shadowsocks服务端优化设置

推特上两位推友@m0d8ye（libev版的作者）和@_zzzh提供的shadowsocks服务端网络优化方案，基本原理相似，都是通过修改 sysctl.conf 相关参数实施的，目标是在高并发、高延迟的网络环境下提高shadowsocks的响应和链接速度。

@m0d8ye提供的 sysctl.conf 修改参数：

net.core.wmem_max = 12582912

net.core.rmem_max = 12582912

net.ipv4.tcp_rmem = 10240 87380 12582912

net.ipv4.tcp_wmem = 10240 87380 12582912

net.ipv4.ip_local_port_range = 18000 65535

net.ipv4.netfilter.ip_conntrack_tcp_timeout_time_wait = 1

net.ipv4.tcp_window_scaling = 1

net.ipv4.tcp_max_syn_backlog = 3240000

net.core.somaxconn = 3240000

net.ipv4.tcp_max_tw_buckets = 1440000

net.ipv4.tcp_congestion_control = cubic

net.ipv4.tcp_tw_reuse = 1

net.ipv4.tcp_fin_timeout = 15

net.ipv4.tcp_syn_retries = 2

net.ipv4.tcp_synack_retries = 2

net.ipv4.tcp_tw_recycle = 1

@_zzzh（原文： 高流量大并发linux Tcp 性能调优 ）提供的sysctl.conf 修改参数：

net.ipv4.tcp_syncookies = 1

net.ipv4.tcp_tw_reuse = 1

net.ipv4.tcp_tw_recycle = 1

net.ipv4.tcp_fin_timeout = 30

net.ipv4.tcp_keepalive_time = 1200

net.ipv4.ip_local_port_range = 10000 65000

net.ipv4.tcp_max_syn_backlog = 8192

net.ipv4.tcp_max_tw_buckets = 5000

net.core.rmem_max = 67108864

net.core.wmem_max = 67108864

net.ipv4.tcp_rmem = 4096 87380 67108864

net.ipv4.tcp_wmem = 4096 65536 67108864

net.core.netdev_max_backlog = 250000

net.ipv4.tcp_mtu_probing=1

net.ipv4.tcp_congestion_control=hybla

sysctl net.ipv4.tcp_available_congestion_control
/sbin/modprobe tcp_hybla
nano /etc/sysctl.conf
sysctl -p

由于本人的shadowsocks为自用，高并发的多人使用效果没做具体测试，效果未知。但按方案二将拥塞算法由cubic改为hybla模式后，在晚高峰时段观看视频的速度确实有显著改善，推荐大家尝试。

原文：http://ift.tt/1jEIn4b

via 细节的力量 http://ift.tt/1jEIltb