from __future__ import absolute_import import copy import logging import socket from kafka.client_async import KafkaClient, selectors import kafka.errors as Errors from kafka.errors import ( IncompatibleBrokerVersion, KafkaConfigurationError, KafkaConnectionError, NodeNotReadyError, NotControllerError) from kafka.metrics import MetricConfig, Metrics from kafka.protocol.admin import ( CreateTopicsRequest, DeleteTopicsRequest, DescribeConfigsRequest, AlterConfigsRequest, CreatePartitionsRequest, ListGroupsRequest, DescribeGroupsRequest) from kafka.protocol.commit import GroupCoordinatorRequest from kafka.protocol.metadata import MetadataRequest from kafka.version import __version__ log = logging.getLogger(__name__) class KafkaAdmin(object): """An class for administering the kafka cluster. Warning: This is an unstable interface that was recently added and is subject to change without warning. In particular, many methods currently return raw protocol tuples. In future releases, we plan to make these into nicer, more pythonic objects. Unfortunately, this will likely break those interfaces. The KafkaAdmin class will negotiate for the latest version of each message protocol format supported by both the kafka-python client library and the kafka broker. Usage of optional fields from protocol versions that are not supported by the broker will result in IncompatibleBrokerVersion exceptions. Use of this class requires a minimum broker version >= 0.10.0.0. Keyword Arguments: bootstrap_servers: 'host[:port]' string (or list of 'host[:port]' strings) that the consumer should contact to bootstrap initial cluster metadata. This does not have to be the full node list. It just needs to have at least one broker that will respond to a Metadata API Request. Default port is 9092. If no servers are specified, will default to localhost:9092. client_id (str): a name for this client. This string is passed in each request to servers and can be used to identify specific server-side log entries that correspond to this client. Also submitted to GroupCoordinator for logging with respect to consumer group administration. Default: 'kafka-python-{version}' reconnect_backoff_ms (int): The amount of time in milliseconds to wait before attempting to reconnect to a given host. Default: 50. reconnect_backoff_max_ms (int): The maximum amount of time in milliseconds to wait when reconnecting to a broker that has repeatedly failed to connect. If provided, the backoff per host will increase exponentially for each consecutive connection failure, up to this maximum. To avoid connection storms, a randomization factor of 0.2 will be applied to the backoff resulting in a random range between 20% below and 20% above the computed value. Default: 1000. request_timeout_ms (int): Client request timeout in milliseconds. Default: 30000. connections_max_idle_ms: Close idle connections after the number of milliseconds specified by this config. The broker closes idle connections after connections.max.idle.ms, so this avoids hitting unexpected socket disconnected errors on the client. Default: 540000 retry_backoff_ms (int): Milliseconds to backoff when retrying on errors. Default: 100. max_in_flight_requests_per_connection (int): Requests are pipelined to kafka brokers up to this number of maximum requests per broker connection. Default: 5. receive_buffer_bytes (int): The size of the TCP receive buffer (SO_RCVBUF) to use when reading data. Default: None (relies on system defaults). Java client defaults to 32768. send_buffer_bytes (int): The size of the TCP send buffer (SO_SNDBUF) to use when sending data. Default: None (relies on system defaults). Java client defaults to 131072. socket_options (list): List of tuple-arguments to socket.setsockopt to apply to broker connection sockets. Default: [(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)] metadata_max_age_ms (int): The period of time in milliseconds after which we force a refresh of metadata even if we haven't seen any partition leadership changes to proactively discover any new brokers or partitions. Default: 300000 security_protocol (str): Protocol used to communicate with brokers. Valid values are: PLAINTEXT, SSL. Default: PLAINTEXT. ssl_context (ssl.SSLContext): Pre-configured SSLContext for wrapping socket connections. If provided, all other ssl_* configurations will be ignored. Default: None. ssl_check_hostname (bool): Flag to configure whether SSL handshake should verify that the certificate matches the broker's hostname. Default: True. ssl_cafile (str): Optional filename of CA file to use in certificate veriication. Default: None. ssl_certfile (str): Optional filename of file in PEM format containing the client certificate, as well as any CA certificates needed to establish the certificate's authenticity. Default: None. ssl_keyfile (str): Optional filename containing the client private key. Default: None. ssl_password (str): Optional password to be used when loading the certificate chain. Default: None. ssl_crlfile (str): Optional filename containing the CRL to check for certificate expiration. By default, no CRL check is done. When providing a file, only the leaf certificate will be checked against this CRL. The CRL can only be checked with Python 3.4+ or 2.7.9+. Default: None. api_version (tuple): Specify which Kafka API version to use. If set to None, KafkaClient will attempt to infer the broker version by probing various APIs. Example: (0, 10, 2). Default: None api_version_auto_timeout_ms (int): number of milliseconds to throw a timeout exception from the constructor when checking the broker api version. Only applies if api_version is None selector (selectors.BaseSelector): Provide a specific selector implementation to use for I/O multiplexing. Default: selectors.DefaultSelector metrics (kafka.metrics.Metrics): Optionally provide a metrics instance for capturing network IO stats. Default: None. metric_group_prefix (str): Prefix for metric names. Default: '' sasl_mechanism (str): string picking sasl mechanism when security_protocol is SASL_PLAINTEXT or SASL_SSL. Currently only PLAIN is supported. Default: None sasl_plain_username (str): username for sasl PLAIN authentication. Default: None sasl_plain_password (str): password for sasl PLAIN authentication. Default: None sasl_kerberos_service_name (str): Service name to include in GSSAPI sasl mechanism handshake. Default: 'kafka' """ DEFAULT_CONFIG = { # client configs 'bootstrap_servers': 'localhost', 'client_id': 'kafka-python-' + __version__, 'request_timeout_ms': 30000, 'connections_max_idle_ms': 9 * 60 * 1000, 'reconnect_backoff_ms': 50, 'reconnect_backoff_max_ms': 1000, 'max_in_flight_requests_per_connection': 5, 'receive_buffer_bytes': None, 'send_buffer_bytes': None, 'socket_options': [(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)], 'sock_chunk_bytes': 4096, # undocumented experimental option 'sock_chunk_buffer_count': 1000, # undocumented experimental option 'retry_backoff_ms': 100, 'metadata_max_age_ms': 300000, 'security_protocol': 'PLAINTEXT', 'ssl_context': None, 'ssl_check_hostname': True, 'ssl_cafile': None, 'ssl_certfile': None, 'ssl_keyfile': None, 'ssl_password': None, 'ssl_crlfile': None, 'api_version': None, 'api_version_auto_timeout_ms': 2000, 'selector': selectors.DefaultSelector, 'sasl_mechanism': None, 'sasl_plain_username': None, 'sasl_plain_password': None, 'sasl_kerberos_service_name': 'kafka', # metrics configs 'metric_reporters' : [], 'metrics_num_samples': 2, 'metrics_sample_window_ms': 30000, } def __init__(self, **configs): log.debug("Starting Kafka administration interface") extra_configs = set(configs).difference(self.DEFAULT_CONFIG) if extra_configs: raise KafkaConfigurationError("Unrecognized configs: %s" % (extra_configs,)) self.config = copy.copy(self.DEFAULT_CONFIG) self.config.update(configs) # Configure metrics metrics_tags = {'client-id': self.config['client_id']} metric_config = MetricConfig(samples=self.config['metrics_num_samples'], time_window_ms=self.config['metrics_sample_window_ms'], tags=metrics_tags) reporters = [reporter() for reporter in self.config['metric_reporters']] self._metrics = Metrics(metric_config, reporters) self._client = KafkaClient(metrics=self._metrics, metric_group_prefix='admin', **self.config) # Get auto-discovered version from client if necessary if self.config['api_version'] is None: self.config['api_version'] = self._client.config['api_version'] self._closed = False self._refresh_controller_id() log.debug('Kafka administration interface started') def close(self): """Close the administration connection to the kafka broker""" if not hasattr(self, '_closed') or self._closed: log.info('Kafka administration interface already closed') return self._metrics.close() self._client.close() self._closed = True log.debug('Kafka administration interface has closed') def _matching_api_version(self, operation): """Find matching api version, the lesser of either the latest api version the library supports, or the max version supported by the broker :param operation: An operation array from kafka.protocol :return: The max matching version number between client and broker """ version = min(len(operation) - 1, self._client.get_api_versions()[operation[0].API_KEY][1]) if version < self._client.get_api_versions()[operation[0].API_KEY][0]: # max library version is less than min broker version. Not sure any brokers # actually set a min version greater than 0 right now, tho. But maybe in the future? raise IncompatibleBrokerVersion( "No version of the '{}' kafka protocol is supported by both the client and broker." .format(operation.__name__)) return version def _validate_timeout(self, timeout_ms): """Validate the timeout is set or use the configuration default :param timeout_ms: The timeout provided by api call, in milliseconds :return: The timeout to use for the operation """ return timeout_ms or self.config['request_timeout_ms'] def _refresh_controller_id(self): """Determine the kafka cluster controller """ response = self._send_request_to_node( self._client.least_loaded_node(), MetadataRequest[1]([]) ) self._controller_id = response.controller_id version = self._client.check_version(self._controller_id) if version < (0, 10, 0): raise IncompatibleBrokerVersion( "The controller appears to be running Kafka {}. KafkaAdmin requires brokers >= 0.10.0.0." .format(version)) def _find_group_coordinator_id(self, group_id): """Find the broker node_id of the coordinator of the given group. Sends a FindCoordinatorRequest message to the cluster. Will block until the FindCoordinatorResponse is received. Any errors are immediately raised. :param group_id: The consumer group ID. This is typically the group name as a string. :return: The node_id of the broker that is the coordinator. """ # Note: Java may change how this is implemented in KAFKA-6791. # # TODO add support for dynamically picking version of # GroupCoordinatorRequest which was renamed to FindCoordinatorRequest. # When I experimented with this, GroupCoordinatorResponse_v1 didn't # match GroupCoordinatorResponse_v0 and I couldn't figure out why. gc_request = GroupCoordinatorRequest[0](group_id) gc_response = self._send_request_to_node(self._client.least_loaded_node(), gc_request) # use the extra error checking in add_group_coordinator() rather than # immediately returning the group coordinator. success = self._client.cluster.add_group_coordinator(group_id, gc_response) if not success: error_type = Errors.for_code(gc_response.error_code) assert error_type is not Errors.NoError # Note: When error_type.retriable, Java will retry... see # KafkaAdminClient's handleFindCoordinatorError method raise error_type( "Could not identify group coordinator for group_id '{}' from response '{}'." .format(group_id, gc_response)) group_coordinator = self._client.cluster.coordinator_for_group(group_id) # will be None if the coordinator was never populated, which should never happen here assert group_coordinator is not None # will be -1 if add_group_coordinator() failed... but by this point the # error should have been raised. assert group_coordinator != -1 return group_coordinator def _send_request_to_node(self, node, request): """Send a kafka protocol message to a specific broker. Will block until the message result is received. :param node: The broker id to which to send the message :param request: The message to send :return: The kafka protocol response for the message :exception: The exception if the message could not be sent """ while not self._client.ready(node): # connection to broker not ready, poll until it is or send will fail with NodeNotReadyError self._client.poll() future = self._client.send(node, request) self._client.poll(future=future) if future.succeeded(): return future.value else: raise future.exception # pylint: disable-msg=raising-bad-type def _send(self, request): """Send a kafka protocol message to the cluster controller. Will block until the message result is received. :param request: The message to send :return The kafka protocol response for the message :exception NodeNotReadyError: If the controller connection can't be established """ remaining_tries = 2 while remaining_tries > 0: remaining_tries = remaining_tries - 1 try: return self._send_request_to_node(self._controller_id, request) except (NotControllerError, KafkaConnectionError) as e: # controller changed? refresh it self._refresh_controller_id() raise NodeNotReadyError(self._controller_id) @staticmethod def _convert_new_topic_request(new_topic): return ( new_topic.name, new_topic.num_partitions, new_topic.replication_factor, [ (partition_id, replicas) for partition_id, replicas in new_topic.replica_assignments.items() ], [ (config_key, config_value) for config_key, config_value in new_topic.topic_configs.items() ] ) def create_topics(self, new_topics, timeout_ms=None, validate_only=None): """Create new topics in the cluster. :param new_topics: Array of NewTopic objects :param timeout_ms: Milliseconds to wait for new topics to be created before broker returns :param validate_only: If True, don't actually create new topics. Not supported by all versions. :return: Appropriate version of CreateTopicResponse class """ version = self._matching_api_version(CreateTopicsRequest) timeout_ms = self._validate_timeout(timeout_ms) if version == 0: if validate_only: raise IncompatibleBrokerVersion( "validate_only requires CreateTopicsRequest >= v1, which is not supported by Kafka {}." .format(self.config['api_version'])) request = CreateTopicsRequest[version]( create_topic_requests = [self._convert_new_topic_request(new_topic) for new_topic in new_topics], timeout = timeout_ms ) elif version <= 2: validate_only = validate_only or False request = CreateTopicsRequest[version]( create_topic_requests = [self._convert_new_topic_request(new_topic) for new_topic in new_topics], timeout = timeout_ms, validate_only = validate_only ) else: raise NotImplementedError( "Support for CreateTopics v{} has not yet been added to KafkaAdmin." .format(version)) return self._send(request) def delete_topics(self, topics, timeout_ms=None): """Delete topics from the cluster :param topics: Array of topic name strings :param timeout_ms: Milliseconds to wait for topics to be deleted before broker returns :return: Appropriate version of DeleteTopicsResponse class """ version = self._matching_api_version(DeleteTopicsRequest) timeout_ms = self._validate_timeout(timeout_ms) if version <= 1: request = DeleteTopicsRequest[version]( topics = topics, timeout = timeout_ms ) else: raise NotImplementedError( "Support for DeleteTopics v{} has not yet been added to KafkaAdmin." .format(version)) return self._send(request) # list topics functionality is in ClusterMetadata # describe topics functionality is in ClusterMetadata # describe cluster functionality is in ClusterMetadata # describe_acls protocol not implemented # create_acls protocol not implemented # delete_acls protocol not implemented @staticmethod def _convert_describe_config_resource_request(config_resource): return ( config_resource.resource_type, config_resource.name, [ config_key for config_key, config_value in config_resource.configs.items() ] if config_resource.configs else None ) def describe_configs(self, config_resources, include_synonyms=None): """Fetch configuration parameters for one or more kafka resources. :param config_resources: An array of ConfigResource objects. Any keys in ConfigResource.configs dict will be used to filter the result. The configs dict should be None to get all values. An empty dict will get zero values (as per kafka protocol). :param include_synonyms: If True, return synonyms in response. Not supported by all versions. :return: Appropriate version of DescribeConfigsResponse class """ version = self._matching_api_version(DescribeConfigsRequest) if version == 0: if include_synonyms: raise IncompatibleBrokerVersion( "include_synonyms requires DescribeConfigsRequest >= v1, which is not supported by Kafka {}." .format(self.config['api_version'])) request = DescribeConfigsRequest[version]( resources = [self._convert_describe_config_resource_request(config_resource) for config_resource in config_resources] ) elif version <= 1: include_synonyms = include_synonyms or False request = DescribeConfigsRequest[version]( resources = [self._convert_describe_config_resource_request(config_resource) for config_resource in config_resources], include_synonyms = include_synonyms ) else: raise NotImplementedError( "Support for DescribeConfigs v{} has not yet been added to KafkaAdmin." .format(version)) return self._send(request) @staticmethod def _convert_alter_config_resource_request(config_resource): return ( config_resource.resource_type, config_resource.name, [ (config_key, config_value) for config_key, config_value in config_resource.configs.items() ] ) def alter_configs(self, config_resources): """Alter configuration parameters of one or more kafka resources. :param config_resources: An array of ConfigResource objects. :return: Appropriate version of AlterConfigsResponse class """ version = self._matching_api_version(AlterConfigsRequest) if version == 0: request = AlterConfigsRequest[version]( resources = [self._convert_alter_config_resource_request(config_resource) for config_resource in config_resources] ) else: raise NotImplementedError( "Support for AlterConfigs v{} has not yet been added to KafkaAdmin." .format(version)) return self._send(request) # alter replica logs dir protocol not implemented # describe log dirs protocol not implemented @staticmethod def _convert_create_partitions_request(topic_name, new_partitions): return ( topic_name, ( new_partitions.total_count, new_partitions.new_assignments ) ) def create_partitions(self, topic_partitions, timeout_ms=None, validate_only=None): """Create additional partitions for an existing topic. :param topic_partitions: A map of topic name strings to NewPartition objects :param timeout_ms: Milliseconds to wait for new partitions to be created before broker returns :param validate_only: If True, don't actually create new partitions. :return: Appropriate version of CreatePartitionsResponse class """ version = self._matching_api_version(CreatePartitionsRequest) timeout_ms = self._validate_timeout(timeout_ms) validate_only = validate_only or False if version == 0: request = CreatePartitionsRequest[version]( topic_partitions = [self._convert_create_partitions_request(topic_name, new_partitions) for topic_name, new_partitions in topic_partitions.items()], timeout = timeout_ms, validate_only = validate_only ) else: raise NotImplementedError( "Support for CreatePartitions v{} has not yet been added to KafkaAdmin." .format(version)) return self._send(request) # delete records protocol not implemented # create delegation token protocol not implemented # renew delegation token protocol not implemented # expire delegation_token protocol not implemented # describe delegation_token protocol not implemented def describe_consumer_groups(self, group_ids, group_coordinator_id=None): """Describe a set of consumer groups. Any errors are immediately raised. :param group_ids: A list of consumer group IDs. These are typically the group names as strings. :param group_coordinator_id: The node_id of the groups' coordinator broker. If set to None, it will query the cluster for each group to find that group's coordinator. Explicitly specifying this can be useful for avoiding extra network round trips if you already know the group coordinator. This is only useful when all the group_ids have the same coordinator, otherwise it will error. Default: None. :return: A list of group descriptions. For now the group descriptions are the raw results from the DescribeGroupsResponse. Long-term, we plan to change this to return namedtuples as well as decoding the partition assignments. """ group_descriptions = [] version = self._matching_api_version(DescribeGroupsRequest) for group_id in group_ids: if group_coordinator_id is None: this_groups_coordinator_id = self._find_group_coordinator_id(group_id) if version <= 1: # Note: KAFKA-6788 A potential optimization is to group the # request per coordinator and send one request with a list of # all consumer groups. Java still hasn't implemented this # because the error checking is hard to get right when some # groups error and others don't. request = DescribeGroupsRequest[version](groups=(group_id,)) response = self._send_request_to_node(this_groups_coordinator_id, request) assert len(response.groups) == 1 # TODO need to implement converting the response tuple into # a more accessible interface like a namedtuple and then stop # hardcoding tuple indices here. Several Java examples, # including KafkaAdminClient.java group_description = response.groups[0] error_code = group_description[0] error_type = Errors.for_code(error_code) # Java has the note: KAFKA-6789, we can retry based on the error code if error_type is not Errors.NoError: raise error_type( "Request '{}' failed with response '{}'." .format(request, response)) # TODO Java checks the group protocol type, and if consumer # (ConsumerProtocol.PROTOCOL_TYPE) or empty string, it decodes # the members' partition assignments... that hasn't yet been # implemented here so just return the raw struct results group_descriptions.append(group_description) else: raise NotImplementedError( "Support for DescribeGroups v{} has not yet been added to KafkaAdmin." .format(version)) return group_descriptions def list_consumer_groups(self): """List all consumer groups known to the cluster. :return: Appropriate version of ListGroupsResponse class """ version = self._matching_api_version(ListGroupsRequest) if version <= 1: request = ListGroupsRequest[version]() else: raise NotImplementedError( "Support for ListGroups v{} has not yet been added to KafkaAdmin." .format(version)) return self._send(request) # delete groups protocol not implemented