title: Error reading from large Cassandra table with Spark, getting "Remote RPC client disassociated"
body: <p>I set stand alone spark cluster (with cassandra) and i did it but when i read data i get error.My cluster has 3 nodes and each node has 64 GB ram and 20 cores. I'm sharing some Spark-env.sh configuration like spark_executor_cores: 5, spark_executor_memory:5G, spark_worker_cores:20 and spark_worker_memory:45g.</p>
  <p>I want to give another information, when i read small table there is no problem but when i read big table i get error. Error description at below. Also when i start pyspark i use this command:</p>
  <pre><code>$ ./pyspark --master spark://10.0.0.100:7077
      --packages com.datastax.spark:spark-cassandra-connector_2.12:3.1.0
      --conf spark.driver.extraJavaOptions=-Xss1024m
      --conf spark.driver.port:36605
      --conf spark.driver.blockManager.port=42365
  </code></pre>
  <p>Thanks for your interest</p>
  <pre><code>ERROR TaskSchedulerImpl: Lost executor 5 on 10.0.0.10: Remote RPC client disassociated. likely due to containers exceeding threshold, or network issues. Chec driver logs for WARN messages
  WARN TaskSetManager: Lost task 0.0 in stage 0.0 (TID 0) (10.0.0.10 executor 5): ExecutorLostFailure (executor 5 exited caused by one of the runnning task) reason: remote RPC client disassociated.
  WARN TaskSetManager: Lost task 0.1 in stage 0.0 (TID 1) (10.0.0.11 executor 2):Java.lang.StackOverflowError
   at java.base/java.nio.ByteBuffer.position(ByteBuffer.java:1094)
   at java.base/java.nio.HeapByteBuffer.get(HeapByteBuffer.java:184)
   at org.apache.spark.util.ByteBufferInputStream.read(ObjectInputStream.scala:49)
   at java.base/java.io.ObjectInputStream$PeekInputStream.read(ObjectInputStream.java:2887)
   at java.base/java.io.ObjectInputStream$PeekInputStream.readFully(ObjectInputStream.java:2903)
   at java.base/java.io.ObjectInputStream$BlockDataInputStream.readUTFBody(ObjectInputStream.java:3678) 
   at java.base/java.io.ObjectInputStream$BlockDataInputStream.readUTF(ObjectInputStream.java:3678)
  at java.base/java.io.ObjectInputStream.readString(ObjectInputStream.java:2058)
  at java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1663)
  at java.base/java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2490)
  at java.base/java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2384)
  at java.base/java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2222)
  at java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1681)
  at java.base/java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2490)
  at java.base/java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2384)
  at java.base/java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2222)
  at java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1681)
  at java.base/java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2490)
  at java.base/java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2384)
  at java.base/java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2222)
  at java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1681)
  at java.base/java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2490)
  at java.base/java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2384)
  at java.base/java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2222)
  </code></pre>