scheduler opt-in forwarding (#1801)

banking-bench/src/main.rs

@@ -474,6 +474,7 @@ fn main() {
         Arc::new(connection_cache),
         bank_forks.clone(),
         &Arc::new(PrioritizationFeeCache::new(0u64)),
+        false,
     );
 
     // This is so that the signal_receiver does not go out of scope after the closure.

core/benches/banking_stage.rs

@@ -303,6 +303,7 @@ fn bench_banking(bencher: &mut Bencher, tx_type: TransactionType) {
         Arc::new(ConnectionCache::new("connection_cache_test")),
         bank_forks,
         &Arc::new(PrioritizationFeeCache::new(0u64)),
+        false,
     );
 
     let chunk_len = verified.len() / CHUNKS;

core/src/banking_stage.rs

@@ -339,6 +339,7 @@ impl BankingStage {
         connection_cache: Arc<ConnectionCache>,
         bank_forks: Arc<RwLock<BankForks>>,
         prioritization_fee_cache: &Arc<PrioritizationFeeCache>,
+        enable_forwarding: bool,
     ) -> Self {
         Self::new_num_threads(
             block_production_method,
@@ -354,6 +355,7 @@ impl BankingStage {
             connection_cache,
             bank_forks,
             prioritization_fee_cache,
+            enable_forwarding,
         )
     }
 
@@ -372,6 +374,7 @@ impl BankingStage {
         connection_cache: Arc<ConnectionCache>,
         bank_forks: Arc<RwLock<BankForks>>,
         prioritization_fee_cache: &Arc<PrioritizationFeeCache>,
+        enable_forwarding: bool,
     ) -> Self {
         match block_production_method {
             BlockProductionMethod::ThreadLocalMultiIterator => {
@@ -403,6 +406,7 @@ impl BankingStage {
                 connection_cache,
                 bank_forks,
                 prioritization_fee_cache,
+                enable_forwarding,
             ),
         }
     }
@@ -505,6 +509,7 @@ impl BankingStage {
         connection_cache: Arc<ConnectionCache>,
         bank_forks: Arc<RwLock<BankForks>>,
         prioritization_fee_cache: &Arc<PrioritizationFeeCache>,
+        enable_forwarding: bool,
     ) -> Self {
         assert!(num_threads >= MIN_TOTAL_THREADS);
         // Single thread to generate entries from many banks.
@@ -586,13 +591,15 @@ impl BankingStage {
             )
         }
 
-        let forwarder = Forwarder::new(
-            poh_recorder.clone(),
-            bank_forks.clone(),
-            cluster_info.clone(),
-            connection_cache.clone(),
-            data_budget.clone(),
-        );
+        let forwarder = enable_forwarding.then(|| {
+            Forwarder::new(
+                poh_recorder.clone(),
+                bank_forks.clone(),
+                cluster_info.clone(),
+                connection_cache.clone(),
+                data_budget.clone(),
+            )
+        });
 
         // Spawn the central scheduler thread
         bank_thread_hdls.push({
@@ -883,6 +890,7 @@ mod tests {
                 Arc::new(ConnectionCache::new("connection_cache_test")),
                 bank_forks,
                 &Arc::new(PrioritizationFeeCache::new(0u64)),
+                false,
             );
             drop(non_vote_sender);
             drop(tpu_vote_sender);
@@ -938,6 +946,7 @@ mod tests {
                 Arc::new(ConnectionCache::new("connection_cache_test")),
                 bank_forks,
                 &Arc::new(PrioritizationFeeCache::new(0u64)),
+                false,
             );
             trace!("sending bank");
             drop(non_vote_sender);
@@ -1017,6 +1026,7 @@ mod tests {
                 Arc::new(ConnectionCache::new("connection_cache_test")),
                 bank_forks.clone(), // keep a local-copy of bank-forks so worker threads do not lose weak access to bank-forks
                 &Arc::new(PrioritizationFeeCache::new(0u64)),
+                false,
             );
 
             // fund another account so we can send 2 good transactions in a single batch.
@@ -1378,6 +1388,7 @@ mod tests {
                 Arc::new(ConnectionCache::new("connection_cache_test")),
                 bank_forks,
                 &Arc::new(PrioritizationFeeCache::new(0u64)),
+                false,
             );
 
             let keypairs = (0..100).map(|_| Keypair::new()).collect_vec();

core/src/banking_stage/transaction_scheduler/scheduler_controller.rs

@@ -65,8 +65,8 @@ pub(crate) struct SchedulerController {
     timing_metrics: SchedulerTimingMetrics,
     /// Metric report handles for the worker threads.
     worker_metrics: Vec<Arc<ConsumeWorkerMetrics>>,
-    /// State for forwarding packets to the leader.
-    forwarder: Forwarder,
+    /// State for forwarding packets to the leader, if enabled.
+    forwarder: Option<Forwarder>,
 }
 
 impl SchedulerController {
@@ -76,7 +76,7 @@ impl SchedulerController {
         bank_forks: Arc<RwLock<BankForks>>,
         scheduler: PrioGraphScheduler,
         worker_metrics: Vec<Arc<ConsumeWorkerMetrics>>,
-        forwarder: Forwarder,
+        forwarder: Option<Forwarder>,
     ) -> Self {
         Self {
             decision_maker,
@@ -147,6 +147,7 @@ impl SchedulerController {
         &mut self,
         decision: &BufferedPacketsDecision,
     ) -> Result<(), SchedulerError> {
+        let forwarding_enabled = self.forwarder.is_some();
         match decision {
             BufferedPacketsDecision::Consume(bank_start) => {
                 let (scheduling_summary, schedule_time_us) = measure_us!(self.scheduler.schedule(
@@ -186,16 +187,30 @@ impl SchedulerController {
                 });
             }
             BufferedPacketsDecision::Forward => {
-                let (_, forward_time_us) = measure_us!(self.forward_packets(false));
-                self.timing_metrics.update(|timing_metrics| {
-                    saturating_add_assign!(timing_metrics.forward_time_us, forward_time_us);
-                });
+                if forwarding_enabled {
+                    let (_, forward_time_us) = measure_us!(self.forward_packets(false));
+                    self.timing_metrics.update(|timing_metrics| {
+                        saturating_add_assign!(timing_metrics.forward_time_us, forward_time_us);
+                    });
+                } else {
+                    let (_, clear_time_us) = measure_us!(self.clear_container());
+                    self.timing_metrics.update(|timing_metrics| {
+                        saturating_add_assign!(timing_metrics.clear_time_us, clear_time_us);
+                    });
+                }
             }
             BufferedPacketsDecision::ForwardAndHold => {
-                let (_, forward_time_us) = measure_us!(self.forward_packets(true));
-                self.timing_metrics.update(|timing_metrics| {
-                    saturating_add_assign!(timing_metrics.forward_time_us, forward_time_us);
-                });
+                if forwarding_enabled {
+                    let (_, forward_time_us) = measure_us!(self.forward_packets(true));
+                    self.timing_metrics.update(|timing_metrics| {
+                        saturating_add_assign!(timing_metrics.forward_time_us, forward_time_us);
+                    });
+                } else {
+                    let (_, clean_time_us) = measure_us!(self.clean_queue());
+                    self.timing_metrics.update(|timing_metrics| {
+                        saturating_add_assign!(timing_metrics.clean_time_us, clean_time_us);
+                    });
+                }
             }
             BufferedPacketsDecision::Hold => {}
         }
@@ -234,6 +249,7 @@ impl SchedulerController {
         let start = Instant::now();
         let bank = self.bank_forks.read().unwrap().working_bank();
         let feature_set = &bank.feature_set;
+        let forwarder = self.forwarder.as_mut().expect("forwarder must exist");
 
         // Pop from the container in chunks, filter using bank checks, then attempt to forward.
         // This doubles as a way to clean the queue as well as forwarding transactions.
@@ -282,7 +298,7 @@ impl SchedulerController {
 
                 // If not already forwarded and can be forwarded, add to forwardable packets.
                 if state.should_forward()
-                    && self.forwarder.try_add_packet(
+                    && forwarder.try_add_packet(
                         sanitized_transaction,
                         immutable_packet,
                         feature_set,
@@ -300,9 +316,8 @@ impl SchedulerController {
         }
 
         // Forward each batch of transactions
-        self.forwarder
-            .forward_batched_packets(&ForwardOption::ForwardTransaction);
-        self.forwarder.clear_batches();
+        forwarder.forward_batched_packets(&ForwardOption::ForwardTransaction);
+        forwarder.clear_batches();
 
         // If we hit the time limit. Drop everything that was not checked/processed.
         // If we cannot run these simple checks in time, then we cannot run them during
@@ -330,7 +345,6 @@ impl SchedulerController {
 
     /// Clears the transaction state container.
     /// This only clears pending transactions, and does **not** clear in-flight transactions.
-    #[allow(dead_code)]
     fn clear_container(&mut self) {
         let mut num_dropped_on_clear: usize = 0;
         while let Some(id) = self.container.pop() {
@@ -346,7 +360,6 @@ impl SchedulerController {
     /// Clean unprocessable transactions from the queue. These will be transactions that are
     /// expired, already processed, or are no longer sanitizable.
     /// This only clears pending transactions, and does **not** clear in-flight transactions.
-    #[allow(dead_code)]
     fn clean_queue(&mut self) {
         // Clean up any transactions that have already been processed, are too old, or do not have
         // valid nonce accounts.
@@ -424,17 +437,19 @@ impl SchedulerController {
         let remaining_queue_capacity = self.container.remaining_queue_capacity();
 
         const MAX_PACKET_RECEIVE_TIME: Duration = Duration::from_millis(100);
-        let recv_timeout = match decision {
-            BufferedPacketsDecision::Consume(_) => {
+        let (recv_timeout, should_buffer) = match decision {
+            BufferedPacketsDecision::Consume(_) => (
                 if self.container.is_empty() {
                     MAX_PACKET_RECEIVE_TIME
                 } else {
                     Duration::ZERO
-                }
+                },
+                true,
+            ),
+            BufferedPacketsDecision::Forward => (MAX_PACKET_RECEIVE_TIME, false),
+            BufferedPacketsDecision::ForwardAndHold | BufferedPacketsDecision::Hold => {
+                (MAX_PACKET_RECEIVE_TIME, true)
             }
-            BufferedPacketsDecision::Forward
-            | BufferedPacketsDecision::ForwardAndHold
-            | BufferedPacketsDecision::Hold => MAX_PACKET_RECEIVE_TIME,
         };
 
         let (received_packet_results, receive_time_us) = measure_us!(self
@@ -456,11 +471,21 @@ impl SchedulerController {
                     saturating_add_assign!(count_metrics.num_received, num_received_packets);
                 });
 
-                let (_, buffer_time_us) =
-                    measure_us!(self.buffer_packets(receive_packet_results.deserialized_packets));
-                self.timing_metrics.update(|timing_metrics| {
-                    saturating_add_assign!(timing_metrics.buffer_time_us, buffer_time_us);
-                });
+                if should_buffer {
+                    let (_, buffer_time_us) = measure_us!(
+                        self.buffer_packets(receive_packet_results.deserialized_packets)
+                    );
+                    self.timing_metrics.update(|timing_metrics| {
+                        saturating_add_assign!(timing_metrics.buffer_time_us, buffer_time_us);
+                    });
+                } else {
+                    self.count_metrics.update(|count_metrics| {
+                        saturating_add_assign!(
+                            count_metrics.num_dropped_on_receive,
+                            num_received_packets
+                        );
+                    });
+                }
             }
             Err(RecvTimeoutError::Timeout) => {}
             Err(RecvTimeoutError::Disconnected) => return false,
@@ -636,14 +661,13 @@ mod tests {
             banking_stage::{
                 consumer::TARGET_NUM_TRANSACTIONS_PER_BATCH,
                 scheduler_messages::{ConsumeWork, FinishedConsumeWork, TransactionBatchId},
-                tests::{create_slow_genesis_config, new_test_cluster_info},
+                tests::create_slow_genesis_config,
             },
             banking_trace::BankingPacketBatch,
             sigverify::SigverifyTracerPacketStats,
         },
         crossbeam_channel::{unbounded, Receiver, Sender},
         itertools::Itertools,
-        solana_client::connection_cache::ConnectionCache,
         solana_ledger::{
             blockstore::Blockstore, genesis_utils::GenesisConfigInfo,
             get_tmp_ledger_path_auto_delete, leader_schedule_cache::LeaderScheduleCache,
@@ -712,17 +736,6 @@ mod tests {
         let (consume_work_senders, consume_work_receivers) = create_channels(num_threads);
         let (finished_consume_work_sender, finished_consume_work_receiver) = unbounded();
 
-        let validator_keypair = Arc::new(Keypair::new());
-        let (_local_node, cluster_info) = new_test_cluster_info(Some(validator_keypair));
-        let cluster_info = Arc::new(cluster_info);
-        let forwarder = Forwarder::new(
-            poh_recorder.clone(),
-            bank_forks.clone(),
-            cluster_info,
-            Arc::new(ConnectionCache::new("connection_cache_test")),
-            Arc::default(),
-        );
-
         let test_frame = TestFrame {
             bank,
             mint_keypair,
@@ -741,7 +754,7 @@ mod tests {
             bank_forks,
             PrioGraphScheduler::new(consume_work_senders, finished_consume_work_receiver),
             vec![], // no actual workers with metrics to report, this can be empty
-            forwarder,
+            None,
         );
 
         (test_frame, scheduler_controller)

core/src/banking_stage/transaction_scheduler/scheduler_metrics.rs

@@ -271,6 +271,10 @@ pub struct SchedulerTimingMetricsInner {
     pub schedule_filter_time_us: u64,
     /// Time spent scheduling transactions.
     pub schedule_time_us: u64,
+    /// Time spent clearing transactions from the container.
+    pub clear_time_us: u64,
+    /// Time spent cleaning expired or processed transactions from the container.
+    pub clean_time_us: u64,
     /// Time spent forwarding transactions.
     pub forward_time_us: u64,
     /// Time spent receiving completed transactions.
@@ -312,6 +316,8 @@ impl SchedulerTimingMetricsInner {
             ("buffer_time_us", self.buffer_time_us, i64),
             ("schedule_filter_time_us", self.schedule_filter_time_us, i64),
             ("schedule_time_us", self.schedule_time_us, i64),
+            ("clear_time_us", self.clear_time_us, i64),
+            ("clean_time_us", self.clean_time_us, i64),
             ("forward_time_us", self.forward_time_us, i64),
             (
                 "receive_completed_time_us",
@@ -331,6 +337,8 @@ impl SchedulerTimingMetricsInner {
         self.buffer_time_us = 0;
         self.schedule_filter_time_us = 0;
         self.schedule_time_us = 0;
+        self.clear_time_us = 0;
+        self.clean_time_us = 0;
         self.forward_time_us = 0;
         self.receive_completed_time_us = 0;
     }

core/src/tpu.rs

@@ -116,6 +116,7 @@ impl Tpu {
         tpu_max_connections_per_ipaddr_per_minute: u64,
         prioritization_fee_cache: &Arc<PrioritizationFeeCache>,
         block_production_method: BlockProductionMethod,
+        enable_block_production_forwarding: bool,
         _generator_config: Option<GeneratorConfig>, /* vestigial code for replay invalidator */
     ) -> (Self, Vec<Arc<dyn NotifyKeyUpdate + Sync + Send>>) {
         let TpuSockets {
@@ -246,6 +247,7 @@ impl Tpu {
             connection_cache.clone(),
             bank_forks.clone(),
             prioritization_fee_cache,
+            enable_block_production_forwarding,
         );
 
         let (entry_receiver, tpu_entry_notifier) =

core/src/validator.rs

@@ -266,6 +266,7 @@ pub struct ValidatorConfig {
     pub banking_trace_dir_byte_limit: banking_trace::DirByteLimit,
     pub block_verification_method: BlockVerificationMethod,
     pub block_production_method: BlockProductionMethod,
+    pub enable_block_production_forwarding: bool,
     pub generator_config: Option<GeneratorConfig>,
     pub use_snapshot_archives_at_startup: UseSnapshotArchivesAtStartup,
     pub wen_restart_proto_path: Option<PathBuf>,
@@ -337,6 +338,7 @@ impl Default for ValidatorConfig {
             banking_trace_dir_byte_limit: 0,
             block_verification_method: BlockVerificationMethod::default(),
             block_production_method: BlockProductionMethod::default(),
+            enable_block_production_forwarding: false,
             generator_config: None,
             use_snapshot_archives_at_startup: UseSnapshotArchivesAtStartup::default(),
             wen_restart_proto_path: None,
@@ -355,6 +357,7 @@ impl ValidatorConfig {
             enforce_ulimit_nofile: false,
             rpc_config: JsonRpcConfig::default_for_test(),
             block_production_method: BlockProductionMethod::default(),
+            enable_block_production_forwarding: true, // enable forwarding by default for tests
             replay_forks_threads: NonZeroUsize::new(1).expect("1 is non-zero"),
             replay_transactions_threads: NonZeroUsize::new(get_max_thread_count())
                 .expect("thread count is non-zero"),
@@ -1432,6 +1435,7 @@ impl Validator {
             tpu_max_connections_per_ipaddr_per_minute,
             &prioritization_fee_cache,
             config.block_production_method.clone(),
+            config.enable_block_production_forwarding,
             config.generator_config.clone(),
         );