Class: Kafka::Client
- Inherits:
-
Object
- Object
- Kafka::Client
- Defined in:
- lib/kafka/client.rb
Instance Method Summary collapse
-
#alter_configs(broker_id, configs = []) ⇒ nil
Alter broker configs.
-
#alter_topic(name, configs = {}) ⇒ nil
Alter the configuration of a topic.
- #apis ⇒ Object
-
#async_producer(delivery_interval: 0, delivery_threshold: 0, max_queue_size: 1000, max_retries: -1,, retry_backoff: 0, **options) ⇒ AsyncProducer
Creates a new AsyncProducer instance.
-
#brokers ⇒ Array<Kafka::BrokerInfo>
List all brokers in the cluster.
-
#close ⇒ nil
Closes all connections to the Kafka brokers and frees up used resources.
-
#consumer(group_id:, session_timeout: 30, rebalance_timeout: 60, offset_commit_interval: 10, offset_commit_threshold: 0, heartbeat_interval: 10, offset_retention_time: nil, fetcher_max_queue_size: 100) ⇒ Consumer
Creates a new Kafka consumer.
-
#controller_broker ⇒ Kafka::BrokerInfo
The current controller broker in the cluster.
-
#create_partitions_for(name, num_partitions: 1, timeout: 30) ⇒ nil
Create partitions for a topic.
-
#create_topic(name, num_partitions: 1, replication_factor: 1, timeout: 30, config: {}) ⇒ nil
Creates a topic in the cluster.
-
#delete_topic(name, timeout: 30) ⇒ nil
Delete a topic in the cluster.
-
#deliver_message(value, key: nil, headers: {}, topic:, partition: nil, partition_key: nil, retries: 1) ⇒ nil
Delivers a single message to the Kafka cluster.
-
#describe_configs(broker_id, configs = []) ⇒ Array<Kafka::Protocol::DescribeConfigsResponse::ConfigEntry>
Describe broker configs.
-
#describe_group(group_id) ⇒ Kafka::Protocol::DescribeGroupsResponse::Group
Describe a consumer group.
-
#describe_topic(name, configs = []) ⇒ Hash<String, String>
Describe the configuration of a topic.
-
#each_message(topic:, start_from_beginning: true, max_wait_time: 5, min_bytes: 1, max_bytes: 1048576, &block) ⇒ nil
Enumerate all messages in a topic.
-
#fetch_group_offsets(group_id) ⇒ Hash<String, Hash<Integer, Kafka::Protocol::OffsetFetchResponse::PartitionOffsetInfo>>
Fetch all committed offsets for a consumer group.
-
#fetch_messages(topic:, partition:, offset: :latest, max_wait_time: 5, min_bytes: 1, max_bytes: 1048576, retries: 1) ⇒ Array<Kafka::FetchedMessage>
Fetches a batch of messages from a single partition.
-
#groups ⇒ Array<String>
Lists all consumer groups in the cluster.
- #has_topic?(topic) ⇒ Boolean
-
#initialize(seed_brokers:, client_id: "ruby-kafka", logger: nil, connect_timeout: nil, socket_timeout: nil, ssl_ca_cert_file_path: nil, ssl_ca_cert: nil, ssl_client_cert: nil, ssl_client_cert_key: nil, ssl_client_cert_key_password: nil, ssl_client_cert_chain: nil, sasl_gssapi_principal: nil, sasl_gssapi_keytab: nil, sasl_plain_authzid: '', sasl_plain_username: nil, sasl_plain_password: nil, sasl_scram_username: nil, sasl_scram_password: nil, sasl_scram_mechanism: nil, sasl_over_ssl: true, ssl_ca_certs_from_system: false, sasl_oauth_token_provider: nil, ssl_verify_hostname: true) ⇒ Client
constructor
Initializes a new Kafka client.
-
#last_offset_for(topic, partition) ⇒ Integer
Retrieve the offset of the last message in a partition.
-
#last_offsets_for(*topics) ⇒ Hash<String, Hash<Integer, Integer>>
Retrieve the offset of the last message in each partition of the specified topics.
-
#partitions_for(topic) ⇒ Integer
Counts the number of partitions in a topic.
-
#producer(compression_codec: nil, compression_threshold: 1, ack_timeout: 5, required_acks: :all, max_retries: 2, retry_backoff: 1, max_buffer_size: 1000, max_buffer_bytesize: 10_000_000, idempotent: false, transactional: false, transactional_id: nil, transactional_timeout: 60) ⇒ Kafka::Producer
Initializes a new Kafka producer.
-
#supports_api?(api_key, version = nil) ⇒ Boolean
Check whether current cluster supports a specific version or not.
-
#topics ⇒ Array<String>
Lists all topics in the cluster.
Constructor Details
#initialize(seed_brokers:, client_id: "ruby-kafka", logger: nil, connect_timeout: nil, socket_timeout: nil, ssl_ca_cert_file_path: nil, ssl_ca_cert: nil, ssl_client_cert: nil, ssl_client_cert_key: nil, ssl_client_cert_key_password: nil, ssl_client_cert_chain: nil, sasl_gssapi_principal: nil, sasl_gssapi_keytab: nil, sasl_plain_authzid: '', sasl_plain_username: nil, sasl_plain_password: nil, sasl_scram_username: nil, sasl_scram_password: nil, sasl_scram_mechanism: nil, sasl_over_ssl: true, ssl_ca_certs_from_system: false, sasl_oauth_token_provider: nil, ssl_verify_hostname: true) ⇒ Client
Initializes a new Kafka client.
69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 |
# File 'lib/kafka/client.rb', line 69 def initialize(seed_brokers:, client_id: "ruby-kafka", logger: nil, connect_timeout: nil, socket_timeout: nil, ssl_ca_cert_file_path: nil, ssl_ca_cert: nil, ssl_client_cert: nil, ssl_client_cert_key: nil, ssl_client_cert_key_password: nil, ssl_client_cert_chain: nil, sasl_gssapi_principal: nil, sasl_gssapi_keytab: nil, sasl_plain_authzid: '', sasl_plain_username: nil, sasl_plain_password: nil, sasl_scram_username: nil, sasl_scram_password: nil, sasl_scram_mechanism: nil, sasl_over_ssl: true, ssl_ca_certs_from_system: false, sasl_oauth_token_provider: nil, ssl_verify_hostname: true) @logger = TaggedLogger.new(logger) @instrumenter = Instrumenter.new(client_id: client_id) @seed_brokers = normalize_seed_brokers(seed_brokers) ssl_context = SslContext.build( ca_cert_file_path: ssl_ca_cert_file_path, ca_cert: ssl_ca_cert, client_cert: ssl_client_cert, client_cert_key: ssl_client_cert_key, client_cert_key_password: ssl_client_cert_key_password, client_cert_chain: ssl_client_cert_chain, ca_certs_from_system: ssl_ca_certs_from_system, verify_hostname: ssl_verify_hostname ) sasl_authenticator = SaslAuthenticator.new( sasl_gssapi_principal: sasl_gssapi_principal, sasl_gssapi_keytab: sasl_gssapi_keytab, sasl_plain_authzid: sasl_plain_authzid, sasl_plain_username: sasl_plain_username, sasl_plain_password: sasl_plain_password, sasl_scram_username: sasl_scram_username, sasl_scram_password: sasl_scram_password, sasl_scram_mechanism: sasl_scram_mechanism, sasl_oauth_token_provider: sasl_oauth_token_provider, logger: @logger ) if sasl_authenticator.enabled? && sasl_over_ssl && ssl_context.nil? raise ArgumentError, "SASL authentication requires that SSL is configured" end @connection_builder = ConnectionBuilder.new( client_id: client_id, connect_timeout: connect_timeout, socket_timeout: socket_timeout, ssl_context: ssl_context, logger: @logger, instrumenter: @instrumenter, sasl_authenticator: sasl_authenticator ) @cluster = initialize_cluster end |
Instance Method Details
#alter_configs(broker_id, configs = []) ⇒ nil
Alter broker configs
552 553 554 |
# File 'lib/kafka/client.rb', line 552 def alter_configs(broker_id, configs = []) @cluster.alter_configs(broker_id, configs) end |
#alter_topic(name, configs = {}) ⇒ nil
This is an alpha level API and is subject to change.
Alter the configuration of a topic.
Configuration keys must match Kafka's topic-level configs.
629 630 631 |
# File 'lib/kafka/client.rb', line 629 def alter_topic(name, configs = {}) @cluster.alter_topic(name, configs) end |
#apis ⇒ Object
738 739 740 |
# File 'lib/kafka/client.rb', line 738 def apis @cluster.apis end |
#async_producer(delivery_interval: 0, delivery_threshold: 0, max_queue_size: 1000, max_retries: -1,, retry_backoff: 0, **options) ⇒ AsyncProducer
Creates a new AsyncProducer instance.
All parameters allowed by #producer can be passed. In addition to this, a few extra parameters can be passed when creating an async producer.
307 308 309 310 311 312 313 314 315 316 317 318 319 320 |
# File 'lib/kafka/client.rb', line 307 def async_producer(delivery_interval: 0, delivery_threshold: 0, max_queue_size: 1000, max_retries: -1, retry_backoff: 0, **) sync_producer = producer(**) AsyncProducer.new( sync_producer: sync_producer, delivery_interval: delivery_interval, delivery_threshold: delivery_threshold, max_queue_size: max_queue_size, max_retries: max_retries, retry_backoff: retry_backoff, instrumenter: @instrumenter, logger: @logger, ) end |
#brokers ⇒ Array<Kafka::BrokerInfo>
List all brokers in the cluster.
745 746 747 |
# File 'lib/kafka/client.rb', line 745 def brokers @cluster.cluster_info.brokers end |
#close ⇒ nil
Closes all connections to the Kafka brokers and frees up used resources.
759 760 761 |
# File 'lib/kafka/client.rb', line 759 def close @cluster.disconnect end |
#consumer(group_id:, session_timeout: 30, rebalance_timeout: 60, offset_commit_interval: 10, offset_commit_threshold: 0, heartbeat_interval: 10, offset_retention_time: nil, fetcher_max_queue_size: 100) ⇒ Consumer
Creates a new Kafka consumer.
340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 |
# File 'lib/kafka/client.rb', line 340 def consumer( group_id:, session_timeout: 30, rebalance_timeout: 60, offset_commit_interval: 10, offset_commit_threshold: 0, heartbeat_interval: 10, offset_retention_time: nil, fetcher_max_queue_size: 100 ) cluster = initialize_cluster instrumenter = DecoratingInstrumenter.new(@instrumenter, { group_id: group_id, }) # The Kafka protocol expects the retention time to be in ms. retention_time = (offset_retention_time && offset_retention_time * 1_000) || -1 group = ConsumerGroup.new( cluster: cluster, logger: @logger, group_id: group_id, session_timeout: session_timeout, rebalance_timeout: rebalance_timeout, retention_time: retention_time, instrumenter: instrumenter, ) fetcher = Fetcher.new( cluster: initialize_cluster, group: group, logger: @logger, instrumenter: instrumenter, max_queue_size: fetcher_max_queue_size ) offset_manager = OffsetManager.new( cluster: cluster, group: group, fetcher: fetcher, logger: @logger, commit_interval: offset_commit_interval, commit_threshold: offset_commit_threshold, offset_retention_time: offset_retention_time ) heartbeat = Heartbeat.new( group: group, interval: heartbeat_interval, instrumenter: instrumenter ) Consumer.new( cluster: cluster, logger: @logger, instrumenter: instrumenter, group: group, offset_manager: offset_manager, fetcher: fetcher, session_timeout: session_timeout, heartbeat: heartbeat, ) end |
#controller_broker ⇒ Kafka::BrokerInfo
The current controller broker in the cluster.
752 753 754 |
# File 'lib/kafka/client.rb', line 752 def controller_broker brokers.find {|broker| broker.node_id == @cluster.cluster_info.controller_id } end |
#create_partitions_for(name, num_partitions: 1, timeout: 30) ⇒ nil
Create partitions for a topic.
the topic partitions to be added.
657 658 659 |
# File 'lib/kafka/client.rb', line 657 def create_partitions_for(name, num_partitions: 1, timeout: 30) @cluster.create_partitions_for(name, num_partitions: num_partitions, timeout: timeout) end |
#create_topic(name, num_partitions: 1, replication_factor: 1, timeout: 30, config: {}) ⇒ nil
Creates a topic in the cluster.
576 577 578 579 580 581 582 583 584 |
# File 'lib/kafka/client.rb', line 576 def create_topic(name, num_partitions: 1, replication_factor: 1, timeout: 30, config: {}) @cluster.create_topic( name, num_partitions: num_partitions, replication_factor: replication_factor, timeout: timeout, config: config, ) end |
#delete_topic(name, timeout: 30) ⇒ nil
Delete a topic in the cluster.
592 593 594 |
# File 'lib/kafka/client.rb', line 592 def delete_topic(name, timeout: 30) @cluster.delete_topic(name, timeout: timeout) end |
#deliver_message(value, key: nil, headers: {}, topic:, partition: nil, partition_key: nil, retries: 1) ⇒ nil
Delivers a single message to the Kafka cluster.
Note: Only use this API for low-throughput scenarios. If you want to deliver many messages at a high rate, or if you want to configure the way messages are sent, use the #producer or #async_producer APIs instead.
138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 |
# File 'lib/kafka/client.rb', line 138 def (value, key: nil, headers: {}, topic:, partition: nil, partition_key: nil, retries: 1) create_time = Time.now # We want to fail fast if `topic` isn't a String topic = topic.to_str = PendingMessage.new( value: value, key: key, headers: headers, topic: topic, partition: partition, partition_key: partition_key, create_time: create_time ) if partition.nil? partition_count = @cluster.partitions_for(topic).count partition = Partitioner.partition_for_key(partition_count, ) end buffer = MessageBuffer.new buffer.write( value: .value, key: .key, headers: .headers, topic: .topic, partition: partition, create_time: .create_time, ) @cluster.add_target_topics([topic]) compressor = Compressor.new( instrumenter: @instrumenter, ) transaction_manager = TransactionManager.new( cluster: @cluster, logger: @logger, idempotent: false, transactional: false ) operation = ProduceOperation.new( cluster: @cluster, transaction_manager: transaction_manager, buffer: buffer, required_acks: 1, ack_timeout: 10, compressor: compressor, logger: @logger, instrumenter: @instrumenter, ) attempt = 1 begin operation.execute unless buffer.empty? raise DeliveryFailed.new(nil, []) end rescue Kafka::Error => e @cluster.mark_as_stale! if attempt >= (retries + 1) raise else attempt += 1 @logger.warn "Error while delivering message, #{e.class}: #{e.}; retrying after 1s..." sleep 1 retry end end end |
#describe_configs(broker_id, configs = []) ⇒ Array<Kafka::Protocol::DescribeConfigsResponse::ConfigEntry>
Describe broker configs
543 544 545 |
# File 'lib/kafka/client.rb', line 543 def describe_configs(broker_id, configs = []) @cluster.describe_configs(broker_id, configs) end |
#describe_group(group_id) ⇒ Kafka::Protocol::DescribeGroupsResponse::Group
Describe a consumer group
637 638 639 |
# File 'lib/kafka/client.rb', line 637 def describe_group(group_id) @cluster.describe_group(group_id) end |
#describe_topic(name, configs = []) ⇒ Hash<String, String>
This is an alpha level API and is subject to change.
Describe the configuration of a topic.
Retrieves the topic configuration from the Kafka brokers. Configuration names refer to Kafka's topic-level configs.
611 612 613 |
# File 'lib/kafka/client.rb', line 611 def describe_topic(name, configs = []) @cluster.describe_topic(name, configs) end |
#each_message(topic:, start_from_beginning: true, max_wait_time: 5, min_bytes: 1, max_bytes: 1048576, &block) ⇒ nil
Enumerate all messages in a topic.
512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 |
# File 'lib/kafka/client.rb', line 512 def (topic:, start_from_beginning: true, max_wait_time: 5, min_bytes: 1, max_bytes: 1048576, &block) default_offset ||= start_from_beginning ? :earliest : :latest offsets = Hash.new { default_offset } loop do operation = FetchOperation.new( cluster: @cluster, logger: @logger, min_bytes: min_bytes, max_wait_time: max_wait_time, ) @cluster.partitions_for(topic).map(&:partition_id).each do |partition| partition_offset = offsets[partition] operation.fetch_from_partition(topic, partition, offset: partition_offset, max_bytes: max_bytes) end batches = operation.execute batches.each do |batch| batch..each(&block) offsets[batch.partition] = batch.last_offset + 1 unless batch.unknown_last_offset? end end end |
#fetch_group_offsets(group_id) ⇒ Hash<String, Hash<Integer, Kafka::Protocol::OffsetFetchResponse::PartitionOffsetInfo>>
Fetch all committed offsets for a consumer group
645 646 647 |
# File 'lib/kafka/client.rb', line 645 def fetch_group_offsets(group_id) @cluster.fetch_group_offsets(group_id) end |
#fetch_messages(topic:, partition:, offset: :latest, max_wait_time: 5, min_bytes: 1, max_bytes: 1048576, retries: 1) ⇒ Array<Kafka::FetchedMessage>
Fetches a batch of messages from a single partition. Note that it's possible to get back empty batches.
The starting point for the fetch can be configured with the :offset
argument.
If you pass a number, the fetch will start at that offset. However, there are
two special Symbol values that can be passed instead:
:earliest
— the first offset in the partition.:latest
— the next offset that will be written to, effectively making the call block until there is a new message in the partition.
The Kafka protocol specifies the numeric values of these two options: -2 and -1, respectively. You can also pass in these numbers directly.
Example
When enumerating the messages in a partition, you typically fetch batches sequentially.
offset = :earliest
loop do
= kafka.(
topic: "my-topic",
partition: 42,
offset: offset,
)
.each do ||
puts .offset, .key, .value
# Set the next offset that should be read to be the subsequent
# offset.
offset = .offset + 1
end
end
See a working example in examples/simple-consumer.rb
.
464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 |
# File 'lib/kafka/client.rb', line 464 def (topic:, partition:, offset: :latest, max_wait_time: 5, min_bytes: 1, max_bytes: 1048576, retries: 1) operation = FetchOperation.new( cluster: @cluster, logger: @logger, min_bytes: min_bytes, max_bytes: max_bytes, max_wait_time: max_wait_time, ) operation.fetch_from_partition(topic, partition, offset: offset, max_bytes: max_bytes) attempt = 1 begin operation.execute.flat_map {|batch| batch. } rescue Kafka::Error => e @cluster.mark_as_stale! if attempt >= (retries + 1) raise else attempt += 1 @logger.warn "Error while fetching messages, #{e.class}: #{e.}; retrying..." retry end end end |
#groups ⇒ Array<String>
Lists all consumer groups in the cluster
679 680 681 |
# File 'lib/kafka/client.rb', line 679 def groups @cluster.list_groups end |
#has_topic?(topic) ⇒ Boolean
683 684 685 686 687 |
# File 'lib/kafka/client.rb', line 683 def has_topic?(topic) @cluster.clear_target_topics @cluster.add_target_topics([topic]) @cluster.topics.include?(topic) end |
#last_offset_for(topic, partition) ⇒ Integer
Retrieve the offset of the last message in a partition. If there are no messages in the partition -1 is returned.
704 705 706 707 708 |
# File 'lib/kafka/client.rb', line 704 def last_offset_for(topic, partition) # The offset resolution API will return the offset of the "next" message to # be written when resolving the "latest" offset, so we subtract one. @cluster.resolve_offset(topic, partition, :latest) - 1 end |
#last_offsets_for(*topics) ⇒ Hash<String, Hash<Integer, Integer>>
Retrieve the offset of the last message in each partition of the specified topics.
720 721 722 723 724 725 726 727 |
# File 'lib/kafka/client.rb', line 720 def last_offsets_for(*topics) @cluster.add_target_topics(topics) topics.map {|topic| partition_ids = @cluster.partitions_for(topic).collect(&:partition_id) partition_offsets = @cluster.resolve_offsets(topic, partition_ids, :latest) [topic, partition_offsets.collect { |k, v| [k, v - 1] }.to_h] }.to_h end |
#partitions_for(topic) ⇒ Integer
Counts the number of partitions in a topic.
693 694 695 |
# File 'lib/kafka/client.rb', line 693 def partitions_for(topic) @cluster.partitions_for(topic).count end |
#producer(compression_codec: nil, compression_threshold: 1, ack_timeout: 5, required_acks: :all, max_retries: 2, retry_backoff: 1, max_buffer_size: 1000, max_buffer_bytesize: 10_000_000, idempotent: false, transactional: false, transactional_id: nil, transactional_timeout: 60) ⇒ Kafka::Producer
Initializes a new Kafka producer.
248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 |
# File 'lib/kafka/client.rb', line 248 def producer( compression_codec: nil, compression_threshold: 1, ack_timeout: 5, required_acks: :all, max_retries: 2, retry_backoff: 1, max_buffer_size: 1000, max_buffer_bytesize: 10_000_000, idempotent: false, transactional: false, transactional_id: nil, transactional_timeout: 60 ) cluster = initialize_cluster compressor = Compressor.new( codec_name: compression_codec, threshold: compression_threshold, instrumenter: @instrumenter, ) transaction_manager = TransactionManager.new( cluster: cluster, logger: @logger, idempotent: idempotent, transactional: transactional, transactional_id: transactional_id, transactional_timeout: transactional_timeout, ) Producer.new( cluster: cluster, transaction_manager: transaction_manager, logger: @logger, instrumenter: @instrumenter, compressor: compressor, ack_timeout: ack_timeout, required_acks: required_acks, max_retries: max_retries, retry_backoff: retry_backoff, max_buffer_size: max_buffer_size, max_buffer_bytesize: max_buffer_bytesize, ) end |
#supports_api?(api_key, version = nil) ⇒ Boolean
Check whether current cluster supports a specific version or not
734 735 736 |
# File 'lib/kafka/client.rb', line 734 def supports_api?(api_key, version = nil) @cluster.supports_api?(api_key, version) end |
#topics ⇒ Array<String>
Lists all topics in the cluster.
664 665 666 667 668 669 670 671 672 673 674 |
# File 'lib/kafka/client.rb', line 664 def topics attempts = 0 begin attempts += 1 @cluster.list_topics rescue Kafka::ConnectionError @cluster.mark_as_stale! retry unless attempts > 1 raise end end |