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Benjamin Lerer commented on CASSANDRA-13149: -------------------------------------------- I had a quick look at the code and it seems to me that the code can trigger the assertion even with {{System#currentTimeMillis}} being monotonic. As the time is being retrieved before the start of the loop adding the values [here| https://github.com/apache/cassandra/blob/cassandra-3.0/src/java/org/apache/cassandra/cql3/Lists.java#L425] another query might end up being faster and change the last time before all the value got added. Even if the {{PrecisionTime#getNext}} method was used only once per update we could have a race condition and trigger the assertion. The best solution would be in my opinion to avoid sharing {{PrecisionTime}} and create one instance per operation. [~slebresne] does my analysis and my proposed solution make sense to you? > AssertionError prepending to a list > ----------------------------------- > > Key: CASSANDRA-13149 > URL: https://issues.apache.org/jira/browse/CASSANDRA-13149 > Project: Cassandra > Issue Type: Bug > Components: CQL > Environment: 3.0.8 > Reporter: Steven Warren > > Prepending to a list produces the following AssertionError randomly. Changing > the update to append (and sort in the client) works around the issue. > {code} > java.lang.AssertionError: null > at > org.apache.cassandra.cql3.Lists$PrecisionTime.getNext(Lists.java:275) > ~[apache-cassandra-3.0.8.jar:3.0.8] > at org.apache.cassandra.cql3.Lists$Prepender.execute(Lists.java:430) > ~[apache-cassandra-3.0.8.jar:3.0.8] > at > org.apache.cassandra.cql3.statements.UpdateStatement.addUpdateForKey(UpdateStatement.java:94) > ~[apache-cassandra-3.0.8.jar:3.0.8] > at > org.apache.cassandra.cql3.statements.ModificationStatement.addUpdates(ModificationStatement.java:682) > ~[apache-cassandra-3.0.8.jar:3.0.8] > at > org.apache.cassandra.cql3.statements.ModificationStatement.getMutations(ModificationStatement.java:613) > ~[apache-cassandra-3.0.8.jar:3.0.8] > at > org.apache.cassandra.cql3.statements.ModificationStatement.executeWithoutCondition(ModificationStatement.java:420) > ~[apache-cassandra-3.0.8.jar:3.0.8] > at > org.apache.cassandra.cql3.statements.ModificationStatement.execute(ModificationStatement.java:408) > ~[apache-cassandra-3.0.8.jar:3.0.8] > at > org.apache.cassandra.cql3.QueryProcessor.processStatement(QueryProcessor.java:206) > ~[apache-cassandra-3.0.8.jar:3.0.8] > at > org.apache.cassandra.cql3.QueryProcessor.processPrepared(QueryProcessor.java:487) > ~[apache-cassandra-3.0.8.jar:3.0.8] > at > org.apache.cassandra.cql3.QueryProcessor.processPrepared(QueryProcessor.java:464) > ~[apache-cassandra-3.0.8.jar:3.0.8] > at > org.apache.cassandra.transport.messages.ExecuteMessage.execute(ExecuteMessage.java:130) > ~[apache-cassandra-3.0.8.jar:3.0.8] > at > org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:507) > [apache-cassandra-3.0.8.jar:3.0.8] > at > org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:401) > [apache-cassandra-3.0.8.jar:3.0.8] > at > io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) > [netty-all-4.0.23.Final.jar:4.0.23.Final] > at > io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333) > [netty-all-4.0.23.Final.jar:4.0.23.Final] > at > io.netty.channel.AbstractChannelHandlerContext.access$700(AbstractChannelHandlerContext.java:32) > [netty-all-4.0.23.Final.jar:4.0.23.Final] > at > io.netty.channel.AbstractChannelHandlerContext$8.run(AbstractChannelHandlerContext.java:324) > [netty-all-4.0.23.Final.jar:4.0.23.Final] > at > java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) > [na:1.8.0_101] > at > org.apache.cassandra.concurrent.AbstractLocalAwareExecutorService$FutureTask.run(AbstractLocalAwareExecutorService.java:164) > [apache-cassandra-3.0.8.jar:3.0.8] > at org.apache.cassandra.concurrent.SEPWorker.run(SEPWorker.java:105) > [apache-cassandra-3.0.8.jar:3.0.8] > at java.lang.Thread.run(Thread.java:745) [na:1.8.0_101] > {code} -- This message was sent by Atlassian JIRA (v6.3.15#6346) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org