def perform_resharding(masters_with_slots, masters_without_slots, source):
amount_of_masters = len(masters_with_slots) + len(masters_without_slots)
i = 0
for master_with_slots in masters_with_slots:
shards_amount_master_will_give = master_with_slots.calculate_amount_of_shards(
amount_of_masters)
logger.debug("%s will give %s shards per split" %
(master_with_slots, shards_amount_master_will_give))
shards_amount_per_one_master = int(shards_amount_master_will_give)
for master_without_slots in masters_without_slots:
cmd_args = [
'--cluster', 'reshard', source, '--cluster-from',
master_with_slots.node_id, '--cluster-to',
master_without_slots.node_id, '--cluster-slots',
str(shards_amount_per_one_master), '--cluster-yes'
]
logger.debug(
"Sharding %s to %s %s slots" %
(master_with_slots.node_id, master_without_slots.node_id,
shards_amount_per_one_master))
run_redis_cli_cmd(cmd_args, False)
logger.debug('Soon will run sanity check')
time.sleep(5)
cmd_args = [
'--cluster', 'fix',
master_without_slots.ip + ":" + str(master_without_slots.port)
]
result = run_redis_cli_cmd(cmd_args, True)
logger.debug('Sanity check returned code %s' %
(str(result.returncode)))
i += 1
def is_valid_redis_node(node_address):
logging.debug('Validating connection to the %s', node_address)
host, port = util.split_address(node_address)
cmd_args = ['-c', '-h', host, '-p', port, 'ping']
result = util.run_redis_cli_cmd(cmd_args, True)
parsed_cmd_result = result.stdout.decode("utf-8").rstrip()
if parsed_cmd_result == "PONG":
cmd_args = ['-c', '-h', host, '-p', port, 'cluster', 'info']
result = util.run_redis_cli_cmd(cmd_args, True)
parsed_cmd_result = result.stdout.decode("utf-8").rstrip()
if parsed_cmd_result.find("cluster_size:0") >= 0:
logging.error(
'Managed to establish a connection with the %s node. But node is a part of an empty redis cluster',
node_address)
return False
logging.debug('Successfully established connection to %s',
node_address)
return True
logging.error(
'Could not establish connection with the %s node. Returned code: %s',
node_address, result.returncode)
return False
def add_node_to_cluster(source, target, target_role):
for redis_node_address in target:
host, port = split_address(redis_node_address)
if is_ip(host):
is_valid_redis_node(redis_node_address)
logging.info('Adding %s with the %s role to the cluster ', target, target_role)
full_node_address = host + ":" + str(port)
cmd = ['--cluster', 'add-node', full_node_address, source]
if target_role == "slave":
cmd.append("--cluster-slave")
result = run_redis_cli_cmd(cmd, True)
if result.returncode == 0:
logging.info('[V] Node %s was added to the cluster with role %s', full_node_address, target_role)
else:
logging.error(
'[X] Node %s was NOT added to the cluster. '
'Check if the given node is in clustered mode, '
'if is it empty or if this node is already part of the cluster',
full_node_address)
else:
logging.error(
'[X] %s node does not have a valid address', target)
def get_slot_distribution(host, port):
cmd_args = ['-c', '-h', host, '-p', port, 'cluster', 'nodes']
result = util.run_redis_cli_cmd(cmd_args, True)
result_as_array = parse_cmd_output_to_array(result.stdout)
return extract_cluster_masters(result_as_array)