[HADOOP-7055] Update of commons logging libraries causes EventCounter to count logging events incorrectly

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.21.0, 0.21.1, 0.22.0, 0.23.0
• Fix Version/s: 0.23.0
• Component/s: metrics
• Hadoop Flags: Reviewed
• Assignee: Jingguo Yao
• Reporter: Jingguo Yao
• Created: 30/Nov/10 08:53
• Updated: 15/Nov/11 00:50
• Resolved: 12/May/11 18:41

Description

Hadoop 0.20.2 uses commons logging 1.0.4. EventCounter works correctly with this version of commons logging. Hadoop 0.21.0 uses commons logging 1.1.1 which causes EventCounter to count logging events incorrectly. I have verified it with Hadoop 0.21.0. After start-up of hadoop, I checked jvmmetrics.log after several minutes. In every metrics record, "logError=0, logFatal=0, logInfo=3, logWarn=0" was shown. The following text is an example.

jvm.metrics: hostName=jingguolin, processName=DataNode, sessionId=, gcCount=3, gcTimeMillis=31, logError=0, logFatal=0, logInfo=3, logWarn=0, maxMemoryM=888.9375, memHeapCommittedM=38.0625, memHeapUsedM=3.6539612, memNonHeapCommittedM=18.25, memNonHeapUsedM=11.335686, threadsBlocked=0, threadsNew=0, threadsRunnable=8, threadsTerminated=0, threadsTimedWaiting=6, threadsWaiting=6

Then I stopped hadoop and replaced commons logging 1.1.1 with 1.0.4. After the re-start of hadoop, a lot of logging events showed up in jvmmetrics.log.

I have checked the source code of Log4JLogger for both 1.0.4 (http://svn.apache.org/viewvc/commons/proper/logging/tags/LOGGING_1_0_4/src/java/org/apache/commons/logging/impl/Log4JLogger.java?view=markup) and 1.1.1 (http://svn.apache.org/viewvc/commons/proper/logging/tags/commons-logging-1.1.1/src/java/org/apache/commons/logging/impl/Log4JLogger.java?view=markup). For 1.0.4, Level instances such as Level.INFO are used to construct LoggingEvent. But for 1.1.1, Priority instances such as Priority.INFO are used to construct LoggingEvent. So 1.1.1 version's event.getLevel() always returns Priority instances. EventCounter append method's "==" check always fails between a Level instance and a Priority instance. For "logInfo=3" metrics records produced by commons logging 1.1.1., I think that these 3 logging events are produced by log4j code directly instead of through commons logging API. The following code is EventCounter's append method.

public void append(LoggingEvent event) {
Level level = event.getLevel();
if (level == Level.INFO)

{ counts.incr(INFO); }

else if (level == Level.WARN)

{ counts.incr(WARN); }

else if (level == Level.ERROR)

{ counts.incr(ERROR); }

else if (level == Level.FATAL)

{ counts.incr(FATAL); }

}

Issue Links

• is part of: HADOOP-6920 Metrics2: metrics instrumentation