(LedgerStore) Rate-limit RocksDB perf sample by a minimum time interval (#25093)

#### Problem
When the number of RocksDB read/write operations spikes, its payload size
might exceed the limit (413 Payload Too Large).

#### Summary of Changes
This PR rate-limit the perf-sampling of RocksDB read/write operations by one second
in addition to the existing sampling that is configurable via the hidden validator
argument --rocksdb-perf-sample-interval.

ledger/src/blockstore_db.rs

@@ -536,7 +536,7 @@ impl Rocks {
     fn write(&self, batch: RWriteBatch) -> Result<()> {
         let is_perf_enabled = maybe_enable_rocksdb_perf(
             self.column_options.rocks_perf_sample_interval,
-            &self.write_batch_perf_status.op_count,
+            &self.write_batch_perf_status,
         );
         let result = self.db.write(batch);
         if is_perf_enabled {
@@ -1302,7 +1302,7 @@ where
     pub fn get_bytes(&self, key: C::Index) -> Result<Option<Vec<u8>>> {
         let is_perf_enabled = maybe_enable_rocksdb_perf(
             self.column_options.rocks_perf_sample_interval,
-            &self.read_perf_status.op_count,
+            &self.read_perf_status,
         );
         let result = self.backend.get_cf(self.handle(), &C::key(key));
         if is_perf_enabled {
@@ -1380,7 +1380,7 @@ where
     pub fn put_bytes(&self, key: C::Index, value: &[u8]) -> Result<()> {
         let is_perf_enabled = maybe_enable_rocksdb_perf(
             self.column_options.rocks_perf_sample_interval,
-            &self.write_perf_status.op_count,
+            &self.write_perf_status,
         );
         let result = self.backend.put_cf(self.handle(), &C::key(key), value);
         if is_perf_enabled {
@@ -1407,7 +1407,7 @@ where
         let mut result = Ok(None);
         let is_perf_enabled = maybe_enable_rocksdb_perf(
             self.column_options.rocks_perf_sample_interval,
-            &self.read_perf_status.op_count,
+            &self.read_perf_status,
         );
         if let Some(serialized_value) = self.backend.get_cf(self.handle(), &C::key(key))? {
             let value = deserialize(&serialized_value)?;
@@ -1424,7 +1424,7 @@ where
     pub fn put(&self, key: C::Index, value: &C::Type) -> Result<()> {
         let is_perf_enabled = maybe_enable_rocksdb_perf(
             self.column_options.rocks_perf_sample_interval,
-            &self.write_perf_status.op_count,
+            &self.write_perf_status,
         );
         let serialized_value = serialize(value)?;
 
@@ -1441,7 +1441,7 @@ where
     pub fn delete(&self, key: C::Index) -> Result<()> {
         let is_perf_enabled = maybe_enable_rocksdb_perf(
             self.column_options.rocks_perf_sample_interval,
-            &self.write_perf_status.op_count,
+            &self.write_perf_status,
         );
         let result = self.backend.delete_cf(self.handle(), &C::key(key));
         if is_perf_enabled {
@@ -1461,7 +1461,7 @@ where
     ) -> Result<Option<C::Type>> {
         let is_perf_enabled = maybe_enable_rocksdb_perf(
             self.column_options.rocks_perf_sample_interval,
-            &self.read_perf_status.op_count,
+            &self.read_perf_status,
         );
         let result = self.backend.get_cf(self.handle(), &C::key(key));
         if is_perf_enabled {
@@ -1482,7 +1482,7 @@ where
     pub fn get_protobuf(&self, key: C::Index) -> Result<Option<C::Type>> {
         let is_perf_enabled = maybe_enable_rocksdb_perf(
             self.column_options.rocks_perf_sample_interval,
-            &self.read_perf_status.op_count,
+            &self.read_perf_status,
         );
         let result = self.backend.get_cf(self.handle(), &C::key(key));
         if is_perf_enabled {
@@ -1502,7 +1502,7 @@ where
 
         let is_perf_enabled = maybe_enable_rocksdb_perf(
             self.column_options.rocks_perf_sample_interval,
-            &self.write_perf_status.op_count,
+            &self.write_perf_status,
         );
         let result = self.backend.put_cf(self.handle(), &C::key(key), &buf);
         if is_perf_enabled {

ledger/src/blockstore_metrics.rs

@@ -7,13 +7,15 @@ use {
         PerfContext,
     },
     solana_metrics::datapoint_info,
+    solana_sdk::timing::timestamp,
     std::{
         cell::RefCell,
         fmt::Debug,
         sync::{
-            atomic::{AtomicUsize, Ordering},
+            atomic::{AtomicU64, AtomicUsize, Ordering},
             Arc,
         },
+        time::Duration,
     },
 };
 
@@ -236,6 +238,9 @@ impl BlockstoreRocksDbColumnFamilyMetrics {
 // Thread local instance of RocksDB's PerfContext.
 thread_local! {static PER_THREAD_ROCKS_PERF_CONTEXT: RefCell<PerfContext> = RefCell::new(PerfContext::default());}
 
+// The minimum time duration between two RocksDB perf samples of the same operation.
+const PERF_SAMPLING_MIN_DURATION: Duration = Duration::from_secs(1);
+
 /// The function enables RocksDB PerfContext once for every `sample_interval`.
 ///
 /// PerfContext is a thread-local struct defined in RocksDB for collecting
@@ -245,25 +250,16 @@ thread_local! {static PER_THREAD_ROCKS_PERF_CONTEXT: RefCell<PerfContext> = RefC
 /// and the PerfContext of the ubsequent RocksDB operation will be collected.
 pub(crate) fn maybe_enable_rocksdb_perf(
     sample_interval: usize,
-    perf_samples_counter: &AtomicUsize,
+    perf_status: &PerfSamplingStatus,
 ) -> bool {
-    if sample_interval == 0 {
-        return false;
-    }
-
-    if perf_samples_counter.fetch_add(1, Ordering::Relaxed) < sample_interval {
-        return false;
-    }
-    // Ideally, fetch_sub(*sample_interval) should be used to keep it
-    // super precise.  However, since we do not use Mutex to protect the
-    // above check and the below operation, we simply reset it to 0.
-    perf_samples_counter.store(0, Ordering::Relaxed);
-
+    if perf_status.should_sample(sample_interval) {
         set_perf_stats(PerfStatsLevel::EnableTime);
         PER_THREAD_ROCKS_PERF_CONTEXT.with(|perf_context| {
             perf_context.borrow_mut().reset();
         });
-    true
+        return true;
+    }
+    false
 }
 
 /// Reports the collected PerfContext and disables the PerfContext after
@@ -516,7 +512,43 @@ pub(crate) fn report_rocksdb_write_perf(metric_header: &'static str) {
 /// A struct that holds the current status of RocksDB perf sampling.
 pub struct PerfSamplingStatus {
     // The number of RocksDB operations since the last perf sample.
-    pub(crate) op_count: AtomicUsize,
+    op_count: AtomicUsize,
+    // The timestamp of the latest operation with perf stats collection.
+    last_sample_time_ms: AtomicU64,
+}
+
+impl PerfSamplingStatus {
+    fn should_sample(&self, sample_count_interval: usize) -> bool {
+        if sample_count_interval == 0 {
+            return false;
+        }
+
+        // Rate-limiting based on the number of samples.
+        if self.op_count.fetch_add(1, Ordering::Relaxed) < sample_count_interval {
+            return false;
+        }
+        self.op_count.store(0, Ordering::Relaxed);
+
+        // Rate-limiting based on the time duration.
+        let current_time_ms = timestamp();
+        let old_time_ms = self.last_sample_time_ms.load(Ordering::Relaxed);
+        if old_time_ms + (PERF_SAMPLING_MIN_DURATION.as_millis() as u64) > current_time_ms {
+            return false;
+        }
+
+        // If the `last_sample_time_ms` has a different value than `old_time_ms`,
+        // it means some other thread has performed the sampling and updated
+        // the last sample time.  In this case, the current thread will skip
+        // the current sample.
+        self.last_sample_time_ms
+            .compare_exchange_weak(
+                old_time_ms,
+                current_time_ms,
+                Ordering::Relaxed,
+                Ordering::Relaxed,
+            )
+            .is_ok()
+    }
 }
 
 pub trait ColumnMetrics {