运行spark app时，屏幕上总会刷屏似的输出大量日志信息，详细介绍程序运行过程，但这样有时也不便我们调试应用。只输出警告和程序输出一般就足够我们参考，再详细的内容课题通过web ui更直观的查看。
# Set everything to be logged to the console log4j.rootCategory=WARN, console log4j.appender.console=org.apache.log4j.ConsoleAppender log4j.appender.console.target=System.err log4j.appender.console.layout=org.apache.log4j.PatternLayout log4j.appender.console.layout.ConversionPattern=%d{yy/MM/dd HH:mm:ss} %p %c{1}: %m%n # Settings to quiet third party logs that are too verbose log4j.logger.org.spark-project.jetty=WARN log4j.logger.org.spark-project.jetty.util.component.AbstractLifeCycle=ERROR log4j.logger.org.apache.spark.repl.SparkIMain$exprTyper=INFO log4j.logger.org.apache.spark.repl.SparkILoop$SparkILoopInterpreter=INFO