job sometimes fails on launch when using session mode

13/10/08 18:32:07 INFO examples.OrderedWordCount: Creating Tez Session
13/10/08 18:32:07 INFO client.RMProxy: Connecting to ResourceManager at /0.0.0.0:54311
13/10/08 18:32:09 INFO impl.YarnClientImpl: Submitted application application_1381281978874_0005 to ResourceManager at /0.0.0.0:54311
13/10/08 18:32:09 INFO examples.OrderedWordCount: Created Tez Session
13/10/08 18:32:09 INFO client.TezSession: Shutting down Tez Session, sessionName=OrderedWordCountSession, applicationId=application_1381281978874_0005
13/10/08 18:32:09 INFO client.TezSession: Could not connect to AM, killing session via YARN, sessionName=OrderedWordCountSession, applicationId=application_1381281978874_0005
13/10/08 18:32:09 INFO impl.YarnClientImpl: Killing application application_1381281978874_0005
org.apache.hadoop.mapred.FileAlreadyExistsException: Output directory /out1 already exists
at org.apache.tez.mapreduce.examples.OrderedWordCount.main(OrderedWordCount.java:357)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:72)
at org.apache.hadoop.util.ProgramDriver.run(ProgramDriver.java:144)
at org.apache.tez.mapreduce.examples.ExampleDriver.main(ExampleDriver.java:79)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.util.RunJar.main(RunJar.java:212)