Hi Spark devs, I'm seeing a stacktrace where the classloader that reads from the REPL is hung, and blocking all progress on that executor. Below is that hung thread's stacktrace, and also the stacktrace of another hung thread.
I thought maybe there was an issue with the REPL's JVM on the other side, but didn't see anything useful in that stacktrace either. Any ideas what I should be looking for? Thanks! Andrew "Executor task launch worker-0" daemon prio=10 tid=0x00007f780c208000 nid=0x6ae9 runnable [0x00007f78c2eeb000] java.lang.Thread.State: RUNNABLE at java.net.SocketInputStream.socketRead0(Native Method) at java.net.SocketInputStream.read(SocketInputStream.java:152) at java.net.SocketInputStream.read(SocketInputStream.java:122) at java.io.BufferedInputStream.fill(BufferedInputStream.java:235) at java.io.BufferedInputStream.read1(BufferedInputStream.java:275) at java.io.BufferedInputStream.read(BufferedInputStream.java:334) - locked <0x00007f7e13ea9560> (a java.io.BufferedInputStream) at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:687) at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:633) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1323) - locked <0x00007f7e13e9eeb0> (a sun.net.www.protocol.http.HttpURLConnection) at java.net.URL.openStream(URL.java:1037) at org.apache.spark.repl.ExecutorClassLoader.findClassLocally(ExecutorClassLoader.scala:86) at org.apache.spark.repl.ExecutorClassLoader.findClass(ExecutorClassLoader.scala:63) at java.lang.ClassLoader.loadClass(ClassLoader.java:425) - locked <0x00007f7fc9018980> (a org.apache.spark.repl.ExecutorClassLoader) at java.lang.ClassLoader.loadClass(ClassLoader.java:358) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:270) at org.apache.avro.util.ClassUtils.forName(ClassUtils.java:102) at org.apache.avro.util.ClassUtils.forName(ClassUtils.java:82) at org.apache.avro.specific.SpecificData.getClass(SpecificData.java:132) at org.apache.avro.specific.SpecificDatumReader.setSchema(SpecificDatumReader.java:69) at org.apache.avro.file.DataFileStream.initialize(DataFileStream.java:126) at org.apache.avro.file.DataFileReader.<init>(DataFileReader.java:97) at org.apache.avro.file.DataFileReader.openReader(DataFileReader.java:59) at org.apache.avro.mapred.AvroRecordReader.<init>(AvroRecordReader.java:41) at org.apache.avro.mapred.AvroInputFormat.getRecordReader(AvroInputFormat.java:71) at org.apache.spark.rdd.HadoopRDD$$anon$1.<init>(HadoopRDD.scala:193) at org.apache.spark.rdd.HadoopRDD.compute(HadoopRDD.scala:184) at org.apache.spark.rdd.HadoopRDD.compute(HadoopRDD.scala:93) at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:262) at org.apache.spark.rdd.RDD.iterator(RDD.scala:229) at org.apache.spark.rdd.MappedRDD.compute(MappedRDD.scala:31) at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:262) at org.apache.spark.rdd.RDD.iterator(RDD.scala:229) at org.apache.spark.rdd.MappedRDD.compute(MappedRDD.scala:31) at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:262) And the other threads are stuck on the Class.forName0() method too: "Executor task launch worker-4" daemon prio=10 tid=0x00007f780c20f000 nid=0x6aed waiting for monitor entry [0x00007f78c2ae8000] java.lang.Thread.State: BLOCKED (on object monitor) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:270) at org.apache.avro.util.ClassUtils.forName(ClassUtils.java:102) at org.apache.avro.util.ClassUtils.forName(ClassUtils.java:79) at org.apache.avro.specific.SpecificData.getClass(SpecificData.java:132) at org.apache.avro.specific.SpecificDatumReader.setSchema(SpecificDatumReader.java:69) at org.apache.avro.file.DataFileStream.initialize(DataFileStream.java:126) at org.apache.avro.file.DataFileReader.<init>(DataFileReader.java:97) at org.apache.avro.file.DataFileReader.openReader(DataFileReader.java:59) at org.apache.avro.mapred.AvroRecordReader.<init>(AvroRecordReader.java:41) at org.apache.avro.mapred.AvroInputFormat.getRecordReader(AvroInputFormat.java:71) at org.apache.spark.rdd.HadoopRDD$$anon$1.<init>(HadoopRDD.scala:193) at org.apache.spark.rdd.HadoopRDD.compute(HadoopRDD.scala:184) at org.apache.spark.rdd.HadoopRDD.compute(HadoopRDD.scala:93) at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:262) at org.apache.spark.rdd.RDD.iterator(RDD.scala:229) at org.apache.spark.rdd.MappedRDD.compute(MappedRDD.scala:31) at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:262) asdf