bulk_create: Use a (large) batch_size with MySQL.

(imported from commit 529fef7dd55bb8a5f4e286f7c896f4b14b0d1b8d)

zephyr/lib/bulk_create.py

@@ -3,9 +3,9 @@ from django.conf import settings
 # Django bulk_create method accepts a batch_size directly.
 def batch_bulk_create(cls, cls_list, batch_size=150):
     if "sqlite" not in settings.DATABASES["default"]["ENGINE"]:
-        # We only need to do the below batching nonsense with sqlite.
-        cls.objects.bulk_create(cls_list)
-        return
+        # We don't need a low batch size with mysql, but we do need
+        # one to avoid "MySQL Server has gone away" errors
+        batch_size = 2000
     while len(cls_list) > 0:
         current_batch = cls_list[0:batch_size]
         cls.objects.bulk_create(current_batch)