Exception thrown if fluo yarn commands run on empty Zookeeper

[mikewalch]

This exception is thrown every time the command fluo-dev deploy is run with fresh Zookeeper.

No root node '/' exists in ZK which causes exception. Commands should check if root node exists before reading ZK.

Exception in thread "YarnTwillRunnerService STARTING" java.lang.RuntimeException: java.util.concurrent.ExecutionException: org.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode = NoNode for /
    at com.google.common.base.Throwables.propagate(Throwables.java:160)
    at com.google.common.util.concurrent.AbstractIdleService$1$1.run(AbstractIdleService.java:47)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.util.concurrent.ExecutionException: org.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode = NoNode for /
    at com.google.common.util.concurrent.AbstractFuture$Sync.getValue(AbstractFuture.java:294)
    at com.google.common.util.concurrent.AbstractFuture$Sync.get(AbstractFuture.java:281)
    at com.google.common.util.concurrent.AbstractFuture.get(AbstractFuture.java:116)
    at org.apache.twill.yarn.YarnTwillRunnerService.startUp(YarnTwillRunnerService.java:304)
    at com.google.common.util.concurrent.AbstractIdleService$1$1.run(AbstractIdleService.java:43)
    ... 1 more