From 1bfd6d0b256c47812b9a62f5e0c296b5a0be1f33 Mon Sep 17 00:00:00 2001
From: Dmitri Makarov <dmakarov@alumni.stanford.edu>
Date: Fri, 27 Sep 2024 14:09:52 -0400
Subject: [PATCH] Add ancient slots shrinking stats

---
 accounts-db/src/accounts_db.rs         | 43 ++++++++++++++++++++++++++
 accounts-db/src/ancient_append_vecs.rs |  3 ++
 2 files changed, 46 insertions(+)

diff --git a/accounts-db/src/accounts_db.rs b/accounts-db/src/accounts_db.rs
index b162ee1abe9330..1e69623a546ac3 100644
--- a/accounts-db/src/accounts_db.rs
+++ b/accounts-db/src/accounts_db.rs
@@ -1997,6 +1997,7 @@ pub(crate) struct ShrinkAncientStats {
     pub(crate) slots_eligible_to_shrink: AtomicU64,
     pub(crate) total_dead_bytes: AtomicU64,
     pub(crate) total_alive_bytes: AtomicU64,
+    pub(crate) ideal_storage_size: AtomicU64,
 }
 
 #[derive(Debug, Default)]
@@ -2043,9 +2044,12 @@ pub struct ShrinkStats {
     index_scan_returned_none: AtomicU64,
     index_scan_returned_some: AtomicU64,
     accounts_loaded: AtomicU64,
+    initial_candidates_count: AtomicU64,
     purged_zero_lamports: AtomicU64,
     accounts_not_found_in_index: AtomicU64,
     num_ancient_slots_shrunk: AtomicU64,
+    ancient_slots_added_to_shrink: AtomicU64,
+    ancient_bytes_added_to_shrink: AtomicU64,
 }
 
 impl ShrinkStats {
@@ -2053,6 +2057,18 @@ impl ShrinkStats {
         if self.last_report.should_update(1000) {
             datapoint_info!(
                 "shrink_stats",
+                (
+                    "ancient_slots_added_to_shrink",
+                    self.ancient_slots_added_to_shrink
+                        .swap(0, Ordering::Relaxed) as i64,
+                    i64
+                ),
+                (
+                    "ancient_bytes_added_to_shrink",
+                    self.ancient_bytes_added_to_shrink
+                        .swap(0, Ordering::Relaxed) as i64,
+                    i64
+                ),
                 (
                     "num_slots_shrunk",
                     self.num_slots_shrunk.swap(0, Ordering::Relaxed) as i64,
@@ -2169,6 +2185,11 @@ impl ShrinkStats {
                     self.accounts_not_found_in_index.swap(0, Ordering::Relaxed),
                     i64
                 ),
+                (
+                    "initial_candidates_count",
+                    self.initial_candidates_count.swap(0, Ordering::Relaxed),
+                    i64
+                ),
             );
         }
     }
@@ -2328,6 +2349,11 @@ impl ShrinkAncientStats {
                 self.slots_eligible_to_shrink.swap(0, Ordering::Relaxed),
                 i64
             ),
+            (
+                "ideal_storage_size",
+                self.ideal_storage_size.swap(0, Ordering::Relaxed),
+                i64
+            ),
             (
                 "total_dead_bytes",
                 self.total_dead_bytes.swap(0, Ordering::Relaxed),
@@ -5074,6 +5100,10 @@ impl AccountsDb {
         let shrink_candidates_slots =
             std::mem::take(&mut *self.shrink_candidate_slots.lock().unwrap());
 
+        self.shrink_stats
+            .initial_candidates_count
+            .store(shrink_candidates_slots.len() as u64, Ordering::Relaxed);
+
         let (mut shrink_slots, shrink_slots_next_batch) = {
             if let AccountShrinkThreshold::TotalSpace { shrink_ratio } = self.shrink_ratio {
                 let (shrink_slots, shrink_slots_next_batch) =
@@ -5096,6 +5126,7 @@ impl AccountsDb {
         };
 
         let mut limit = 2;
+        let mut ancient_slots_added = 0;
         if shrink_slots.len() >= limit {
             limit = shrink_slots.len() + 1;
         }
@@ -5113,6 +5144,10 @@ impl AccountsDb {
                     continue;
                 }
                 *capacity = 0;
+                ancient_slots_added += 1;
+                self.shrink_stats
+                    .ancient_bytes_added_to_shrink
+                    .fetch_add(store.alive_bytes() as u64, Ordering::Relaxed);
                 shrink_slots.insert(*slot, store);
 
                 if shrink_slots.len() >= limit {
@@ -5120,6 +5155,14 @@ impl AccountsDb {
                 }
             }
         }
+        log::debug!(
+            "ancient_slots_added: {ancient_slots_added}, {}, avail: {}",
+            shrink_slots.len(),
+            ancients.len()
+        );
+        self.shrink_stats
+            .ancient_slots_added_to_shrink
+            .fetch_add(ancient_slots_added, Ordering::Relaxed);
         if shrink_slots.is_empty()
             && shrink_slots_next_batch
                 .as_ref()
diff --git a/accounts-db/src/ancient_append_vecs.rs b/accounts-db/src/ancient_append_vecs.rs
index 6c8d3396d57252..757777424407b8 100644
--- a/accounts-db/src/ancient_append_vecs.rs
+++ b/accounts-db/src/ancient_append_vecs.rs
@@ -609,6 +609,9 @@ impl AccountsDb {
             (infos.total_alive_bytes.0 / tuning.max_ancient_slots.max(1) as u64 * 2).max(5_000_000),
         )
         .unwrap();
+        self.shrink_ancient_stats
+            .ideal_storage_size
+            .store(tuning.ideal_storage_size.into(), Ordering::Relaxed);
         self.shrink_ancient_stats
             .slots_eligible_to_shrink
             .fetch_add(should_shrink_count as u64, Ordering::Relaxed);