The nova.openstack.common.rpc.matchmaker Module

The MatchMaker classes should except a Topic or Fanout exchange key and return keys for direct exchanges, per (approximate) AMQP parlance.

class Binding

Bases: object

A binding on which to perform a lookup.

test(key)

class DirectBinding

Bases: nova.openstack.common.rpc.matchmaker.Binding

Specifies a host in the key via a ‘.’ character Although dots are used in the key, the behavior here is that it maps directly to a host, thus direct.

test(key)

class DirectExchange

Bases: nova.openstack.common.rpc.matchmaker.Exchange

Exchange where all topic keys are split, sending to second half. i.e. “compute.host” sends a message to “compute.host” running on “host”

run(key)

class Exchange

Bases: object

Implements lookups. Subclass this to support hashtables, dns, etc.

run(key)

class FanoutBinding

Bases: nova.openstack.common.rpc.matchmaker.Binding

Match on fanout keys, where key starts with ‘fanout.’ string.

test(key)

class FanoutRingExchange(ring=None)

Bases: nova.openstack.common.rpc.matchmaker.RingExchange

Fanout Exchange based on a hashmap.

run(key)

class HeartbeatMatchMakerBase

Bases: nova.openstack.common.rpc.matchmaker.MatchMakerBase

Base for a heart-beat capable MatchMaker. Provides common methods for registering, unregistering, and maintaining heartbeats.

ack_alive(key, host)

Acknowledge that a host.topic is alive. Used internally for updating heartbeats, but may also be used publically to acknowledge a system is alive (i.e. rpc message successfully sent to host)

backend_register(key, host)

Implements registration logic. Called by register(self,key,host)

backend_unregister(key, key_host)

Implements de-registration logic. Called by unregister(self,key,host)

register(key, host)

Register a host on a backend. Heartbeats, if applicable, may keepalive registration.

send_heartbeats()

Send all heartbeats. Use start_heartbeat to spawn a heartbeat greenthread, which loops this method.

start_heartbeat()

Implementation of MatchMakerBase.start_heartbeat Launches greenthread looping send_heartbeats(), yielding for CONF.matchmaker_heartbeat_freq seconds between iterations.

stop_heartbeat()

Destroys the heartbeat greenthread.

unregister(key, host)

Unregister a topic.

class LocalhostExchange(host='localhost')

Bases: nova.openstack.common.rpc.matchmaker.Exchange

Exchange where all direct topics are local.

run(key)

class MatchMakerBase

Bases: object

Match Maker Base Class. Build off HeartbeatMatchMakerBase if building a heartbeat-capable MatchMaker.

ack_alive(key, host)

Acknowledge that a key.host is alive. Used internally for updating heartbeats, but may also be used publically to acknowledge a system is alive (i.e. rpc message successfully sent to host)

add_binding(binding, rule, last=True)

expire(topic, host)

Explicitly expire a host’s registration.

is_alive(topic, host)

Checks if a host is alive.

queues(key)

register(key, host)

Register a host on a backend. Heartbeats, if applicable, may keepalive registration.

send_heartbeats()

Send all heartbeats. Use start_heartbeat to spawn a heartbeat greenthread, which loops this method.

start_heartbeat()

Spawn heartbeat greenthread.

stop_heartbeat()

Destroys the heartbeat greenthread.

unregister(key, host)

Unregister a topic.

exception MatchMakerException

Bases: exceptions.Exception

Signified a match could not be found.

message = u'Match not found by MatchMaker.'

class MatchMakerLocalhost(host='localhost')

Bases: nova.openstack.common.rpc.matchmaker.MatchMakerBase

Match Maker where all bare topics resolve to localhost. Useful for testing.

class MatchMakerRing(ring=None)

Bases: nova.openstack.common.rpc.matchmaker.MatchMakerBase

Match Maker where hosts are loaded from a static hashmap.

class MatchMakerStub

Bases: nova.openstack.common.rpc.matchmaker.MatchMakerBase

Match Maker where topics are untouched. Useful for testing, or for AMQP/brokered queues. Will not work where knowledge of hosts is known (i.e. zeromq)

class RingExchange(ring=None)

Bases: nova.openstack.common.rpc.matchmaker.Exchange

Match Maker where hosts are loaded from a static file containing a hashmap (JSON formatted).

__init__ takes optional ring dictionary argument, otherwise loads the ringfile from CONF.mathcmaker_ringfile.

class RoundRobinRingExchange(ring=None)

Bases: nova.openstack.common.rpc.matchmaker.RingExchange

A Topic Exchange based on a hashmap.

run(key)

class StubExchange

Bases: nova.openstack.common.rpc.matchmaker.Exchange

Exchange that does nothing.

run(key)

class TopicBinding

Bases: nova.openstack.common.rpc.matchmaker.Binding

Where a ‘bare’ key without dots. AMQP generally considers topic exchanges to be those with dots, but we deviate here in terminology as the behavior here matches that of a topic exchange (whereas where there are dots, behavior matches that of a direct exchange.

test(key)