Progress update: metrics fix and regression test validated

Co-authored-by: pinodeca <32303022+pinodeca@users.noreply.github.com>

Author: Copilot

src/monitoring.rs

@@ -304,7 +304,6 @@ pub fn metrics() -> TableIterator<
     ),
 > {
     let pg_conn_str = postgres_connection_string();
-    let provider_schema = backend_duroxide_schema();
 
     let rt = match tokio::runtime::Builder::new_current_thread()
         .enable_all()
@@ -315,21 +314,60 @@ pub fn metrics() -> TableIterator<
     };
 
     let results = rt.block_on(async {
-        let store = match new_backend_provider(&pg_conn_str, provider_schema).await {
-            Ok(s) => s,
+        let pool = match sqlx::postgres::PgPoolOptions::new()
+            .max_connections(1)
+            .connect(&pg_conn_str)
+            .await
+        {
+            Ok(pool) => pool,
             Err(_) => return vec![],
         };
 
-        let client = Client::new(store);
-
-        match client.get_system_metrics().await {
-            Ok(m) => vec![(
-                m.total_instances as i64,
-                m.running_instances as i64,
-                m.completed_instances as i64,
-                m.failed_instances as i64,
-                m.total_executions as i64,
-                m.total_events as i64,
+        let row: Result<(i64, i64, i64, i64, i64, i64), sqlx::Error> = sqlx::query_as(
+            r#"
+            SELECT
+                i.total_instances,
+                i.running_instances,
+                i.completed_instances,
+                i.failed_instances,
+                e.total_executions,
+                h.total_events
+            FROM (
+                SELECT
+                    COUNT(*)::BIGINT AS total_instances,
+                    COUNT(*) FILTER (WHERE status = 'running')::BIGINT AS running_instances,
+                    COUNT(*) FILTER (WHERE status = 'completed')::BIGINT AS completed_instances,
+                    COUNT(*) FILTER (WHERE status = 'failed')::BIGINT AS failed_instances
+                FROM df.instances
+            ) i
+            CROSS JOIN (
+                SELECT COUNT(*)::BIGINT AS total_executions
+                FROM duroxide.executions
+            ) e
+            CROSS JOIN (
+                SELECT COUNT(*)::BIGINT AS total_events
+                FROM duroxide.history
+            ) h
+            "#,
+        )
+        .fetch_one(&pool)
+        .await;
+
+        match row {
+            Ok((
+                total_instances,
+                running_instances,
+                completed_instances,
+                failed_instances,
+                total_executions,
+                total_events,
+            )) => vec![(
+                total_instances,
+                running_instances,
+                completed_instances,
+                failed_instances,
+                total_executions,
+                total_events,
             )],
             Err(_) => vec![],
         }

tests/e2e/sql/05_monitoring_and_explain.sql

@@ -57,6 +57,80 @@ END $$;
 
 DROP TABLE _test_state;
 
+-- Regression: rolled-back df.start() should not inflate failed_instances in df.metrics()
+DO $$
+DECLARE
+    total_metrics BIGINT;
+    running_metrics BIGINT;
+    completed_metrics BIGINT;
+    failed_metrics BIGINT;
+    previous_failed_metrics BIGINT := -1;
+    stable_checks INT := 0;
+    attempts INT := 0;
+    total_instances BIGINT;
+    running_instances BIGINT;
+    completed_instances BIGINT;
+    failed_instances BIGINT;
+BEGIN
+    BEGIN
+        PERFORM df.start('SELECT 1', 'rollback-metrics-probe');
+        RAISE EXCEPTION 'force rollback';
+    EXCEPTION
+        WHEN OTHERS THEN NULL;
+    END;
+
+    -- Worker waits up to 5s for an instance row after dequeue. Poll until
+    -- failed_instances stabilizes for 3 checks after at least ~6s.
+    LOOP
+        SELECT m.failed_instances INTO failed_metrics FROM df.metrics() m;
+
+        IF failed_metrics = previous_failed_metrics THEN
+            stable_checks := stable_checks + 1;
+        ELSE
+            stable_checks := 0;
+            previous_failed_metrics := failed_metrics;
+        END IF;
+
+        EXIT WHEN (attempts >= 12 AND stable_checks >= 3) OR attempts >= 60;
+        PERFORM pg_sleep(0.5);
+        attempts := attempts + 1;
+    END LOOP;
+
+    SELECT m.total_instances, m.running_instances, m.completed_instances, m.failed_instances
+      INTO total_metrics, running_metrics, completed_metrics, failed_metrics
+      FROM df.metrics() m;
+
+    SELECT
+        COUNT(*)::BIGINT,
+        COUNT(*) FILTER (WHERE lower(status) = 'running')::BIGINT,
+        COUNT(*) FILTER (WHERE lower(status) = 'completed')::BIGINT,
+        COUNT(*) FILTER (WHERE lower(status) = 'failed')::BIGINT
+      INTO total_instances, running_instances, completed_instances, failed_instances
+      FROM df.instances;
+
+    IF total_metrics != total_instances THEN
+        RAISE EXCEPTION 'TEST FAILED: metrics total_instances=% does not match df.instances=%',
+            total_metrics, total_instances;
+    END IF;
+
+    IF running_metrics != running_instances THEN
+        RAISE EXCEPTION 'TEST FAILED: metrics running_instances=% does not match df.instances=%',
+            running_metrics, running_instances;
+    END IF;
+
+    IF completed_metrics != completed_instances THEN
+        RAISE EXCEPTION 'TEST FAILED: metrics completed_instances=% does not match df.instances=%',
+            completed_metrics, completed_instances;
+    END IF;
+
+    IF failed_metrics != failed_instances THEN
+        RAISE EXCEPTION 'TEST FAILED: metrics failed_instances=% does not match df.instances=%',
+            failed_metrics, failed_instances;
+    END IF;
+
+    RAISE NOTICE 'TEST PASSED: rollback metrics consistency';
+END $$;
+
 -- === Test: 10_explain ===
 
 -- Test dry-run explain (use $body$ to avoid conflict with inner $$)