pageserver: shutdown timeline metrics during delete

pageserver/src/tenant/timeline/delete.rs

@@ -26,6 +26,10 @@ use crate::{
 use super::{Timeline, TimelineResources};
 
 /// Now that the Timeline is in Stopping state, request all the related tasks to shut down.
+///
+/// This is essentially a hand-crafted subset of Timeline::shutdown, which exists because we
+/// rely on keeping Timeline partially alive in order to access its RemoteTimelineClient for remote
+/// deletion.
 async fn stop_tasks(timeline: &Timeline) -> Result<(), DeleteTimelineError> {
     debug_assert_current_span_has_tenant_and_timeline_id();
     // Notify any timeline work to drop out of loops/requests
@@ -82,6 +86,8 @@ async fn stop_tasks(timeline: &Timeline) -> Result<(), DeleteTimelineError> {
         ))?
     });
 
+    timeline.metrics.shutdown();
+
     tracing::debug!("Waiting for gate...");
     timeline.gate.close().await;
     tracing::debug!("Shutdown complete");

test_runner/regress/test_timeline_delete.py

@@ -88,6 +88,14 @@ def test_timeline_delete(neon_simple_env: NeonEnv):
     timeline_path = env.pageserver.timeline_dir(env.initial_tenant, leaf_timeline_id)
     assert timeline_path.exists()
 
+    # Before deleting, timeline metrics should be present
+    assert (
+        ps_http.get_metric_value(
+            "pageserver_current_logical_size", {"timeline_id": str(leaf_timeline_id)}
+        )
+        is not None
+    )
+
     # retry deletes when compaction or gc is running in pageserver
     # TODO: review whether this wait_until is actually necessary, we do an await() internally
     wait_until(
@@ -106,6 +114,14 @@ def test_timeline_delete(neon_simple_env: NeonEnv):
         ps_http.timeline_detail(env.initial_tenant, leaf_timeline_id)
     assert exc.value.status_code == 404
 
+    # Check metrics were cleaned up
+    assert (
+        ps_http.get_metric_value(
+            "pageserver_current_logical_size", {"timeline_id": str(leaf_timeline_id)}
+        )
+        is None
+    )
+
     wait_until(
         number_of_iterations=3,
         interval=0.2,