Throttle unstaked quic streams for a given connection (solana-labs#34562

)

* Throttle unstaked quic streams for a given connection

* Fix interval duration check

* move wait to handle_chunk

* set max unistreams to 0

* drop new streams

* cleanup

* some more cleanup

* fix tests

* update test and stop code

* fix bench-tps

bench-tps/src/send_batch.rs

@@ -248,9 +248,13 @@ where
     fn send<C: BenchTpsClient + ?Sized>(&self, client: &Arc<C>) {
         let mut send_txs = Measure::start("send_and_clone_txs");
         let batch: Vec<_> = self.iter().map(|(_keypair, tx)| tx.clone()).collect();
-        client.send_batch(batch).expect("transfer");
+        let result = client.send_batch(batch);
         send_txs.stop();
-        debug!("send {} {}", self.len(), send_txs);
+        if result.is_err() {
+            debug!("Failed to send batch {result:?}");
+        } else {
+            debug!("send {} {}", self.len(), send_txs);
+        }
     }
 
     fn verify<C: 'static + BenchTpsClient + Send + Sync + ?Sized>(

local-cluster/tests/local_cluster.rs

@@ -2926,24 +2926,26 @@ fn setup_transfer_scan_threads(
                     .get_latest_blockhash_with_commitment(CommitmentConfig::processed())
                     .unwrap();
                 for i in 0..starting_keypairs_.len() {
-                    client
-                        .async_transfer(
-                            1,
-                            &starting_keypairs_[i],
-                            &target_keypairs_[i].pubkey(),
-                            blockhash,
-                        )
-                        .unwrap();
+                    let result = client.async_transfer(
+                        1,
+                        &starting_keypairs_[i],
+                        &target_keypairs_[i].pubkey(),
+                        blockhash,
+                    );
+                    if result.is_err() {
+                        debug!("Failed in transfer for starting keypair: {:?}", result);
+                    }
                 }
                 for i in 0..starting_keypairs_.len() {
-                    client
-                        .async_transfer(
-                            1,
-                            &target_keypairs_[i],
-                            &starting_keypairs_[i].pubkey(),
-                            blockhash,
-                        )
-                        .unwrap();
+                    let result = client.async_transfer(
+                        1,
+                        &target_keypairs_[i],
+                        &starting_keypairs_[i].pubkey(),
+                        blockhash,
+                    );
+                    if result.is_err() {
+                        debug!("Failed in transfer for starting keypair: {:?}", result);
+                    }
                 }
             }
         })

quic-client/tests/quic_client.rs

@@ -46,7 +46,7 @@ mod tests {
                 assert_eq!(p.meta().size, num_bytes);
             }
         }
-        assert_eq!(total_packets, num_expected_packets);
+        assert!(total_packets > 0);
     }
 
     fn server_args() -> (UdpSocket, Arc<AtomicBool>, Keypair, IpAddr) {
@@ -139,7 +139,7 @@ mod tests {
                 assert_eq!(p.meta().size, num_bytes);
             }
         }
-        assert_eq!(total_packets, num_expected_packets);
+        assert!(total_packets > 0);
     }
 
     #[tokio::test]
@@ -182,7 +182,9 @@ mod tests {
         let num_bytes = PACKET_DATA_SIZE;
         let num_expected_packets: usize = 3000;
         let packets = vec![vec![0u8; PACKET_DATA_SIZE]; num_expected_packets];
-        assert!(client.send_data_batch(&packets).await.is_ok());
+        for packet in packets {
+            let _ = client.send_data(&packet).await;
+        }
 
         nonblocking_check_packets(receiver, num_bytes, num_expected_packets).await;
         exit.store(true, Ordering::Relaxed);

streamer/src/nonblocking/quic.rs

@@ -1,6 +1,6 @@
 use {
     crate::{
-        quic::{configure_server, QuicServerError, StreamStats},
+        quic::{configure_server, QuicServerError, StreamStats, MAX_UNSTAKED_CONNECTIONS},
         streamer::StakedNodes,
         tls_certificates::get_pubkey_from_tls_certificate,
     },
@@ -39,6 +39,10 @@ use {
     tokio::{task::JoinHandle, time::timeout},
 };
 
+/// Limit to 500K PPS
+const MAX_STREAMS_PER_100MS: u64 = 500_000 / 10;
+const MAX_UNSTAKED_STREAMS_PERCENT: u64 = 20;
+const STREAM_THROTTLING_INTERVAL: Duration = Duration::from_millis(100);
 const WAIT_FOR_STREAM_TIMEOUT: Duration = Duration::from_millis(100);
 pub const DEFAULT_WAIT_FOR_CHUNK_TIMEOUT: Duration = Duration::from_secs(10);
 
@@ -55,6 +59,7 @@ const CONNECTION_CLOSE_REASON_EXCEED_MAX_STREAM_COUNT: &[u8] = b"exceed_max_stre
 
 const CONNECTION_CLOSE_CODE_TOO_MANY: u32 = 4;
 const CONNECTION_CLOSE_REASON_TOO_MANY: &[u8] = b"too_many";
+const STREAM_STOP_CODE_THROTTLING: u32 = 15;
 
 // A sequence of bytes that is part of a packet
 // along with where in the packet it is
@@ -264,6 +269,7 @@ enum ConnectionHandlerError {
     MaxStreamError,
 }
 
+#[derive(Clone)]
 struct NewConnectionHandlerParams {
     // In principle, the code can be made to work with a crossbeam channel
     // as long as we're careful never to use a blocking recv or send call
@@ -348,13 +354,11 @@ fn handle_and_cache_new_connection(
             drop(connection_table_l);
             tokio::spawn(handle_connection(
                 connection,
-                params.packet_sender.clone(),
                 remote_addr,
-                params.remote_pubkey,
                 last_update,
                 connection_table,
                 stream_exit,
-                params.stats.clone(),
+                params.clone(),
                 peer_type,
                 wait_for_chunk_timeout,
             ));
@@ -681,19 +685,42 @@ async fn packet_batch_sender(
     }
 }
 
-#[allow(clippy::too_many_arguments)]
+fn max_streams_for_connection_in_100ms(
+    connection_type: ConnectionPeerType,
+    stake: u64,
+    total_stake: u64,
+) -> u64 {
+    if matches!(connection_type, ConnectionPeerType::Unstaked) || stake == 0 {
+        Percentage::from(MAX_UNSTAKED_STREAMS_PERCENT)
+            .apply_to(MAX_STREAMS_PER_100MS)
+            .saturating_div(MAX_UNSTAKED_CONNECTIONS as u64)
+    } else {
+        let max_total_staked_streams: u64 = MAX_STREAMS_PER_100MS
+            - Percentage::from(MAX_UNSTAKED_STREAMS_PERCENT).apply_to(MAX_STREAMS_PER_100MS);
+        ((max_total_staked_streams as f64 / total_stake as f64) * stake as f64) as u64
+    }
+}
+
+fn reset_throttling_params_if_needed(last_instant: &mut tokio::time::Instant) -> bool {
+    if tokio::time::Instant::now().duration_since(*last_instant) > STREAM_THROTTLING_INTERVAL {
+        *last_instant = tokio::time::Instant::now();
+        true
+    } else {
+        false
+    }
+}
+
 async fn handle_connection(
     connection: Connection,
-    packet_sender: AsyncSender<PacketAccumulator>,
     remote_addr: SocketAddr,
-    remote_pubkey: Option<Pubkey>,
     last_update: Arc<AtomicU64>,
     connection_table: Arc<Mutex<ConnectionTable>>,
     stream_exit: Arc<AtomicBool>,
-    stats: Arc<StreamStats>,
+    params: NewConnectionHandlerParams,
     peer_type: ConnectionPeerType,
     wait_for_chunk_timeout: Duration,
 ) {
+    let stats = params.stats;
     debug!(
         "quic new connection {} streams: {} connections: {}",
         remote_addr,
@@ -702,17 +729,28 @@ async fn handle_connection(
     );
     let stable_id = connection.stable_id();
     stats.total_connections.fetch_add(1, Ordering::Relaxed);
+    let max_streams_per_100ms =
+        max_streams_for_connection_in_100ms(peer_type, params.stake, params.total_stake);
+    let mut last_throttling_instant = tokio::time::Instant::now();
+    let mut streams_in_current_interval = 0;
     while !stream_exit.load(Ordering::Relaxed) {
         if let Ok(stream) =
             tokio::time::timeout(WAIT_FOR_STREAM_TIMEOUT, connection.accept_uni()).await
         {
             match stream {
                 Ok(mut stream) => {
+                    if reset_throttling_params_if_needed(&mut last_throttling_instant) {
+                        streams_in_current_interval = 0;
+                    } else if streams_in_current_interval >= max_streams_per_100ms {
+                        let _ = stream.stop(VarInt::from_u32(STREAM_STOP_CODE_THROTTLING));
+                        continue;
+                    }
+                    streams_in_current_interval = streams_in_current_interval.saturating_add(1);
                     stats.total_streams.fetch_add(1, Ordering::Relaxed);
                     stats.total_new_streams.fetch_add(1, Ordering::Relaxed);
                     let stream_exit = stream_exit.clone();
                     let stats = stats.clone();
-                    let packet_sender = packet_sender.clone();
+                    let packet_sender = params.packet_sender.clone();
                     let last_update = last_update.clone();
                     tokio::spawn(async move {
                         let mut maybe_batch = None;
@@ -765,7 +803,7 @@ async fn handle_connection(
     }
 
     let removed_connection_count = connection_table.lock().unwrap().remove_connection(
-        ConnectionTableKey::new(remote_addr.ip(), remote_pubkey),
+        ConnectionTableKey::new(remote_addr.ip(), params.remote_pubkey),
         remote_addr.port(),
         stable_id,
     );
@@ -1989,4 +2027,40 @@ pub mod test {
             compute_receive_window_ratio_for_staked_node(max_stake, min_stake, max_stake + 10);
         assert_eq!(ratio, max_ratio);
     }
+
+    #[test]
+    fn test_max_streams_for_connection_in_100ms() {
+        // 50K packets per ms * 20% / 500 max unstaked connections
+        assert_eq!(
+            max_streams_for_connection_in_100ms(ConnectionPeerType::Unstaked, 0, 10000),
+            20
+        );
+
+        // 50K packets per ms * 20% / 500 max unstaked connections
+        assert_eq!(
+            max_streams_for_connection_in_100ms(ConnectionPeerType::Unstaked, 10, 10000),
+            20
+        );
+
+        // If stake is 0, same limits as unstaked connections will apply.
+        // 50K packets per ms * 20% / 500 max unstaked connections
+        assert_eq!(
+            max_streams_for_connection_in_100ms(ConnectionPeerType::Staked, 0, 10000),
+            20
+        );
+
+        // max staked streams = 50K packets per ms * 80% = 40K
+        // function = 40K * stake / total_stake
+        assert_eq!(
+            max_streams_for_connection_in_100ms(ConnectionPeerType::Staked, 15, 10000),
+            60
+        );
+
+        // max staked streams = 50K packets per ms * 80% = 40K
+        // function = 40K * stake / total_stake
+        assert_eq!(
+            max_streams_for_connection_in_100ms(ConnectionPeerType::Staked, 1000, 10000),
+            4000
+        );
+    }
 }