[fix] Sleep random time U(0.5s;2s) between submissions

scripts/grid_queue.py

@@ -316,6 +316,8 @@ def main():
                         continue
                     logger.info('Job submitted with ID %d' % exec_id)
                     job_ids.append(exec_id)
+                    import random
+                    time.sleep(random.uniform(0.5, 2))
 
             else:
                 logger.warning('Quota exceeded. No jobs can be scheduled now! Sleeping')