Hi,   I have run into the below error while launching pyspark. Would appreciate any help on this.   -sh-4.1$ pyspark Python 2.6.6 (r266:84292, Aug 18 2016, 08:36:59) [GCC 4.4.7 20120313 (Red Hat 4.4.7-17)] on linux2 Type "help", "copyright", "credits" or "license" for more information. Setting default log level to "WARN". To adjust logging level use sc.setLogLevel(newLevel). 18/11/12 11:20:25 ERROR spark.SparkContext: Error initializing SparkContext. org.apache.hadoop.yarn.exceptions.YarnException: Failed to submit application_1537380011359_1185346 to YARN : Application rejected by queue placement policy         at org.apache.hadoop.yarn.client.api.impl.YarnClientImpl.submitApplication(YarnClientImpl.java:257)         at org.apache.spark.deploy.yarn.Client.submitApplication(Client.scala:148)         at org.apache.spark.scheduler.cluster.YarnClientSchedulerBackend.start(YarnClientSchedulerBackend.scala:57)         at org.apache.spark.scheduler.TaskSchedulerImpl.start(TaskSchedulerImpl.scala:157)         at org.apache.spark.SparkContext.<init>(SparkContext.scala:542)         at org.apache.spark.api.java.JavaSparkContext.<init>(JavaSparkContext.scala:59)         at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)         at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)         at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)         at java.lang.reflect.Constructor.newInstance(Constructor.java:526)         at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:234)         at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:381)         at py4j.Gateway.invoke(Gateway.java:214)         at py4j.commands.ConstructorCommand.invokeConstructor(ConstructorCommand.java:79)         at py4j.commands.ConstructorCommand.execute(ConstructorCommand.java:68)         at py4j.GatewayConnection.run(GatewayConnection.java:209)         at java.lang.Thread.run(Thread.java:744) 18/11/12 11:20:26 WARN cluster.YarnSchedulerBackend$YarnSchedulerEndpoint: Attempted to request executors before the AM has registered! 18/11/12 11:20:26 ERROR util.Utils: Uncaught exception in thread Thread-2 java.lang.NullPointerException         at org.apache.spark.network.shuffle.ExternalShuffleClient.close(ExternalShuffleClient.java:152)         at org.apache.spark.storage.BlockManager.stop(BlockManager.scala:1264)         at org.apache.spark.SparkEnv.stop(SparkEnv.scala:96)         at org.apache.spark.SparkContext$$anonfun$stop$12.apply$mcV$sp(SparkContext.scala:1768)         at org.apache.spark.util.Utils$.tryLogNonFatalError(Utils.scala:1230)         at org.apache.spark.SparkContext.stop(SparkContext.scala:1767)         at org.apache.spark.SparkContext.<init>(SparkContext.scala:614)         at org.apache.spark.api.java.JavaSparkContext.<init>(JavaSparkContext.scala:59)         at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)         at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)         at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)         at java.lang.reflect.Constructor.newInstance(Constructor.java:526)         at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:234)         at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:381)         at py4j.Gateway.invoke(Gateway.java:214)         at py4j.commands.ConstructorCommand.invokeConstructor(ConstructorCommand.java:79)         at py4j.commands.ConstructorCommand.execute(ConstructorCommand.java:68)         at py4j.GatewayConnection.run(GatewayConnection.java:209)         at java.lang.Thread.run(Thread.java:744) Traceback (most recent call last):   File "/opt/cloudera/parcels/CDH-5.9.1-1.cdh5.9.1.p2671.2910/lib/spark/python/pyspark/shell.py", line 43, in <module>     sc = SparkContext(pyFiles=add_files)   File "/opt/cloudera/parcels/CDH-5.9.1-1.cdh5.9.1.p2671.2910/lib/spark/python/pyspark/context.py", line 115, in __init__     conf, jsc, profiler_cls)   File "/opt/cloudera/parcels/CDH-5.9.1-1.cdh5.9.1.p2671.2910/lib/spark/python/pyspark/context.py", line 172, in _do_init     self._jsc = jsc or self._initialize_context(self._conf._jconf)   File "/opt/cloudera/parcels/CDH-5.9.1-1.cdh5.9.1.p2671.2910/lib/spark/python/pyspark/context.py", line 235, in _initialize_context     return self._jvm.JavaSparkContext(jconf)   File "/opt/cloudera/parcels/CDH-5.9.1-1.cdh5.9.1.p2671.2910/lib/spark/python/lib/py4j-0.9-src.zip/py4j/java_gateway.py", line 1064, in __call__   File "/opt/cloudera/parcels/CDH-5.9.1-1.cdh5.9.1.p2671.2910/lib/spark/python/lib/py4j-0.9-src.zip/py4j/protocol.py", line 308, in get_return_value py4j.protocol.Py4JJavaError: An error occurred while calling None.org.apache.spark.api.java.JavaSparkContext. : org.apache.hadoop.yarn.exceptions.YarnException: Failed to submit application_1537380011359_1185346 to YARN : Application rejected by queue placement policy         at org.apache.hadoop.yarn.client.api.impl.YarnClientImpl.submitApplication(YarnClientImpl.java:257)         at org.apache.spark.deploy.yarn.Client.submitApplication(Client.scala:148)         at org.apache.spark.scheduler.cluster.YarnClientSchedulerBackend.start(YarnClientSchedulerBackend.scala:57)         at org.apache.spark.scheduler.TaskSchedulerImpl.start(TaskSchedulerImpl.scala:157)         at org.apache.spark.SparkContext.<init>(SparkContext.scala:542)         at org.apache.spark.api.java.JavaSparkContext.<init>(JavaSparkContext.scala:59)         at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)         at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)         at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)         at java.lang.reflect.Constructor.newInstance(Constructor.java:526)         at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:234)         at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:381)         at py4j.Gateway.invoke(Gateway.java:214)         at py4j.commands.ConstructorCommand.invokeConstructor(ConstructorCommand.java:79)         at py4j.commands.ConstructorCommand.execute(ConstructorCommand.java:68)         at py4j.GatewayConnection.run(GatewayConnection.java:209)         at java.lang.Thread.run(Thread.java:744) ... 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