code: public void onStartWithServer(ExecutionContext<I> context, ExecutionInfo info) {
          for (ExecutionListener<I, O> listener: listeners) {
              try {
                  if (!isListenerDisabled(listener)) {
                      listener.onStartWithServer(context.getChildContext(listener), info);
                  }
              } catch (Throwable e) {
                  if (e instanceof AbortExecutionException) {
                      throw (AbortExecutionException) e;
                  }
                  logger.error("Error invoking listener " + listener, e);
              }
          }
      }
docs: Called when a server is chosen and the request is going to be executed on the server.