Dear Raghu, I add the line: “PCollection<Integer> reshuffled = windowKV.apply(Reshuffle.viaRandomKey());” in my program.
I tried to control the streaming data size: 100,000/1sec to decrease the processing time. The following settings are used for my project. 1. One topic / 2 partitions [cid:[email protected]] 2. Two workers / two executors 3. The spark-default setting is: spark.executor.instances=2 spark.executor.cores=4 spark.executor.memory=2048m spark.default.parallelism=200 spark.streaming.blockInterval=50ms spark.streaming.kafka.maxRatePerPartition=50,000 spark.streaming.backpressure.enabled=true spark.streaming.concurrentJobs = 1 spark.executor.extraJavaOptions=-XX:+UseConcMarkSweepGC spark.executor.extraJavaOptions=-Xss100M spark.shuffle.consolidateFiles=true spark.streaming.unpersist=true spark.streaming.stopGracefullyOnShutdown=true I hope that the data size is controlled at 100,000. Here, [cid:[email protected]] The data size is always over 100,000. The setting of “spark.streaming.kafka.maxRatePerPartition” confused me. That does not seem to work for me. Rick From: Raghu Angadi [mailto:[email protected]] Sent: Saturday, January 26, 2019 3:06 AM To: [email protected] Subject: Re: kafkaIO Consumer Rebalance with Spark Runner You have 32 partitions. Reading can not be distributed to more than 32 parallel tasks. If you have a log of processing for each record after reading, you can reshuffle the messages before processing them, that way the processing could be distributed to more tasks. Search for previous threads about reshuffle in Beam lists. On Thu, Jan 24, 2019 at 7:23 PM <[email protected]<mailto:[email protected]>> wrote: Dear all, I am using the kafkaIO sdk in my project (Beam with Spark runner). The problem about task skew is shown as the following figure. [cid:[email protected]] My running environment is: OS: Ubuntn 14.04.4 LTS The version of related tools is: java version: "1.8.0_151" Beam version: 2.9.0 (Spark runner with Standalone mode) Spark version: 2.3.1 Standalone mode Execution condition: Master/Driver node: ubuntu7 Worker nodes: ubuntu8 (4 Executors); ubuntu9 (4 Executors) The number of executors is 8 Kafka Broker: 2.10-0.10.1.1 Broker node at ubuntu7 Kafka Client: The topic: kafkasink32 kafkasink32 Partitions: 32 The programming of my project for kafkaIO SDK is as: ============================================================================== Map<String, Object> map = ImmutableMap.<String, Object>builder() .put("group.id<http://group.id>", (Object)"test-consumer-group") .build(); List<TopicPartition> topicPartitions = new ArrayList(); for(int i = 0; i < 32; i++) { topicPartitions.add(new TopicPartition("kafkasink32",i)); } PCollection<KV<Long, String>> readKafkaData = p.apply(KafkaIO.<Long, String>read() .withBootstrapServers("ubuntu7:9092") .updateConsumerProperties(map) .withKeyDeserializer(LongDeserializer.class) .withValueDeserializer(StringDeserializer.class) .withTopicPartitions(topicPartitions) .withoutMetadata() ); ============================================================================== Here I have two directions to solve this problem: 1. Using the following sdk from spark streaming https://jaceklaskowski.gitbooks.io/spark-streaming/spark-streaming-kafka-LocationStrategy.html LocationStrategies.PreferConsistent: Use in most cases as it consistently distributes partitions across all executors. If we would like to use this feature, we have not idea to set this in kafkaIO SDK. 2. Setting the related configurations of kafka to perform the consumer rebalance set consumer group? Set group.id<http://group.id>? If we need to do No2., could someone give me some ideas to set configurations? If anyone provides any direction to help us to overcome this problem, we would appreciate it. Thanks. Sincerely yours, Rick -- 本信件可能包含工研院機密資訊，非指定之收件者，請勿使用或揭露本信件內容，並請銷毀此信件。 This email may contain confidential information. Please do not use or disclose it in any way and delete it if you are not the intended recipient. -- 本信件可能包含工研院機密資訊，非指定之收件者，請勿使用或揭露本信件內容，並請銷毀此信件。 This email may contain confidential information. Please do not use or disclose it in any way and delete it if you are not the intended recipient.
