Enables scheduler to send multiple executions in local mode (hydro-pr…

…oject#37)

By default, in cluster mode, schedulers only send one function execution request to an executor and wait to hear back before sending another. This can cause timing issues in local mode, so we don't wait for a response after every request.

cloudburst/server/scheduler/policy/default_policy.py

@@ -155,7 +155,7 @@ def pick_executor(self, references, function_name=None):
 
         # Remove this IP/tid pair from the system's metadata until it notifies
         # us that it is available again, but only do this for non-DAG requests.
-        if not function_name:
+        if not self.local and not function_name:
             self.unpinned_executors.discard(max_ip)
 
         self.unique_executors.add(max_ip)