Merge "Add 'requires_beating' property to coordination driver"

tooz/coordination.py

@@ -64,6 +64,14 @@ class LeaderElected(Event):
 @six.add_metaclass(abc.ABCMeta)
 class CoordinationDriver(object):
 
+    requires_beating = False
+    """
+    Usage requirement that if true requires that the :py:meth:`~.heartbeat`
+    be called periodically (at a given rate) to avoid locks, sessions and
+    other from being automatically closed/discarded by the coordinators
+    backing store.
+    """
+
     def __init__(self):
         self._started = False
         self._hooks_join_group = collections.defaultdict(Hooks)

tooz/drivers/memcached.py

@@ -145,6 +145,9 @@ class MemcachedDriver(coordination._RunWatchersMixin,
     #: String used to keep a key/member alive (until it next expires).
     STILL_ALIVE = b"It's alive!"
 
+    #: This driver requires constant periodic (heart) beatings.
+    requires_beating = True
+
     def __init__(self, member_id, parsed_url, options):
         super(MemcachedDriver, self).__init__()
         options = utils.collapse(options)

tooz/drivers/redis.py

@@ -286,6 +286,9 @@ return 1
     .. _Lua: http://www.lua.org
     """
 
+    #: This driver requires constant periodic (heart) beatings.
+    requires_beating = True
+
     def __init__(self, member_id, parsed_url, options):
         super(RedisDriver, self).__init__()
         options = utils.collapse(options, exclude=self.CLIENT_LIST_ARGS)