Joshuawangzj created SPARK-21045: ------------------------------------ Summary: Spark executor is blocked instead of throwing exception because exception occur when python worker send exception trace stack info to Java Gateway Key: SPARK-21045 URL: https://issues.apache.org/jira/browse/SPARK-21045 Project: Spark Issue Type: Bug Components: PySpark Affects Versions: 2.1.1, 2.0.2, 2.0.1 Reporter: Joshuawangzj
My pyspark program is always blocking in product yarn cluster. Then I jstack and found : {code} "Executor task launch worker for task 0" #60 daemon prio=5 os_prio=31 tid=0x00007fb2f44e3000 nid=0xa003 runnable [0x0000000123b4a000] java.lang.Thread.State: RUNNABLE at java.net.SocketInputStream.socketRead0(Native Method) at java.net.SocketInputStream.socketRead(SocketInputStream.java:116) at java.net.SocketInputStream.read(SocketInputStream.java:170) at java.net.SocketInputStream.read(SocketInputStream.java:141) at java.io.BufferedInputStream.fill(BufferedInputStream.java:246) at java.io.BufferedInputStream.read(BufferedInputStream.java:265) - locked <0x00000007acab1c98> (a java.io.BufferedInputStream) at java.io.DataInputStream.readInt(DataInputStream.java:387) at org.apache.spark.api.python.PythonRunner$$anon$1.read(PythonRDD.scala:190) at org.apache.spark.api.python.PythonRunner$$anon$1.<init>(PythonRDD.scala:234) at org.apache.spark.api.python.PythonRunner.compute(PythonRDD.scala:152) at org.apache.spark.api.python.PythonRDD.compute(PythonRDD.scala:63) at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:323) at org.apache.spark.rdd.RDD.iterator(RDD.scala:287) at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:87) at org.apache.spark.scheduler.Task.run(Task.scala:99) at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:322) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) {code} It is blocking in socket read. I view the log on blocking executor and found error: {code} Traceback (most recent call last): File "/Users/wangzejie/software/spark/python/lib/pyspark.zip/pyspark/worker.py", line 178, in main write_with_length(traceback.format_exc().encode("utf-8"), outfile) UnicodeDecodeError: 'ascii' codec can't decode byte 0xe4 in position 618: ordinal not in range(128) {code} Finally I found the problem: {code:title=worker.py|borderStyle=solid} # 178 line in spark 2.1.1 except Exception: try: write_int(SpecialLengths.PYTHON_EXCEPTION_THROWN, outfile) write_with_length(traceback.format_exc().encode("utf-8"), outfile) except IOError: # JVM close the socket pass except Exception: # Write the error to stderr if it happened while serializing print("PySpark worker failed with exception:", file=sys.stderr) print(traceback.format_exc(), file=sys.stderr) {code} when write_with_length(traceback.format_exc().encode("utf-8"), outfile) occur exception like UnicodeDecodeError, the python worker can't send the trace info, but when the PythonRDD get PYTHON_EXCEPTION_THROWN, It should read the trace info length next. So it is blocking. {code:title=PythonRDD.scala|borderStyle=solid} # 190 line in spark 2.1.1 case SpecialLengths.PYTHON_EXCEPTION_THROWN => // Signals that an exception has been thrown in python val exLength = stream.readInt() // It is possible to be blocked {code} -- This message was sent by Atlassian JIRA (v6.3.15#6346) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org