Thank you guys, it is the port issue. On Wed, Jul 20, 2016 at 11:03 AM, Igor Berman wrote: > in addition check what ip the master is binding to(with nestat) > > On 20 July 2016 at 06:12, Andrew Ehrlich wrote: > >> Troubleshooting steps: >> >> $ telnet localhost 7077 (on master, to confirm port is open) >> $ telnet 7077 (on slave, to confirm port is blocked) >> >> If the port is available on the master from the master, but not on the >> master from the slave, check firewall settings on the master: >> https://help.ubuntu.com/lts/serverguide/firewall.html >> >> On Jul 19, 2016, at 6:25 PM, Neil Chang wrote: >> >> Hi, >> I have two virtual pcs on private cloud (ubuntu 14). I installed spark >> 2.0 preview on both machines. I then tried to test it with standalone mode. >> I have no problem start the master. However, when I start the worker >> (slave) on another machine, it makes many attempts to connect to master and >> failed at the end. >> I can ssh from each machine to another without any problem. I can also >> run a master and worker at the same machine without any problem. >> >> What did I miss? Any clue? >> >> here are the messages: >> >> WARN NativeCodeLoader: Unable to load native-hadoop library for your >> platform ... using builtin-java classes where applicable >> .............. >> INFO Worker: Connecting to master ip:7077 ... >> INFO Worker: Retrying connection to master (attempt #1) >> .............. >> INFO Worker: Retrying connection to master (attempt #7) >> java.lang.IllegalArgumentException: requirement failed: TransportClient >> has not yet been set. >> at scala.Predef$.require(Predef.scala:224) >> ....... >> WARN NettyRocEnv: Ignored failure: java.io.IOException: Connecting to >> ip:7077 timed out >> WARN Worker: Failed to connect to master ip.7077 >> >> >> >> Thanks, >> Neil >> >> >> >