kafka/tools/assigner/actions/setrf.py
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import random
from collections import deque
from kafka.tools.assigner.actions import ActionModule
from kafka.tools.exceptions import ConfigurationException
class ActionSetRF(ActionModule):
name = "set-replication-factor"
helpstr = "Increase the replication factor of the specified topics"
def __init__(self, args, cluster):
super(ActionSetRF, self).__init__(args, cluster)
if args.replication_factor < 1:
raise ConfigurationException("You cannot set replication-factor below 1")
if args.replication_factor > self.cluster.num_brokers():
raise ConfigurationException("You cannot set replication-factor greater than the number of brokers in the cluster")
self.target_rf = self.args.replication_factor
@classmethod
def _add_args(cls, parser):
parser.add_argument('-t', '--topics', help='List of topics to alter', required=True, nargs='*')
parser.add_argument('-r', '--replication-factor', help='Target replication factor', required=True, type=int)
def process_cluster(self):
# Randomize a broker list to use for new replicas once. We'll round robin it from here
idlist = list(self.cluster.brokers.keys())
random.shuffle(idlist)
brokers = deque(idlist)
for partition in self.cluster.partitions(self.args.exclude_topics):
if partition.topic.name not in self.args.topics:
continue
while len(partition.replicas) < self.target_rf:
broker_id = brokers.popleft()
brokers.append(broker_id)
broker = self.cluster.brokers[broker_id]
if broker in partition.replicas:
continue
partition.add_replica(broker)
while len(partition.replicas) > self.target_rf:
partition.remove_replica(partition.replicas[-1])