EC2

Optimize Network Kernel Parameters

For high load environments consisting of many Fluentd instances, please add these parameters to your /etc/sysctl.conf file. Please either type sysctl -p or reboot your node to have the changes take effect.

net.core.somaxconn = 1024
net.core.netdev_max_backlog = 5000
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_wmem = 4096 12582912 16777216
net.ipv4.tcp_rmem = 4096 12582912 16777216
net.ipv4.tcp_max_syn_backlog = 8096
net.ipv4.tcp_slow_start_after_idle = 0
net.ipv4.tcp_tw_reuse = 1
net.ipv4.ip_local_port_range = 10240 65535

These kernel options were originally taken from the presentation “How Netflix Tunes EC2 Instances for Performance” by Brendan Gregg, Senior Performance Architect at AWS re:Invent 2017.