Don't completely die if get auth_chain or querying auth_chain requests fail

synapse/handlers/federation.py

@@ -787,6 +787,7 @@ class FederationHandler(BaseHandler):
         if missing_auth:
             logger.debug("Missing auth: %s", missing_auth)
             # If we don't have all the auth events, we need to get them.
+            try:
                 remote_auth_chain = yield self.replication_layer.get_event_auth(
                     origin, event.room_id, event.event_id
                 )
@@ -822,6 +823,9 @@ class FederationHandler(BaseHandler):
                             auth_events[(e.type, e.state_key)] = e
                     except AuthError:
                         pass
+            except:
+                # FIXME:
+                logger.exception("Failed to get auth chain")
 
         # FIXME: Assumes we have and stored all the state for all the
         # prev_events
@@ -836,6 +840,7 @@ class FederationHandler(BaseHandler):
             auth_ids = self.auth.compute_auth_events(event, context)
             local_auth_chain = yield self.store.get_auth_chain(auth_ids)
 
+            try:
                 # 2. Get remote difference.
                 result = yield self.replication_layer.query_auth(
                     origin,
@@ -878,6 +883,10 @@ class FederationHandler(BaseHandler):
                     except AuthError:
                         pass
 
+            except:
+                # FIXME:
+                logger.exception("Failed to query auth chain")
+
             # 4. Look at rejects and their proofs.
             # TODO.