Parth Gandhi created SPARK-27112: ------------------------------------ Summary: Spark Scheduler encounters two independent Deadlocks when trying to kill executors either due to dynamic allocation or blacklisting Key: SPARK-27112 URL: https://issues.apache.org/jira/browse/SPARK-27112 Project: Spark Issue Type: Bug Components: Scheduler, Spark Core Affects Versions: 2.4.0, 3.0.0 Reporter: Parth Gandhi
Recently, a few spark users in the organization have reported that their jobs were getting stuck. On further analysis, it was found out that there exist two independent deadlocks and either of them occur under different circumstances. The screenshots for these two deadlocks are attached here. We were able to reproduce the deadlocks with the following piece of code: {code:java} import org.apache.hadoop.conf.Configuration import org.apache.hadoop.fs.{FileSystem, Path} import org.apache.spark._ import org.apache.spark.TaskContext // Simple example of Word Count in Scala object ScalaWordCount { def main(args: Array[String]) { if (args.length < 2) { System.err.println("Usage: ScalaWordCount <inputFilesURI> <outputFilesUri>") System.exit(1) } val conf = new SparkConf().setAppName("Scala Word Count") val sc = new SparkContext(conf) // get the input file uri val inputFilesUri = args(0) // get the output file uri val outputFilesUri = args(1) while (true) { val textFile = sc.textFile(inputFilesUri) val counts = textFile.flatMap(line => line.split(" ")) .map(word => {if (TaskContext.get.partitionId == 5 && TaskContext.get.attemptNumber == 0) throw new Exception("Fail for blacklisting") else (word, 1)}) .reduceByKey(_ + _) counts.saveAsTextFile(outputFilesUri) val conf: Configuration = new Configuration() val path: Path = new Path(outputFilesUri) val hdfs: FileSystem = FileSystem.get(conf) hdfs.delete(path, true) } sc.stop() } } {code} Additionally, to ensure that the deadlock surfaces up soon enough, I also added a small delay in the Spark code here: [https://github.com/apache/spark/blob/master/core/src/main/scala/org/apache/spark/scheduler/BlacklistTracker.scala#L256] {code:java} executorIdToFailureList.remove(exec) updateNextExpiryTime() Thread.sleep(2000) killBlacklistedExecutor(exec) {code} -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org