diff options
Diffstat (limited to 'kafka/cluster.py')
| -rw-r--r-- | kafka/cluster.py | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/kafka/cluster.py b/kafka/cluster.py new file mode 100644 index 0000000..84ad1d3 --- /dev/null +++ b/kafka/cluster.py @@ -0,0 +1,189 @@ +from __future__ import absolute_import + +import copy +import logging +import random +import time + +import kafka.common as Errors +from kafka.common import BrokerMetadata +from .future import Future + +log = logging.getLogger(__name__) + + +class ClusterMetadata(object): + DEFAULT_CONFIG = { + 'retry_backoff_ms': 100, + 'metadata_max_age_ms': 300000, + } + + def __init__(self, **configs): + self._brokers = {} + self._partitions = {} + self._groups = {} + self._version = 0 + self._last_refresh_ms = 0 + self._last_successful_refresh_ms = 0 + self._need_update = False + self._future = None + self._listeners = set() + + self.config = copy.copy(self.DEFAULT_CONFIG) + for key in self.config: + if key in configs: + self.config[key] = configs[key] + + def brokers(self): + return set(self._brokers.values()) + + def broker_metadata(self, broker_id): + return self._brokers.get(broker_id) + + def partitions_for_topic(self, topic): + if topic not in self._partitions: + return None + return set(self._partitions[topic].keys()) + + def leader_for_partition(self, partition): + if partition.topic not in self._partitions: + return None + return self._partitions[partition.topic].get(partition.partition) + + def coordinator_for_group(self, group): + return self._groups.get(group) + + def ttl(self): + """Milliseconds until metadata should be refreshed""" + now = time.time() * 1000 + if self._need_update: + ttl = 0 + else: + ttl = self._last_successful_refresh_ms + self.config['metadata_max_age_ms'] - now + retry = self._last_refresh_ms + self.config['retry_backoff_ms'] - now + return max(ttl, retry, 0) + + def request_update(self): + """ + Flags metadata for update, return Future() + + Actual update must be handled separately. This method will only + change the reported ttl() + """ + self._need_update = True + if not self._future or self._future.is_done: + self._future = Future() + return self._future + + def topics(self): + return set(self._partitions.keys()) + + def failed_update(self, exception): + if self._future: + self._future.failure(exception) + self._future = None + self._last_refresh_ms = time.time() * 1000 + + def update_metadata(self, metadata): + # In the common case where we ask for a single topic and get back an + # error, we should fail the future + if len(metadata.topics) == 1 and metadata.topics[0][0] != 0: + error_code, topic, _ = metadata.topics[0] + error = Errors.for_code(error_code)(topic) + return self.failed_update(error) + + if not metadata.brokers: + log.warning("No broker metadata found in MetadataResponse") + + for node_id, host, port in metadata.brokers: + self._brokers.update({ + node_id: BrokerMetadata(node_id, host, port) + }) + + # Drop any UnknownTopic, InvalidTopic, and TopicAuthorizationFailed + # but retain LeaderNotAvailable because it means topic is initializing + self._partitions = {} + + for error_code, topic, partitions in metadata.topics: + error_type = Errors.for_code(error_code) + if error_type is Errors.NoError: + self._partitions[topic] = {} + for _, partition, leader, _, _ in partitions: + self._partitions[topic][partition] = leader + elif error_type is Errors.LeaderNotAvailableError: + log.error("Topic %s is not available during auto-create" + " initialization", topic) + elif error_type is Errors.UnknownTopicOrPartitionError: + log.error("Topic %s not found in cluster metadata", topic) + elif error_type is Errors.TopicAuthorizationFailedError: + log.error("Topic %s is not authorized for this client", topic) + elif error_type is Errors.InvalidTopicError: + log.error("'%s' is not a valid topic name", topic) + else: + log.error("Error fetching metadata for topic %s: %s", + topic, error_type) + + if self._future: + self._future.success(self) + self._future = None + self._need_update = False + self._version += 1 + now = time.time() * 1000 + self._last_refresh_ms = now + self._last_successful_refresh_ms = now + log.debug("Updated cluster metadata version %d to %s", + self._version, self) + + for listener in self._listeners: + listener(self) + + def add_listener(self, listener): + """Add a callback function to be called on each metadata update""" + self._listeners.add(listener) + + def remove_listener(self, listener): + """Remove a previously added listener callback""" + self._listeners.remove(listener) + + def add_group_coordinator(self, group, response): + """Update with metadata for a group coordinator + + group: name of group from GroupCoordinatorRequest + response: GroupCoordinatorResponse + + returns True if metadata is updated, False on error + """ + log.debug("Updating coordinator for %s: %s", group, response) + error_type = Errors.for_code(response.error_code) + if error_type is not Errors.NoError: + log.error("GroupCoordinatorResponse error: %s", error_type) + self._groups[group] = -1 + return False + + node_id = response.coordinator_id + coordinator = BrokerMetadata( + response.coordinator_id, + response.host, + response.port) + + # Assume that group coordinators are just brokers + # (this is true now, but could diverge in future) + if node_id not in self._brokers: + self._brokers[node_id] = coordinator + + # If this happens, either brokers have moved without + # changing IDs, or our assumption above is wrong + elif coordinator != self._brokers[node_id]: + log.error("GroupCoordinator metadata conflicts with existing" + " broker metadata. Coordinator: %s, Broker: %s", + coordinator, self._brokers[node_id]) + self._groups[group] = node_id + return False + + log.info("Group coordinator for %s is %s", group, coordinator) + self._groups[group] = node_id + return True + + def __str__(self): + return 'Cluster(brokers: %d, topics: %d, groups: %d)' % \ + (len(self._brokers), len(self._partitions), len(self._groups)) |