Are you trying to access the UI from another machine? If so, first confirm that you don't have a network issue by opening the UI from the master node itself.For example:yum -y install lynx lynx ip_address:8080If this succeeds, then you likely have something blocking you from accessing the web page from another machine.NickOn Tue, Apr 1, 2014 at 6:30 PM, yxzhao <email@example.com> wrote: >> http://spark.incubator.apache.org/docs/latest/spark-standalone.html#monitoring-and-logging> As the above shows: > "> Monitoring and Logging> Spark’s standalone mode offers a web-based user interface to monitor the> cluster. The master and each worker has its own web UI that shows cluster> and job statistics. By default you can access the web UI for the master at > port 8080. The port can be changed either in the configuration file or via> command-line options.>> "> But I cannot open the web ui. The master ip is 10.1.255.202 so I input:> http://10.1.255.202 :8080 in my web browser. Bui the webpage is not > available.> Thanks.>>>> --> View this message in context: http://apache-spark-user-list.1001560.n3.nabble.com/Cannot-Access-Web-UI-tp3599.html > Sent from the Apache Spark User List mailing list archive at Nabble.com.