diff --git a/exercise b/exercise
index 70ae66ee4..f334b0a20 160000
--- a/exercise
+++ b/exercise
@@ -1 +1 @@
-Subproject commit 70ae66ee4b80ac134bedbe3123eebe7e973e984a
+Subproject commit f334b0a2019474ec0e031cb87cdc2ed020d8142f
diff --git a/extra-addons b/extra-addons
index 265e2490e..546b26371 160000
--- a/extra-addons
+++ b/extra-addons
@@ -1 +1 @@
-Subproject commit 265e2490e92b945b20ddb11b9761fef5896ce518
+Subproject commit 546b2637171effc29b51dc1a13651c3014c8a67a
diff --git a/odoo/service/server.py b/odoo/service/server.py
index 5f4a96da8..a31bd68e7 100644
--- a/odoo/service/server.py
+++ b/odoo/service/server.py
@@ -448,36 +448,36 @@ class ThreadedServer(CommonServer):
         # On NOTIFY, all workers are awaken at the same time, sleeping
         # just a bit prevents they all poll the database at the exact
         # same time. This is known as the thundering herd effect.
+        pass
+        # from odoo.addons.base.models.ir_cron import ir_cron
+        # conn = odoo.sql_db.db_connect('postgres')
+        # with conn.cursor() as cr:
+        #     pg_conn = cr._cnx
+        #     # LISTEN / NOTIFY doesn't work in recovery mode
+        #     cr.execute("SELECT pg_is_in_recovery()")
+        #     in_recovery = cr.fetchone()[0]
+        #     if not in_recovery:
+        #         cr.execute("LISTEN cron_trigger")
+        #     else:
+        #         _logger.warning("PG cluster in recovery mode, cron trigger not activated")
+        #     cr.commit()
 
-        from odoo.addons.base.models.ir_cron import ir_cron
-        conn = odoo.sql_db.db_connect('postgres')
-        with conn.cursor() as cr:
-            pg_conn = cr._cnx
-            # LISTEN / NOTIFY doesn't work in recovery mode
-            cr.execute("SELECT pg_is_in_recovery()")
-            in_recovery = cr.fetchone()[0]
-            if not in_recovery:
-                cr.execute("LISTEN cron_trigger")
-            else:
-                _logger.warning("PG cluster in recovery mode, cron trigger not activated")
-            cr.commit()
+        #     while True:
+        #         select.select([pg_conn], [], [], SLEEP_INTERVAL + number)
+        #         time.sleep(number / 100)
+        #         pg_conn.poll()
 
-            while True:
-                select.select([pg_conn], [], [], SLEEP_INTERVAL + number)
-                time.sleep(number / 100)
-                pg_conn.poll()
-
-                registries = odoo.modules.registry.Registry.registries
-                _logger.debug('cron%d polling for jobs', number)
-                for db_name, registry in registries.d.items():
-                    if registry.ready:
-                        thread = threading.current_thread()
-                        thread.start_time = time.time()
-                        try:
-                            ir_cron._process_jobs(db_name)
-                        except Exception:
-                            _logger.warning('cron%d encountered an Exception:', number, exc_info=True)
-                        thread.start_time = None
+        #         registries = odoo.modules.registry.Registry.registries
+        #         _logger.debug('cron%d polling for jobs', number)
+        #         for db_name, registry in registries.d.items():
+        #             if registry.ready:
+        #                 thread = threading.current_thread()
+        #                 thread.start_time = time.time()
+        #                 try:
+        #                     ir_cron._process_jobs(db_name)
+        #                 except Exception:
+        #                     _logger.warning('cron%d encountered an Exception:', number, exc_info=True)
+        #                 thread.start_time = None
 
     def cron_spawn(self):
         """ Start the above runner function in a daemon thread.