openstack
/
oslo.messaging
Code Issues Proposed changes

[zmq] Redis TTL for values 

Redis as a key-value storage has limitations on values
expiration by ttl, only keys can expire. Regarding this
we need to introduce some redundancy and register hostnames
as keys along with general target keys to make them expire
on ttl timeout.

Change-Id: Ic0b06d8ec27b63ca49afe941a32020b5e532598c
This commit is contained in:
ozamiatin 2016-12-31 03:24:44 +02:00 committed by Oleksii Zamiatin
parent 96d506377f
commit e39be47b06
1 changed files with 32 additions and 4 deletions
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36
oslo_messaging/_drivers/zmq_driver/matchmaker/zmq_matchmaker_redis.py
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@ -160,13 +160,21 @@ class MatchmakerRedisBase(zmq_matchmaker_base.MatchmakerBase):
def _smembers(self, key):
pass
@abc.abstractmethod
def _ttl(self, key):
pass
@no_reraise
def register_publisher(self, hostname, expire=-1):
self._sadd(_PUBLISHERS_KEY, ','.join(hostname), expire)
hostname = ','.join(hostname)
self._sadd(_PUBLISHERS_KEY, hostname, expire)
self._sadd(hostname, ' ', expire)
@no_reraise
def unregister_publisher(self, hostname):
self._srem(_PUBLISHERS_KEY, ','.join(hostname))
hostname = ','.join(hostname)
self._srem(_PUBLISHERS_KEY, hostname)
self._srem(hostname, ' ')
@empty_list_on_error
def get_publishers(self):
@ -176,10 +184,12 @@ class MatchmakerRedisBase(zmq_matchmaker_base.MatchmakerBase):
@no_reraise
def register_router(self, hostname, expire=-1):
self._sadd(_ROUTERS_KEY, hostname, expire)
self._sadd(hostname, ' ', expire)
@no_reraise
def unregister_router(self, hostname):
self._srem(_ROUTERS_KEY, hostname)
self._srem(hostname, ' ')
@empty_list_on_error
def get_routers(self):
@ -192,18 +202,22 @@ class MatchmakerRedisBase(zmq_matchmaker_base.MatchmakerBase):
if target.server:
key = zmq_address.target_to_key(target, listener_type)
self._sadd(key, hostname, expire)
self._sadd(hostname, ' ', expire)
key = zmq_address.prefix_str(target.topic, listener_type)
self._sadd(key, hostname, expire)
self._sadd(hostname, ' ', expire)
@no_reraise
def unregister(self, target, hostname, listener_type):
if target.server:
key = zmq_address.target_to_key(target, listener_type)
self._srem(key, hostname)
self._srem(hostname, ' ')
key = zmq_address.prefix_str(target.topic, listener_type)
self._srem(key, hostname)
self._srem(hostname, ' ')
def get_hosts(self, target, listener_type):
hosts = []
@ -315,9 +329,19 @@ class MatchmakerRedis(MatchmakerRedisBase):
def _srem(self, redis_instance, key, value):
redis_instance.srem(key, value)
@read_from_redis_connection_warn
def _ttl(self, redis_instance, key):
# NOTE(ozamiatin): If the specialized key doesn't exist,
# TTL fuction would return -2. If key exists,
# but doesn't have expiration associated,
# TTL func would return -1. For more information,
# please visit http://redis.io/commands/ttl
return redis_instance.ttl(key)
@read_from_redis_connection_warn
def _smembers(self, redis_instance, key):
return redis_instance.smembers(key)
hosts = redis_instance.smembers(key)
return [host for host in hosts if redis_instance.ttl(host) >= -1]
class MatchmakerRedisAvailabilityUpdater(zmq_updater.UpdaterBase):
@ -421,4 +445,8 @@ class MatchmakerSentinel(MatchmakerRedisBase):
self._redis_master.srem(key, value)
def _smembers(self, key):
return self._redis_slave.smembers(key)
hosts = self._redis_slave.smembers(key)
return [host for host in hosts if self._ttl(host) >= -1]
def _ttl(self, key):
return self._redis_slave.ttl(key)