高并发、大流量网卡调优

周五晚上LVS集群的一台LB由于CPU单核耗尽挂掉了，最后查到原因是网卡调优没有生效，今天查了一下网卡调优的资料，感谢同事higkoo给我讲解了一下这方面的东西，下面是关于我们公司网卡调优的相关知识，欢迎大家共同探讨，让我们的机器跑的更high。

1、Broadcom的网卡建议关闭GRO功能

ethtool -K eth0 gro off
ethtool -K eth1 gro off
ethtool -K eth2 gro off
ethtool -K eth3 gro off

2、关闭irqbalance服务并手动分配网卡中断

service irqbalance stop
chkconfig irqbalance off
# 查看网卡中断号
grep ethx /proc/interrupts
# 分配到每颗颗CPU核上
cat /proc/irq/{84,85,86,87,88,89,90,91,92,93}/smp_affinity
echo 1 > /proc/irq/84/smp_affinity
echo 2 > /proc/irq/85/smp_affinity
echo 4 > /proc/irq/86/smp_affinity
echo 8 > /proc/irq/87/smp_affinity
echo 10 > /proc/irq/88/smp_affinity
echo 20 > /proc/irq/89/smp_affinity
echo 40 > /proc/irq/90/smp_affinity
echo 80 > /proc/irq/91/smp_affinity
echo 100 > /proc/irq/92/smp_affinity
echo 200 > /proc/irq/93/smp_affinity
PS:smp_affinity的值可以用下面脚本算哈，此脚本来自：http://rfyiamcool.blog.51cto.com/1030776/1335700
#!/bin/bash
#
echo "统计cpu的16进制"
[ $# -ne 1 ] && echo ‘$1 is Cpu core number’ && exit 1
CCN=$1
echo “Print eth0 affinity”
for((i=0; i<${CCN}; i++))
do
echo ==============================
echo "Cpu Core $i is affinity"
((affinity=(1<<i)))
echo "obase=16;${affinity}" | bc
done
使用方法：sh 脚本名字 空格 cpu核数

 

3、开启网卡的RPS功能 （Linux内核2.6.38或以上版本支持）

# Enable RPS (Receive Packet Steering)
rfc=4096
cc=$(grep -c processor /proc/cpuinfo)
rsfe=$(echo $cc*$rfc | bc)
sysctl -w net.core.rps_sock_flow_entries=$rsfe
for fileRps in $(ls /sys/class/net/eth*/queues/rx-*/rps_cpus)
do
echo fff > $fileRps
done
for fileRfc in $(ls /sys/class/net/eth*/queues/rx-*/rps_flow_cnt)
do
echo $rfc > $fileRfc
done
tail /sys/class/net/eth*/queues/rx-*/{rps_cpus,rps_flow_cnt}

献上一个完整的脚本：

vi /opt/sbin/change_irq.sh
#!/bin/bash
ethtool -K eth0 gro off
ethtool -K eth1 gro off
ethtool -K eth2 gro off
ethtool -K eth3 gro off
service irqbalance stop
chkconfig irqbalance off
cat /proc/irq/{84,85,86,87,88,89,90,91,92,93}/smp_affinity
echo 1 > /proc/irq/84/smp_affinity
echo 2 > /proc/irq/85/smp_affinity
echo 4 > /proc/irq/86/smp_affinity
echo 8 > /proc/irq/87/smp_affinity
echo 10 > /proc/irq/88/smp_affinity
echo 20 > /proc/irq/89/smp_affinity
echo 40 > /proc/irq/90/smp_affinity
echo 80 > /proc/irq/91/smp_affinity
echo 100 > /proc/irq/92/smp_affinity
echo 200 > /proc/irq/93/smp_affinity
# Enable RPS (Receive Packet Steering)
rfc=4096
cc=$(grep -c processor /proc/cpuinfo)
rsfe=$(echo $cc*$rfc | bc)
sysctl -w net.core.rps_sock_flow_entries=$rsfe
for fileRps in $(ls /sys/class/net/eth*/queues/rx-*/rps_cpus)
do
echo fff > $fileRps
done
for fileRfc in $(ls /sys/class/net/eth*/queues/rx-*/rps_flow_cnt)
do
echo $rfc > $fileRfc
done
tail /sys/class/net/eth*/queues/rx-*/{rps_cpus,rps_flow_cnt}
chmod +x /opt/sbin/change_irq.sh
echo "/opt/sbin/change_irq.sh" >> /etc/rc.local
PS：记得修改网卡中断号，别直接拿来用哦

 

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