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Showing posts with label keepalived. Show all posts
Showing posts with label keepalived. Show all posts

Thursday, June 26, 2014

Virtual Ip With Keepalived as Front end for HAproxy server's

Install Keepalived
Virtual Ip 192.168.216.100

HAproxy Ip 192.168.216.101
1. Install Keepalived package:

On RHEL/CentOS:

$ yum install -y centos-release
$ yum install -y keepalived
$ chkconfig keepalived on

2. Tell kernel to allow binding non-local IP into the hosts and apply the changes:

$ echo "net.ipv4.ip_nonlocal_bind = 1" >> /etc/sysctl.conf
$ sysctl -p

Configure Keepalived and Virtual IP
1. Login into LB1 and add following line into /etc/keepalived/keepalived.conf:

vrrp_script chk_haproxy {
script "killall -0 haproxy" # verify the pid existance
interval 2 # check every 2 seconds
weight 2 # add 2 points of prio if OK
}

vrrp_instance VI_1 {
interface eth2 # interface to monitor
state MASTER
virtual_router_id 51 # Assign one ID for this route
priority 101 # 101 on master, 100 on backup
virtual_ipaddress {
192.168.216.100 # the virtual IP
}
track_script {
chk_haproxy
}
}
2. Login into LB2 and add following line into /etc/keepalived/keepalived.conf:

vrrp_script chk_haproxy {
script "killall -0 haproxy" # verify the pid existance
interval 2 # check every 2 seconds
weight 2 # add 2 points of prio if OK
}

vrrp_instance VI_1 {
interface eth2 # interface to monitor
state MASTER
virtual_router_id 51 # Assign one ID for this route
priority 100 # 101 on master, 100 on backup
virtual_ipaddress {
192.168.216.100 # the virtual IP
}
track_script {
chk_haproxy
}
}
3. Start Keepalived in both nodes:

$ sudo /etc/init.d/keepalived start
4. Verify the Keepalived status. LB1 should hold the VIP and the MASTER state while LB2 should run as BACKUP state without VIP:

LB1 IP:

$ ip a | grep -e inet.*eth2
inet 192.168.216.101/24 brd 192.168.216.255 scope global eth2
inet 192.168.216.100/32 scope global eth2