From 687af3e3a4883155d36aa5b709b0c6f502bd9fa5 Mon Sep 17 00:00:00 2001
From: Michael Vines <mvines@gmail.com>
Date: Wed, 4 Jul 2018 14:17:42 -0700
Subject: [PATCH] Document source of magic net.core.rmem_max value

---
 multinode-demo/common.sh | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/multinode-demo/common.sh b/multinode-demo/common.sh
index fb1ad40d13..36a9800858 100644
--- a/multinode-demo/common.sh
+++ b/multinode-demo/common.sh
@@ -58,7 +58,13 @@ export RUST_LOG=${RUST_LOG:-solana=info} # if RUST_LOG is unset, default to info
 export RUST_BACKTRACE=1
 
 tune_networking() {
-  [[ $(uname) = Linux ]] && (set -x; sudo sysctl -w net.core.rmem_max=26214400 1>/dev/null 2>/dev/null)
+  # Reference: https://medium.com/@CameronSparr/increase-os-udp-buffers-to-improve-performance-51d167bb1360
+  [[ $(uname) = Linux ]] && (
+    set -x
+    # TODO: Check values and warn instead, it's a little rude to set them here.
+    sudo sysctl -w net.core.rmem_max=26214400 1>/dev/null 2>/dev/null
+    sudo sysctl -w net.core.rmem_default=26214400 1>/dev/null 2>/dev/null
+  )
 }
 
 SOLANA_CONFIG_DIR=${SNAP_DATA:-$PWD}/config