Hi, We are not exactly sure what is causing this problem. But after compaction happens (after 1 week ttl). We start getting this exception:
WARN [SharedPool-Worker-1] 2016-09-26 04:07:19,849 AbstractLocalAwareExecutorService.java:169 - Uncaught exception on thread Thread[SharedPool-Worker-1,5,main]: {} java.lang.NullPointerException: null at org.apache.cassandra.db.Slices$ArrayBackedSlices$ComponentOfSlice.isEQ(Slices.java:748) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.Slices$ArrayBackedSlices.toCQLString(Slices.java:659) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.filter.ClusteringIndexSliceFilter.toCQLString(ClusteringIndexSliceFilter.java:150) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.SinglePartitionReadCommand.appendCQLWhereClause(SinglePartitionReadCommand.java:911) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.ReadCommand.toCQLString(ReadCommand.java:560) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.ReadCommand$1MetricRecording.onClose(ReadCommand.java:506) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.transform.BasePartitions.runOnClose(BasePartitions.java:70) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.transform.BaseIterator.close(BaseIterator.java:76) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.ReadCommandVerbHandler.doVerb(ReadCommandVerbHandler.java:48) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.net.MessageDeliveryTask.run(MessageDeliveryTask.java:67) ~[apache-cassandra-3.0.9.jar:3.0.9] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[na:1.8.0_102] at org.apache.cassandra.concurrent.AbstractLocalAwareExecutorService$FutureTask.run(AbstractLocalAwareExecutorService.java:164) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.concurrent.AbstractLocalAwareExecutorService$LocalSessionFutureTask.run(AbstractLocalAwareExecutorService.java:136) [apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.concurrent.SEPWorker.run(SEPWorker.java:105) [apache-cassandra-3.0.9.jar:3.0.9] at java.lang.Thread.run(Thread.java:745) [na:1.8.0_102] WARN [SharedPool-Worker-2] 2016-09-26 04:07:20,639 AbstractLocalAwareExecutorService.java:169 - Uncaught exception on thread Thread[SharedPool-Worker-2,5,main]: {} java.lang.RuntimeException: java.lang.NullPointerException at org.apache.cassandra.service.StorageProxy$DroppableRunnable.run(StorageProxy.java:2470) ~[apache-cassandra-3.0.9.jar:3.0.9] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[na:1.8.0_102] at org.apache.cassandra.concurrent.AbstractLocalAwareExecutorService$FutureTask.run(AbstractLocalAwareExecutorService.java:164) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.concurrent.AbstractLocalAwareExecutorService$LocalSessionFutureTask.run(AbstractLocalAwareExecutorService.java:136) [apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.concurrent.SEPWorker.run(SEPWorker.java:105) [apache-cassandra-3.0.9.jar:3.0.9] at java.lang.Thread.run(Thread.java:745) [na:1.8.0_102] Caused by: java.lang.NullPointerException: null at org.apache.cassandra.db.Slices$ArrayBackedSlices$ComponentOfSlice.isEQ(Slices.java:748) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.Slices$ArrayBackedSlices.toCQLString(Slices.java:659) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.filter.ClusteringIndexSliceFilter.toCQLString(ClusteringIndexSliceFilter.java:150) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.SinglePartitionReadCommand.appendCQLWhereClause(SinglePartitionReadCommand.java:911) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.ReadCommand.toCQLString(ReadCommand.java:560) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.ReadCommand$1MetricRecording.onClose(ReadCommand.java:506) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.transform.BasePartitions.runOnClose(BasePartitions.java:70) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.db.transform.BaseIterator.close(BaseIterator.java:76) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.service.StorageProxy$LocalReadRunnable.runMayThrow(StorageProxy.java:1797) ~[apache-cassandra-3.0.9.jar:3.0.9] at org.apache.cassandra.service.StorageProxy$DroppableRunnable.run(StorageProxy.java:2466) ~[apache-cassandra-3.0.9.jar:3.0.9] ... 5 common frames omitted We have no idea how to solve this. I am losing sleep over this, please help! Cassandra: 3.0.9 (also happened in 3.0.8) Java: Oracle jdk "1.8.0_102" jemalloc enabled Regards, Nikhil Sharma