Implement the static membership feature to Kafka input

CHANGELOG.md

@@ -1,3 +1,6 @@
+# Unreleased
+ - Added config `group_instance_id` to use the Kafka's consumer static membership feature [#135](https://github.com/logstash-plugins/logstash-integration-kafka/pull/135)
+
 ## 11.0.0
   - Changed Kafka client to 3.3.1, requires Logstash >= 8.3.0. 
   - Deprecated `default` value for setting `client_dns_lookup` forcing to `use_all_dns_ips` when explicitly used [#130](https://github.com/logstash-plugins/logstash-integration-kafka/pull/130)

docs/input-kafka.asciidoc

@@ -113,6 +113,7 @@ See the https://kafka.apache.org/{kafka_client_doc}/documentation for more detai
 | <<plugins-{type}s-{plugin}-fetch_max_wait_ms>> |<<number,number>>|No
 | <<plugins-{type}s-{plugin}-fetch_min_bytes>> |<<number,number>>|No
 | <<plugins-{type}s-{plugin}-group_id>> |<<string,string>>|No
+| <<plugins-{type}s-{plugin}-group_instance_id>> |<<string,string>>|No
 | <<plugins-{type}s-{plugin}-heartbeat_interval_ms>> |<<number,number>>|No
 | <<plugins-{type}s-{plugin}-isolation_level>> |<<string,string>>|No
 | <<plugins-{type}s-{plugin}-jaas_path>> |a valid filesystem path|No
@@ -344,6 +345,27 @@ NOTE: In cases when multiple inputs are being used in a single pipeline, reading
 it's essential to set a different `group_id => ...` for each input. Setting a unique `client_id => ...`
 is also recommended.
 
+[id="plugins-{type}s-{plugin}-group_instance_id"]
+===== `group_instance_id`
+
+* Value type is <<string,string>>
+* Optional, there is no default value for this setting.
+
+The static membership identifier for this consumer. Static membership feature was introduced in
+https://cwiki.apache.org/confluence/display/KAFKA/KIP-345%3A+Introduce+static+membership+protocol+to+reduce+consumer+rebalances[KIP-345],
+available under Kafka property `group.instance.id` and aims to avoid rebalances in contexts where a lot of data
+has to be handed off after a consumer goes offline.
+This mitigates the cases where the service state is heavy and rebalance of one topic partition from instance
+A to B means huge amount of data transfer. Client that goes offline and online frequently, if using this settings
+avoid frequent and heavy rebalances.
+
+NOTE: It has to be unique across all the clients belonging to the same <<plugins-{type}s-{plugin}-group_id>>, in case another client connects
+with same `group.instance.id` value then the oldest is kicked off.
+Generally could be something like a hostname, an IP or anything that uniquely identifies the client application.
+
+NOTE: In cases when multiple threads are configured, `consumer_threads` is greater than one, a suffix is appended to
+the `group_instance_id` to avoid collisions.
+
 [id="plugins-{type}s-{plugin}-heartbeat_interval_ms"]
 ===== `heartbeat_interval_ms` 
 

kafka_test_setup.sh

@@ -48,6 +48,7 @@ build/kafka/bin/kafka-topics.sh --create --partitions 1 --replication-factor 1 -
 build/kafka/bin/kafka-topics.sh --create --partitions 1 --replication-factor 1 --topic logstash_integration_lz4_topic --bootstrap-server localhost:9092
 build/kafka/bin/kafka-topics.sh --create --partitions 1 --replication-factor 1 --topic logstash_integration_zstd_topic --bootstrap-server localhost:9092
 build/kafka/bin/kafka-topics.sh --create --partitions 3 --replication-factor 1 --topic logstash_integration_partitioner_topic --bootstrap-server localhost:9092
+build/kafka/bin/kafka-topics.sh --create --partitions 3 --replication-factor 1 --topic logstash_integration_static_membership_topic --bootstrap-server localhost:9092
 curl -s -o build/apache_logs.txt https://s3.amazonaws.com/data.elasticsearch.org/apache_logs/apache_logs.txt
 cat build/apache_logs.txt | build/kafka/bin/kafka-console-producer.sh --topic logstash_integration_topic_plain --broker-list localhost:9092
 cat build/apache_logs.txt | build/kafka/bin/kafka-console-producer.sh --topic logstash_integration_topic_snappy --broker-list localhost:9092 --compression-codec snappy

lib/logstash/inputs/kafka.rb

@@ -124,6 +124,11 @@ class LogStash::Inputs::Kafka < LogStash::Inputs::Base
   # that happens to be made up of multiple processors. Messages in a topic will be distributed to all
   # Logstash instances with the same `group_id`
   config :group_id, :validate => :string, :default => "logstash"
+  # Set a static group instance id used in static membership feature to avoid rebalancing when a
+  # consumer goes offline. If set and `consumer_threads` is greater than 1 then for each
+  # consumer crated by each thread an artificial suffix is appended to the user provided `group_instance_id`
+  # to avoid clashing.
+  config :group_instance_id, :validate => :string
   # The expected time between heartbeats to the consumer coordinator. Heartbeats are used to ensure 
   # that the consumer's session stays active and to facilitate rebalancing when new
   # consumers join or leave the group. The value must be set lower than
@@ -136,7 +141,7 @@ class LogStash::Inputs::Kafka < LogStash::Inputs::Base
   # been aborted. Non-transactional messages will be returned unconditionally in either mode.
   config :isolation_level, :validate => ["read_uncommitted", "read_committed"], :default => "read_uncommitted" # Kafka default
   # Java Class used to deserialize the record's key
-  config :key_deserializer_class, :validate => :string, :default => "org.apache.kafka.common.serialization.StringDeserializer"
+  config :key_deserializer_class, :validate => :string, :default => DEFAULT_DESERIALIZER_CLASS
   # The maximum delay between invocations of poll() when using consumer group management. This places 
   # an upper bound on the amount of time that the consumer can be idle before fetching more records. 
   # If poll() is not called before expiration of this timeout, then the consumer is considered failed and 
@@ -287,7 +292,10 @@ def extract_metadata_level(decorate_events_setting)
 
   public
   def run(logstash_queue)
-    @runner_consumers = consumer_threads.times.map { |i| subscribe(create_consumer("#{client_id}-#{i}")) }
+    @runner_consumers = consumer_threads.times.map do |i|
+      thread_group_instance_id = consumer_threads > 1 && group_instance_id ? "#{group_instance_id}-#{i}" : group_instance_id
+      subscribe(create_consumer("#{client_id}-#{i}", thread_group_instance_id))
+    end
     @runner_threads = @runner_consumers.map.with_index { |consumer, i| thread_runner(logstash_queue, consumer,
                                                                                      "kafka-input-worker-#{client_id}-#{i}") }
     @runner_threads.each(&:start)
@@ -335,6 +343,9 @@ def do_poll(consumer)
     rescue org.apache.kafka.common.errors.WakeupException => e
       logger.debug("Wake up from poll", :kafka_error_message => e)
       raise e unless stop?
+    rescue org.apache.kafka.common.errors.FencedInstanceIdException => e
+      logger.error("Another consumer with same group.instance.id has connected")
+      raise e unless stop?
     rescue => e
       logger.error("Unable to poll Kafka consumer",
                    :kafka_error_message => e,
@@ -389,7 +400,7 @@ def maybe_commit_offset(consumer)
   end
 
   private
-  def create_consumer(client_id)
+  def create_consumer(client_id, group_instance_id)
     begin
       props = java.util.Properties.new
       kafka = org.apache.kafka.clients.consumer.ConsumerConfig
@@ -407,6 +418,10 @@ def create_consumer(client_id)
       props.put(kafka::FETCH_MAX_WAIT_MS_CONFIG, fetch_max_wait_ms.to_s) unless fetch_max_wait_ms.nil?
       props.put(kafka::FETCH_MIN_BYTES_CONFIG, fetch_min_bytes.to_s) unless fetch_min_bytes.nil?
       props.put(kafka::GROUP_ID_CONFIG, group_id)
+      if group_instance_id
+        # group_instance_id in case of nil can't be set
+        props.put(kafka::GROUP_INSTANCE_ID_CONFIG, group_instance_id)
+      end
       props.put(kafka::HEARTBEAT_INTERVAL_MS_CONFIG, heartbeat_interval_ms.to_s) unless heartbeat_interval_ms.nil?
       props.put(kafka::ISOLATION_LEVEL_CONFIG, isolation_level)
       props.put(kafka::KEY_DESERIALIZER_CLASS_CONFIG, key_deserializer_class)

spec/integration/inputs/kafka_spec.rb

@@ -79,6 +79,7 @@ def send_message(record)
     producer = org.apache.kafka.clients.producer.KafkaProducer.new(props)
 
     producer.send(record)
+    producer.flush
     producer.close
   end
 
@@ -185,10 +186,109 @@ def send_message(record)
       end
     end
   end
+
+  context "static membership 'group.instance.id' setting" do
+    let(:consumer_config) do
+      {
+        "topics" => ["logstash_integration_static_membership_topic"],
+        "group_id" => "logstash",
+        "consumer_threads" => 1,
+        # this is needed because the worker thread could be executed little after the producer sent the "up" message
+        "auto_offset_reset" => "earliest",
+        "group_instance_id" => "test_static_group_id"
+      }
+    end
+
+    let(:logger) { double("logger") }
+    before :each do
+      allow(LogStash::Inputs::Kafka).to receive(:logger).and_return(logger)
+      [:error, :warn, :info, :debug].each do |level|
+        allow(logger).to receive(level)
+      end
+    end
+
+    it "input plugin disconnects from the broker when another client with same static membership connects" do
+      queue = java.util.concurrent.ArrayBlockingQueue.new(10)
+      kafka_input = LogStash::Inputs::Kafka.new(consumer_config)
+      kafka_input.register
+
+      expect(logger).to receive(:error).with("Another consumer with same group.instance.id has connected")
+
+      input_worker = java.lang.Thread.new { kafka_input.run(queue) }
+      begin
+        input_worker.start
+        wait_kafka_input_is_ready("logstash_integration_static_membership_topic", queue)
+        saboteur_kafka_consumer = create_consumer_and_start_consuming("test_static_group_id")
+        saboteur_kafka_consumer.run # ask to be scheduled
+        saboteur_kafka_consumer.join
+
+        expect(saboteur_kafka_consumer.value).to eq("saboteur exited")
+      ensure
+        input_worker.join(30_000)
+      end
+    end
+
+    context "when the plugin is configured with multiple consumer threads" do
+      let(:multi_consumer_config) { consumer_config.merge({"consumer_threads" => 2}) }
+
+      it "should avoid to connect with same 'group.instance.id'" do
+        queue = java.util.concurrent.ArrayBlockingQueue.new(10)
+        kafka_input = LogStash::Inputs::Kafka.new(multi_consumer_config)
+        kafka_input.register
+
+        expect(logger).to_not receive(:error).with("Another consumer with same group.instance.id has connected")
+
+        input_worker = java.lang.Thread.new { kafka_input.run(queue) }
+        begin
+          input_worker.start
+          wait_kafka_input_is_ready("logstash_integration_static_membership_topic", queue)
+        ensure
+          kafka_input.stop
+          input_worker.join(1_000)
+        end
+      end
+    end
+  end
+end
+
+# return consumer Ruby Thread
+def create_consumer_and_start_consuming(static_group_id)
+  props = java.util.Properties.new
+  kafka = org.apache.kafka.clients.consumer.ConsumerConfig
+  props.put(kafka::BOOTSTRAP_SERVERS_CONFIG, "localhost:9092")
+  props.put(kafka::KEY_DESERIALIZER_CLASS_CONFIG, LogStash::Inputs::Kafka::DEFAULT_DESERIALIZER_CLASS)
+  props.put(kafka::VALUE_DESERIALIZER_CLASS_CONFIG, LogStash::Inputs::Kafka::DEFAULT_DESERIALIZER_CLASS)
+  props.put(kafka::GROUP_ID_CONFIG, "logstash")
+  props.put(kafka::GROUP_INSTANCE_ID_CONFIG, static_group_id)
+  consumer = org.apache.kafka.clients.consumer.KafkaConsumer.new(props)
+
+  Thread.new do
+    LogStash::Util::set_thread_name("integration_test_simple_consumer")
+    begin
+      consumer.subscribe(["logstash_integration_static_membership_topic"])
+      records = consumer.poll(java.time.Duration.ofSeconds(3))
+      "saboteur exited"
+    rescue => e
+      e # return the exception reached in thread.value
+    ensure
+      consumer.close
+    end
+  end
 end
 
 private
 
+def wait_kafka_input_is_ready(topic, queue)
+  # this is needed to give time to the kafka input to be up and running
+  header = org.apache.kafka.common.header.internals.RecordHeader.new("name", "Ping Up".to_java_bytes)
+  record = org.apache.kafka.clients.producer.ProducerRecord.new(topic, 0, "key", "value", [header])
+  send_message(record)
+
+  # Wait the message is processed
+  message = queue.poll(1, java.util.concurrent.TimeUnit::MINUTES)
+  expect(message).to_not eq(nil)
+end
+
 def consume_messages(config, queue: Queue.new, timeout:, event_count:)
   kafka_input = LogStash::Inputs::Kafka.new(config)
   kafka_input.register

spec/unit/inputs/kafka_spec.rb

@@ -297,7 +297,7 @@
           to receive(:new).with(hash_including('client.rack' => 'EU-R1')).
               and_return kafka_client = double('kafka-consumer')
 
-      expect( subject.send(:create_consumer, 'sample_client-0') ).to be kafka_client
+      expect( subject.send(:create_consumer, 'sample_client-0', 'group_instance_id') ).to be kafka_client
     end
   end
 
@@ -309,7 +309,7 @@
           to receive(:new).with(hash_including('session.timeout.ms' => '25000', 'max.poll.interval.ms' => '345000')).
               and_return kafka_client = double('kafka-consumer')
 
-      expect( subject.send(:create_consumer, 'sample_client-1') ).to be kafka_client
+      expect( subject.send(:create_consumer, 'sample_client-1', 'group_instance_id') ).to be kafka_client
     end
   end
 
@@ -321,7 +321,7 @@
           to receive(:new).with(hash_including('session.timeout.ms' => '25200', 'max.poll.interval.ms' => '123000')).
               and_return kafka_client = double('kafka-consumer')
 
-      expect( subject.send(:create_consumer, 'sample_client-2') ).to be kafka_client
+      expect( subject.send(:create_consumer, 'sample_client-2', 'group_instance_id') ).to be kafka_client
     end
   end
 
@@ -333,7 +333,7 @@
           to receive(:new).with(hash_including('enable.auto.commit' => 'false', 'check.crcs' => 'true')).
               and_return kafka_client = double('kafka-consumer')
 
-      expect( subject.send(:create_consumer, 'sample_client-3') ).to be kafka_client
+      expect( subject.send(:create_consumer, 'sample_client-3', 'group_instance_id') ).to be kafka_client
       expect( subject.enable_auto_commit ).to be false
     end
   end
@@ -346,7 +346,7 @@
           to receive(:new).with(hash_including('enable.auto.commit' => 'true', 'check.crcs' => 'false')).
               and_return kafka_client = double('kafka-consumer')
 
-      expect( subject.send(:create_consumer, 'sample_client-4') ).to be kafka_client
+      expect( subject.send(:create_consumer, 'sample_client-4', 'group_instance_id') ).to be kafka_client
       expect( subject.enable_auto_commit ).to be true
     end
   end