[FLUME-2537] SpillableMemoryChannel throws NPE when sink throws exception

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 1.5.0.1
• Component/s: Channel

Environment

JAVA:
java version "1.8.0_20-ea"
Java(TM) SE Runtime Environment (build 1.8.0_20-ea-b23)
Java HotSpot(TM) 64-Bit Server VM (build 25.20-b22, mixed mode)

Config:
a1.sources = r1
a1.channels = c1
a1.sinks = k1

a1.sources.r1.type = ...

1. Describe the sink
   a1.sinks.k1.type = avro
   a1.sinks.k1.hostname = flume-test
   a1.sinks.k1.port=8080

1. Use a channel which buffers events in memory
   a1.channels.c1.type = SPILLABLEMEMORY
   a1.channels.c1.memoryCapacity = 10
   a1.channels.c1.byteCapacity=655270
   a1.channels.c1.overflowCapacity = 1000000
   a1.channels.c1.transactionCapacity = 5

1. Bind the source and sink to the channel
   a1.sources.r1.channels = c1
   a1.sinks.k1.channel = c1

• Assignee: Unassigned
• Reporter: Dave Lund
• Created: 05/Nov/14 12:38
• Updated: 05/Nov/14 12:38

Description

I'm aware that the spillablememory channel is an ongoing effort and not production ready but thought I'd submit this to help improve it.

I've created a rather simple test case where I use a spillablememory channel connecting to an avro sink (this sink is pointing to another flume agent as a next hop). When I shutdown the flume in the next hop, which causes the avro client to get a ConnectionRefused exception, the SpillableMemoryChannel attempts to rollback the transaction, but gets the following NPE:

java.lang.NullPointerException
at org.apache.flume.channel.SpillableMemoryChannel$SpillableMemoryTransaction.doRollback(SpillableMemoryChannel.java:574)
at org.apache.flume.channel.BasicTransactionSemantics.rollback(BasicTransactionSemantics.java:168)
at org.apache.flume.sink.AbstractRpcSink.process(AbstractRpcSink.java:383)
at org.apache.flume.sink.DefaultSinkProcessor.process(DefaultSinkProcessor.java:68)
at org.apache.flume.SinkRunner$PollingRunner.run(SinkRunner.java:147)
at java.lang.Thread.run(Thread.java:745)