Google的新TCP拥塞算法BBR

更新:Debian9都发布好久了,用Debian9吧 不需要折腾内核就能直接开启BBR

上个月网友发现Google在GitHub上的项目Google/BBR. 前几天发现在几个Linux发行版中的候选版内核已经实装,而里面刚好也有Debian.

在看了Telegram群组里的说明后自己试着新开一台机器用上了BBR.

对比测试后发现提升确实非常大,gce美西在试用默认算法的情况下重庆电信HTTP下载大概在100~200K/s左右,而切换到BBR以后HTTP下载速率可以达到3000~4000K/s.

Debian系统具体步骤:

• 添加experimental源

deb http://httpredir.debian.org/debian experimental main

• 安装新内核

==目前最新4.9内核预选版为rc8==

apt -t experimental install linux-image-4.9.0-rc8-amd64-unsigned

==目前的版本==

apt -t experimental install linux-image-4.9.0-trunk-amd64-unsigned

==进入unstable源==

deb http://httpredir.debian.org/debian unstable main

添加源后可通过apt-cache search [packagename]搜索对应包,比如你想要搜索内核的话:

#apt-cache search linux-image
linux-headers-3.16.0-4-amd64 - Header files for Linux 3.16.0-4-amd64
linux-image-3.16.0-4-amd64 - Linux 3.16 for 64-bit PCs
linux-image-3.16.0-4-amd64-dbg - Debugging symbols for Linux 3.16.0-4-amd64
linux-image-amd64 - Linux for 64-bit PCs (meta-package)
linux-image-amd64-dbg - Debugging symbols for Linux amd64 configuration (meta-package)
linux-headers-4.8.0-0.bpo.2-amd64 - Header files for Linux 4.8.0-0.bpo.2-amd64
linux-headers-4.8.0-0.bpo.2-rt-amd64 - Header files for Linux 4.8.0-0.bpo.2-rt-amd64
linux-image-4.8.0-0.bpo.2-amd64-dbg - Debugging symbols for Linux 4.8.0-0.bpo.2-amd64
linux-image-4.8.0-0.bpo.2-amd64-unsigned - Linux 4.8 for 64-bit PCs
linux-image-4.8.0-0.bpo.2-rt-amd64-dbg - Debugging symbols for Linux 4.8.0-0.bpo.2-rt-amd64
linux-image-4.8.0-0.bpo.2-rt-amd64-unsigned - Linux 4.8 for 64-bit PCs, PREEMPT_RT
linux-headers-4.8.0-2-grsec-amd64 - Header files for Linux 4.8.0-2-grsec-amd64
linux-image-4.8.0-2-grsec-amd64 - Linux 4.8 for 64-bit PCs, Grsecurity protection
linux-image-grsec-amd64 - Linux image meta-package, grsec featureset
linux-image-rt-amd64 - Linux for 64-bit PCs (meta-package), PREEMPT_RT
linux-image-rt-amd64-dbg - Debugging symbols for Linux rt-amd64 configuration (meta-package)
linux-image-4.8.0-0.bpo.2-amd64 - Linux 4.8 for 64-bit PCs (signed)
linux-image-4.8.0-0.bpo.2-rt-amd64 - Linux 4.8 for 64-bit PCs, PREEMPT_RT (signed)
linux-image-4.9.0-trunk-amd64-unsigned - Linux 4.9 for 64-bit PCs
linux-image-4.9.0-rc8-amd64-unsigned - Linux 4.9-rc8 for 64-bit PCs
linux-image-4.9.0-1-amd64 - Linux 4.9 for 64-bit PCs (signed)

安装时可能会提示 Depends: linux-base (>= 4.3~) but 3.5 is to be installed, 解决办法:

# 如果没有添加backports源需要手动添加
apt-get install linux-base -t jessie-backports

安装结束后需要重启. 重启后uname -a查看到的信息应该会显示内核已经切换到4.9.0rc了

Linux magic 4.9.0-rc8-amd64 #1 SMP Debian 4.9~rc8-1~exp1 (2016-12-05) x86_64 GNU/Linux

这时候表示已经安装成功.

• 更新sysctl配置 编辑/etc/sysctl.conf

net.core.default_qdisc=fq
net.ipv4.tcp_congestion_control=bbr

编辑完成后通过sysctl -p更改.