disk index: add stat: disk_index_failed_resizes (#31039)

bucket_map/src/bucket.rs

@@ -443,14 +443,15 @@ impl<'b, T: Clone + Copy + 'static> Bucket<T> {
             }
             let mut m = Measure::start("grow_index");
             //debug!("GROW_INDEX: {}", current_capacity_pow2);
-            let increment = 1;
-            for i in increment.. {
+            let mut count = 0;
+            loop {
+                count += 1;
                 let mut index = BucketStorage::new_with_capacity(
                     Arc::clone(&self.drives),
                     1,
                     std::mem::size_of::<IndexEntry<T>>() as u64,
                     // the subtle `+ i` here causes us to grow from the starting size by a power of 2 on each iteration of the for loop
-                    Capacity::Pow2(starting_size_pow2 + i),
+                    Capacity::Pow2(starting_size_pow2 + count),
                     self.index.max_search,
                     Arc::clone(&self.stats.index),
                     Arc::clone(&self.index.count),
@@ -487,6 +488,12 @@ impl<'b, T: Clone + Copy + 'static> Bucket<T> {
                 }
             }
             m.stop();
+            if count > 1 {
+                self.stats
+                    .index
+                    .failed_resizes
+                    .fetch_add(count as u64 - 1, Ordering::Relaxed);
+            }
             self.stats.index.resizes.fetch_add(1, Ordering::Relaxed);
             self.stats
                 .index

bucket_map/src/bucket_stats.rs

@@ -6,6 +6,7 @@ use std::sync::{
 #[derive(Debug, Default)]
 pub struct BucketStats {
     pub resizes: AtomicU64,
+    pub failed_resizes: AtomicU64,
     pub max_size: AtomicU64,
     pub resize_us: AtomicU64,
     pub new_file_us: AtomicU64,

runtime/src/bucket_map_holder_stats.rs

@@ -404,6 +404,12 @@ impl BucketMapHolderStats {
                         .unwrap_or_default(),
                     i64
                 ),
+                (
+                    "disk_index_failed_resizes",
+                    disk.map(|disk| disk.stats.index.failed_resizes.swap(0, Ordering::Relaxed))
+                        .unwrap_or_default(),
+                    i64
+                ),
                 (
                     "disk_index_max_size",
                     disk.map(|disk| { disk.stats.index.max_size.swap(0, Ordering::Relaxed) })