[CASSANDRA-14215] Cassandra does not respect hint window for CAS

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 3.0.17, 3.11.3, 4.0-alpha1, 4.0
• Component/s: Consistency/Hints, Feature/Lightweight Transactions, Legacy/Streaming and Messaging
• Labels: LWT
• Severity: Normal
• Since Version: 3.0.0
• Assignee: Kurt Greaves
• Reporter: Arijit Banerjee

Authors

Kurt Greaves

Reviewers

Aleksey Yeschenko

• Created: 06/Feb/18 02:38
• Updated: 15/May/20 08:05
• Resolved: 15/Mar/18 14:27

Description

On Cassandra 3.0.9, it was observed that Cassandra continues to write hints even though a node remains down (and does not come up) for longer than the default 3 hour window.

 

After doing "nodetool setlogginglevel org.apache.cassandra TRACE", we see the following log line in cassandra (debug) logs:
StorageProxy.java:2625 - Adding hints for [/10.0.100.84]

 

One possible code path seems to be:

cas -> commitPaxos(proposal, consistencyForCommit, true); -> submitHint (in StorageProxy.java)

 

The "true" parameter above explicitly states that a hint should be recorded and ignores the time window calculation performed by the shouldHint method invoked in other code paths. Is there a reason for this behavior?

 

Edit: There are actually two stacks that seem to be producing hints, the "cas" and "syncWriteBatchedMutations" methods. I have posted them below.

 

A third issue seems to be that Cassandra seems to reset the timer which counts how long a node has been down after a restart. Thus if Cassandra is restarted on a good node, it continues to accumulate hints for a down node over the next three hours.

 

WARN [SharedPool-Worker-14] 2018-02-06 22:15:51,136 StorageProxy.java:2636 - Adding hints for [/10.0.100.84] with stack trace: java.lang.Throwable: at org.apache.cassandra.service.StorageProxy.stackTrace(StorageProxy.java:2608) at org.apache.cassandra.service.StorageProxy.submitHint(StorageProxy.java:2617) at org.apache.cassandra.service.StorageProxy.submitHint(StorageProxy.java:2603) at org.apache.cassandra.service.StorageProxy.commitPaxos(StorageProxy.java:540) at org.apache.cassandra.service.StorageProxy.cas(StorageProxy.java:282) at org.apache.cassandra.cql3.statements.ModificationStatement.executeWithCondition(ModificationStatement.java:432) at org.apache.cassandra.cql3.statements.ModificationStatement.execute(ModificationStatement.java:407) at org.apache.cassandra.cql3.QueryProcessor.processStatement(QueryProcessor.java:206) at org.apache.cassandra.cql3.QueryProcessor.process(QueryProcessor.java:237) at org.apache.cassandra.cql3.QueryProcessor.process(QueryProcessor.java:222) at org.apache.cassandra.transport.messages.QueryMessage.execute(QueryMessage.java:115) at org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:513) at org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:407) at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333) at io.netty.channel.AbstractChannelHandlerContext.access$700(AbstractChannelHandlerContext.java:32) at io.netty.channel.AbstractChannelHandlerContext$8.run(AbstractChannelHandlerContext.java:324) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at org.apache.cassandra.concurrent.AbstractLocalAwareExecutorService$FutureTask.run(AbstractLocalAwareExecutorService.java:164) at org.apache.cassandra.concurrent.SEPWorker.run(SEPWorker.java:105) at java.lang.Thread.run(Thread.java:748) WARN

[SharedPool-Worker-8] 2018-02-06 22:15:51,153 StorageProxy.java:2636 - Adding hints for [/10.0.100.84] with stack trace: java.lang.Throwable: at org.apache.cassandra.service.StorageProxy.stackTrace(StorageProxy.java:2608) at org.apache.cassandra.service.StorageProxy.submitHint(StorageProxy.java:2617) at org.apache.cassandra.service.StorageProxy.sendToHintedEndpoints(StorageProxy.java:1247) at org.apache.cassandra.service.StorageProxy.syncWriteBatchedMutations(StorageProxy.java:1014) at org.apache.cassandra.service.StorageProxy.mutateAtomically(StorageProxy.java:899) at org.apache.cassandra.service.StorageProxy.mutateWithTriggers(StorageProxy.java:834) at org.apache.cassandra.cql3.statements.BatchStatement.executeWithoutConditions(BatchStatement.java:365) at org.apache.cassandra.cql3.statements.BatchStatement.execute(BatchStatement.java:343) at org.apache.cassandra.cql3.statements.BatchStatement.execute(BatchStatement.java:329) at org.apache.cassandra.cql3.statements.BatchStatement.execute(BatchStatement.java:324) at org.apache.cassandra.cql3.QueryProcessor.processStatement(QueryProcessor.java:206) at org.apache.cassandra.cql3.QueryProcessor.process(QueryProcessor.java:237) at org.apache.cassandra.cql3.QueryProcessor.process(QueryProcessor.java:222) at org.apache.cassandra.transport.messages.QueryMessage.execute(QueryMessage.java:115) at org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:513) at org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:407) at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333) at io.netty.channel.AbstractChannelHandlerContext.access$700(AbstractChannelHandlerContext.java:32) at io.netty.channel.AbstractChannelHandlerContext$8.run(AbstractChannelHandlerContext.java:324) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at org.apache.cassandra.concurrent.AbstractLocalAwareExecutorService$FutureTask.run(AbstractLocalAwareExecutorService.java:164) at org.apache.cassandra.concurrent.SEPWorker.run(SEPWorker.java:105) at java.lang.Thread.run(Thread.java:748)