Treat super low staked as unstaked in streamer QOS (solana-labs#701)

* Treat super low staked with QOS of unstaked * simplify * address some comment from Pankaj
lijunwangs · Apr 10, 2024 · 92ebf0f · 92ebf0f
1 parent 006cf28
commit 92ebf0f
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Showing 2 changed files with 13 additions and 6 deletions.
diff --git a/streamer/src/nonblocking/quic.rs b/streamer/src/nonblocking/quic.rs
@@ -1,7 +1,8 @@
 use {
     crate::{
         nonblocking::stream_throttle::{
-            ConnectionStreamCounter, StakedStreamLoadEMA, STREAM_STOP_CODE_THROTTLING,
+            ConnectionStreamCounter, StakedStreamLoadEMA, MAX_STREAMS_PER_MS,
+            STREAM_STOP_CODE_THROTTLING, STREAM_THROTTLING_INTERVAL_MS,
         },
         quic::{configure_server, QuicServerError, StreamStats},
         streamer::StakedNodes,
@@ -500,10 +501,16 @@ async fn setup_connection(
                         stats.clone(),
                     ),
                     |(pubkey, stake, total_stake, max_stake, min_stake)| {
-                        let peer_type = if stake > 0 {
-                            ConnectionPeerType::Staked(stake)
-                        } else {
+                        // The heuristic is that the stake should be large engouh to have 1 stream pass throuh within one throttle
+                        // interval during which we allow max (MAX_STREAMS_PER_MS * STREAM_THROTTLING_INTERVAL_MS) streams.
+                        let min_stake_ratio =
+                            1_f64 / (MAX_STREAMS_PER_MS * STREAM_THROTTLING_INTERVAL_MS) as f64;
+                        let stake_ratio = stake as f64 / total_stake as f64;
+                        let peer_type = if stake_ratio < min_stake_ratio {
+                            // If it is a staked connection with ultra low stake ratio, treat it as unstaked.
                             ConnectionPeerType::Unstaked
+                        } else {
+                            ConnectionPeerType::Staked(stake)
                         };
                         NewConnectionHandlerParams {
                             packet_sender,

diff --git a/streamer/src/nonblocking/stream_throttle.rs b/streamer/src/nonblocking/stream_throttle.rs
@@ -12,9 +12,9 @@ use {
 };
 
 /// Limit to 250K PPS
-const MAX_STREAMS_PER_MS: u64 = 250;
+pub const MAX_STREAMS_PER_MS: u64 = 250;
 const MAX_UNSTAKED_STREAMS_PERCENT: u64 = 20;
-const STREAM_THROTTLING_INTERVAL_MS: u64 = 100;
+pub const STREAM_THROTTLING_INTERVAL_MS: u64 = 100;
 pub const STREAM_STOP_CODE_THROTTLING: u32 = 15;
 const STREAM_LOAD_EMA_INTERVAL_MS: u64 = 5;
 const STREAM_LOAD_EMA_INTERVAL_COUNT: u64 = 10;