONF.

  • publisher_id – The optional publisher ID for the notifier. Overrides service and host arguments.

Returns:

A new RPC notifier reference.

neutron_lib.rpc.get_server(target, endpoints, serializer=None)

Get a new RPC server reference.

Parameters:

  • target – The target for the new RPC server.

  • endpoints – The endpoints for the RPC server.

  • serializer – The optional serialize to use for the RPC server.

Returns:

A new RPC server reference.

neutron_lib.rpc.init(conf, rpc_ext_mods=None)

Initialize the global RPC objects.

Parameters:

  • conf – The oslo conf to use for initialization.

  • rpc_ext_mods – Exception modules to expose via RPC.

Returns:

None.