a.rb

log4j:ERROR setFile(null,true) call failed.
java.io.FileNotFoundException: /usr/local/Cellar/hadoop/2.7.1/libexec/logs/userlogs/application_1451365016523_0018/container_1451365016523_0018_01_000001 (Is a directory)
	at java.io.FileOutputStream.open0(Native Method)
	at java.io.FileOutputStream.open(FileOutputStream.java:270)
	at java.io.FileOutputStream.<init>(FileOutputStream.java:213)
	at java.io.FileOutputStream.<init>(FileOutputStream.java:133)
	at org.apache.log4j.FileAppender.setFile(FileAppender.java:294)
	at org.apache.log4j.FileAppender.activateOptions(FileAppender.java:165)
	at org.apache.hadoop.yarn.ContainerLogAppender.activateOptions(ContainerLogAppender.java:55)
	at org.apache.log4j.config.PropertySetter.activate(PropertySetter.java:307)
	at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:172)
	at org.apache.log4j.config.PropertySetter.setProperties(PropertySetter.java:104)
	at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigurator.java:842)
	at org.apache.log4j.PropertyConfigurator.parseCategory(PropertyConfigurator.java:768)
	at org.apache.log4j.PropertyConfigurator.configureRootCategory(PropertyConfigurator.java:648)
	at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:514)
	at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:580)
	at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:526)
	at org.apache.log4j.LogManager.<clinit>(LogManager.java:127)
	at org.apache.log4j.Logger.getLogger(Logger.java:104)
	at org.apache.commons.logging.impl.Log4JLogger.getLogger(Log4JLogger.java:262)
	at org.apache.commons.logging.impl.Log4JLogger.<init>(Log4JLogger.java:108)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
	at org.apache.commons.logging.impl.LogFactoryImpl.createLogFromClass(LogFactoryImpl.java:1025)
	at org.apache.commons.logging.impl.LogFactoryImpl.discoverLogImplementation(LogFactoryImpl.java:844)
	at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:541)
	at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:292)
	at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:269)
	at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:657)
	at org.apache.hadoop.service.AbstractService.<clinit>(AbstractService.java:43)