nginx优化

背景

     客户端发起请求 通过slb 给到nginx，然后nginx再给到后端，经常出现请求接口超时，nginx日志都没有问题（也就是给到nginx处理的请求都完成了），查看slb的流量，远远小于带宽（网络层面应该没有问题），所以问题应该在请求到达nginx操作系统层面。优化nginx在操作系统上面的请求。

worker_processes  8;  改为核心数

events {
    use epoll;
    worker_connections 65535;
    multi_accept on;  #可以一次建立多个连接
}

   sendfile on;
   tcp_nopush on;
   tcp_nodelay on;
   keepalive_timeout 65; 

   gzip on;
   client_header_buffer_size 512k;
   large_client_header_buffers 4 512k;
   proxy_send_timeout 600;
   proxy_read_timeout 600;
   proxy_connect_timeout 600;
   client_max_body_size 500m;

vim /etc/sysctl.conf

vm.swappiness = 0
kernel.sysrq = 1

net.ipv4.neigh.default.gc_stale_time = 120

# see details in https://help.aliyun.com/knowledge_detail/39428.html
net.ipv4.conf.all.rp_filter = 0
net.ipv4.conf.default.rp_filter = 0
net.ipv4.conf.default.arp_announce = 2
net.ipv4.conf.lo.arp_announce = 2
net.ipv4.conf.all.arp_announce = 2

# see details in https://help.aliyun.com/knowledge_detail/41334.html
net.ipv4.tcp_max_tw_buckets = 5000
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_synack_retries = 2

net.ipv6.conf.lo.disable_ipv6 = 1

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1

kernel.msgmnb = 65536
kernel.msgmax = 65536
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.core.somaxconn = 40960
net.ipv4.tcp_fin_timeout = 10
net.ipv4.tcp_keepalive_time = 150
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 0
net.ipv4.tcp_max_tw_buckets = 20000
net.ipv4.tcp_max_syn_backlog = 8096
net.ipv4.ip_local_port_range = 1024 65000

下面的命令 可能和上面的效果一样，直接运行

echo "0" > /proc/sys/net/ipv4/tcp_tw_recycle
echo "0" > /proc/sys/net/ipv4/cp_timestamps
sysctl -w net.ipv4.tcp_tw_recycle=0
sysctl -w net.ipv4.tcp_timestamps=0

net.ipv4.tcp_tw_recycle = 0

ulimit -a   这个也调整一下

cat wxpt.access.log-20210518 |grep jianhuochakucun |grep -v "ups_status:200"

 location /oms_order {   

      proxy_pass http://omsorder/;
　　proxy_redirect default;
　　proxy_read_timeout 300;
　　proxy_connect_timeout 300;
　　proxy_send_timeout 300;
　　client_max_body_size 50m;
　　proxy_buffer_size 16k;
　　proxy_buffering on;
　　proxy_buffers 4 64k;
　　proxy_busy_buffers_size 128k;
　　proxy_temp_file_write_size 128k;

}

proxy_ignore_client_abort off；
当客户端网络中断请求时，nginx服务器中断其对后端服务器的请求。即如果此项设置为on开启，则服务器会忽略客户端中断并一直等着代理服务执行返回，如果设置为off，则客户端中断后nginx也会中断客户端请求并立即记录499日志，默认为off