diff --git a/ardumont/schedule_with_queue_length_check.py b/ardumont/schedule_with_queue_length_check.py
index e731bab..6cb2997 100755
--- a/ardumont/schedule_with_queue_length_check.py
+++ b/ardumont/schedule_with_queue_length_check.py
@@ -1,157 +1,172 @@
 #!/usr/bin/env python3
 
 # Copyright (C) 2017  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 
 import click
 import sys
 import time
 
 from swh.model.hashutil import hash_to_hex
 
 try:
     from swh.indexer.producer import gen_sha1
 except ImportError:
     pass
 
 from swh.scheduler.celery_backend.config import app as main_app
 
 # Max batch size for tasks
 MAX_NUM_TASKS = 10000
 
 MAX_WAITING_TIME = 10
 
 
-def stdin_to_svn_tasks():
+def stdin_to_svn_tasks(batch_size):
     """Generates from stdin the proper task argument for the loader-svn
        worker.
 
+    Args:
+        batch_size (int): Not used
+
+    Yields:
+        expected dictionary of 'arguments' key
+
     """
     for line in sys.stdin:
         line = line.rstrip()
         values = line.split(' ')
         origin = values[0]
         path = values[1]
         visit_date = 'Tue, 3 May 2016 17:16:32 +0200'
         yield {
             'arguments': {
                 'args': [path, origin, visit_date],
                 'kwargs': {
                     'start_from_scratch': True,
                 }
             },
         }
 
 
-def stdin_to_index_tasks():
+def stdin_to_index_tasks(batch_size=1000):
     """Generates from stdin the proper task argument for the orchestrator.
 
+    Args:
+        batch_size (int): Number of sha1s to group together
+
+    Yields:
+        expected dictionary of 'arguments' key
+
     """
-    for sha1s in gen_sha1(batch=1000):
+    for sha1s in gen_sha1(batch=batch_size):
         yield {
             'arguments': {
                 'args': [sha1s],
                 'kwargs': {}
             },
         }
 
 
 def print_last_hash(d):
     """Given a dict of arguments, take the sha1s list, print the last
        element as hex hash.
 
     """
     l = d['args']
     if l:
         print(hash_to_hex(l[0][-1]))
 
 
 QUEUES = {
     'svndump': {  # for svn, we use the same queue for length checking
                   # and scheduling
         'task_name': 'swh.loader.svn.tasks.MountAndLoadSvnRepositoryTsk',
         # to_task the function to use to transform the input in task
         'task_generator_fn': stdin_to_svn_tasks,
         'print_fn': print,
     },
     'indexer': {  # for indexer, we schedule using the orchestrator's queue
                   # we check the length on the mimetype queue though
         'task_name': 'swh.indexer.tasks.SWHOrchestratorAllContentsTask',
         'queue_to_check': 'swh.indexer.tasks.SWHContentMimetypeTask',
         'task_generator_fn': stdin_to_index_tasks,
         'print_fn': print_last_hash,
     }
 }
 
 
 @click.command(help='Read from stdin and send message to queue ')
 @click.option('--queue-name', help='Queue concerned')
 @click.option('--threshold', help='Threshold for the queue',
               type=click.INT,
               default=MAX_NUM_TASKS)
+@click.option('--batch-size', help='Batch size if batching is possible',
+              type=click.INT,
+              default=1000)
 @click.option('--waiting-time', help='Waiting time between checks',
               type=click.INT,
               default=MAX_WAITING_TIME)
-def main(queue_name, threshold, waiting_time, app=main_app):
+def main(queue_name, threshold, batch_size, waiting_time, app=main_app):
     if queue_name not in QUEUES:
         raise ValueError("Unsupported %s, possible values: %s" % (
             queue_name, QUEUES))
 
     for module in app.conf.CELERY_IMPORTS:
         __import__(module)
 
     queue_information = QUEUES[queue_name]
     task_name = queue_information['task_name']
     scheduling_task = app.tasks[task_name]
 
     queue_to_check = queue_information.get('queue_to_check', task_name)
     checking_task = app.tasks[queue_to_check]
     checking_queue_name = checking_task.task_queue
 
     while True:
         throttled = False
         remains_data = False
         pending_tasks = []
 
         queue_length = app.get_queue_length(checking_queue_name)
 
         if queue_length < threshold:
             nb_tasks_to_send = threshold - queue_length
         else:     # queue_length >= threshold
             nb_tasks_to_send = 0
             throttled = True
 
         if nb_tasks_to_send > 0:
             count = 0
             task_fn = queue_information['task_generator_fn']
-            for _task in task_fn():
+            for _task in task_fn(batch_size):
                 pending_tasks.append(_task)
                 count += 1
 
                 if count >= nb_tasks_to_send:
                     throttled = True
                     remains_data = True
                     break
 
             if not pending_tasks:
                 # check for some more data on stdin
                 if not remains_data:
                     # if no more data, we break to exit
                     break
 
             print_fn = queue_information.get('print_fn', print)
             for _task in pending_tasks:
                 args = _task['arguments']['args']
                 kwargs = _task['arguments']['kwargs']
                 scheduling_task.delay(*args, **kwargs)
                 print_fn(_task['arguments'])
 
         if throttled:
             time.sleep(waiting_time)
 
 
 if __name__ == '__main__':
     main()