@AfterClass
  public static void tearDown() {
    System.clearProperty("log4j.configurationFile");
    LogManager.shutdown();
  }
Test configuration and use of SlidingFilenameRolloverStrategy
@see SlidingFilenameRolloverStrategy
ql/src/test/org/apache/hadoop/hive/ql/log/TestSlidingFilenameRolloverStrategy.java