Index: zorg/trunk/llvmbisect/llvmlab/gcs.py
===================================================================
--- zorg/trunk/llvmbisect/llvmlab/gcs.py
+++ zorg/trunk/llvmbisect/llvmlab/gcs.py
@@ -3,6 +3,7 @@
 """
 import os
 import requests
+import urllib3
 
 # Root URL to use for our queries.
 GCS = "https://www.googleapis.com/storage/v1/"
@@ -11,6 +12,21 @@
 
 BUCKET = os.getenv("BUCKET", DEFAULT_BUCKET)
 
+class HttpClient(object):
+    def __init__(self):
+        self.session = requests.Session()
+        # Retry after 0s, 0.2s, 0.4s.
+        retry = urllib3.util.retry.Retry(total=3, backoff_factor=0.1)
+        adapter = requests.adapters.HTTPAdapter(max_retries=retry)
+        self.session.mount('https://', adapter)
+
+    def get(self, url, **kwargs):
+        if "timeout" not in kwargs:
+            kwargs["timeout"] = 5  # seconds
+        return self.session.get(url, **kwargs)
+
+HTTP_CLIENT = HttpClient()
+
 
 def fetch_builders():
     """Each build kind is stored as a folder in the GCS bucket.
@@ -18,7 +34,7 @@
     compilers.
     """
     params = {'delimiter': "/", 'fields': "prefixes,nextPageToken"}
-    r = requests.get(GCS + "b/" + BUCKET + "/o", params=params)
+    r = HTTP_CLIENT.get(GCS + "b/" + BUCKET + "/o", params=params)
     r.raise_for_status()
     reply_data = r.json()
     assert "nextPageToken" not in reply_data.keys(), "Too many builders!"
@@ -36,13 +52,13 @@
     params = {'delimiter': "/",
              "fields": "nextPageToken,kind,items(name, mediaLink)",
              'prefix': project + "/"}
-    r = requests.get(GCS + "b/" + BUCKET + "/o", params=params)
+    r = HTTP_CLIENT.get(GCS + "b/" + BUCKET + "/o", params=params)
     r.raise_for_status()
     reply_data = r.json()
     all_data['items'].extend(reply_data['items'])
     while reply_data.get('nextPageToken'):
         params['pageToken'] = reply_data['nextPageToken']
-        r = requests.get(GCS + "b/" + BUCKET + "/o", params=params)
+        r = HTTP_CLIENT.get(GCS + "b/" + BUCKET + "/o", params=params)
         r.raise_for_status()
         reply_data = r.json()
         all_data['items'].extend(reply_data['items'])
@@ -54,7 +70,7 @@
 
 def get_compiler(url, filename):
     """Get the compiler at the url, and save to filename."""
-    r = requests.get(url)
+    r = HTTP_CLIENT.get(url)
     r.raise_for_status()
     with open(filename, 'wb') as fd:
         for chunk in r.iter_content(CHUNK_SIZE):