161d9ffcf8
- Use RoundRobinPartitionAssignor by default - Define AbstractPartitionAssignor for custom assignors - metrics still TODO
64 lines
2.2 KiB
Python
64 lines
2.2 KiB
Python
import collections
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import itertools
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import logging
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import six
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from .abstract import AbstractPartitionAssignor
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from ...common import TopicPartition
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from ..consumer import ConsumerProtocolMemberMetadata, ConsumerProtocolMemberAssignment
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log = logging.getLogger(__name__)
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class RoundRobinPartitionAssignor(AbstractPartitionAssignor):
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name = 'roundrobin'
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version = 0
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@classmethod
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def assign(cls, cluster, member_metadata):
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all_topics = set()
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for metadata in six.itervalues(member_metadata):
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all_topics.update(metadata.subscription)
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all_topic_partitions = []
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for topic in all_topics:
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partitions = cluster.partitions_for_topic(topic)
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if partitions is None:
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log.warning('No partition metadata for topic %s', topic)
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continue
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for partition in partitions:
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all_topic_partitions.append(TopicPartition(topic, partition))
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all_topic_partitions.sort()
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# construct {member_id: {topic: [partition, ...]}}
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assignment = collections.defaultdict(lambda: collections.defaultdict(list))
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member_iter = itertools.cycle(sorted(member_metadata.keys()))
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for partition in all_topic_partitions:
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member_id = member_iter.next()
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# Because we constructed all_topic_partitions from the set of
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# member subscribed topics, we should be safe assuming that
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# each topic in all_topic_partitions is in at least one member
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# subscription; otherwise this could yield an infinite loop
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while partition.topic not in member_metadata[member_id].subscription:
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member_id = member_iter.next()
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assignment[member_id][partition.topic].append(partition.partition)
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protocol_assignment = {}
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for member_id in member_metadata:
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protocol_assignment[member_id] = ConsumerProtocolMemberAssignment(
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cls.version,
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assignment[member_id].items(),
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b'')
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return protocol_assignment
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@classmethod
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def metadata(cls, topics):
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return ConsumerProtocolMemberMetadata(cls.version, list(topics), b'')
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@classmethod
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def on_assignment(cls, assignment):
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pass
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