feat(nimbus): default to group_id for desktop (#12540)

Because

* In anticipation of the release of multiprofile support in desktop, it
is time to switch the default randomization unit for desktop to group_id
for all new experiments
* We need to support both normandy_id and group_id for a period while
currently live experiments still exist using normandy_id because when
they pause they need to be reserialized and we need to preserve the
normandy_id path
* When there are no more live experiments using normandy_id we can
remove the code for it entirely

This commit

* Changes use_group_id to default to True
* Filters the cases where group_id is used to only include desktop
* Updates tests

fixes #12537

Author: jaredlockhart

experimenter/experimenter/experiments/migrations/0281_alter_nimbusexperiment_use_group_id.py

@@ -0,0 +1,17 @@
+# Generated by Django 5.1.8 on 2025-04-28 15:47
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("experiments", "0280_nimbusexperiment_equal_branch_ratio"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="nimbusexperiment",
+            name="use_group_id",
+            field=models.BooleanField(default=True),
+        ),
+    ]

experimenter/experimenter/experiments/models.py

@@ -370,7 +370,7 @@ class NimbusExperiment(NimbusConstants, TargetingConstants, FilterMixin, models.
         blank=True,
         verbose_name="Subscribers",
     )
-    use_group_id = models.BooleanField(default=False)
+    use_group_id = models.BooleanField(default=True)
     objects = NimbusExperimentManager()
     is_firefox_labs_opt_in = models.BooleanField(
         "Is Experiment a Firefox Labs Opt-In?", default=False
@@ -1136,7 +1136,7 @@ def bucket_namespace(self):
                 keys.append(self.targeting_config_slug)
             keys.append("rollout")
 
-        if self.use_group_id:
+        if self.is_desktop and self.use_group_id:
             keys.append(BucketRandomizationUnit.GROUP_ID)
 
         return "-".join(keys)
@@ -1795,7 +1795,10 @@ def __str__(self):  # pragma: no cover
 
     @property
     def randomization_unit(self):
-        if self.bucket_ranges.filter(experiment__use_group_id=True).exists():
+        if self.bucket_ranges.filter(
+            experiment__use_group_id=True,
+            experiment__application=NimbusExperiment.Application.DESKTOP,
+        ).exists():
             return BucketRandomizationUnit.GROUP_ID
         return NimbusExperiment.APPLICATION_CONFIGS[self.application].randomization_unit
 

experimenter/experimenter/experiments/tests/test_changelog_utils.py

@@ -117,7 +117,7 @@ def test_outputs_expected_schema_for_empty_experiment(self):
                 "takeaways_summary": None,
                 "targeting_config_slug": NimbusExperiment.TargetingConfig.NO_TARGETING,
                 "total_enrolled_clients": 0,
-                "use_group_id": False,
+                "use_group_id": True,
                 "vp_signoff": False,
                 "warn_feature_schema": False,
                 "published_date": None,
@@ -231,7 +231,7 @@ def test_outputs_expected_schema_for_complete_experiment(self):
                 "takeaways_summary": None,
                 "targeting_config_slug": experiment.targeting_config_slug,
                 "total_enrolled_clients": experiment.total_enrolled_clients,
-                "use_group_id": False,
+                "use_group_id": True,
                 "vp_signoff": False,
                 "warn_feature_schema": False,
                 "published_date": experiment.published_date,

experimenter/experimenter/experiments/tests/test_models.py

@@ -1246,7 +1246,10 @@ def test_launch_month_returns_enrollment_start_date(self):
         self.assertEqual(experiment.launch_month, experiment.release_date.strftime("%B"))
 
     @parameterized.expand(
-        [[NimbusExperiment.Status.LIVE], [NimbusExperiment.Status.COMPLETE]]
+        [
+            [NimbusExperiment.Status.LIVE],
+            [NimbusExperiment.Status.COMPLETE],
+        ]
     )
     def test_start_date_uses_most_recent_start_change_without_cache(self, status):
         experiment = NimbusExperimentFactory.create(status=status)
@@ -1265,7 +1268,10 @@ def test_start_date_uses_most_recent_start_change_without_cache(self, status):
         self.assertEqual(experiment.start_date, start_change.changed_on.date())
 
     @parameterized.expand(
-        [[NimbusExperiment.Status.LIVE], [NimbusExperiment.Status.COMPLETE]]
+        [
+            [NimbusExperiment.Status.LIVE],
+            [NimbusExperiment.Status.COMPLETE],
+        ]
     )
     def test_start_date_uses_cached_start_date(self, status):
         cached_date = datetime.date(2022, 1, 1)
@@ -2205,7 +2211,7 @@ def test_allocate_buckets_generates_bucket_range(self):
         self.assertEqual(experiment.bucket_range.count, 5000)
         self.assertEqual(
             experiment.bucket_range.isolation_group.name,
-            "firefox-desktop-feature-release",
+            "firefox-desktop-feature-release-group_id",
         )
 
     def test_allocate_buckets_creates_new_bucket_range_if_population_changes(self):
@@ -2235,7 +2241,7 @@ def test_allocate_buckets_for_live_approved_rollout(self):
         self.assertEqual(experiment.bucket_range.count, 5000)
         self.assertEqual(
             experiment.bucket_range.isolation_group.name,
-            "firefox-desktop-feature-release-mac_only-rollout",
+            "firefox-desktop-feature-release-mac_only-rollout-group_id",
         )
 
     def test_allocate_buckets_deletes_buckets_and_empty_isolation_group(self):
@@ -2318,7 +2324,7 @@ def test_bucket_namespace_changes_for_rollout(self):
         self.assertNotEqual(original_namespace, experiment.bucket_namespace)
         self.assertEqual(
             experiment.bucket_namespace,
-            "firefox-desktop-feature-release-mac_only-rollout",
+            "firefox-desktop-feature-release-mac_only-rollout-group_id",
         )
 
     def test_required_experiments_branches(self):
@@ -3742,10 +3748,16 @@ def test_empty_isolation_group_creates_isolation_group_and_bucket_range(self):
         self.assertEqual(bucket.isolation_group.name, experiment.slug)
         self.assertEqual(bucket.isolation_group.instance, 1)
         self.assertEqual(bucket.isolation_group.total, NimbusExperiment.BUCKET_TOTAL)
-        self.assertEqual(
-            bucket.isolation_group.randomization_unit,
-            experiment.application_config.randomization_unit,
-        )
+        if experiment.is_desktop:
+            self.assertEqual(
+                bucket.isolation_group.randomization_unit,
+                BucketRandomizationUnit.GROUP_ID,
+            )
+        else:
+            self.assertEqual(
+                bucket.isolation_group.randomization_unit,
+                experiment.application_config.randomization_unit,
+            )
 
     def test_existing_isolation_group_adds_bucket_range(self):
         """
@@ -3764,10 +3776,16 @@ def test_existing_isolation_group_adds_bucket_range(self):
         self.assertEqual(bucket.end, 99)
         self.assertEqual(bucket.count, 100)
         self.assertEqual(bucket.isolation_group, isolation_group)
-        self.assertEqual(
-            bucket.isolation_group.randomization_unit,
-            experiment.application_config.randomization_unit,
-        )
+        if experiment.is_desktop:
+            self.assertEqual(
+                bucket.isolation_group.randomization_unit,
+                BucketRandomizationUnit.GROUP_ID,
+            )
+        else:
+            self.assertEqual(
+                bucket.isolation_group.randomization_unit,
+                experiment.application_config.randomization_unit,
+            )
 
     def test_existing_isolation_group_with_buckets_adds_next_bucket_range(self):
         """
@@ -3789,10 +3807,16 @@ def test_existing_isolation_group_with_buckets_adds_next_bucket_range(self):
         self.assertEqual(bucket.end, 199)
         self.assertEqual(bucket.count, 100)
         self.assertEqual(bucket.isolation_group, isolation_group)
-        self.assertEqual(
-            bucket.isolation_group.randomization_unit,
-            experiment.application_config.randomization_unit,
-        )
+        if experiment.is_desktop:
+            self.assertEqual(
+                bucket.isolation_group.randomization_unit,
+                BucketRandomizationUnit.GROUP_ID,
+            )
+        else:
+            self.assertEqual(
+                bucket.isolation_group.randomization_unit,
+                experiment.application_config.randomization_unit,
+            )
 
     def test_full_isolation_group_creates_next_isolation_group_adds_bucket_range(
         self,
@@ -3819,10 +3843,17 @@ def test_full_isolation_group_creates_next_isolation_group_adds_bucket_range(
         self.assertEqual(bucket.count, 100)
         self.assertEqual(bucket.isolation_group.name, isolation_group.name)
         self.assertEqual(bucket.isolation_group.instance, isolation_group.instance + 1)
-        self.assertEqual(
-            bucket.isolation_group.randomization_unit,
-            experiment.application_config.randomization_unit,
-        )
+
+        if experiment.is_desktop:
+            self.assertEqual(
+                bucket.isolation_group.randomization_unit,
+                BucketRandomizationUnit.GROUP_ID,
+            )
+        else:
+            self.assertEqual(
+                bucket.isolation_group.randomization_unit,
+                experiment.application_config.randomization_unit,
+            )
 
     def test_isolation_group_with_group_id(
         self,