lvs+并发的优化方法教程

这篇文章主要介绍"lvs+并发的优化方法教程"，在日常操作中，相信很多人在lvs+并发的优化方法教程问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答"lvs+并发的优化方法教程"的疑惑有所帮助！接下来，请跟着小编一起来学习吧！

1 缘起

在一次实际项目中，lvs 只能承载量很低，需要对lvs和Linux内核参数进行优化。

2 为什么使用lvs+keepalived架构

（1）LVS可以实现负载均衡，但是不能够进行健康检查。比如一个RS出现故障，LVS 仍然会把请求转发给故障的RS服务器，这样就会导致请求的无效性；keepalived 软件可以进行健康检查。

（2）使用keepalived能同时实现 LVS 的高可用性，解决 LVS 单点故障的问题。

3 lvs+keepalived部署

3.1 部署图

注意：
（1）lvs+keepalived至少需要2台服务器。
（2）需要一个VIP。
（3）RS服务器不能和LVS以及Keepalived复用。

4.2 lvs+keepalived部署（2台DS服务器）

• 安装ipvs和keepalived

yum install ipvsadm keepalived -y

• keepalived配置

注意：
（1）keepalived是否需要争抢主IP，如果不需要，需要把state都修改为BACKUP，并配置nopreempt。
（2）persistence_timeout的作用是：在一定时间内使来自于同一个Client的所有TCP请求被负载到同一个RealServer上，查看ipvsadm -S -n

主节点

#主节点( MASTER )配置文件 cat > /etc/keepalived/keepalived.conf <<'EOF' ! Configuration File for keepalived global_defs {    router_id LVS_DEVEL } vrrp_instance VI_1 {     state BACKUP  ! 主为master，不争抢模式改为BACKUP     nopreempt  !不争抢模式添加     interface eth0     virtual_router_id 51     priority 100     advert_int 1     authentication {         auth_type PASS         auth_pass 1111     }     virtual_ipaddress {         192.168.112.10     } } virtual_server 192.168.112.10 80 {     delay_loop 6     lb_algo rr     lb_kind DR     ! persistence_timeout 0     protocol TCP     real_server 192.168.112.13 80 {         weight 1         TCP_CHECK {             connect_timeout 10             retry 3             delay_before_retry 3             connect_port 80         }     }     real_server 192.168.112.14 80 {         weight 1         TCP_CHECK {             connect_timeout 10             retry 3             delay_before_retry 3             connect_port 80         }     }     real_server 192.168.112.15 80 {         weight 1         TCP_CHECK {             connect_timeout 10             retry 3             delay_before_retry 3             connect_port 80         }     } } EOF

从节点

cat > /etc/keepalived/keepalived.conf <<'EOF' ! Configuration File for keepalived global_defs {    router_id LVS_DEVEL } vrrp_instance VI_1 {     state BACKUP     nopreempt  ! 不争抢模式添加     interface eth0     virtual_router_id 51     priority 90     advert_int 1     authentication {         auth_type PASS         auth_pass 1111     }     virtual_ipaddress {         192.168.112.10     } } virtual_server 192.168.112.10 80 {     delay_loop 6     lb_algo rr     lb_kind DR     ! persistence_timeout 0     protocol TCP     real_server 192.168.112.13 80 {         weight 1         TCP_CHECK {             connect_timeout 10             retry 3             delay_before_retry 3             connect_port 80         }     }     real_server 192.168.112.14 80 {         weight 1         TCP_CHECK {             connect_timeout 10             retry 3             delay_before_retry 3             connect_port 80         }     }     real_server 192.168.112.15 80 {         weight 1         TCP_CHECK {             connect_timeout 10             retry 3             delay_before_retry 3             connect_port 80         }     } } EOF

• 内核参数

echo 1 > /proc/sys/net/ipv4/ip_forward  sysctl -w net.ipv4.ip_forward=1

• 启动

systemctl enable keepalived  systemctl start keepalived

4.3 真实服务器配置

• 配置脚本

不需要在lvs+keepalived的服务器上配置，需要在所有的真实服务器上配置。注意vip必须与前面keepalived上的vip相同。

# vim lvs_dr_rs.sh SNS_VIP=192.168.112.10 /etc/rc.d/init.d/functions case "$1" in start)        ifconfig lo:0 $SNS_VIP netmask 255.255.255.255 broadcast $SNS_VIP        /sbin/route add -host $SNS_VIP dev lo:0        echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore        echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce        echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore        echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce        sysctl -p >/dev/null 2>&1        echo "RealServer Start OK"        ;; stop)        ifconfig lo:0 down        route del $SNS_VIP >/dev/null 2>&1        echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore        echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce        echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore        echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce        echo "RealServer Stoped"        ;; *)        echo "Usage: $0 {start|stop}"        exit 1 esac exit 0 执行生效 # 所有RS节点上分别执行脚本： chmod +x lvs_dr_rs.sh  ./lvs_dr_rs.sh start

5 参数优化

5.1 LVS参数

• 增大ipvs模块hash table的大小

ipvs模块hash table默认值为2^12=4096，改为2^20=1048576。可以用ipvsadm -l命令查询当前hash table的大小。

IP Virtual Server version 1.2.1 (size=4096)

修改方法：

在/etc/modprobe.d/目录下添加文件ip_vs.conf，内容为：

options ip_vs conn_tab_bits=20

重新加载ipvs模块。

IP Virtual Server version 1.2.1 (size=1048576)

• 修改 LVS 表中的 timeout

ipvsadm --set  900 60 300  ipvsadm -ln --timeout Timeout (tcp tcpfin udp): 900 60 300

5.2 文件句柄及进程数

*  soft nofile 1024000 *  hard nofile 1024000 *  soft nproc 1024000 *  hard nproc 1024000

5.3 内核参数

fs.file-max = 1048576 net.ipv4.ip_forward = 1 net.core.wmem_default = 8388608 net.core.wmem_max = 16777216 net.core.rmem_default = 8388608 net.core.rmem_max = 16777216 net.core.somaxconn = 65535 net.core.optmem_max = 81920 net.core.netdev_max_backlog = 262144 net.ipv4.route.gc_timeout = 20 net.ipv4.tcp_syncookies = 1 net.ipv4.tcp_abort_on_overflow = 1 net.ipv4.tcp_max_tw_buckets = 6000 net.ipv4.tcp_sack = 1 net.ipv4.tcp_window_scaling = 1 net.ipv4.tcp_no_metrics_save = 1 net.ipv4.tcp_rmem = 32768   131072  16777216 net.ipv4.tcp_wmem = 8192   131072  16777216 net.ipv4.tcp_mem = 94500000 915000000 927000000 net.ipv4.tcp_max_syn_backlog = 262144 net.ipv4.tcp_max_orphans = 3276800 net.ipv4.tcp_timestamps = 0 net.ipv4.tcp_synack_retries = 1 net.ipv4.tcp_syn_retries = 1 net.ipv4.tcp_tw_recycle = 1 net.ipv4.tcp_tw_reuse = 1 net.ipv4.tcp_fin_timeout = 10 net.ipv4.tcp_keepalive_time = 120 net.ipv4.tcp_keepalive_probes = 3 net.ipv4.tcp_keepalive_intvl = 15 net.ipv4.tcp_retries2 = 5 net.ipv4.ip_local_port_range = 1024    65000 net.ipv4.conf.default.rp_filter = 1 net.ipv4.conf.default.accept_source_route = 0 net.ipv4.conf.all.arp_ignore = 1 net.ipv4.conf.all.arp_announce = 2 #modprobe ip_conntrack  net.netfilter.nf_conntrack_tcp_timeout_established = 180 net.netfilter.nf_conntrack_max = 1048576 net.nf_conntrack_max = 1048576 kernel.sysrq = 0 kernel.core_uses_pid = 1 kernel.msgmnb = 65536 kernel.msgmax = 65536 kernel.shmmax = 68719476736 kernel.shmall = 4294967296

注意：
net.ipv4.tcp_tw_recycle = 1有坑，在nat环境下慎用。

越是大并发，越要注意net.ipv4.tcp_max_tw_buckets的值不能太大。

到此，关于"lvs+并发的优化方法教程"的学习就结束了，希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习，快去试试吧！若想继续学习更多相关知识，请继续关注网站，小编会继续努力为大家带来更多实用的文章！