Reputation: 6159
In my application I'm scooping a table of 5million rows and 151 columns using spark partitioning like below and persisting it to DISK_ONLY
val query = "(select * from destinationlarge) as dest"
val options = Map(
"url" -> "jdbc:mysql://IPADDRESS:3306/test?useSSL=false",
"driver" -> "com.mysql.jdbc.Driver",
"dbtable" -> query,
"user" -> "root",
"password" -> "root")
val destination = spark.read.options(options).jdbc(options("url"), options("dbtable"), "0", 1, 5, 4, new java.util.Properties()).rdd.map(_.mkString(",")).persist(StorageLevel.DISK_ONLY)
The cluster is having 5 datanodes and 1 namenode of hardware configuration i3 4 cores and 4 GB RAM each, after sometime of execution one of the executor is dead and throwing the below ERROR
Exception in thread "main" org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 0.0 failed 4 times, most recent failure: Lost task 0.3 in stage 0.0 (TID 6, datanode5, executor 6): ExecutorLostFailure (executor 6 exited caused by one of the running tasks) Reason: Executor heartbeat timed out after 139401 ms
Driver stacktrace:
at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1435)
at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1423)
at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1422)
at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:48)
at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1422)
at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:802)
at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:802)
at scala.Option.foreach(Option.scala:257)
at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:802)
at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.doOnReceive(DAGScheduler.scala:1650)
at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1605)
at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1594)
at org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:48)
at org.apache.spark.scheduler.DAGScheduler.runJob(DAGScheduler.scala:628)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:1925)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:1938)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:1951)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:1965)
at org.apache.spark.rdd.RDD.count(RDD.scala:1158)
at com.syntel.spark.sparkDVT$.main(sparkDVT.scala:68)
at com.syntel.spark.sparkDVT.main(sparkDVT.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.apache.spark.deploy.SparkSubmit$.org$apache$spark$deploy$SparkSubmit$$runMain(SparkSubmit.scala:750)
at org.apache.spark.deploy.SparkSubmit$.doRunMain$1(SparkSubmit.scala:187)
at org.apache.spark.deploy.SparkSubmit$.submit(SparkSubmit.scala:212)
at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:126)
at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)
lowerbound=1
,upperbound=5
,number of partitions is 4
suggested in this link (https://www.dezyre.com/article/how-data-partitioning-in-spark-helps-achieve-more-parallelism/297) total number of cores is equal to number of partitions that is 4 cores in all the nodes so 4 partitions.
spark-submit
spark-submit --class "com.syntel.spark.sparkDVT" --master yarn --jars --executor-memory 512m --executor-cores 1 --num-executors 5 /root/sparkdvtmysql_2.11-1.0.jar
Correct me if I'm wrong
Thanks
Upvotes: 1
Views: 3556
Reputation: 35444
I would recommend you use DataFame(in Spark 2.0 i.e DataSet[Row]) as is, because DataSet uses Encoders so that it will have very little memory footprint than RDD.
val destination = spark.read
.options(options)
.format("jdbc")
.load()
If you want concat columns by delimiter you can use concat_ws() - example here
destination
.withColumn("column", concat_ws(", ",
destination.columns.map(destination.col(_)).toSeq : _*))
.select("id, column") // id will be used for subtraction with other df
.persist(StorageLevel.DISK_ONLY)
Check this SO post - Comaparing RDD/DF/DS which you the idea of how Dataset diffrent from RDD and it's advantages.
This may not answer your question entirely. I will update the asnwer as per my comment response
Upvotes: 4