report to prometheus

Signed-off-by: Alex Chi Z <[email protected]>

pageserver/src/aux_file.rs

@@ -1,8 +1,6 @@
-use std::sync::{
-    atomic::{AtomicIsize, AtomicUsize},
-    Arc,
-};
+use std::sync::Arc;
 
+use ::metrics::IntGauge;
 use bytes::{Buf, BufMut, Bytes};
 use pageserver_api::key::{Key, AUX_KEY_PREFIX, METADATA_KEY_SIZE};
 use tracing::warn;
@@ -147,43 +145,51 @@ pub fn encode_file_value(files: &[(&str, &[u8])]) -> anyhow::Result<Vec<u8>> {
 
 /// An estimation of the size of aux files.
 pub struct AuxFileSizeEstimator {
+    aux_file_size_gauge: IntGauge,
     size: Arc<std::sync::Mutex<Option<isize>>>,
 }
 
 impl AuxFileSizeEstimator {
-    pub fn new() -> Self {
+    pub fn new(aux_file_size_gauge: IntGauge) -> Self {
         Self {
+            aux_file_size_gauge,
             size: Arc::new(std::sync::Mutex::new(None)),
         }
     }
 
     pub fn on_base_backup(&self, new_size: usize) {
         let mut guard = self.size.lock().unwrap();
         *guard = Some(new_size as isize);
+        self.report(new_size as isize);
     }
 
     pub fn on_add(&self, file_size: usize) {
         let mut guard = self.size.lock().unwrap();
         if let Some(size) = &mut *guard {
             *size += file_size as isize;
+            self.report(*size);
         }
     }
 
     pub fn on_remove(&self, file_size: usize) {
         let mut guard = self.size.lock().unwrap();
         if let Some(size) = &mut *guard {
             *size -= file_size as isize;
+            self.report(*size);
         }
     }
 
     pub fn on_update(&self, old_size: usize, new_size: usize) {
         let mut guard = self.size.lock().unwrap();
         if let Some(size) = &mut *guard {
             *size += new_size as isize - old_size as isize;
+            self.report(*size);
         }
     }
 
-    pub fn report(&self) {}
+    pub fn report(&self, size: isize) {
+        self.aux_file_size_gauge.set(size as i64);
+    }
 }
 
 #[cfg(test)]

pageserver/src/metrics.rs

@@ -585,6 +585,15 @@ static CURRENT_LOGICAL_SIZE: Lazy<UIntGaugeVec> = Lazy::new(|| {
     .expect("failed to define current logical size metric")
 });
 
+static AUX_FILE_SIZE: Lazy<IntGaugeVec> = Lazy::new(|| {
+    register_int_gauge_vec!(
+        "pageserver_aux_file_estimated_size",
+        "The size of all aux files for a timeline in aux file v2 store.",
+        &["tenant_id", "timeline_id"]
+    )
+    .expect("failed to define a metric")
+});
+
 pub(crate) mod initial_logical_size {
     use metrics::{register_int_counter, register_int_counter_vec, IntCounter, IntCounterVec};
     use once_cell::sync::Lazy;
@@ -2115,6 +2124,7 @@ pub(crate) struct TimelineMetrics {
     resident_physical_size_gauge: UIntGauge,
     /// copy of LayeredTimeline.current_logical_size
     pub current_logical_size_gauge: UIntGauge,
+    pub aux_file_size_gauge: IntGauge,
     pub directory_entries_count_gauge: Lazy<UIntGauge, Box<dyn Send + Fn() -> UIntGauge>>,
     pub evictions: IntCounter,
     pub evictions_with_low_residence_duration: std::sync::RwLock<EvictionsWithLowResidenceDuration>,
@@ -2187,6 +2197,9 @@ impl TimelineMetrics {
         let current_logical_size_gauge = CURRENT_LOGICAL_SIZE
             .get_metric_with_label_values(&[&tenant_id, &shard_id, &timeline_id])
             .unwrap();
+        let aux_file_size_gauge = AUX_FILE_SIZE
+            .get_metric_with_label_values(&[&tenant_id, &timeline_id])
+            .unwrap();
         // TODO use impl Trait syntax here once we have ability to use it: https://github.com/rust-lang/rust/issues/63065
         let directory_entries_count_gauge_closure = {
             let tenant_shard_id = *tenant_shard_id;
@@ -2224,6 +2237,7 @@ impl TimelineMetrics {
             last_record_gauge,
             resident_physical_size_gauge,
             current_logical_size_gauge,
+            aux_file_size_gauge,
             directory_entries_count_gauge,
             evictions,
             evictions_with_low_residence_duration: std::sync::RwLock::new(
@@ -2264,6 +2278,7 @@ impl TimelineMetrics {
             let _ = metric.remove_label_values(&[tenant_id, shard_id, timeline_id]);
         }
         let _ = EVICTIONS.remove_label_values(&[tenant_id, shard_id, timeline_id]);
+        let _ = AUX_FILE_SIZE.remove_label_values(&[tenant_id, timeline_id]);
 
         self.evictions_with_low_residence_duration
             .write()

pageserver/src/pgdatadir_mapping.rs

@@ -704,9 +704,9 @@ impl Timeline {
             let v = v.context("get value")?;
             let v = aux_file::decode_file_value_bytes(&v).context("value decode")?;
             for (fname, content) in v {
-                result.insert(fname, content);
                 sz += fname.len();
                 sz += content.len();
+                result.insert(fname, content);
             }
         }
         self.aux_file_size_estimator.on_base_backup(sz);

pageserver/src/tenant/timeline.rs

@@ -2160,6 +2160,16 @@ impl Timeline {
         };
 
         Arc::new_cyclic(|myself| {
+            let metrics = TimelineMetrics::new(
+                &tenant_shard_id,
+                &timeline_id,
+                crate::metrics::EvictionsWithLowResidenceDurationBuilder::new(
+                    "mtime",
+                    evictions_low_residence_duration_metric_threshold,
+                ),
+            );
+            let aux_file_metrics = metrics.aux_file_size_gauge.clone();
+
             let mut result = Timeline {
                 conf,
                 tenant_conf,
@@ -2191,14 +2201,7 @@ impl Timeline {
                 ancestor_timeline: ancestor,
                 ancestor_lsn: metadata.ancestor_lsn(),
 
-                metrics: TimelineMetrics::new(
-                    &tenant_shard_id,
-                    &timeline_id,
-                    crate::metrics::EvictionsWithLowResidenceDurationBuilder::new(
-                        "mtime",
-                        evictions_low_residence_duration_metric_threshold,
-                    ),
-                ),
+                metrics,
 
                 query_metrics: crate::metrics::SmgrQueryTimePerTimeline::new(
                     &tenant_shard_id,
@@ -2263,7 +2266,7 @@ impl Timeline {
                     n_deltas: 0,
                 }),
 
-                aux_file_size_estimator: AuxFileSizeEstimator::new(),
+                aux_file_size_estimator: AuxFileSizeEstimator::new(aux_file_metrics),
             };
             result.repartition_threshold =
                 result.get_checkpoint_distance() / REPARTITION_FREQ_IN_CHECKPOINT_DISTANCE;

test_runner/fixtures/metrics.py

@@ -149,6 +149,7 @@ def histogram(prefix_without_trailing_underscore: str) -> List[str]:
     "pageserver_storage_operations_seconds_sum_total",
     "pageserver_evictions_total",
     "pageserver_evictions_with_low_residence_duration_total",
+    "pageserver_aux_file_estimated_size",
     *PAGESERVER_PER_TENANT_REMOTE_TIMELINE_CLIENT_METRICS,
     # "pageserver_directory_entries_count", -- only used if above a certain threshold
     # "pageserver_broken_tenants_count" -- used only for broken