Thanks for the information Johnny We’ll dig more into our Akka plugin settings, we’re right now doing adjustments on the consistency and replication strategy settings since our management only wants to budget for 2 DCs instead of 3 right now so we’re trying to figure out what adjustments we need to make to survive a DC outage.
RICHARD NEY TECHNICAL DIRECTOR, RESEARCH & DEVELOPMENT +1 (978) 848.6640 WORK +1 (916) 846.2353 MOBILE UNITED STATES richard....@aspect.com<mailto:richard....@aspect.com> aspect.com<http://www.aspect.com/> [mailSigLogo-rev.jpg] From: Johnny Miller <joh...@digitalis.io> Reply-To: "user@cassandra.apache.org" <user@cassandra.apache.org> Date: Monday, January 2, 2017 at 1:28 PM To: "user@cassandra.apache.org" <user@cassandra.apache.org> Subject: Re: Trying to find cause of exception Richard, From looking at the stack trace in your Cassandra logs, you might be hitting a variation of this bug: https://issues.apache.org/jira/browse/CASSANDRA-11353 https://issues.apache.org/jira/browse/CASSANDRA-10944 https://github.com/apache/cassandra/blob/cassandra-3.X/NEWS.txt I notice your on 3.3 - although 10944 was marked as fixed in 3.3.0, there seems to have been a merge issue. You would probably want to upgrade to > 3.5 and see if it gets resolved. However, I am not sure it would account for the behaviour your describing - but it would be worth trying. Also, depending on the Java driver version/Akka Cassandra Persistence, you may be encountering some strangeness there - it would be useful to drop the logging level on the Java driver down to debug to see if there is anything apparent information. If your not seeing any nodes down via nodetool status and your app is still thinking no replicas are available - its a bit strange. Also, have a look at what the getHost/getAddress methods one the ReadTimeoutException are returning - it should tell you the coordinator that was used to service the request, which might help It would also be worth checking that the application conf for your Akka Persistence is setup correctly (https://github.com/akka/akka-persistence-cassandra/blob/master/src/main/resources/reference.conf) - things like local-datacenter, replication-strategy, write-consistency, read-consistency (is there a reason its ONE and not LOCAL_ONE) etc. Regards, Johnny -- Johnny Miller Co-Founder & CTO @ digitalis.io<http://digitalis.io> | Fully Managed Open Source Data Technologies +44(0)20 8123 4053 | joh...@digitalis.io<mailto:joh...@digitalis.io> On 2 Jan 2017, at 18:59, Ney, Richard <richard....@aspect.com<mailto:richard....@aspect.com>> wrote: Hi Amit, I’m seeing “not marking as down” in the logs like this one, WARN [GossipTasks:1] 2016-12-29 08:48:02,665 FailureDetector.java:287 - Not marking nodes down due to local pause of 6641241564 > 5000000000 Now the end of the system.log files on all three nodes in one of the data centers are full of NullPointerExceptions and AssertionErrors like these below, would these errors be the cause or a symptom? WARN [SharedPool-Worker-1] 2017-01-02 07:13:56,441 AbstractLocalAwareExecutorService.java:169 - Uncaught exception on thread Thread[SharedPool-Worker-1,5,main]: {} java.lang.NullPointerException: null WARN [SharedPool-Worker-1] 2017-01-02 07:15:02,865 AbstractLocalAwareExecutorService.java:169 - Uncaught exception on thread Thread[SharedPool-Worker-1,5,main]: {} java.lang.AssertionError: null at org.apache.cassandra.db.rows.BufferCell.<init>(BufferCell.java:49) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.rows.BufferCell.tombstone(BufferCell.java:88) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.rows.BufferCell.tombstone(BufferCell.java:83) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.rows.BufferCell.purge(BufferCell.java:175) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.rows.ComplexColumnData.lambda$purge$107(ComplexColumnData.java:165) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.utils.btree.BTree$FiltrationTracker.apply(BTree.java:650) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.utils.btree.BTree.transformAndFilter(BTree.java:693) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.utils.btree.BTree.transformAndFilter(BTree.java:668) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.rows.ComplexColumnData.transformAndFilter(ComplexColumnData.java:170) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.rows.ComplexColumnData.purge(ComplexColumnData.java:165) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.rows.ComplexColumnData.purge(ComplexColumnData.java:43) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.rows.BTreeRow.lambda$purge$102(BTreeRow.java:333) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.utils.btree.BTree$FiltrationTracker.apply(BTree.java:650) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.utils.btree.BTree.transformAndFilter(BTree.java:693) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.utils.btree.BTree.transformAndFilter(BTree.java:668) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.rows.BTreeRow.transformAndFilter(BTreeRow.java:338) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.rows.BTreeRow.purge(BTreeRow.java:333) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.partitions.PurgeFunction.applyToRow(PurgeFunction.java:88) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.transform.BaseRows.hasNext(BaseRows.java:116) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.rows.UnfilteredRowIteratorSerializer.serialize(UnfilteredRowIteratorSerializer.java:133) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.rows.UnfilteredRowIteratorSerializer.serialize(UnfilteredRowIteratorSerializer.java:89) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.rows.UnfilteredRowIteratorSerializer.serialize(UnfilteredRowIteratorSerializer.java:79) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.partitions.UnfilteredPartitionIterators$Serializer.serialize(UnfilteredPartitionIterators.java:294) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.ReadResponse$LocalDataResponse.build(ReadResponse.java:134) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.ReadResponse$LocalDataResponse.<init>(ReadResponse.java:127) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.ReadResponse$LocalDataResponse.<init>(ReadResponse.java:123) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.ReadResponse.createDataResponse(ReadResponse.java:65) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.ReadCommand.createResponse(ReadCommand.java:292) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.db.ReadCommandVerbHandler.doVerb(ReadCommandVerbHandler.java:50) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.net.MessageDeliveryTask.run(MessageDeliveryTask.java:64) ~[apache-cassandra-3.3.0.jar:3.3.0] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[na:1.8.0_111] at org.apache.cassandra.concurrent.AbstractLocalAwareExecutorService$FutureTask.run(AbstractLocalAwareExecutorService.java:164) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.concurrent.AbstractLocalAwareExecutorService$LocalSessionFutureTask.run(AbstractLocalAwareExecutorService.java:136) [apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.concurrent.SEPWorker.run(SEPWorker.java:105) [apache-cassandra-3.3.0.jar:3.3.0] at java.lang.Thread.run(Thread.java:745) [na:1.8.0_111] WARN [SharedPool-Worker-2] 2017-01-02 07:15:03,132 AbstractLocalAwareExecutorService.java:169 - Uncaught exception on thread Thread[SharedPool-Worker-2,5,main]: {} java.lang.RuntimeException: java.lang.NullPointerException at org.apache.cassandra.service.StorageProxy$DroppableRunnable.run(StorageProxy.java:2461) ~[apache-cassandra-3.3.0.jar:3.3.0] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[na:1.8.0_111] at org.apache.cassandra.concurrent.AbstractLocalAwareExecutorService$FutureTask.run(AbstractLocalAwareExecutorService.java:164) ~[apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.concurrent.AbstractLocalAwareExecutorService$LocalSessionFutureTask.run(AbstractLocalAwareExecutorService.java:136) [apache-cassandra-3.3.0.jar:3.3.0] at org.apache.cassandra.concurrent.SEPWorker.run(SEPWorker.java:105) [apache-cassandra-3.3.0.jar:3.3.0] at java.lang.Thread.run(Thread.java:745) [na:1.8.0_111] Caused by: java.lang.NullPointerException: null RICHARD NEY TECHNICAL DIRECTOR, RESEARCH & DEVELOPMENT +1 (978) 848.6640 WORK +1 (916) 846.2353 MOBILE UNITED STATES richard....@aspect.com<mailto:richard....@aspect.com> aspect.com<http://www.aspect.com/> <image001.png> From: Amit Singh F <amit.f.si...@ericsson.com<mailto:amit.f.si...@ericsson.com>> Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>> Date: Monday, January 2, 2017 at 4:34 AM To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>> Subject: RE: Trying to find cause of exception Hello, Few pointers : a.) Can you check in system.log for similar msgs like “marking as down” on the node which gives err msg if yes, then please check for GC pause . Heavy load is one of the reason for this. b.) Can you try connecting cqlsh to that node once you get this kind of msgs. Are you able to connect? Regards Amit From: Ney, Richard [mailto:richard....@aspect.com] Sent: Monday, January 02, 2017 3:30 PM To: user@cassandra.apache.org<mailto:user@cassandra.apache.org> Subject: Trying to find cause of exception My development team has been trying to track down the cause of this Read timeout (30 seconds or more at times) exception below. We’re running a 2 data center deployment with 3 nodes in each data center. Our tables are setup with replication factor = 2 and we have 16G dedicated to the heap with the G1GC for garbage collection. Our systems are AWS M4.2xlarge with 8 CPUs and 32GB of RAM and we have 2 general purpose EBS volumes on each node of 500GB each. Once we start getting these timeouts the cluster doesn’t recover and we are required to shut all Cassandra node down and restart. If anyone has any tips on where to look or what commands to run to help us diagnose this issue we’d be eternally grateful. 2017-01-02 04:33:35.161 [ERROR] [report-compute.ffbec924-ce44-11e6-9e21-0adb9d2dd624] [reportCompute] [ahlworkerslave2.bos.manhattan.aspect-cloud.net:31312<http://ahlworkerslave2.bos.manhattan.aspect-cloud.net:31312/>] [WorktypeMetrics] Persistence failure when replaying events for persistenceId [/fsms/pens/worktypes/bmwbpy.314]. Last known sequence number [0] java.util.concurrent.ExecutionException: com.datastax.driver.core.exceptions.ReadTimeoutException: Cassandra timeout during read query at consistency ONE (1 responses were required but only 0 replica responded) at com.google.common.util.concurrent.AbstractFuture$Sync.getValue(AbstractFuture.java:299) at com.google.common.util.concurrent.AbstractFuture$Sync.get(AbstractFuture.java:286) at com.google.common.util.concurrent.AbstractFuture.get(AbstractFuture.java:116) at akka.persistence.cassandra.package$$anon$1$$anonfun$run$1.apply(package.scala:17) at scala.util.Try$.apply(Try.scala:192) Caused by: com.datastax.driver.core.exceptions.ReadTimeoutException: Cassandra timeout during read query at consistency ONE (1 responses were required but only 0 replica responded) at com.datastax.driver.core.exceptions.ReadTimeoutException.copy(ReadTimeoutException.java:115) at com.datastax.driver.core.Responses$Error.asException(Responses.java:124) at com.datastax.driver.core.RequestHandler$SpeculativeExecution.onSet(RequestHandler.java:477) at com.datastax.driver.core.Connection$Dispatcher.channelRead0(Connection.java:1005) at com.datastax.driver.core.Connection$Dispatcher.channelRead0(Connection.java:928) Caused by: com.datastax.driver.core.exceptions.ReadTimeoutException: Cassandra timeout during read query at consistency ONE (1 responses were required but only 0 replica responded) at com.datastax.driver.core.Responses$Error$1.decode(Responses.java:62) at com.datastax.driver.core.Responses$Error$1.decode(Responses.java:37) at com.datastax.driver.core.Message$ProtocolDecoder.decode(Message.java:266) at com.datastax.driver.core.Message$ProtocolDecoder.decode(Message.java:246) at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:89) RICHARD NEY TECHNICAL DIRECTOR, RESEARCH & DEVELOPMENT +1 (978) 848.6640 WORK +1 (916) 846.2353 MOBILE UNITED STATES richard....@aspect.com<mailto:richard....@aspect.com> aspect.com<http://www.aspect.com/> <image002.png> This email (including any attachments) is proprietary to Aspect Software, Inc. and may contain information that is confidential. If you have received this message in error, please do not read, copy or forward this message. Please notify the sender immediately, delete it from your system and destroy any copies. You may not further disclose or distribute this email or its attachments. This email (including any attachments) is proprietary to Aspect Software, Inc. and may contain information that is confidential. If you have received this message in error, please do not read, copy or forward this message. Please notify the sender immediately, delete it from your system and destroy any copies. You may not further disclose or distribute this email or its attachments. -- Any views or opinions presented are solely those of the author and do not necessarily represent those of the company. digitalis.io<http://digitalis.io/> is a trading name of Digitalis.io Ltd. Company Number: 98499457 Registered in England and Wales. 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