log4j RollingFileAppender 性能

Question

I need to log heavily for further analysis so when file is rolled the whole flow stuck for a while doing something like this:

"org.springframework.kafka.KafkaListenerEndpointContainer#1-1-C-1" - Thread t@56
   java.lang.Thread.State: BLOCKED
    at org.apache.logging.log4j.core.appender.rolling.RollingFileManager.checkRollover(RollingFileManager.java:174)
    - waiting to lock <2afdff68> (a org.apache.logging.log4j.core.appender.rolling.RollingFileManager) owned by "SrpResultsProcessor-8" t@90
    at org.apache.logging.log4j.core.appender.RollingFileAppender.append(RollingFileAppender.java:280)
    at org.apache.logging.log4j.core.config.AppenderControl.tryCallAppender(AppenderControl.java:156)
    at org.apache.logging.log4j.core.config.AppenderControl.callAppender0(AppenderControl.java:129)
    at org.apache.logging.log4j.core.config.AppenderControl.callAppenderPreventRecursion(AppenderControl.java:120)
    at org.apache.logging.log4j.core.config.AppenderControl.callAppender(AppenderControl.java:84)
    at org.apache.logging.log4j.core.config.LoggerConfig.callAppenders(LoggerConfig.java:447)
    at org.apache.logging.log4j.core.config.LoggerConfig.processLogEvent(LoggerConfig.java:432)
    at org.apache.logging.log4j.core.config.LoggerConfig.log(LoggerConfig.java:416)
    at org.apache.logging.log4j.core.config.LoggerConfig.log(LoggerConfig.java:402)
    at org.apache.logging.log4j.core.config.AwaitCompletionReliabilityStrategy.log(AwaitCompletionReliabilityStrategy.java:63)
    at org.apache.logging.log4j.core.Logger.logMessage(Logger.java:146)
    at org.apache.logging.log4j.spi.AbstractLogger.logMessageSafely(AbstractLogger.java:2091)
    at org.apache.logging.log4j.spi.AbstractLogger.logMessage(AbstractLogger.java:2005)
    at org.apache.logging.log4j.spi.AbstractLogger.logIfEnabled(AbstractLogger.java:1876)
    at org.apache.logging.slf4j.Log4jLogger.debug(Log4jLogger.java:124)
...    

Here is my yaml config:

Configuration:
name: default

Appenders:

  RollingFile:
    - name: stdout
      fileName: ../logs/${component.name}.log
      filePattern: "../logs/archive/${component.name}_%d{yyyy-MM-dd}_%i.log.zip"
      PatternLayout:
        pattern: "%d{ISO8601} %-5level [%t] %logger{36} - %msg%n"
      Policies:
        SizeBasedTriggeringPolicy:
          size: 300 MB
      DefaultRollOverStrategy:
        max: 20
        Delete:
          basePath: ../logs
          maxDepth: 2
          IfFileName:
            glob: "*/${component.name}_*.log.zip"
            IfAccumulatedFileCount:
              exceeds: 50

    - name: stderr
      fileName: ../logs/${component.name}.err
      filePattern: "../logs/archive/${component.name}_%d{yyyy-MM-dd}_%i.err.zip"
      PatternLayout:
        pattern: "%d{ISO8601} %-5level [%t] %logger{36} - %msg%n"
      Policies:
        SizeBasedTriggeringPolicy:
          size: 300 MB
      DefaultRollOverStrategy:
        max: 5
        Delete:
          basePath: ../logs
          maxDepth: 2
          IfFileName:
            glob: "*/${component.name}_*.err.zip"
            IfAccumulatedFileCount:
              exceeds: 10
...

Any ideas to improve performance of the 'rolling'?

Answer 1

-DLog4jContextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector

来源

Answer 2

This is a problem with high concurrency, and it works as designed. The file system (I/O) doesn't have the enough performance as required.

The synchronized makes BLOCKED some Java monitor when trying to acquire the resource.

/**
 * Determines if a rollover should occur.
 * @param event The LogEvent.
 */
public synchronized void checkRollover(final LogEvent event) {
    if (triggeringPolicy.isTriggeringEvent(event)) {
        rollover();
    }
}

The solution as mentioned above is to move to Async logging.

https://logging.apache.org/log4j/2.x/manual/async.html