Found 1 master(s), 1 slaves
Logging into master ec2-54-152-145-139.compute-1.amazonaws.com...
Warning: Identity file mykey.pem not accessible: No such file or directory.
Warning: Permanently added 'ec2-54-152-145-139.compute-         1.amazonaws.com,54.152.145.139' (RSA) to the list of known hosts.
Permission denied (publickey).
Traceback (most recent call last):
File "./spark_ec2.py", line 1093, in <module>
    main()
File "./spark_ec2.py", line 1085, in main
real_main()
File "./spark_ec2.py", line 1018, in real_main
ssh_command(opts) + proxy_opt + ['-t', '-t', "%s@%s" % (opts.user, master)])
File "/Users/myuser/anaconda/lib/python2.7/subprocess.py", line 540, in check_call
raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['ssh', '-o',       'StrictHostKeyChecking=no', '-o', 'UserKnownHostsFile=/dev/null', '-i', 'mykey.pem', '-t', '-t', u'root@ec2- 54-152-145-139.compute-1.amazonaws.com']'     returned non-zero exit status 255`