Issue 1087/default batch interval (#1090)

* Set default value for CLEAR_EXPIRED_TOKENS_BATCH_INTERVAL to sleep(0).

* Document default value of 0 for CLEAR_EXPIRED_TOKENS_BATCH_INTERVAL.

Co-authored-by: Andrew Chen Wang <60190294+Andrew-Chen-Wang@users.noreply.github.com>

Author: n2ygk

docs/settings.rst

@@ -345,10 +345,13 @@ The size of delete batches used by ``cleartokens`` management command.
 
 CLEAR_EXPIRED_TOKENS_BATCH_INTERVAL
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Default: ``0.1``
+Default: ``0``
 
 Time of sleep in seconds used by ``cleartokens`` management command between batch deletions.
 
+Set this to a non-zero value (e.g. `0.1`) to add a pause between batch sizes to reduce system
+load when clearing large batches of expired tokens.
+
 
 Settings imported from Django project
 --------------------------

oauth2_provider/settings.py

@@ -102,7 +102,7 @@
     # Should only be required in testing.
     "ALWAYS_RELOAD_OAUTHLIB_CORE": False,
     "CLEAR_EXPIRED_TOKENS_BATCH_SIZE": 10000,
-    "CLEAR_EXPIRED_TOKENS_BATCH_INTERVAL": 0.1,
+    "CLEAR_EXPIRED_TOKENS_BATCH_INTERVAL": 0,
 }
 
 # List of settings that cannot be empty