1
0
Fork 0

feat(openshift): Optimize TCP settings for high throughput and low latency

Apply specific kernel network tuning parameters to the OpenShift profile
(/profiles/openshift/tuned.conf) to support high bandwidth-delay product links.

The following TCP settings are added:
net.ipv4.tcp_notsent_lowat=131072: Sets tcp_notsent_lowat to a value intended to balance throughput and latency while limiting total socket memory usage.
net.ipv4.tcp_slow_start_after_idle=0: Disables slow start after a connection has been idle, allowing immediate maximum throughput upon resuming data transfer.
net.ipv4.tcp_rmem="4096 131072 16777216": Increases the maximum TCP receive buffer size to improve performance on high-bandwidth-delay product connections.
net.ipv4.tcp_wmem="4096 16384 16777216": Increases the maximum TCP send buffer size for similar reasons.

These changes are based on work done by Cloudflare for improving TCP
performance on high bandwidth-delay product links but are more conservative in adjusting rmem and wmem

Reference: https://blog.cloudflare.com/optimizing-tcp-for-high-throughput-and-low-latency/

Signed-off-by: Graham Heffern <gheffern@gmail.com>
This commit is contained in:
Graham Heffern 2025-11-08 09:19:22 -06:00
parent 181472a0be
commit 7a1a288e85

View file

@ -17,6 +17,10 @@ kernel.pid_max=>4194304
fs.aio-max-nr=>1048576
net.netfilter.nf_conntrack_max=1048576
net.ipv4.conf.all.arp_announce=2
net.ipv4.tcp_notsent_lowat=131072
net.ipv4.tcp_slow_start_after_idle=0
net.ipv4.tcp_rmem="4096 131072 16777216"
net.ipv4.tcp_wmem="4096 16384 16777216"
net.ipv4.neigh.default.gc_thresh1=8192
net.ipv4.neigh.default.gc_thresh2=32768
net.ipv4.neigh.default.gc_thresh3=65536