fix(metrics_layer): Fix the failure rate calculation (#68160)

Author: Riccardo Busetti

src/sentry/snuba/metrics/fields/base.py

@@ -23,6 +23,7 @@
     abnormal_sessions,
     abnormal_users,
     addition,
+    all_duration_transactions,
     all_sessions,
     all_spans,
     all_transactions,
@@ -1607,6 +1608,14 @@ def generate_where_statements(
                 project_ids=project_ids, org_id=org_id, metric_ids=metric_ids, alias=alias
             ),
         ),
+        SingularEntityDerivedMetric(
+            metric_mri=TransactionMRI.ALL_DURATION.value,
+            metrics=[TransactionMRI.DURATION.value],
+            unit="transactions",
+            snql=lambda project_ids, org_id, metric_ids, alias=None: all_duration_transactions(
+                metric_ids=metric_ids, alias=alias
+            ),
+        ),
         SingularEntityDerivedMetric(
             metric_mri=TransactionMRI.FAILURE_COUNT.value,
             metrics=[TransactionMRI.DURATION.value],
@@ -1619,7 +1628,7 @@ def generate_where_statements(
             metric_mri=TransactionMRI.FAILURE_RATE.value,
             metrics=[
                 TransactionMRI.FAILURE_COUNT.value,
-                TransactionMRI.ALL.value,
+                TransactionMRI.ALL_DURATION.value,
             ],
             unit="transactions",
             snql=lambda failure_count, tx_count, project_ids, org_id, metric_ids, alias=None: division_float(
@@ -1638,7 +1647,7 @@ def generate_where_statements(
             metric_mri=TransactionMRI.HTTP_ERROR_RATE.value,
             metrics=[
                 TransactionMRI.HTTP_ERROR_COUNT.value,
-                TransactionMRI.ALL.value,
+                TransactionMRI.ALL_DURATION.value,
             ],
             unit="transactions",
             snql=lambda http_error_count, tx_count, project_ids, org_id, metric_ids, alias=None: division_float(

src/sentry/snuba/metrics/fields/snql.py

@@ -476,7 +476,7 @@ def _satisfaction_equivalence(org_id: int, satisfaction_tag_value: str) -> Funct
     )
 
 
-def _metric_id_equivalence(metric_condition: Function) -> Function:
+def _metric_id_equivalence(metric_condition: Function | int) -> Function:
     return Function(
         "equals",
         [
@@ -560,6 +560,18 @@ def all_transactions(
     )
 
 
+def all_duration_transactions(
+    metric_ids: Sequence[int],
+    alias: str | None = None,
+) -> Function:
+    return _count_if_with_conditions(
+        [
+            _metric_id_equivalence(list(metric_ids)[0]),
+        ],
+        alias,
+    )
+
+
 def apdex(satisfactory_snql, tolerable_snql, total_snql, alias: str | None = None) -> Function:
     return division_float(
         arg1_snql=addition(satisfactory_snql, division_float(tolerable_snql, 2)),

src/sentry/snuba/metrics/naming_layer/mri.py

@@ -151,6 +151,7 @@ class TransactionMRI(Enum):
 
     # Derived
     ALL = "e:transactions/all@none"
+    ALL_DURATION = "e:transactions/all_duration@none"
     FAILURE_COUNT = "e:transactions/failure_count@none"
     FAILURE_RATE = "e:transactions/failure_rate@ratio"
     SATISFIED = "e:transactions/satisfied@none"