1 files changed, 24 insertions, 12 deletions
diff --git a/ec2/spark_ec2.py b/ec2/spark_ec2.py
index 725b1e47e0..87b2112fe4 100755
--- a/ec2/spark_ec2.py
+++ b/ec2/spark_ec2.py
@@ -34,6 +34,7 @@ import subprocess
 import sys
 import tarfile
 import tempfile
+import textwrap
 import time
 import urllib2
 import warnings
@@ -681,21 +682,32 @@ def setup_spark_cluster(master, opts):
         print "Ganglia started at http://%s:5080/ganglia" % master
 
 
-def is_ssh_available(host, opts):
+def is_ssh_available(host, opts, print_ssh_output=True):
     """
     Check if SSH is available on a host.
     """
-    try:
-        with open(os.devnull, 'w') as devnull:
-            ret = subprocess.check_call(
-                ssh_command(opts) + ['-t', '-t', '-o', 'ConnectTimeout=3',
-                                     '%s@%s' % (opts.user, host), stringify_command('true')],
-                stdout=devnull,
-                stderr=devnull
-            )
-        return ret == 0
-    except subprocess.CalledProcessError as e:
-        return False
+    s = subprocess.Popen(
+        ssh_command(opts) + ['-t', '-t', '-o', 'ConnectTimeout=3',
+                             '%s@%s' % (opts.user, host), stringify_command('true')],
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT  # we pipe stderr through stdout to preserve output order
+    )
+    cmd_output = s.communicate()[0]  # [1] is stderr, which we redirected to stdout
+
+    if s.returncode != 0 and print_ssh_output:
+        # extra leading newline is for spacing in wait_for_cluster_state()
+        print textwrap.dedent("""\n
+            Warning: SSH connection error. (This could be temporary.)
+            Host: {h}
+            SSH return code: {r}
+            SSH output: {o}
+        """).format(
+            h=host,
+            r=s.returncode,
+            o=cmd_output.strip()
+        )
+
+    return s.returncode == 0
 
 
 def is_cluster_ssh_available(cluster_instances, opts):