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From Cody Koeninger <c...@koeninger.org>
Subject Re: Instability issues with Spark 2.0.1 and Kafka 0.10
Date Fri, 04 Nov 2016 20:24:43 GMT
So just to be clear, the answers to my questions are

- you are not using different group ids, you're using the same group
id everywhere

- you are committing offsets manually

Right?

If you want to eliminate network or kafka misbehavior as a source,
tune poll.ms upwards even higher.

You must use different group ids for different rdds or streams.
Kafka consumers won't behave the way you expect if they are all in the
same group id, and the consumer cache is keyed by group id. Yes, the
executor will tack "spark-executor-" on to the beginning, but if you
give it the same base group id, it will be the same.  And the driver
will use the group id you gave it, unmodified.

Finally, I really can't help you if you're manually writing your own
code to commit offsets directly to Kafka.  Trying to minimize
duplicates that way doesn't really make sense, your system must be
able to handle duplicates if you're using kafka as an offsets store,
it can't do transactional exactly once.

On Fri, Nov 4, 2016 at 1:48 PM, vonnagy <ivan@vadio.com> wrote:
> Here are some examples and details of the scenarios. The KafkaRDD is the most
> error prone to polling
> timeouts and concurrentm modification errors.
>
> *Using KafkaRDD* - This takes a list of channels and processes them in
> parallel using the KafkaRDD directly. they all use the same consumer group
> ('storage-group'), but each has it's own topic and each topic has 4
> partitions. We routinely get timeout errors when polling for data. This
> occurs whether we process in parallel or sequentially.
>
> *Spark Kafka setting:*
> spark.streaming.kafka.consumer.poll.ms=2000
>
> *Kafka Consumer Params:*
> metric.reporters = []
> metadata.max.age.ms = 300000
> partition.assignment.strategy =
> [org.apache.kafka.clients.consumer.RangeAssignor]
> reconnect.backoff.ms = 50
> sasl.kerberos.ticket.renew.window.factor = 0.8
> max.partition.fetch.bytes = 1048576
> bootstrap.servers = [somemachine:31000]
> ssl.keystore.type = JKS
> enable.auto.commit = false
> sasl.mechanism = GSSAPI
> interceptor.classes = null
> exclude.internal.topics = true
> ssl.truststore.password = null
> client.id =
> ssl.endpoint.identification.algorithm = null
> max.poll.records = 1000
> check.crcs = true
> request.timeout.ms = 40000
> heartbeat.interval.ms = 3000
> auto.commit.interval.ms = 5000
> receive.buffer.bytes = 65536
> ssl.truststore.type = JKS
> ssl.truststore.location = null
> ssl.keystore.password = null
> fetch.min.bytes = 1
> send.buffer.bytes = 131072
> value.deserializer = class
> com.vadio.analytics.spark.storage.ClientEventJsonOptionDeserializer
> group.id = storage-group
> retry.backoff.ms = 100
> sasl.kerberos.kinit.cmd = /usr/bin/kinit
> sasl.kerberos.service.name = null
> sasl.kerberos.ticket.renew.jitter = 0.05
> ssl.trustmanager.algorithm = PKIX
> ssl.key.password = null
> fetch.max.wait.ms = 500
> sasl.kerberos.min.time.before.relogin = 60000
> connections.max.idle.ms = 540000
> session.timeout.ms = 30000
> metrics.num.samples = 2
> key.deserializer = class
> org.apache.kafka.common.serialization.StringDeserializer
> ssl.protocol = TLS
> ssl.provider = null
> ssl.enabled.protocols = [TLSv1.2, TLSv1.1, TLSv1]
> ssl.keystore.location = null
> ssl.cipher.suites = null
> security.protocol = PLAINTEXT
> ssl.keymanager.algorithm = SunX509
> metrics.sample.window.ms = 30000
> auto.offset.reset = earliest
>
> *Example usage with KafkaRDD:*
> val channels = Seq("channel1", "channel2")
>
> channels.toParArray.foreach { channel =>
>   val consumer = new KafkaConsumer[K, V](kafkaParams.asJava)
>
>   // Get offsets for the given topic and the consumer group 'storage-group'
>   val offsetRanges = getOffsets("storage-group", channel)
>
>   val ds = KafkaUtils.createRDD[K, V](context,
>         kafkaParams asJava,
>         offsetRanges,
>         PreferConsistent).toDS[V]
>
>   // Do some aggregations
>   ds.agg(...)
>   // Save the data
>   ds.write.mode(SaveMode.Append).parquet(somePath)
>   // Save offsets using a KafkaConsumer
>   consumer.commitSync(newOffsets.asJava)
>   consumer.close()
> }
>
>
> *Example usage with Kafka Stream:*
> This creates a stream and processes events in each partition. At the end of
> processing for
> each partition, we updated the offsets for each partition. This is
> challenging to do, but is better
> then calling commitAysnc on the stream, because that occurs after the
> /entire/ RDD has been
> processed. This method minimizes duplicates in an exactly once environment.
> Since the executors
> use their own custom group "spark-executor-processor-group" and the commit
> is buried in private
> functions we are unable to use the executors cached consumer to update the
> offsets. This requires us
> to go through multiple steps to update the Kafka offsets accordingly.
>
> val offsetRanges = getOffsets("processor-group", "my-topic")
>
> val stream = KafkaUtils.createDirectStream[K, V](context,
>       PreferConsistent,
>       Subscribe[K, V](Seq("my-topic") asJavaCollection,
>         kafkaParams,
>         offsetRanges))
>
> stream.foreachRDD { rdd =>
>     val offsetRanges = rdd.asInstanceOf[HasOffsetRanges].offsetRanges
>
>     // Transform our data
>    rdd.foreachPartition { events =>
>        // Establish a consumer in the executor so we can update offsets
> after each partition.
>        // This class is homegrown and uses the KafkaConsumer to help get/set
> offsets
>        val consumer = new ConsumerUtils(kafkaParams)
>        // do something with our data
>
>        // Write the offsets that were updated in this partition
>        kafkaConsumer.setConsumerOffsets("processor-group",
>           Map(TopicAndPartition(tp.topic, tp.partition) -> endOffset))
>    }
> }
>
>
>
> --
> View this message in context: http://apache-spark-user-list.1001560.n3.nabble.com/Instability-issues-with-Spark-2-0-1-and-Kafka-0-10-tp28017p28020.html
> Sent from the Apache Spark User List mailing list archive at Nabble.com.
>
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