Merge pull request #13307 from edx/jeskew/add_integ_err_catch_csm

Ignore IntegrityErrors upon set_many update save().

lms/djangoapps/courseware/tests/test_model_data.py

@@ -139,7 +139,7 @@ class TestStudentModuleStorage(OtherUserFailureTestMixin, TestCase):
         # to discover if something other than the DjangoXBlockUserStateClient
         # has written to the StudentModule (such as UserStateCache setting the score
         # on the StudentModule).
-        with self.assertNumQueries(2, using='default'):
+        with self.assertNumQueries(4, using='default'):
             with self.assertNumQueries(1, using='student_module_history'):
                 self.kvs.set(user_state_key('a_field'), 'new_value')
         self.assertEquals(1, StudentModule.objects.all().count())
@@ -152,7 +152,7 @@ class TestStudentModuleStorage(OtherUserFailureTestMixin, TestCase):
         # to discover if something other than the DjangoXBlockUserStateClient
         # has written to the StudentModule (such as UserStateCache setting the score
         # on the StudentModule).
-        with self.assertNumQueries(2, using='default'):
+        with self.assertNumQueries(4, using='default'):
             with self.assertNumQueries(1, using='student_module_history'):
                 self.kvs.set(user_state_key('not_a_field'), 'new_value')
         self.assertEquals(1, StudentModule.objects.all().count())
@@ -206,7 +206,7 @@ class TestStudentModuleStorage(OtherUserFailureTestMixin, TestCase):
         # We also need to read the database to discover if something other than the
         # DjangoXBlockUserStateClient has written to the StudentModule (such as
         # UserStateCache setting the score on the StudentModule).
-        with self.assertNumQueries(2, using="default"):
+        with self.assertNumQueries(4, using="default"):
             with self.assertNumQueries(1, using="student_module_history"):
                 self.kvs.set_many(kv_dict)
 

lms/djangoapps/courseware/user_state_client.py

@@ -6,7 +6,7 @@ data in a Django ORM model.
 import itertools
 from operator import attrgetter
 from time import time
-
+import logging
 try:
     import simplejson as json
 except ImportError:
@@ -14,10 +14,14 @@ except ImportError:
 
 import dogstats_wrapper as dog_stats_api
 from django.contrib.auth.models import User
+from django.db import transaction
+from django.db.utils import IntegrityError
 from xblock.fields import Scope
 from courseware.models import StudentModule, BaseStudentModuleHistory
 from edx_user_state_client.interface import XBlockUserStateClient, XBlockUserState
 
+log = logging.getLogger(__name__)
+
 
 class DjangoXBlockUserStateClient(XBlockUserStateClient):
     """
@@ -222,8 +226,19 @@ class DjangoXBlockUserStateClient(XBlockUserStateClient):
                 current_state.update(state)
                 num_fields_after = len(current_state)
                 student_module.state = json.dumps(current_state)
-                # We just read this object, so we know that we can do an update
-                student_module.save(force_update=True)
+                try:
+                    with transaction.atomic():
+                        # Updating the object - force_update guarantees no INSERT will occur.
+                        student_module.save(force_update=True)
+                except IntegrityError:
+                    # The UPDATE above failed. Log information - but ignore the error.
+                    # See https://openedx.atlassian.net/browse/TNL-5365
+                    log.warning("set_many: IntegrityError for student {} - course_id {} - usage key {}".format(
+                        user, repr(unicode(usage_key.course_key)), usage_key
+                    ))
+                    log.warning("set_many: All {} block keys: {}".format(
+                        len(block_keys_to_state), block_keys_to_state.keys()
+                    ))
 
             # The rest of this method exists only to submit DataDog events.
             # Remove it once we're no longer interested in the data.