def get_all(self, group_id):
"""Return all members in a list, or a ServiceGroupUnavailable
exception.
"""
monitor = self._monitors.get(group_id, None)
if monitor is None:
path = "%s/%s" % (CONF.zookeeper.sg_prefix, group_id)
null = open(os.devnull, "w")
local_session = evzookeeper.ZKSession(
CONF.zookeeper.address,
recv_timeout=CONF.zookeeper.recv_timeout,
zklog_fd=null)
monitor = membership.MembershipMonitor(local_session, path)
self._monitors[group_id] = monitor
# Note(maoy): When initialized for the first time, it takes a
# while to retrieve all members from zookeeper. To prevent
# None to be returned, we sleep 5 sec max to wait for data to
# be ready.
for _retry in range(50):
eventlet.sleep(0.1)
all_members = monitor.get_all()
if all_members is not None:
return all_members
all_members = monitor.get_all()
if all_members is None:
raise exception.ServiceGroupUnavailable(driver="ZooKeeperDriver")
return all_members
def get_all(self, group_id):
"""Return all members in a list, or a ServiceGroupUnavailable
exception.
"""
monitor = self._monitors.get(group_id, None)
if monitor is None:
path = "%s/%s" % (CONF.zookeeper.sg_prefix, group_id)
null = open(os.devnull, "w")
local_session = evzookeeper.ZKSession(CONF.zookeeper.address,
recv_timeout=
CONF.zookeeper.recv_timeout,
zklog_fd=null)
monitor = membership.MembershipMonitor(local_session, path)
self._monitors[group_id] = monitor
# Note(maoy): When initialized for the first time, it takes a
# while to retrieve all members from zookeeper. To prevent
# None to be returned, we sleep 5 sec max to wait for data to
# be ready.
timeout = 5 # seconds
interval = 0.1
tries = int(timeout / interval)
for _retry in range(tries):
eventlet.sleep(interval)
all_members = monitor.get_all()
if all_members is not None:
# Stop the tries once the cache is populated
LOG.debug('got info about members in %r: %r',
path, ', '.join(all_members))
break
else:
# if all_members, weren't populated
LOG.warning(_LW('Problem with acquiring the list of '
'children of %(path)r within a given '
'timeout=%(timeout)rs'),
path, timeout)
else:
all_members = monitor.get_all()
if all_members is None:
raise exception.ServiceGroupUnavailable(driver="ZooKeeperDriver")
def have_processes(member):
"""Predicate that given member has processes (subnode exists)."""
value, stat = monitor.get_member_details(member)
# only check nodes that are created by Membership class
if value == 'ZKMembers':
num_children = stat['numChildren']
return num_children > 0
else:
# unknown type of node found - ignoring
return False
# filter only this members that have processes running
all_members = filter(have_processes, all_members)
return all_members
