Lvs+keepalived project practice

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Experiment preparation

client	192.168.4.10
lvs	192.168.2.20/192.168.4.20
lvs1	192.168.4.30
web1	192.168.2.200/192.168.4.200
web2	192.168.2.200/192.168.4.200

this paper 2 An experiment （centos7）
1：lvsNAT experiment
The machine used ：client+lvs+web1+web2
2：lvsDR+keepalived experiment
The machine used ：client+lvs+lvs1+web1+web2

One 、 What is? lvs colony

LVS yes Linux Virtual Server Abbreviation , meaning Linux Virtual server , Is a virtual server cluster system .
lvs The working mode is
NAT： Network address translation
DR： Routing mode
TUN： Tunnel model
Scheduling algorithm ： There is support for 10 Kind of , common 4 Kind of
polling rr：Real Server Take turns providing services
Weighted polling wrr：Real Server According to the weight , Take turns providing services
The minimum connection LC： according to Real Server Number of connections , Allocation request
Weighted least connected WLC： Be similar to wrr, Assign different weights to different servers

Two 、lvs+NAT experiment

1.web1 and web2 install httpd service ( Turn off firewall ,selinux）

yum -y install httpd （2 Taiwan machine ） And have access to http

2.web1 and web2 configure gateway

web1 and web2 Do it at the same time
because lvs Yes 2 Address 2.20 It can be accessed as a network card 4.0 Content of network segment

[[email protected] ~]# nmcli connection modify eth1 ipv4.gateway 192.168.2.20
[[email protected] ~]# ifdown eth1; ifup eth1
[[email protected] ~]#  route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.2.20    0.0.0.0         UG    100    0        0 eth1
192.168.2.0     0.0.0.0         255.255.255.0   U     100    0        0 eth1

3. To configure lvs

Turn on lvs Route forwarding function

[[email protected] ~]# vim /etc/sysctl.conf 
net.ipv4.ip_forward = 1
[[email protected] ~]# sysctl -p // Make profile effective 
net.ipv4.ip_forward = 1

install lvs

 yum install -y ipvsadm

ipvsadm grammar
-A： Add a virtual server （ fictitious IP）
-E： Edit virtual server
-t|u：tcp or udp agreement
-s： Specify scheduling algorithm , Such as rr/wrr/lc/wlc
-a: After creating the virtual server , Add a real server to the virtual server
-r： Real server address
-w: Set weight , The default is 1
-m： Appoint LVS The working mode of NAT
-g： Appoint LVS The working mode of DR

lvs NET To configure

[[email protected] ~]# ipvsadm -A -t 192.168.4.20:80 -s rr // Creating a virtual server scheduling algorithm is polling 
[[email protected] ~]# ipvsadm -a -t 192.168.4.20:80 -r 192.168.2.100 -w 1 -m // Add a real server to the virtual server web1  The weight of 1 nat Pattern 
[[email protected] ~]# ipvsadm -a -t 192.168.4.20:80 -r 192.168.2.200 -w 2 -m 
[[email protected] ~]# ipvsadm -Ln // Check the specific configuration 
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.4.20:80 rr
  -> 192.168.2.100:80             Masq    1      0          0         
  -> 192.168.2.200:80             Masq    2      0          0    
[[email protected] ~]# systemctl stop firewalld.service  Turn off firewall 

Client access lvs Scheduler

3、 ... and 、lvs Routing mode +keepalived Project practice

LVS Of DR Pattern ,LVS Only one network card is needed （4.0 Network segment ）
VIP： Virtual address , The address provided to the user for access
keepalived： Used to implement high availability cluster

1. To configure web1,web2 Of vip：192.168.4.40（2 platform web The machine configuration is the same ）

[[email protected] network-scripts]# cd /etc/sysconfig/network-scripts/
[[email protected] network-scripts]# cp ifcfg-lo ifcfg-lo:0
[[email protected] network-scripts]# vim ifcfg-lo:0
DEVICE=lo:0 //lo It's local 
IPADDR=192.168.4.40 // Configure virtual address 
NETMASK=255.255.255.255 // Here we must 255.255.255.255 Otherwise mistakes 
NETWORK=192.168.4.40 
BROADCAST=192.168.4.40
ONBOOT=yes
NAME=lo:0

2. stay 2 platform web Modify kernel parameters on the server , Make them not respond vip Query request for

[[email protected] network-scripts]#  vim /etc/sysctl.conf
# System default settings live in /usr/lib/sysctl.d/00-system.conf.
# To override those settings, enter new settings here, or in an /etc/sysctl.d/<name>
.conf file
#
# For more information, see sysctl.conf(5) and sysctl.d(5).
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.lo.arp_announce = 2
[[email protected] network-scripts]# sysctl -p // Configuration takes effect 
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.lo.arp_announce = 2

3. lvs install keepalived

 yum install -y keepalived
 yum -y install ipvsadm

The configuration file

[[email protected] ~]# vim /etc/keepalived/keepalived.conf 
! Configuration File for keepalived

global_defs {
    
   notification_email {
    
     [email protected]            // Addressee address 
   }
   notification_email_from [email protected].cn   // sender address 
   smtp_server 127.0.0.1       // Mail server address 
   smtp_connect_timeout 30
   router_id lvs              // Unique category ID
   vrrp_iptables               //  Auto on IPTABLES Release rules 
   vrrp_skip_check_adv_addr
   vrrp_strict
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}

vrrp_instance VI_1 {
    
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
    
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
    
        192.168.4.40/24       // VIP Address 
    }
}

virtual_server 192.168.4.40 80 {
       // LVS Virtual server 
    delay_loop 6              // Health check delay 6 second 
    lb_algo rr                //  Scheduling algorithm 
    lb_kind DR                //  Working mode 
    persistence_timeout 50    // 50 Within seconds, the same client is scheduled to the same server 
    protocol TCP

    real_server 192.168.4.100 80 {
        # real server To configure 
        weight 1              //  The weight 
	TCP_CHECK {
                  //  Yes real server Configuration of health check 
	    connect_timeout 3    // Connection timeout 
	    nb_get_retry    3    // Health check retry times 
	    delay_before_retry 3 // The interval between two inspections 
    }
    }
    real_server 192.168.4.200 80 {
        // real server To configure 
        weight 1              //  The weight 
	TCP_CHECK {
                  //  Yes real server Configuration of health check 
	    connect_timeout 3    //  Connection timeout 
	    nb_get_retry    3    // Health check retry times 
	    delay_before_retry 3 // The interval between two inspections 
	}
    }
}

Start the service to view the configuration

systemctl start keepalived.service

Client access

[[email protected] ~]# curl 192.168.4.40
woshiweb2
[[email protected] ~]# curl 192.168.4.40
woshiweb2
[[email protected] ~]# curl 192.168.4.40
woshiweb2
[[email protected] ~]# curl 192.168.4.40
woshiweb2
[[email protected] ~]# curl 192.168.4.40
woshiweb2

4. lvs1 install keepalived

 yum install -y keepalived
 yum -y install ipvsadm

The configuration file

[[email protected]~]# vim /etc/keepalived/keepalived.conf 
! Configuration File for keepalived

global_defs {
   notification_email {
     [email protected]
   }
   notification_email_from [email protected]
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id lvs1  // Host name 
   vrrp_iptables
   vrrp_skip_check_adv_addr
   vrrp_strict
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}

vrrp_instance VI_1 {
    state BACKUP    // Change the backup mode here 
    interface eth0
    virtual_router_id 51
    priority 80 // Priority is higher than lvs low 
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.4.40/24
    }
}

virtual_server 192.168.4.40 80{
    delay_loop 6
    lb_algo rr
    lb_kind DR
    persistence_timeout 50
    protocol TCP

    real_server 192.168.4.100 80 {
        weight 1
    TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
    real_server 192.168.4.200 80 {
        weight 2
    TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

Start the service

systemctl start keepalived.service

To turn it off lvs Client access