diff --git a/app/master/build.py b/app/master/build.py
index 3a910a5..743830e 100644
--- a/app/master/build.py
+++ b/app/master/build.py
@@ -190,8 +190,7 @@ def complete_subjob(self, subjob_id, payload=None):
             self._mark_subjob_complete(subjob_id)
 
         except Exception:
-            self._logger.exception('Error while completing subjob; marking build as failed.')
-            self.mark_failed('Error occurred while completing subjob {}.'.format(subjob_id))
+            self._logger.exception('Error while processing subjob {} payload'.format(subjob_id))
             raise
 
     def _parse_payload_for_atom_exit_code(self, subjob_id):
diff --git a/app/slave/cluster_slave.py b/app/slave/cluster_slave.py
index e82cf7c..1d30d0b 100644
--- a/app/slave/cluster_slave.py
+++ b/app/slave/cluster_slave.py
@@ -359,13 +359,15 @@ def _execute_subjob(self, build_id, subjob_id, executor, atomic_commands):
         files = {'file': ('payload', open(results_file, 'rb'), 'application/x-compressed')}
 
         self._idle_executors.put(executor)  # work is done; mark executor as idle
-        resp = self._network.post(results_url, data=data, files=files)
-        if resp.ok:
-            self._logger.info('Build {}, Subjob {} completed and sent results to master.', build_id, subjob_id)
-        else:
-            self._logger.error(
-                ('Build {}, Subjob {} encountered an error when sending results to master.'
-                 '\n\tStatus Code {}\n\t{}').format(build_id, subjob_id, resp.status_code, resp.text))
+        for attempt in range(3):
+            resp = self._network.post(results_url, data=data, files=files)
+            if resp.status_code == 200:
+                self._logger.info('Build {}, Subjob {} completed and sent results to master.', build_id, subjob_id)
+                break
+            else:
+                self._logger.error(
+                    ('Build {}, Subjob {} encountered an error when sending results to master.'
+                     '\n\tStatus Code {} attempt {}\n\t{}').format(build_id, subjob_id, resp.status_code, attempt+1, resp.text))
 
     def _notify_master_of_state_change(self, new_state):
         """
diff --git a/app/util/fs.py b/app/util/fs.py
index de354b9..f0bc4b4 100644
--- a/app/util/fs.py
+++ b/app/util/fs.py
@@ -83,6 +83,9 @@ def extract_tar(archive_file, target_dir=None, delete=False):
     if not target_dir:
         target_dir, _ = os.path.split(archive_file)  # default to same directory as tar file
 
+    if not tarfile.is_tarfile(archive_file):
+        raise Exception("Not a tarfile: {}".format(archive_file))
+
     try:
         with tarfile.open(archive_file, 'r:gz') as f:
             f.extractall(target_dir)
diff --git a/app/util/network.py b/app/util/network.py
index b016c29..46897c9 100644
--- a/app/util/network.py
+++ b/app/util/network.py
@@ -51,7 +51,7 @@ def get(self, *args, **kwargs):
         return self._request('GET', *args, **kwargs)
 
     # todo: may be a bad idea to retry -- what if post was successful but just had a response error?
-    @retry_on_exception_exponential_backoff(exceptions=(requests.ConnectionError,))
+    @retry_on_exception_exponential_backoff(exceptions=(requests.ConnectionError,requests.Timeout), initial_delay=1.0)
     def post(self, *args, **kwargs):
         """
         Send a POST request to a url. Arguments to this method, unless otherwise documented below in _request(), are
@@ -75,7 +75,7 @@ def post_with_digest(self, url, request_params, secret, error_on_failure=False):
                          error_on_failure=error_on_failure)
 
     # todo: may be a bad idea to retry -- what if put was successful but just had a response error?
-    @retry_on_exception_exponential_backoff(exceptions=(requests.ConnectionError,))
+    @retry_on_exception_exponential_backoff(exceptions=(requests.ConnectionError,requests.Timeout))
     def put(self, *args, **kwargs):
         """
         Send a PUT request to a url. Arguments to this method, unless otherwise documented below in _request(), are