pageserver: add branch-local consumption metrics

pageserver/src/consumption_metrics/metrics.rs

@@ -18,12 +18,25 @@ use crate::tenant::timeline::logical_size::CurrentLogicalSize;
 // management.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, serde::Serialize, serde::Deserialize)]
 pub(super) enum Name {
-    /// Timeline last_record_lsn, absolute
+    /// Timeline last_record_lsn, absolute.
     #[serde(rename = "written_size")]
     WrittenSize,
     /// Timeline last_record_lsn, incremental
     #[serde(rename = "written_data_bytes_delta")]
     WrittenSizeDelta,
+    /// Written bytes only on this timeline (not including ancestors):
+    /// written_size - ancestor_lsn
+    ///
+    /// On the root branch, this is equivalent to `written_size`.
+    #[serde(rename = "written_size_since_parent")]
+    WrittenSizeSinceParent,
+    /// PITR history size only on this timeline (not including ancestors):
+    /// last_record_lsn - max(pitr_cutoff, ancestor_lsn).
+    ///
+    /// On the root branch, this is its entire PITR history size. Not emitted if GC hasn't computed
+    /// the PITR cutoff yet. 0 if PITR is disabled.
+    #[serde(rename = "pitr_history_size_since_parent")]
+    PitrHistorySizeSinceParent,
     /// Timeline logical size
     #[serde(rename = "timeline_logical_size")]
     LogicalSize,
@@ -157,6 +170,32 @@ impl MetricsKey {
         .incremental_values()
     }
 
+    /// `written_size` - `ancestor_lsn`.
+    const fn written_size_since_parent(
+        tenant_id: TenantId,
+        timeline_id: TimelineId,
+    ) -> AbsoluteValueFactory {
+        MetricsKey {
+            tenant_id,
+            timeline_id: Some(timeline_id),
+            metric: Name::WrittenSizeSinceParent,
+        }
+        .absolute_values()
+    }
+
+    /// `written_size` - max(`pitr_cutoff`, `ancestor_lsn`).
+    const fn pitr_history_size_since_parent(
+        tenant_id: TenantId,
+        timeline_id: TimelineId,
+    ) -> AbsoluteValueFactory {
+        MetricsKey {
+            tenant_id,
+            timeline_id: Some(timeline_id),
+            metric: Name::PitrHistorySizeSinceParent,
+        }
+        .absolute_values()
+    }
+
     /// Exact [`Timeline::get_current_logical_size`].
     ///
     /// [`Timeline::get_current_logical_size`]: crate::tenant::Timeline::get_current_logical_size
@@ -334,7 +373,13 @@ impl TenantSnapshot {
 struct TimelineSnapshot {
     loaded_at: (Lsn, SystemTime),
     last_record_lsn: Lsn,
+    ancestor_lsn: Lsn,
     current_exact_logical_size: Option<u64>,
+    /// Whether PITR is enabled (pitr_interval > 0).
+    pitr_enabled: bool,
+    /// The PITR cutoff LSN. None if not yet initialized. If PITR is disabled, this is approximately
+    /// Some(last_record_lsn), but may lag behind it since it's computed periodically.
+    pitr_cutoff: Option<Lsn>,
 }
 
 impl TimelineSnapshot {
@@ -354,6 +399,9 @@ impl TimelineSnapshot {
         } else {
             let loaded_at = t.loaded_at;
             let last_record_lsn = t.get_last_record_lsn();
+            let ancestor_lsn = t.get_ancestor_lsn();
+            let pitr_enabled = !t.get_pitr_interval().is_zero();
+            let pitr_cutoff = t.gc_info.read().unwrap().cutoffs.time;
 
             let current_exact_logical_size = {
                 let span = tracing::info_span!("collect_metrics_iteration", tenant_id = %t.tenant_shard_id.tenant_id, timeline_id = %t.timeline_id);
@@ -373,7 +421,10 @@ impl TimelineSnapshot {
             Ok(Some(TimelineSnapshot {
                 loaded_at,
                 last_record_lsn,
+                ancestor_lsn,
                 current_exact_logical_size,
+                pitr_enabled,
+                pitr_cutoff,
             }))
         }
     }
@@ -424,6 +475,8 @@ impl TimelineSnapshot {
 
         let up_to = now;
 
+        let written_size_last = written_size_now.value.max(prev.1); // don't regress
+
         if let Some(delta) = written_size_now.value.checked_sub(prev.1) {
             let key_value = written_size_delta_key.from_until(prev.0, up_to, delta);
             // written_size_delta
@@ -441,6 +494,27 @@ impl TimelineSnapshot {
             });
         }
 
+        // Compute the branch-local written size.
+        let written_size_since_parent_key =
+            MetricsKey::written_size_since_parent(tenant_id, timeline_id);
+        metrics.push(
+            written_size_since_parent_key
+                .at(now, written_size_last.saturating_sub(self.ancestor_lsn.0)),
+        );
+
+        // Compute the branch-local PITR history size. Not emitted if GC hasn't yet computed the
+        // PITR cutoff. 0 if PITR is disabled.
+        let pitr_history_size_since_parent_key =
+            MetricsKey::pitr_history_size_since_parent(tenant_id, timeline_id);
+        if !self.pitr_enabled {
+            metrics.push(pitr_history_size_since_parent_key.at(now, 0));
+        } else if let Some(pitr_cutoff) = self.pitr_cutoff {
+            metrics.push(pitr_history_size_since_parent_key.at(
+                now,
+                written_size_last.saturating_sub(pitr_cutoff.max(self.ancestor_lsn).0),
+            ));
+        }
+
         {
             let factory = MetricsKey::timeline_logical_size(tenant_id, timeline_id);
             let current_or_previous = self

pageserver/src/consumption_metrics/metrics/tests.rs

@@ -12,12 +12,17 @@ fn startup_collected_timeline_metrics_before_advancing() {
     let cache = HashMap::new();
 
     let initdb_lsn = Lsn(0x10000);
+    let pitr_cutoff = Lsn(0x11000);
     let disk_consistent_lsn = Lsn(initdb_lsn.0 * 2);
+    let logical_size = 0x42000;
 
     let snap = TimelineSnapshot {
         loaded_at: (disk_consistent_lsn, SystemTime::now()),
         last_record_lsn: disk_consistent_lsn,
-        current_exact_logical_size: Some(0x42000),
+        ancestor_lsn: Lsn(0),
+        current_exact_logical_size: Some(logical_size),
+        pitr_enabled: true,
+        pitr_cutoff: Some(pitr_cutoff),
     };
 
     let now = DateTime::<Utc>::from(SystemTime::now());
@@ -33,7 +38,11 @@ fn startup_collected_timeline_metrics_before_advancing() {
                 0
             ),
             MetricsKey::written_size(tenant_id, timeline_id).at(now, disk_consistent_lsn.0),
-            MetricsKey::timeline_logical_size(tenant_id, timeline_id).at(now, 0x42000)
+            MetricsKey::written_size_since_parent(tenant_id, timeline_id)
+                .at(now, disk_consistent_lsn.0),
+            MetricsKey::pitr_history_size_since_parent(tenant_id, timeline_id)
+                .at(now, disk_consistent_lsn.0 - pitr_cutoff.0),
+            MetricsKey::timeline_logical_size(tenant_id, timeline_id).at(now, logical_size)
         ]
     );
 }
@@ -49,7 +58,9 @@ fn startup_collected_timeline_metrics_second_round() {
     let before = DateTime::<Utc>::from(before);
 
     let initdb_lsn = Lsn(0x10000);
+    let pitr_cutoff = Lsn(0x11000);
     let disk_consistent_lsn = Lsn(initdb_lsn.0 * 2);
+    let logical_size = 0x42000;
 
     let mut metrics = Vec::new();
     let cache = HashMap::from([MetricsKey::written_size(tenant_id, timeline_id)
@@ -59,7 +70,10 @@ fn startup_collected_timeline_metrics_second_round() {
     let snap = TimelineSnapshot {
         loaded_at: (disk_consistent_lsn, init),
         last_record_lsn: disk_consistent_lsn,
-        current_exact_logical_size: Some(0x42000),
+        ancestor_lsn: Lsn(0),
+        current_exact_logical_size: Some(logical_size),
+        pitr_enabled: true,
+        pitr_cutoff: Some(pitr_cutoff),
     };
 
     snap.to_metrics(tenant_id, timeline_id, now, &mut metrics, &cache);
@@ -69,7 +83,11 @@ fn startup_collected_timeline_metrics_second_round() {
         &[
             MetricsKey::written_size_delta(tenant_id, timeline_id).from_until(before, now, 0),
             MetricsKey::written_size(tenant_id, timeline_id).at(now, disk_consistent_lsn.0),
-            MetricsKey::timeline_logical_size(tenant_id, timeline_id).at(now, 0x42000)
+            MetricsKey::written_size_since_parent(tenant_id, timeline_id)
+                .at(now, disk_consistent_lsn.0),
+            MetricsKey::pitr_history_size_since_parent(tenant_id, timeline_id)
+                .at(now, disk_consistent_lsn.0 - pitr_cutoff.0),
+            MetricsKey::timeline_logical_size(tenant_id, timeline_id).at(now, logical_size)
         ]
     );
 }
@@ -86,7 +104,9 @@ fn startup_collected_timeline_metrics_nth_round_at_same_lsn() {
     let before = DateTime::<Utc>::from(before);
 
     let initdb_lsn = Lsn(0x10000);
+    let pitr_cutoff = Lsn(0x11000);
     let disk_consistent_lsn = Lsn(initdb_lsn.0 * 2);
+    let logical_size = 0x42000;
 
     let mut metrics = Vec::new();
     let cache = HashMap::from([
@@ -103,7 +123,10 @@ fn startup_collected_timeline_metrics_nth_round_at_same_lsn() {
     let snap = TimelineSnapshot {
         loaded_at: (disk_consistent_lsn, init),
         last_record_lsn: disk_consistent_lsn,
-        current_exact_logical_size: Some(0x42000),
+        ancestor_lsn: Lsn(0),
+        current_exact_logical_size: Some(logical_size),
+        pitr_enabled: true,
+        pitr_cutoff: Some(pitr_cutoff),
     };
 
     snap.to_metrics(tenant_id, timeline_id, now, &mut metrics, &cache);
@@ -113,16 +136,18 @@ fn startup_collected_timeline_metrics_nth_round_at_same_lsn() {
         &[
             MetricsKey::written_size_delta(tenant_id, timeline_id).from_until(just_before, now, 0),
             MetricsKey::written_size(tenant_id, timeline_id).at(now, disk_consistent_lsn.0),
-            MetricsKey::timeline_logical_size(tenant_id, timeline_id).at(now, 0x42000)
+            MetricsKey::written_size_since_parent(tenant_id, timeline_id)
+                .at(now, disk_consistent_lsn.0),
+            MetricsKey::pitr_history_size_since_parent(tenant_id, timeline_id)
+                .at(now, disk_consistent_lsn.0 - pitr_cutoff.0),
+            MetricsKey::timeline_logical_size(tenant_id, timeline_id).at(now, logical_size)
         ]
     );
 }
 
+/// Tests that written sizes do not regress across restarts.
 #[test]
 fn post_restart_written_sizes_with_rolled_back_last_record_lsn() {
-    // it can happen that we lose the inmemorylayer but have previously sent metrics and we
-    // should never go backwards
-
     let tenant_id = TenantId::generate();
     let timeline_id = TimelineId::generate();
 
@@ -140,7 +165,10 @@ fn post_restart_written_sizes_with_rolled_back_last_record_lsn() {
     let snap = TimelineSnapshot {
         loaded_at: (Lsn(50), at_restart),
         last_record_lsn: Lsn(50),
+        ancestor_lsn: Lsn(0),
         current_exact_logical_size: None,
+        pitr_enabled: true,
+        pitr_cutoff: Some(Lsn(20)),
     };
 
     let mut cache = HashMap::from([
@@ -169,6 +197,8 @@ fn post_restart_written_sizes_with_rolled_back_last_record_lsn() {
                 0
             ),
             MetricsKey::written_size(tenant_id, timeline_id).at(now, 100),
+            MetricsKey::written_size_since_parent(tenant_id, timeline_id).at(now, 100),
+            MetricsKey::pitr_history_size_since_parent(tenant_id, timeline_id).at(now, 80),
         ]
     );
 
@@ -183,6 +213,157 @@ fn post_restart_written_sizes_with_rolled_back_last_record_lsn() {
         &[
             MetricsKey::written_size_delta(tenant_id, timeline_id).from_until(now, later, 0),
             MetricsKey::written_size(tenant_id, timeline_id).at(later, 100),
+            MetricsKey::written_size_since_parent(tenant_id, timeline_id).at(later, 100),
+            MetricsKey::pitr_history_size_since_parent(tenant_id, timeline_id).at(later, 80),
+        ]
+    );
+}
+
+/// Tests that written sizes do not regress across restarts, even on child branches.
+#[test]
+fn post_restart_written_sizes_with_rolled_back_last_record_lsn_and_ancestor_lsn() {
+    let tenant_id = TenantId::generate();
+    let timeline_id = TimelineId::generate();
+
+    let [later, now, at_restart] = time_backwards();
+
+    // FIXME: tests would be so much easier if we did not need to juggle back and forth
+    // SystemTime and DateTime::<Utc> ... Could do the conversion only at upload time?
+    let now = DateTime::<Utc>::from(now);
+    let later = DateTime::<Utc>::from(later);
+    let before_restart = at_restart - std::time::Duration::from_secs(5 * 60);
+    let way_before = before_restart - std::time::Duration::from_secs(10 * 60);
+    let before_restart = DateTime::<Utc>::from(before_restart);
+    let way_before = DateTime::<Utc>::from(way_before);
+
+    let snap = TimelineSnapshot {
+        loaded_at: (Lsn(50), at_restart),
+        last_record_lsn: Lsn(50),
+        ancestor_lsn: Lsn(40),
+        current_exact_logical_size: None,
+        pitr_enabled: true,
+        pitr_cutoff: Some(Lsn(20)),
+    };
+
+    let mut cache = HashMap::from([
+        MetricsKey::written_size(tenant_id, timeline_id)
+            .at(before_restart, 100)
+            .to_kv_pair(),
+        MetricsKey::written_size_delta(tenant_id, timeline_id)
+            .from_until(
+                way_before,
+                before_restart,
+                // not taken into account, but the timestamps are important
+                999_999_999,
+            )
+            .to_kv_pair(),
+    ]);
+
+    let mut metrics = Vec::new();
+    snap.to_metrics(tenant_id, timeline_id, now, &mut metrics, &cache);
+
+    assert_eq!(
+        metrics,
+        &[
+            MetricsKey::written_size_delta(tenant_id, timeline_id).from_until(
+                before_restart,
+                now,
+                0
+            ),
+            MetricsKey::written_size(tenant_id, timeline_id).at(now, 100),
+            MetricsKey::written_size_since_parent(tenant_id, timeline_id).at(now, 60),
+            MetricsKey::pitr_history_size_since_parent(tenant_id, timeline_id).at(now, 60),
+        ]
+    );
+
+    // now if we cache these metrics, and re-run while "still in recovery"
+    cache.extend(metrics.drain(..).map(|x| x.to_kv_pair()));
+
+    // "still in recovery", because our snapshot did not change
+    snap.to_metrics(tenant_id, timeline_id, later, &mut metrics, &cache);
+
+    assert_eq!(
+        metrics,
+        &[
+            MetricsKey::written_size_delta(tenant_id, timeline_id).from_until(now, later, 0),
+            MetricsKey::written_size(tenant_id, timeline_id).at(later, 100),
+            MetricsKey::written_size_since_parent(tenant_id, timeline_id).at(later, 60),
+            MetricsKey::pitr_history_size_since_parent(tenant_id, timeline_id).at(later, 60),
+        ]
+    );
+}
+
+/// Tests that written sizes do not regress across restarts, even on child branches and
+/// with a PITR cutoff after the branch point.
+#[test]
+fn post_restart_written_sizes_with_rolled_back_last_record_lsn_and_ancestor_lsn_and_pitr_cutoff() {
+    let tenant_id = TenantId::generate();
+    let timeline_id = TimelineId::generate();
+
+    let [later, now, at_restart] = time_backwards();
+
+    // FIXME: tests would be so much easier if we did not need to juggle back and forth
+    // SystemTime and DateTime::<Utc> ... Could do the conversion only at upload time?
+    let now = DateTime::<Utc>::from(now);
+    let later = DateTime::<Utc>::from(later);
+    let before_restart = at_restart - std::time::Duration::from_secs(5 * 60);
+    let way_before = before_restart - std::time::Duration::from_secs(10 * 60);
+    let before_restart = DateTime::<Utc>::from(before_restart);
+    let way_before = DateTime::<Utc>::from(way_before);
+
+    let snap = TimelineSnapshot {
+        loaded_at: (Lsn(50), at_restart),
+        last_record_lsn: Lsn(50),
+        ancestor_lsn: Lsn(30),
+        current_exact_logical_size: None,
+        pitr_enabled: true,
+        pitr_cutoff: Some(Lsn(40)),
+    };
+
+    let mut cache = HashMap::from([
+        MetricsKey::written_size(tenant_id, timeline_id)
+            .at(before_restart, 100)
+            .to_kv_pair(),
+        MetricsKey::written_size_delta(tenant_id, timeline_id)
+            .from_until(
+                way_before,
+                before_restart,
+                // not taken into account, but the timestamps are important
+                999_999_999,
+            )
+            .to_kv_pair(),
+    ]);
+
+    let mut metrics = Vec::new();
+    snap.to_metrics(tenant_id, timeline_id, now, &mut metrics, &cache);
+
+    assert_eq!(
+        metrics,
+        &[
+            MetricsKey::written_size_delta(tenant_id, timeline_id).from_until(
+                before_restart,
+                now,
+                0
+            ),
+            MetricsKey::written_size(tenant_id, timeline_id).at(now, 100),
+            MetricsKey::written_size_since_parent(tenant_id, timeline_id).at(now, 70),
+            MetricsKey::pitr_history_size_since_parent(tenant_id, timeline_id).at(now, 60),
+        ]
+    );
+
+    // now if we cache these metrics, and re-run while "still in recovery"
+    cache.extend(metrics.drain(..).map(|x| x.to_kv_pair()));
+
+    // "still in recovery", because our snapshot did not change
+    snap.to_metrics(tenant_id, timeline_id, later, &mut metrics, &cache);
+
+    assert_eq!(
+        metrics,
+        &[
+            MetricsKey::written_size_delta(tenant_id, timeline_id).from_until(now, later, 0),
+            MetricsKey::written_size(tenant_id, timeline_id).at(later, 100),
+            MetricsKey::written_size_since_parent(tenant_id, timeline_id).at(later, 70),
+            MetricsKey::pitr_history_size_since_parent(tenant_id, timeline_id).at(later, 60),
         ]
     );
 }
@@ -201,7 +382,10 @@ fn post_restart_current_exact_logical_size_uses_cached() {
     let snap = TimelineSnapshot {
         loaded_at: (Lsn(50), at_restart),
         last_record_lsn: Lsn(50),
+        ancestor_lsn: Lsn(0),
         current_exact_logical_size: None,
+        pitr_enabled: true,
+        pitr_cutoff: None,
     };
 
     let cache = HashMap::from([MetricsKey::timeline_logical_size(tenant_id, timeline_id)
@@ -286,16 +470,101 @@ fn time_backwards<const N: usize>() -> [std::time::SystemTime; N] {
     times
 }
 
+/// Tests that disabled PITR history does not yield any history size, even when the PITR cutoff
+/// indicates otherwise.
+#[test]
+fn pitr_disabled_yields_no_history_size() {
+    let tenant_id = TenantId::generate();
+    let timeline_id = TimelineId::generate();
+
+    let mut metrics = Vec::new();
+    let cache = HashMap::new();
+
+    let initdb_lsn = Lsn(0x10000);
+    let pitr_cutoff = Lsn(0x11000);
+    let disk_consistent_lsn = Lsn(initdb_lsn.0 * 2);
+
+    let snap = TimelineSnapshot {
+        loaded_at: (disk_consistent_lsn, SystemTime::now()),
+        last_record_lsn: disk_consistent_lsn,
+        ancestor_lsn: Lsn(0),
+        current_exact_logical_size: None,
+        pitr_enabled: false,
+        pitr_cutoff: Some(pitr_cutoff),
+    };
+
+    let now = DateTime::<Utc>::from(SystemTime::now());
+
+    snap.to_metrics(tenant_id, timeline_id, now, &mut metrics, &cache);
+
+    assert_eq!(
+        metrics,
+        &[
+            MetricsKey::written_size_delta(tenant_id, timeline_id).from_until(
+                snap.loaded_at.1.into(),
+                now,
+                0
+            ),
+            MetricsKey::written_size(tenant_id, timeline_id).at(now, disk_consistent_lsn.0),
+            MetricsKey::written_size_since_parent(tenant_id, timeline_id)
+                .at(now, disk_consistent_lsn.0),
+            MetricsKey::pitr_history_size_since_parent(tenant_id, timeline_id).at(now, 0),
+        ]
+    );
+}
+
+/// Tests that uninitialized PITR cutoff does not emit any history size metric at all.
+#[test]
+fn pitr_uninitialized_does_not_emit_history_size() {
+    let tenant_id = TenantId::generate();
+    let timeline_id = TimelineId::generate();
+
+    let mut metrics = Vec::new();
+    let cache = HashMap::new();
+
+    let initdb_lsn = Lsn(0x10000);
+    let disk_consistent_lsn = Lsn(initdb_lsn.0 * 2);
+
+    let snap = TimelineSnapshot {
+        loaded_at: (disk_consistent_lsn, SystemTime::now()),
+        last_record_lsn: disk_consistent_lsn,
+        ancestor_lsn: Lsn(0),
+        current_exact_logical_size: None,
+        pitr_enabled: true,
+        pitr_cutoff: None,
+    };
+
+    let now = DateTime::<Utc>::from(SystemTime::now());
+
+    snap.to_metrics(tenant_id, timeline_id, now, &mut metrics, &cache);
+
+    assert_eq!(
+        metrics,
+        &[
+            MetricsKey::written_size_delta(tenant_id, timeline_id).from_until(
+                snap.loaded_at.1.into(),
+                now,
+                0
+            ),
+            MetricsKey::written_size(tenant_id, timeline_id).at(now, disk_consistent_lsn.0),
+            MetricsKey::written_size_since_parent(tenant_id, timeline_id)
+                .at(now, disk_consistent_lsn.0),
+        ]
+    );
+}
+
 pub(crate) const fn metric_examples_old(
     tenant_id: TenantId,
     timeline_id: TimelineId,
     now: DateTime<Utc>,
     before: DateTime<Utc>,
-) -> [RawMetric; 5] {
+) -> [RawMetric; 7] {
     [
         MetricsKey::written_size(tenant_id, timeline_id).at_old_format(now, 0),
         MetricsKey::written_size_delta(tenant_id, timeline_id)
             .from_until_old_format(before, now, 0),
+        MetricsKey::written_size_since_parent(tenant_id, timeline_id).at_old_format(now, 0),
+        MetricsKey::pitr_history_size_since_parent(tenant_id, timeline_id).at_old_format(now, 0),
         MetricsKey::timeline_logical_size(tenant_id, timeline_id).at_old_format(now, 0),
         MetricsKey::remote_storage_size(tenant_id).at_old_format(now, 0),
         MetricsKey::synthetic_size(tenant_id).at_old_format(now, 1),
@@ -307,10 +576,12 @@ pub(crate) const fn metric_examples(
     timeline_id: TimelineId,
     now: DateTime<Utc>,
     before: DateTime<Utc>,
-) -> [NewRawMetric; 5] {
+) -> [NewRawMetric; 7] {
     [
         MetricsKey::written_size(tenant_id, timeline_id).at(now, 0),
         MetricsKey::written_size_delta(tenant_id, timeline_id).from_until(before, now, 0),
+        MetricsKey::written_size_since_parent(tenant_id, timeline_id).at(now, 0),
+        MetricsKey::pitr_history_size_since_parent(tenant_id, timeline_id).at(now, 0),
         MetricsKey::timeline_logical_size(tenant_id, timeline_id).at(now, 0),
         MetricsKey::remote_storage_size(tenant_id).at(now, 0),
         MetricsKey::synthetic_size(tenant_id).at(now, 1),

pageserver/src/consumption_metrics/upload.rs

@@ -513,6 +513,14 @@ mod tests {
                 line!(),
                 r#"{"type":"incremental","start_time":"2023-09-14T00:00:00.123456789Z","stop_time":"2023-09-15T00:00:00.123456789Z","metric":"written_data_bytes_delta","idempotency_key":"2023-09-15 00:00:00.123456789 UTC-1-0000","value":0,"tenant_id":"00000000000000000000000000000000","timeline_id":"ffffffffffffffffffffffffffffffff"}"#,
             ),
+            (
+                line!(),
+                r#"{"type":"absolute","time":"2023-09-15T00:00:00.123456789Z","metric":"written_size_since_parent","idempotency_key":"2023-09-15 00:00:00.123456789 UTC-1-0000","value":0,"tenant_id":"00000000000000000000000000000000","timeline_id":"ffffffffffffffffffffffffffffffff"}"#,
+            ),
+            (
+                line!(),
+                r#"{"type":"absolute","time":"2023-09-15T00:00:00.123456789Z","metric":"pitr_history_size_since_parent","idempotency_key":"2023-09-15 00:00:00.123456789 UTC-1-0000","value":0,"tenant_id":"00000000000000000000000000000000","timeline_id":"ffffffffffffffffffffffffffffffff"}"#,
+            ),
             (
                 line!(),
                 r#"{"type":"absolute","time":"2023-09-15T00:00:00.123456789Z","metric":"timeline_logical_size","idempotency_key":"2023-09-15 00:00:00.123456789 UTC-1-0000","value":0,"tenant_id":"00000000000000000000000000000000","timeline_id":"ffffffffffffffffffffffffffffffff"}"#,
@@ -560,7 +568,7 @@ mod tests {
         assert_eq!(upgraded_samples, new_samples);
     }
 
-    fn metric_samples_old() -> [RawMetric; 5] {
+    fn metric_samples_old() -> [RawMetric; 7] {
         let tenant_id = TenantId::from_array([0; 16]);
         let timeline_id = TimelineId::from_array([0xff; 16]);
 
@@ -572,7 +580,7 @@ mod tests {
         super::super::metrics::metric_examples_old(tenant_id, timeline_id, now, before)
     }
 
-    fn metric_samples() -> [NewRawMetric; 5] {
+    fn metric_samples() -> [NewRawMetric; 7] {
         let tenant_id = TenantId::from_array([0; 16]);
         let timeline_id = TimelineId::from_array([0xff; 16]);
 

pageserver/src/tenant/timeline.rs

@@ -2544,6 +2544,13 @@ impl Timeline {
             .unwrap_or(self.conf.default_tenant_conf.checkpoint_timeout)
     }
 
+    pub(crate) fn get_pitr_interval(&self) -> Duration {
+        let tenant_conf = &self.tenant_conf.load().tenant_conf;
+        tenant_conf
+            .pitr_interval
+            .unwrap_or(self.conf.default_tenant_conf.pitr_interval)
+    }
+
     fn get_compaction_period(&self) -> Duration {
         let tenant_conf = self.tenant_conf.load().tenant_conf.clone();
         tenant_conf

test_runner/regress/test_pageserver_metric_collection.py

@@ -508,6 +508,9 @@ PER_METRIC_VERIFIERS = {
     "remote_storage_size": CannotVerifyAnything,
     "written_size": WrittenDataVerifier,
     "written_data_bytes_delta": WrittenDataDeltaVerifier,
+    "written_size_since_parent": WrittenDataVerifier,  # same as written_size on root
+    "pitr_cutoff": CannotVerifyAnything,
+    "pitr_history_size_since_parent": WrittenDataVerifier,  # same as written_size on root w/o GC
     "timeline_logical_size": CannotVerifyAnything,
     "synthetic_storage_size": SyntheticSizeVerifier,
 }