[LOG4J2-336] AsyncLogger.log fail with NullPointerException after double reconfigure

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0-beta8
• Fix Version/s: 2.0-beta9
• Component/s: Core

Environment

LUbuntu 13.04, OpenJDK 7

• Assignee: Remko Popma
• Reporter: Andre Bogus
• Created: 07/Aug/13 08:32
• Updated: 14/Aug/13 14:03
• Resolved: 14/Aug/13 12:20

Description

Using reconfigure() to select log files at runtime.
After the second reconfigure, the next log fails with a NullPointerException in org.apache.logging.log4j.core.async.AsyncLoggerConfigHelper:253

It appears that the disruptor has been nulled and not been brought back up by the second reconfigure().

Trying to get a minimal test case I came up with the following log4j2.xml:

<?xml version="1.0" encoding="UTF-8" ?>
<configuration status="debug">
  <appenders>
    <Console name="console" target="SYSTEM_OUT">
      <PatternLayout pattern="%d\{ABSOLUTE\} %6p %c %x - %m%n"/>
    </Console>
  </appenders>
  <loggers>
    <asyncroot level="WARN">
      <appender-ref ref="console" />
    </asyncroot>
  </loggers>
</configuration>

The following Java class did NOT bring up the error, instead it threw a different exception (stack trace below):

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.core.LoggerContext;

public class Log4jAsyncReconfTest {
    private static final Logger log = LogManager.getLogger(Log4jAsyncReconfTest.class);
    public static void main(String[] args) throws InterruptedException {
        System.out.println("test");
        LoggerContext ctx = (LoggerContext) LogManager.getContext(false);
        ctx.reconfigure();
        ctx.reconfigure();
        log.warn("Danger!");
    }
}

---

throws:

java.util.concurrent.RejectedExecutionException: Task com.lmax.disruptor.BatchEventProcessor@7ea4461e rejected from java.util.concurrent.ThreadPoolExecutor@52f79c86[Terminated, pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 1]
at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2048)
at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:821)
at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1372)
at java.util.concurrent.Executors$DelegatedExecutorService.execute(Executors.java:628)
at com.lmax.disruptor.dsl.EventProcessorInfo.start(EventProcessorInfo.java:77)
at com.lmax.disruptor.dsl.Disruptor.start(Disruptor.java:263)
at org.apache.logging.log4j.core.async.AsyncLoggerConfigHelper.initDisruptor(AsyncLoggerConfigHelper.java:119)