From 56aa73d05d6123daee2ea951193d2e1b62521ed1 Mon Sep 17 00:00:00 2001
From: behzad nouri <behzadnouri@gmail.com>
Date: Wed, 31 Jul 2024 09:39:04 -0500
Subject: [PATCH] extends Turbine fanout experiment to larger fanout values

Based on previous Turbine fanout experiment, larger fanouts are more
effective in propagating shreds and reducing repairs:
https://discord.com/channels/428295358100013066/478692221441409024/1265782094211321897

In order to identify optimal fanout value, this commit extends the
experiment with larger fanout values.
---
 sdk/src/feature_set.rs       |  5 +++++
 turbine/src/cluster_nodes.rs | 36 +++++++++++++++++++++---------------
 2 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/sdk/src/feature_set.rs b/sdk/src/feature_set.rs
index 887d2e547f19b2..4626240a949de4 100644
--- a/sdk/src/feature_set.rs
+++ b/sdk/src/feature_set.rs
@@ -841,6 +841,10 @@ pub mod vote_only_retransmitter_signed_fec_sets {
     solana_sdk::declare_id!("RfEcA95xnhuwooVAhUUksEJLZBF7xKCLuqrJoqk4Zph");
 }
 
+pub mod enable_turbine_extended_fanout_experiments {
+    solana_sdk::declare_id!("BZn14Liea52wtBwrXUxTv6vojuTTmfc7XGEDTXrvMD7b");
+}
+
 lazy_static! {
     /// Map of feature identifiers to user-visible description
     pub static ref FEATURE_NAMES: HashMap<Pubkey, &'static str> = [
@@ -1046,6 +1050,7 @@ lazy_static! {
         (move_stake_and_move_lamports_ixs::id(), "Enable MoveStake and MoveLamports stake program instructions #1610"),
         (ed25519_precompile_verify_strict::id(), "Use strict verification in ed25519 precompile SIMD-0152"),
         (vote_only_retransmitter_signed_fec_sets::id(), "vote only on retransmitter signed fec sets"),
+        (enable_turbine_extended_fanout_experiments::id(), "enable turbine extended fanout experiments #"),
         /*************** ADD NEW FEATURES HERE ***************/
     ]
     .iter()
diff --git a/turbine/src/cluster_nodes.rs b/turbine/src/cluster_nodes.rs
index 8cc5f29033fd86..cb399b9d414551 100644
--- a/turbine/src/cluster_nodes.rs
+++ b/turbine/src/cluster_nodes.rs
@@ -564,8 +564,28 @@ pub fn make_test_cluster<R: Rng>(
 }
 
 pub(crate) fn get_data_plane_fanout(shred_slot: Slot, root_bank: &Bank) -> usize {
-    if enable_turbine_fanout_experiments(shred_slot, root_bank) {
+    macro_rules! check_feature_activation {
+        ($feature:ident) => {
+            check_feature_activation(&feature_set::$feature::id(), shred_slot, root_bank)
+        };
+    }
+    if check_feature_activation!(disable_turbine_fanout_experiments) {
+        DATA_PLANE_FANOUT
+    } else if check_feature_activation!(enable_turbine_extended_fanout_experiments) {
         // Allocate ~2% of slots to turbine fanout experiments.
+        match shred_slot % 359 {
+            11 => 1152,
+            61 => 1280,
+            111 => 1024,
+            161 => 1408,
+            211 => 896,
+            261 => 1536,
+            311 => 768,
+            _ => DATA_PLANE_FANOUT,
+        }
+    } else {
+        // feature_set::enable_turbine_fanout_experiments
+        // is already activated on all clusters.
         match shred_slot % 359 {
             11 => 64,
             61 => 768,
@@ -576,23 +596,9 @@ pub(crate) fn get_data_plane_fanout(shred_slot: Slot, root_bank: &Bank) -> usize
             311 => 384,
             _ => DATA_PLANE_FANOUT,
         }
-    } else {
-        DATA_PLANE_FANOUT
     }
 }
 
-fn enable_turbine_fanout_experiments(shred_slot: Slot, root_bank: &Bank) -> bool {
-    check_feature_activation(
-        &feature_set::enable_turbine_fanout_experiments::id(),
-        shred_slot,
-        root_bank,
-    ) && !check_feature_activation(
-        &feature_set::disable_turbine_fanout_experiments::id(),
-        shred_slot,
-        root_bank,
-    )
-}
-
 // Returns true if the feature is effective for the shred slot.
 #[must_use]
 pub fn check_feature_activation(feature: &Pubkey, shred_slot: Slot, root_bank: &Bank) -> bool {