diff --git a/beat/backend/python/execution/messagehandlers.py b/beat/backend/python/execution/messagehandlers.py
index b2f0c26585af3d2d423f3bb66ecf373baa7d068c..5e5e10e4b876c6d4ee56a835ab6daee90a8b1b86 100644
--- a/beat/backend/python/execution/messagehandlers.py
+++ b/beat/backend/python/execution/messagehandlers.py
@@ -47,7 +47,6 @@ import logging
 
 import zmq
 import simplejson
-import requests
 import threading
 
 from ..dataformat import DataFormat
@@ -162,7 +161,7 @@ class MessageHandler(threading.Thread):
                             self.kill_callback()
                         self.stop.set()
                         break
-                    except RuntimeError as e:
+                    except RuntimeError:
                         import traceback
 
                         message = traceback.format_exc()
@@ -173,10 +172,12 @@ class MessageHandler(threading.Thread):
                             self.kill_callback()
                         self.stop.set()
                         break
-                    except:
+                    except Exception:
                         import traceback
 
-                        parser = lambda s: s if len(s) < 20 else s[:20] + "..."
+                        def parser(s):
+                            return s if len(s) < 20 else s[:20] + "..."
+
                         parsed_parts = " ".join([parser(k) for k in parts])
                         message = (
                             "A problem occurred while performing command `%s' "
@@ -249,7 +250,7 @@ class MessageHandler(threading.Thread):
 
         try:
             data_source = self.data_sources[name]
-        except:
+        except Exception:
             raise RemoteException("sys", "Unknown input: %s" % name)
 
         logger.debug("send: %d infos", len(data_source))
@@ -275,12 +276,12 @@ class MessageHandler(threading.Thread):
 
         try:
             data_source = self.data_sources[name]
-        except:
+        except Exception:
             raise RemoteException("sys", "Unknown input: %s" % name)
 
         try:
             index = int(index)
-        except:
+        except Exception:
             raise RemoteException("sys", "Invalid index: %s" % index)
 
         (data, start_index, end_index) = data_source[index]
@@ -351,6 +352,7 @@ class LoopMessageHandler(MessageHandler):
         )
 
         self.callbacks.update({"val": self.validate})
+        self.callbacks.update({"wrt": self.write})
         self.executor = None
 
     def setup(self, algorithm, prefix):
@@ -401,3 +403,10 @@ class LoopMessageHandler(MessageHandler):
 
         self.socket.send_string("True" if is_valid else "False", zmq.SNDMORE)
         self.socket.send(data.pack())
+
+    def write(self):
+        """ Trigger a write on the output"""
+
+        logger.debug("recv: wrt")
+
+        self.executor.write()