[LOG4J2-279] Logging from log4j2 FlumeAppender with BerkeleyDB agent from Jetty webapp to Avro source with full queue raises ClosedByInterruptException

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0-beta7
• Fix Version/s: 2.0-beta8
• Component/s: Flume Appender
• Assignee: Unassigned
• Reporter: Edward Sargisson
• Created: 11/Jun/13 16:49
• Updated: 04/Jul/13 15:15
• Resolved: 04/Jul/13 15:15

Description

Attempting to embed a Flume agent in another app does not work very well. I have found a repro of a very simple Jetty app using the log4j2 FlumeAppender to connect to a subsequent Flume agent with a full channel.

The impact is that I don't believe the BerkeleyDB agent can be safely used.

Steps:
1. Setup an additional Flume server (the subsequent server) with an avro source and make the channel fill up (in my environment the subsequent server gets an OutOfMemoryError and then starts queueing events.)
2. Extract the enclosed project. Edit the flume-embedded-hot-deploy/src/main/resource/log4j2.xml and configure the Agent for the FlumeAppender with the details of the subsequent server.
3. mvn clean install
4. Change to flume-embedded-hot-deploy
5. mvn clean package -P debug (note that you can set it to suspend until a debugger is attached with mvn clean package -P debug,suspend)
6. Wait for Jetty to startup - and then for a few seconds.

Expected results:
Some complaints about the subsequent server being full but an otherwise happy server.

Actual results:
When using the log4j2 Persistent agent (which uses Berkeley DB as a store):
2013-06-03 14:01:14,804 INFO [main] server.AbstractConnector (AbstractConnector.java:265) - Started ServerConnector@75a213c0

{HTTP/1.1} {0.0.0.0:8080}

2013-06-03 14:01:22,779 DEBUG [Thread-3] ipc.NettyTransceiver (NettyTransceiver.java:314) - Disconnecting from collector1-sal-flex-van.dev-globalrelay.net/10.21.30.20:36892
2013-06-03 14:01:22,789 ERROR An exception occurred processing Appender FlumeAppender org.apache.logging.log4j.LoggingException: Exception occurred writing log event
at org.apache.logging.log4j.flume.appender.FlumePersistentManager.send(FlumePersistentManager.java:176)
at org.apache.logging.log4j.flume.appender.FlumeAppender.append(FlumeAppender.java:86)
at org.apache.logging.log4j.core.config.AppenderControl.callAppender(AppenderControl.java:102)
at org.apache.logging.log4j.core.config.LoggerConfig.callAppenders(LoggerConfig.java:424)
at org.apache.logging.log4j.core.config.LoggerConfig.log(LoggerConfig.java:405)
at org.apache.logging.log4j.core.config.LoggerConfig.log(LoggerConfig.java:366)
at org.apache.logging.log4j.core.Logger.log(Logger.java:110)
at org.apache.logging.log4j.spi.AbstractLoggerWrapper.log(AbstractLoggerWrapper.java:55)
at org.slf4j.impl.SLF4JLogger.debug(SLF4JLogger.java:139)
at org.apache.avro.ipc.NettyTransceiver$NettyClientAvroHandler.handleUpstream(NettyTransceiver.java:491)
at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564)
at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendUpstream(DefaultChannelPipeline.java:792)
at org.jboss.netty.handler.codec.frame.FrameDecoder.cleanup(FrameDecoder.java:348)
at org.jboss.netty.handler.codec.frame.FrameDecoder.channelDisconnected(FrameDecoder.java:230)
at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:107)
at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564)
at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:559)
at org.jboss.netty.channel.Channels.fireChannelDisconnected(Channels.java:399)
at org.jboss.netty.channel.Channels$4.run(Channels.java:389)
at org.jboss.netty.channel.socket.ChannelRunnableWrapper.run(ChannelRunnableWrapper.java:41)
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.processEventQueue(AbstractNioWorker.java:352)
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.run(AbstractNioWorker.java:236)
at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:38)
at org.jboss.netty.util.internal.DeadLockProofWorker$1.run(DeadLockProofWorker.java:42)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:722)
Caused by: com.sleepycat.je.ThreadInterruptedException: (JE 5.0.73) Environment must be closed, caused by: com.sleepycat.je.ThreadInterruptedException: Environment invalid because of previous exception: (JE 5.0.73) /var/local/flume/castellan-reader-berkeley-db Channel closed, may be due to thread interrupt THREAD_INTERRUPTED: InterruptedException may cause incorrect internal state, unable to continue. Environment is invalid and must be closed.
at com.sleepycat.je.ThreadInterruptedException.wrapSelf(ThreadInterruptedException.java:99)
at com.sleepycat.je.dbi.EnvironmentImpl.checkIfInvalid(EnvironmentImpl.java:1512)
at com.sleepycat.je.Transaction.checkEnv(Transaction.java:850)
at com.sleepycat.je.Transaction.abort(Transaction.java:204)
at org.apache.logging.log4j.flume.appender.FlumePersistentManager.send(FlumePersistentManager.java:171)
... 26 more
Caused by: com.sleepycat.je.ThreadInterruptedException: Environment invalid because of previous exception: (JE 5.0.73) /var/local/flume/castellan-reader-berkeley-db Channel closed, may be due to thread interrupt THREAD_INTERRUPTED: InterruptedException may cause incorrect internal state, unable to continue. Environment is invalid and must be closed.
at com.sleepycat.je.log.FileManager$LogEndFileDescriptor.force(FileManager.java:3054)
at com.sleepycat.je.log.FileManager$LogEndFileDescriptor.access$500(FileManager.java:2710)
at com.sleepycat.je.log.FileManager.syncLogEnd(FileManager.java:2022)
at com.sleepycat.je.log.FSyncManager.executeFSync(FSyncManager.java:282)
at com.sleepycat.je.log.FSyncManager.fsync(FSyncManager.java:233)
at com.sleepycat.je.log.FileManager.groupSync(FileManager.java:2070)
at com.sleepycat.je.log.LogManager.multiLog(LogManager.java:403)
at com.sleepycat.je.log.LogManager.log(LogManager.java:335)
at com.sleepycat.je.txn.Txn.logCommitEntry(Txn.java:957)
at com.sleepycat.je.txn.Txn.commit(Txn.java:719)
at com.sleepycat.je.txn.Txn.commit(Txn.java:584)
at com.sleepycat.je.Transaction.commit(Transaction.java:317)
at org.apache.logging.log4j.flume.appender.FlumePersistentManager.send(FlumePersistentManager.java:167)
... 26 more
Caused by: java.nio.channels.ClosedByInterruptException
at java.nio.channels.spi.AbstractInterruptibleChannel.end(AbstractInterruptibleChannel.java:202)
at sun.nio.ch.FileChannelImpl.force(FileChannelImpl.java:367)
at com.sleepycat.je.log.FileManager$LogEndFileDescriptor.force(FileManager.java:3043)
... 38 more

Suppositions:
I believe this is an issue with the handling of a failed put or take. The failure path interacts with rollback or the Avro client in bad ways.
For example, the Avro client uses a SynchronousQueue to do rendezvous. That queue uses InterruptedException internally. However, the FileChannel uses the NIO FileChannel (and AbstractInterruptibleChannel) which fails if its thread gets interrupted. My debugging sessions show that java.util.concurrent.CountDownLatch is a common source of InterruptedExceptions. CountDownLatch is also used by the Avro client.

Some docs:
http://jira.codehaus.org/browse/JETTY-80
http://www.oracle.com/technetwork/products/berkeleydb/if-097768.html

Issue Links

• supercedes: FLUME-2067 Logging from log4j2 FlumeAppender with BerkeleyDB agent from Jetty webapp to Avro source with full queue raises ClosedByInterruptException