minio/docs/deployment/kernel-tuning/README.md

Kernel Tuning for MinIO Production Deployment on Linux Servers

List of kernel tuning recommendations for MinIO server deployments, a copy of this script is available here that can be applied on the servers.

NOTE: These are common recommendations on any Linux servers, users must be careful on any premature optimization. These settings are not mandatory, these settings do not fix any hardware issues and should not be considered as an alternative to boost performance to mask underlying hardware problems. Under all circumstances it is recommended to perform this tuning only after performing benchmarks for the hardware with expected baseline results.

#!/bin/bash

cat > sysctl.conf <<EOF
# maximum number of open files/file descriptors
fs.file-max = 4194303

# use as little swap space as possible
vm.swappiness = 1

# prioritize application RAM against disk/swap cache
vm.vfs_cache_pressure = 50

# minimum free memory
vm.min_free_kbytes = 1000000

# follow mellanox best practices https://community.mellanox.com/s/article/linux-sysctl-tuning
# the following changes are recommended for improving IPv4 traffic performance by Mellanox

# disable the TCP timestamps option for better CPU utilization
net.ipv4.tcp_timestamps = 0

# enable the TCP selective acks option for better throughput
net.ipv4.tcp_sack = 1

# increase the maximum length of processor input queues
net.core.netdev_max_backlog = 250000

# increase the TCP maximum and default buffer sizes using setsockopt()
net.core.rmem_max = 4194304
net.core.wmem_max = 4194304
net.core.rmem_default = 4194304
net.core.wmem_default = 4194304
net.core.optmem_max = 4194304

# increase memory thresholds to prevent packet dropping:
net.ipv4.tcp_rmem = "4096 87380 4194304"
net.ipv4.tcp_wmem = "4096 65536 4194304"

# enable low latency mode for TCP:
net.ipv4.tcp_low_latency = 1

# the following variable is used to tell the kernel how much of the socket buffer
# space should be used for TCP window size, and how much to save for an application
# buffer. A value of 1 means the socket buffer will be divided evenly between.
# TCP windows size and application.
net.ipv4.tcp_adv_win_scale = 1

# maximum number of incoming connections
net.core.somaxconn = 65535

# maximum number of packets queued
net.core.netdev_max_backlog = 10000

# queue length of completely established sockets waiting for accept
net.ipv4.tcp_max_syn_backlog = 4096

# time to wait (seconds) for FIN packet
net.ipv4.tcp_fin_timeout = 15

# disable icmp send redirects
net.ipv4.conf.all.send_redirects = 0

# disable icmp accept redirect
net.ipv4.conf.all.accept_redirects = 0

# drop packets with LSR or SSR
net.ipv4.conf.all.accept_source_route = 0

# MTU discovery, only enable when ICMP blackhole detected
net.ipv4.tcp_mtu_probing = 1

EOF

echo "Enabling system level tuning params"
sysctl --quiet --load sysctl.conf && rm -f sysctl.conf

# `Transparent Hugepage Support`*: This is a Linux kernel feature intended to improve
# performance by making more efficient use of processor’s memory-mapping hardware.
# But this may cause https://blogs.oracle.com/linux/performance-issues-with-transparent-huge-pages-thp
# for non-optimized applications. As most Linux distributions set it to `enabled=always` by default,
# we recommend changing this to `enabled=madvise`. This will allow applications optimized
# for transparent hugepages to obtain the performance benefits, while preventing the
# associated problems otherwise. Also, set `transparent_hugepage=madvise` on your kernel
# command line (e.g. in /etc/default/grub) to persistently set this value.

echo "Enabling THP madvise"
echo madvise | sudo tee /sys/kernel/mm/transparent_hugepage/enabled