def rescue_cluster(host, port, subst_host, subst_port):
failed_slots = set(xrange(SLOT_COUNT))
with Talker(host, port) as t:
_ensure_cluster_status_set(t)
for node in _list_masters(t)[0]:
failed_slots -= set(node.assigned_slots)
if len(failed_slots) == 0:
logging.info('No need to rescue cluster at %s:%d', host, port)
return
with Talker(subst_host, subst_port) as s:
_ensure_cluster_status_unset(s)
m = s.talk('cluster', 'meet', host, port)
logging.debug('Ask `cluster meet` Rsp %s', m)
if m.lower() != 'ok':
raise RedisStatusError('Unexpected reply after MEET: %s' % m)
m = s.talk('cluster', 'addslots', *failed_slots)
logging.debug('Ask `cluster addslots` Rsp %s', m)
if m.lower() != 'ok':
raise RedisStatusError('Unexpected reply after ADDSLOTS: %s' %
m)
_poll_check_status(s)
logging.info(
'Instance at %s:%d serves %d slots to rescue the cluster',
subst_host, subst_port, len(failed_slots))
def _poll_check_status(t):
m = t.talk_raw(CMD_CLUSTER_INFO)
logging.debug('Ask `cluster info` Rsp %s', m)
cluster_state = PAT_CLUSTER_STATE.findall(m)
cluster_slot_assigned = PAT_CLUSTER_SLOT_ASSIGNED.findall(m)
if cluster_state[0] != 'ok' or int(cluster_slot_assigned[0]) != SLOT_COUNT:
raise RedisStatusError('Unexpected status: %s' % m)
def _check_slave(slave_host, slave_port, t):
slave_addr = '%s:%d' % (slave_host, slave_port)
for line in t.talk('cluster', 'nodes').split('\n'):
if slave_addr in line:
if 'slave' in line:
return
raise RedisStatusError('%s not switched to a slave' % slave_addr)
def shutdown_cluster(host, port):
with Talker(host, port) as t:
_ensure_cluster_status_set(t)
myself = None
m = t.talk_raw(CMD_CLUSTER_NODES)
logging.debug('Ask `cluster nodes` Rsp %s', m)
nodes_info = filter(None, m.split('\n'))
if len(nodes_info) > 1:
raise RedisStatusError('More than 1 nodes in cluster.')
try:
m = t.talk('cluster', 'reset')
except hiredis.ReplyError, e:
if 'containing keys' in e.message:
raise RedisStatusError('Cluster containing keys')
raise
logging.debug('Ask `cluster delslots` Rsp %s', m)
def replicate(master_host, master_port, slave_host, slave_port):
master_talker = None
t = Talker(slave_host, slave_port)
try:
master_talker = Talker(master_host, master_port)
_ensure_cluster_status_set(master_talker)
myself = _list_nodes(master_talker)[1]
myid = (myself.node_id if myself.role_in_cluster == 'master'
else myself.master_id)
_join_to_cluster(master_host, master_port, t)
logging.info('Instance at %s:%d has joined %s:%d; now set replica',
slave_host, slave_port, master_host, master_port)
m = t.talk('cluster', 'replicate', myid)
logging.debug('Ask `cluster replicate` Rsp %s', m)
if m.lower() != 'ok':
raise RedisStatusError('Unexpected reply after REPCLIATE: %s' % m)
_check_slave(slave_host, slave_port, master_talker)
logging.info('Instance at %s:%d set as replica to %s',
slave_host, slave_port, myid)
finally:
t.close()
if master_talker is not None:
master_talker.close()
def expect_talk_ok(m, slot):
if m.lower() != 'ok':
raise RedisStatusError('\n'.join([
'Error while moving slot [ %d ] between' % slot,
'Source node - %s:%d' % (source_node.host, source_node.port),
'Target node - %s:%d' % (target_node.host, target_node.port),
'Got %s' % m]))
def _join_to_cluster(clst, new):
_ensure_cluster_status_set(clst)
_ensure_cluster_status_unset(new)
m = clst.talk('cluster', 'meet', new.host, new.port)
logging.debug('Ask `cluster meet` Rsp %s', m)
if m.lower() != 'ok':
raise RedisStatusError('Unexpected reply after MEET: %s' % m)
_poll_check_status(new)
def start_cluster(host, port):
with Talker(host, port) as t:
_ensure_cluster_status_unset(t)
m = t.talk('cluster', 'addslots', *xrange(SLOT_COUNT))
logging.debug('Ask `cluster addslots` Rsp %s', m)
if m.lower() != 'ok':
raise RedisStatusError('Unexpected reply after ADDSLOTS: %s' % m)
_poll_check_status(t)
logging.info('Instance at %s:%d started as a standalone cluster', host,
port)
def raise_(self, message):
raise RedisStatusError(message, self.host, self.port)
def addslots(t, begin, end):
m = t.talk('cluster', 'addslots', *xrange(begin, end))
logging.debug('Ask `cluster addslots` Rsp %s', m)
if m.lower() != 'ok':
raise RedisStatusError('Unexpected reply after ADDSLOTS: %s' % m)