def _transfer_slots(redis_conn_from: Redis, redis_id_from: str, redis_conn_to: Redis, redis_id_to: str, slots: list):
"""
Documentation from http://redis.io/commands/cluster-setslot
1. Set the destination node slot to importing state using CLUSTER SETSLOT <slot> IMPORTING <source-node-id>.
2. Set the source node slot to migrating state using CLUSTER SETSLOT <slot> MIGRATING <destination-node-id>.
3. Get keys from the source node with CLUSTER GETKEYSINSLOT command and move them into the destination node
using the MIGRATE command.
4. Use CLUSTER SETSLOT <slot> NODE <destination-node-id> in the source or destination.
"""
print('Transfering %d slots from %s to %s...' % (len(slots), redis_id_from, redis_id_to))
dest_host = redis_conn_to.connection_pool.connection_kwargs['host']
dest_port = redis_conn_to.connection_pool.connection_kwargs['port']
pipeline_to = redis_conn_to.pipeline()
pipeline_from = redis_conn_from.pipeline()
for slot in slots:
# 1, 2
pipeline_to.execute_command('CLUSTER SETSLOT', slot, 'IMPORTING', redis_id_from)
pipeline_from.execute_command('CLUSTER SETSLOT', slot, 'MIGRATING', redis_id_to)
pipeline_to.execute()
pipeline_from.execute()
for slot in slots:
# 3
keys = redis_conn_from.execute_command('CLUSTER GETKEYSINSLOT', slot, 1000000)
if len(keys) > 0:
redis_conn_from.execute_command('MIGRATE', dest_host, dest_port, "", 0, 180000, 'KEYS', *keys)
# 4
redis_conn_to.execute_command('CLUSTER SETSLOT', slot, 'NODE', redis_id_to)
def _add_new_nodes(self, cluster_size):
old_nodes = self.nodes.copy()
nodes_before = self._get_nodes_primitive()
self._docker_scale(cluster_size)
nodes_after = self._get_nodes_primitive()
new_ips = [
':'.join(map(str, x)) for x in set(nodes_after) - set(nodes_before)
]
print(new_ips)
master_ip_port = old_nodes[0]['ip_port']
master_ip, master_port = master_ip_port.split(':')
master_conn = Redis(master_ip, master_port)
print("Adding nodes to the cluster")
for ip in new_ips:
new_ip, new_port = ip.split(':')
master_conn.execute_command('CLUSTER MEET', new_ip, new_port)
print("Preventive fix")
sleep(3)
fix = subprocess.Popen(
['ruby', 'redis-trib.rb', 'fix', master_ip_port],
stdin=subprocess.PIPE,
stdout=subprocess.DEVNULL)
fix.communicate(b'yes\n')
fix.wait()
sleep(3)
new_nodes = [
x for x in self._get_running_nodes() if x['ip_port'] in new_ips
]
slots_per_node = round(16384 / cluster_size)
old_redises = {
x[0]: Redis(x[0], x[1])
for x in (y['ip_port'].split(':') for y in old_nodes)
}
new_redises = [
Redis(x[0], x[1])
for x in (y['ip_port'].split(':') for y in new_nodes)
]
slots_repartition = self._get_slots_repartition(
list(old_redises.values())[0])
for dest_node, dest_redis, i in zip(new_nodes, new_redises,
range(len(new_nodes))):
slots = slots_repartition[i * slots_per_node:(i + 1) *
slots_per_node]
sources_ip = {x[1] for x in slots}
for source_ip in sources_ip:
slots_for_source = [x for x in slots if x[1] == source_ip]
source_redis = old_redises[source_ip]
self._transfer_slots(source_redis, slots_for_source[0][3],
dest_redis, dest_node['id'],
[x[0] for x in slots_for_source])
subprocess.check_call(
['ruby', 'redis-trib.rb', 'info', master_ip_port])
def _add_new_nodes(self, cluster_size):
old_nodes = self.nodes.copy()
nodes_before = self._get_nodes_primitive()
self._docker_scale(cluster_size)
nodes_after = self._get_nodes_primitive()
new_ips = [':'.join(map(str, x)) for x in set(nodes_after) - set(nodes_before)]
print(new_ips)
master_ip_port = old_nodes[0]['ip_port']
master_ip, master_port = master_ip_port.split(':')
master_conn = Redis(master_ip, master_port)
print("Adding nodes to the cluster")
for ip in new_ips:
new_ip, new_port = ip.split(':')
master_conn.execute_command('CLUSTER MEET', new_ip, new_port)
print("Preventive fix")
sleep(3)
fix = subprocess.Popen(['ruby', 'redis-trib.rb', 'fix', master_ip_port], stdin=subprocess.PIPE, stdout=subprocess.DEVNULL)
fix.communicate(b'yes\n')
fix.wait()
sleep(3)
new_nodes = [x for x in self._get_running_nodes() if x['ip_port'] in new_ips]
slots_per_node = round(16384 / cluster_size)
old_redises = {x[0]: Redis(x[0], x[1]) for x in (y['ip_port'].split(':') for y in old_nodes)}
new_redises = [Redis(x[0], x[1]) for x in (y['ip_port'].split(':') for y in new_nodes)]
slots_repartition = self._get_slots_repartition(list(old_redises.values())[0])
for dest_node, dest_redis, i in zip(new_nodes, new_redises, range(len(new_nodes))):
slots = slots_repartition[i * slots_per_node: (i + 1) * slots_per_node]
sources_ip = {x[1] for x in slots}
for source_ip in sources_ip:
slots_for_source = [x for x in slots if x[1] == source_ip]
source_redis = old_redises[source_ip]
self._transfer_slots(source_redis, slots_for_source[0][3],
dest_redis, dest_node['id'],
[x[0] for x in slots_for_source])
subprocess.check_call(['ruby', 'redis-trib.rb', 'info', master_ip_port])
def _get_slots_repartition(any_redis_conn: Redis):
"""
Returns a shuffled list of (slot_number, node_ip, node_port, node_id)
"""
# List of [10923, 16383, [b'10.0.0.4', 6379, b'f1dc21d0b7a24aaea3b3fcd0ef943a35fa2ebb42']]
cluster_slots = any_redis_conn.execute_command('CLUSTER SLOTS')
output = []
for slot in cluster_slots:
for i in range(slot[0], slot[1] + 1):
output.append((i, slot[2][0].decode(), slot[2][1], slot[2][2].decode()))
random.shuffle(output)
return output
def _get_slots_repartition(any_redis_conn: Redis):
"""
Returns a shuffled list of (slot_number, node_ip, node_port, node_id)
"""
# List of [10923, 16383, [b'10.0.0.4', 6379, b'f1dc21d0b7a24aaea3b3fcd0ef943a35fa2ebb42']]
cluster_slots = any_redis_conn.execute_command('CLUSTER SLOTS')
output = []
for slot in cluster_slots:
for i in range(slot[0], slot[1] + 1):
output.append(
(i, slot[2][0].decode(), slot[2][1], slot[2][2].decode()))
random.shuffle(output)
return output
def _transfer_slots(redis_conn_from: Redis, redis_id_from: str,
redis_conn_to: Redis, redis_id_to: str, slots: list):
"""
Documentation from http://redis.io/commands/cluster-setslot
1. Set the destination node slot to importing state using CLUSTER SETSLOT <slot> IMPORTING <source-node-id>.
2. Set the source node slot to migrating state using CLUSTER SETSLOT <slot> MIGRATING <destination-node-id>.
3. Get keys from the source node with CLUSTER GETKEYSINSLOT command and move them into the destination node
using the MIGRATE command.
4. Use CLUSTER SETSLOT <slot> NODE <destination-node-id> in the source or destination.
"""
print('Transfering %d slots from %s to %s...' %
(len(slots), redis_id_from, redis_id_to))
dest_host = redis_conn_to.connection_pool.connection_kwargs['host']
dest_port = redis_conn_to.connection_pool.connection_kwargs['port']
pipeline_to = redis_conn_to.pipeline()
pipeline_from = redis_conn_from.pipeline()
for slot in slots:
# 1, 2
pipeline_to.execute_command('CLUSTER SETSLOT', slot, 'IMPORTING',
redis_id_from)
pipeline_from.execute_command('CLUSTER SETSLOT', slot, 'MIGRATING',
redis_id_to)
pipeline_to.execute()
pipeline_from.execute()
for slot in slots:
# 3
keys = redis_conn_from.execute_command('CLUSTER GETKEYSINSLOT',
slot, 1000000)
if len(keys) > 0:
redis_conn_from.execute_command('MIGRATE', dest_host,
dest_port, "", 0, 180000,
'KEYS', *keys)
# 4
redis_conn_to.execute_command('CLUSTER SETSLOT', slot, 'NODE',
redis_id_to)
