- change the condition so that we don't reset the cache if it's zero

- set the cache if it doesn't exist so there is an expiry of 24 hours.

app/notifications/process_notifications.py

@@ -149,8 +149,15 @@ def persist_notification(
     if not simulated:
         dao_create_notification(notification)
         if key_type != KEY_TYPE_TEST and current_app.config['REDIS_ENABLED']:
-            redis_store.incr(redis.daily_limit_cache_key(service.id))
-
+            cache_key = redis.daily_limit_cache_key(service.id)
+            if redis_store.get(cache_key) is None:
+                # if cache does not exist set the cache to 1 with an expiry of 24 hours,
+                # The cache should be set by the time we create the notification
+                # but in case it is this will make sure the expiry is set to 24 hours,
+                # where if we let the incr method create the cache it will be set a ttl.
+                redis_store.set(cache_key, 1, ex=86400)
+            else:
+                redis_store.incr(cache_key)
         current_app.logger.info(
             "{} {} created at {}".format(notification_type, notification_id, notification_created_at)
         )

app/notifications/validators.py

@@ -61,7 +61,7 @@ def check_service_over_daily_message_limit(key_type, service):
     if key_type != KEY_TYPE_TEST and current_app.config['REDIS_ENABLED']:
         cache_key = daily_limit_cache_key(service.id)
         service_stats = redis_store.get(cache_key)
-        if not service_stats:
+        if service_stats is None:
             # first message of the day, set the cache to 0 and the expiry to 24 hours
             service_stats = 0
             redis_store.set(cache_key, service_stats, ex=86400)