You can't create a network connection to kafka on the driver and then serialize it to send it the executor. That's likely why you're getting serialization errors.
Kafka producers are thread safe and designed for use as a singleton. Use a lazy singleton instance of the producer on the executor, don't pass it in. On Mon, Dec 18, 2017 at 9:20 AM, Silvio Fiorito < silvio.fior...@granturing.com> wrote: > Couldn’t you readStream from Kafka, do your transformations, map your rows > from the transformed input into what you want need to send to Kafka, then > writeStream to Kafka? > > > > > > *From: *Liana Napalkova <liana.napalk...@eurecat.org> > *Date: *Monday, December 18, 2017 at 10:07 AM > *To: *Silvio Fiorito <silvio.fior...@granturing.com>, " > user@spark.apache.org" <user@spark.apache.org> > > *Subject: *Re: How to properly execute `foreachPartition` in Spark 2.2 > > > > I need to firstly read from Kafka queue into a DataFrame. Then I should > perform some transformations with the data. Finally, for each row in the > DataFrame I should conditionally apply KafkaProducer in order to send some > data to Kafka. > > So, I am both consuming and producing the data from/to Kafka. > > > ------------------------------ > > *From:* Silvio Fiorito <silvio.fior...@granturing.com> > *Sent:* 18 December 2017 16:00:39 > *To:* Liana Napalkova; user@spark.apache.org > *Subject:* Re: How to properly execute `foreachPartition` in Spark 2.2 > > > > Why don’t you just use the Kafka sink for Spark 2.2? > > > > https://spark.apache.org/docs/2.2.0/structured-streaming- > kafka-integration.html#creating-a-kafka-sink-for-streaming-queries > > > > > > > > *From: *Liana Napalkova <liana.napalk...@eurecat.org> > *Date: *Monday, December 18, 2017 at 9:45 AM > *To: *"user@spark.apache.org" <user@spark.apache.org> > *Subject: *How to properly execute `foreachPartition` in Spark 2.2 > > > > Hi, > > > > I wonder how to properly execute `foreachPartition` in Spark 2.2. Below I > explain the problem is details. I appreciate any help. > > > > In Spark 1.6 I was doing something similar to this: > > > > DstreamFromKafka.foreachRDD(session => { > session.foreachPartition { partitionOfRecords => > println("Setting the producer.") > val producer = Utils.createProducer(mySet. > value("metadataBrokerList"), > > mySet.value("batchSize"), > > mySet.value("lingerMS")) > partitionOfRecords.foreach(s => { > > //... > > > > However, I cannot find the proper way to do the similar thing in Spark > 2.2. I tried to write my own class by extending `ForeachWriter`, but I get > Task Serialization error when passing `KafkaProducer`. > > *class *MyTestClass( > // *val inputparams*: String) > *extends *Serializable > { > > *val **spark *= SparkSession > .*builder*() > .appName("TEST") > //.config("spark.sql.warehouse.dir", kafkaData) > .enableHiveSupport() > .getOrCreate() > > *import **spark*.implicits._ > > *val *df: Dataset[String] = *spark*.readStream > .format("kafka") > .option("kafka.bootstrap.servers", "localhost:9092") > .option("subscribe", "test") > .option("startingOffsets", "latest") > .option("failOnDataLoss", "true") > .load() > .selectExpr("CAST(key AS STRING)", "CAST(value AS STRING)").as[(String, > String)] // Kafka sends bytes > .map(_._2) > > *val *producer = // create KafkaProducer > > *val *writer = *new *MyForeachWriter(producer: KafkaProducer[String,String]) > > *val *query = df > .writeStream > .foreach(writer) > .start > > query.awaitTermination() > > *spark*.stop() > > > *class *MyForeachWriter *extends *ForeachWriter[String] *with *Serializable { > > *var **producer*: KafkaProducer[String,String] = _ > > *def this*(producer: KafkaProducer[String,String]) > { > *this*() > *this*.*producer *= producer > } > > *override def *process(row: String): Unit = > { > // ... > } > > *override def *close(errorOrNull: Throwable): Unit = {} > > *override def *open(partitionId: Long, version: Long): Boolean = { > > *true *} > > } > > > > > > *Liana Napalkova, PhD* > > *Big Data Analytics Unit* > * ------------------------------ * > > > > > > *T +34 **93 238 14 00 (ext. 1248)* > *M +34 **633 426 677* > > *liana.napalk...@eurecat.org <liana.napalk...@eurecat.org>* > ------------------------------ > > Carrer Camí Antic de València 54 > <https://maps.google.com/?q=Cam%C3%AD+Antic+de+Val%C3%A8ncia+54&entry=gmail&source=g>-56, > Edifici A - 08005 - Barcelona > www.eurecat.org > > Ascamm, BDigital, Barcelona Media i Cetemmsa ara som Eurecat > > > ------------------------------ > DISCLAIMER: Aquest missatge pot contenir informació confidencial. Si vostè > no n'és el destinatari, si us plau, esborri'l i faci'ns-ho saber > immediatament a la següent adreça: le...@eurecat.org Si el destinatari > d'aquest missatge no consent la utilització del correu electrònic via > Internet i la gravació de missatges, li preguem que ens ho comuniqui > immediatament. > > DISCLAIMER: Este mensaje puede contener información confidencial. Si usted > no es el destinatario del mensaje, por favor bórrelo y notifíquenoslo > inmediatamente a la siguiente dirección: le...@eurecat.org Si el > destinatario de este mensaje no consintiera la utilización del correo > electrónico vía Internet y la grabación de los mensajes, rogamos lo ponga > en nuestro conocimiento de forma inmediata. > > DISCLAIMER: Privileged/Confidential Information may be contained in this > message. If you are not the addressee indicated in this message you should > destroy this message, and notify us immediately to the following address: > le...@eurecat.org. If the addressee of this message does not consent to > the use of Internet e-mail and message recording, please notify us > immediately. > ------------------------------ > > > ------------------------------ > DISCLAIMER: Aquest missatge pot contenir informació confidencial. Si vostè > no n'és el destinatari, si us plau, esborri'l i faci'ns-ho saber > immediatament a la següent adreça: le...@eurecat.org Si el destinatari > d'aquest missatge no consent la utilització del correu electrònic via > Internet i la gravació de missatges, li preguem que ens ho comuniqui > immediatament. > > DISCLAIMER: Este mensaje puede contener información confidencial. Si usted > no es el destinatario del mensaje, por favor bórrelo y notifíquenoslo > inmediatamente a la siguiente dirección: le...@eurecat.org Si el > destinatario de este mensaje no consintiera la utilización del correo > electrónico vía Internet y la grabación de los mensajes, rogamos lo ponga > en nuestro conocimiento de forma inmediata. > > DISCLAIMER: Privileged/Confidential Information may be contained in this > message. If you are not the addressee indicated in this message you should > destroy this message, and notify us immediately to the following address: > le...@eurecat.org. If the addressee of this message does not consent to > the use of Internet e-mail and message recording, please notify us > immediately. > ------------------------------ > > >
