RE: kafka offset commit in spark streaming 1.2
If you’re using WAL with Kafka, Spark Streaming will ignore this configuration(autocommit.enable) and explicitly call commitOffset to update offset to Kafka AFTER WAL is done. No matter what you’re setting with autocommit.enable, internally Spark Streaming will set it to false to turn off autocommit mechanism. Thanks Jerry From: Shushant Arora [mailto:shushantaror...@gmail.com] Sent: Monday, July 6, 2015 8:11 PM To: user Subject: kafka offset commit in spark streaming 1.2 In spark streaming 1.2 , Is offset of kafka message consumed are updated in zookeeper only after writing in WAL if WAL and checkpointig are enabled or is it depends upon kafkaparams while initialing the kafkaDstream. MapString,String kafkaParams = new HashMapString, String(); kafkaParams.put(zookeeper.connect,ip:2181); kafkaParams.put(group.idhttp://group.id, testgroup); kafkaParams.put(zookeeper.session.timeout.mshttp://zookeeper.session.timeout.ms, 1); kafkaParams.put(autocommit.enable,true); kafkaParams.put(zookeeper.sync.time.mshttp://zookeeper.sync.time.ms, 250); kafkaStreams.add(KafkaUtils.createStream(jssc, byte[].class, byte[].class,kafka.serializer.DefaultDecoder.class , kafka.serializer.DefaultDecoder.class, kafkaParams, topicsMap, StorageLevel.MEMORY_ONLY())); Here since I have set autocommit.enable to true , does spark streaming will ignore this and always call explicit commitOffset high level consumer connector or does it depends on parameter passed? Since if it depends upon parameter and receiver calls explicit commit only when autocommit is false, then I should override the default autocommit to false from true while enabling WAL, since it may give duplicate in case of failure if WAL is enabled and autocommit is true.
RE: kafka offset commit in spark streaming 1.2
Please see the inline comments. From: Shushant Arora [mailto:shushantaror...@gmail.com] Sent: Monday, July 6, 2015 8:51 PM To: Shao, Saisai Cc: user Subject: Re: kafka offset commit in spark streaming 1.2 So If WAL is disabled, how developer can commit offset explicitly in spark streaming app since we don't write code which will be executed in receiver ? I think it is difficult for user to commit offset explicitly in receiver-based Spark Streaming Kafka API. If you want to explicitly commit offset, you could try Spark Streaming Kafka direct API, which is newly added in Spark 1.3+, where you could manage the offsets yourself, it is implemented based on Kafka’s low-level API. Plus since offset commitment is asynchronoous, is it possible -it may happen last offset is not commited yet and next stream batch started on receiver and it may get duplicate data ? Yes, it is possible, so receiver based Spark Streaming Kafka API cannot guarantee no duplication and no data lost. If you enable WAL, no data lost can be guaranteed by still you will meet duplication. So the best way is to use Spark Streaming Kafka direct API with your own offset management to make sure exact-once. On Mon, Jul 6, 2015 at 6:16 PM, Shao, Saisai saisai.s...@intel.commailto:saisai.s...@intel.com wrote: If you disable WAL, Spark Streaming itself will not manage any offset related things, is auto commit is enabled by true, Kafka itself will update offsets in a time-based way, if auto commit is disabled, no any part will call commitOffset, you need to call this API yourself. Also Kafka’s offset commitment mechanism is actually a timer way, so it is asynchronized with replication. From: Shushant Arora [mailto:shushantaror...@gmail.commailto:shushantaror...@gmail.com] Sent: Monday, July 6, 2015 8:30 PM To: Shao, Saisai Cc: user Subject: Re: kafka offset commit in spark streaming 1.2 And what if I disable WAL and use replication of receiver data using StorageLevel.MEMORY_ONLY2(). Will it commit offset after replicating the message or will it use autocommit.enable value. And if it uses this value what if autocommit.enable is set to false then when does receiver calls commitOffset? On Mon, Jul 6, 2015 at 5:53 PM, Shao, Saisai saisai.s...@intel.commailto:saisai.s...@intel.com wrote: If you’re using WAL with Kafka, Spark Streaming will ignore this configuration(autocommit.enable) and explicitly call commitOffset to update offset to Kafka AFTER WAL is done. No matter what you’re setting with autocommit.enable, internally Spark Streaming will set it to false to turn off autocommit mechanism. Thanks Jerry From: Shushant Arora [mailto:shushantaror...@gmail.commailto:shushantaror...@gmail.com] Sent: Monday, July 6, 2015 8:11 PM To: user Subject: kafka offset commit in spark streaming 1.2 In spark streaming 1.2 , Is offset of kafka message consumed are updated in zookeeper only after writing in WAL if WAL and checkpointig are enabled or is it depends upon kafkaparams while initialing the kafkaDstream. MapString,String kafkaParams = new HashMapString, String(); kafkaParams.put(zookeeper.connect,ip:2181); kafkaParams.put(group.idhttp://group.id, testgroup); kafkaParams.put(zookeeper.session.timeout.mshttp://zookeeper.session.timeout.ms, 1); kafkaParams.put(autocommit.enable,true); kafkaParams.put(zookeeper.sync.time.mshttp://zookeeper.sync.time.ms, 250); kafkaStreams.add(KafkaUtils.createStream(jssc, byte[].class, byte[].class,kafka.serializer.DefaultDecoder.class , kafka.serializer.DefaultDecoder.class, kafkaParams, topicsMap, StorageLevel.MEMORY_ONLY())); Here since I have set autocommit.enable to true , does spark streaming will ignore this and always call explicit commitOffset high level consumer connector or does it depends on parameter passed? Since if it depends upon parameter and receiver calls explicit commit only when autocommit is false, then I should override the default autocommit to false from true while enabling WAL, since it may give duplicate in case of failure if WAL is enabled and autocommit is true.
RE: kafka offset commit in spark streaming 1.2
If you disable WAL, Spark Streaming itself will not manage any offset related things, is auto commit is enabled by true, Kafka itself will update offsets in a time-based way, if auto commit is disabled, no any part will call commitOffset, you need to call this API yourself. Also Kafka’s offset commitment mechanism is actually a timer way, so it is asynchronized with replication. From: Shushant Arora [mailto:shushantaror...@gmail.com] Sent: Monday, July 6, 2015 8:30 PM To: Shao, Saisai Cc: user Subject: Re: kafka offset commit in spark streaming 1.2 And what if I disable WAL and use replication of receiver data using StorageLevel.MEMORY_ONLY2(). Will it commit offset after replicating the message or will it use autocommit.enable value. And if it uses this value what if autocommit.enable is set to false then when does receiver calls commitOffset? On Mon, Jul 6, 2015 at 5:53 PM, Shao, Saisai saisai.s...@intel.commailto:saisai.s...@intel.com wrote: If you’re using WAL with Kafka, Spark Streaming will ignore this configuration(autocommit.enable) and explicitly call commitOffset to update offset to Kafka AFTER WAL is done. No matter what you’re setting with autocommit.enable, internally Spark Streaming will set it to false to turn off autocommit mechanism. Thanks Jerry From: Shushant Arora [mailto:shushantaror...@gmail.commailto:shushantaror...@gmail.com] Sent: Monday, July 6, 2015 8:11 PM To: user Subject: kafka offset commit in spark streaming 1.2 In spark streaming 1.2 , Is offset of kafka message consumed are updated in zookeeper only after writing in WAL if WAL and checkpointig are enabled or is it depends upon kafkaparams while initialing the kafkaDstream. MapString,String kafkaParams = new HashMapString, String(); kafkaParams.put(zookeeper.connect,ip:2181); kafkaParams.put(group.idhttp://group.id, testgroup); kafkaParams.put(zookeeper.session.timeout.mshttp://zookeeper.session.timeout.ms, 1); kafkaParams.put(autocommit.enable,true); kafkaParams.put(zookeeper.sync.time.mshttp://zookeeper.sync.time.ms, 250); kafkaStreams.add(KafkaUtils.createStream(jssc, byte[].class, byte[].class,kafka.serializer.DefaultDecoder.class , kafka.serializer.DefaultDecoder.class, kafkaParams, topicsMap, StorageLevel.MEMORY_ONLY())); Here since I have set autocommit.enable to true , does spark streaming will ignore this and always call explicit commitOffset high level consumer connector or does it depends on parameter passed? Since if it depends upon parameter and receiver calls explicit commit only when autocommit is false, then I should override the default autocommit to false from true while enabling WAL, since it may give duplicate in case of failure if WAL is enabled and autocommit is true.
Re: kafka offset commit in spark streaming 1.2
So If WAL is disabled, how developer can commit offset explicitly in spark streaming app since we don't write code which will be executed in receiver ? Plus since offset commitment is asynchronoous, is it possible -it may happen last offset is not commited yet and next stream batch started on receiver and it may get duplicate data ? On Mon, Jul 6, 2015 at 6:16 PM, Shao, Saisai saisai.s...@intel.com wrote: If you disable WAL, Spark Streaming itself will not manage any offset related things, is auto commit is enabled by true, Kafka itself will update offsets in a time-based way, if auto commit is disabled, no any part will call commitOffset, you need to call this API yourself. Also Kafka’s offset commitment mechanism is actually a timer way, so it is asynchronized with replication. *From:* Shushant Arora [mailto:shushantaror...@gmail.com] *Sent:* Monday, July 6, 2015 8:30 PM *To:* Shao, Saisai *Cc:* user *Subject:* Re: kafka offset commit in spark streaming 1.2 And what if I disable WAL and use replication of receiver data using StorageLevel.MEMORY_ONLY2(). Will it commit offset after replicating the message or will it use autocommit.enable value. And if it uses this value what if autocommit.enable is set to false then when does receiver calls commitOffset? On Mon, Jul 6, 2015 at 5:53 PM, Shao, Saisai saisai.s...@intel.com wrote: If you’re using WAL with Kafka, Spark Streaming will ignore this configuration(autocommit.enable) and explicitly call commitOffset to update offset to Kafka AFTER WAL is done. No matter what you’re setting with autocommit.enable, internally Spark Streaming will set it to false to turn off autocommit mechanism. Thanks Jerry *From:* Shushant Arora [mailto:shushantaror...@gmail.com] *Sent:* Monday, July 6, 2015 8:11 PM *To:* user *Subject:* kafka offset commit in spark streaming 1.2 In spark streaming 1.2 , Is offset of kafka message consumed are updated in zookeeper only after writing in WAL if WAL and checkpointig are enabled or is it depends upon kafkaparams while initialing the kafkaDstream. MapString,String kafkaParams = new HashMapString, String(); kafkaParams.put(zookeeper.connect,ip:2181); kafkaParams.put(group.id, testgroup); kafkaParams.put(zookeeper.session.timeout.ms, 1); kafkaParams.put(autocommit.enable,true); kafkaParams.put(zookeeper.sync.time.ms, 250); kafkaStreams.add(KafkaUtils.createStream(jssc, byte[].class, byte[].class,kafka.serializer.DefaultDecoder.class , kafka.serializer.DefaultDecoder.class, kafkaParams, topicsMap, StorageLevel.MEMORY_ONLY())); Here since I have set autocommit.enable to true , does spark streaming will ignore this and always call explicit commitOffset high level consumer connector or does it depends on parameter passed? Since if it depends upon parameter and receiver calls explicit commit only when autocommit is false, then I should override the default autocommit to false from true while enabling WAL, since it may give duplicate in case of failure if WAL is enabled and autocommit is true.