Keepalive Configurations
Keepalive install
1
| sudo apt install keepalived libipset13
|
Configuration for High Availability
Configuration should be done on the two nodes, setting one as master and one as backup. Master will serve traffic unless unavailable, at which time the backup node will take over serving traffic until master is available again.
Master Configuration
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
| # /etc/keepalived/keepalived.conf
# Keepalive configuration for Master node
vrrp_instance DNS {
state MASTER
interface eth0
virtual_router_id 55 # Must match backup
priority 150 # Higher than backup
advert_int 1
unicast_src_ip 192.168.0.10
unicast_peer {
192.168.0.11
}
authentication {
auth_type PASS
auth_pass password # Use same on backup
}
virtual_ipaddress {
192.168.0.100/24
}
}
|
Backup Configuration
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
| # /etc/keepalived/keepalived.conf
# Keepalive configuration for backup node
vrrp_instance DNS {
state BACKUP
interface eth0
virtual_router_id 55
priority 100
advert_int 1
unicast_src_ip 192.168.0.11
unicast_peer {
192.168.0.10
}
authentication {
auth_type PASS
auth_pass password
}
virtual_ipaddress {
192.168.0.100/24
}
}
|
Configuration as load balancer.
Alternatively to being used for high availability, keepalive can also be configured as a load balancer using the below configuration. Additionally, both HA and load balance can be combined, however that configuration is not covered here.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
| # /etc/keepalived/keepalived.conf
# Load Balancer node
vrrp_instance LB1 {
state MASTER
interface eth0
virtual_router_id 51
priority 100
virtual_ipaddress {
192.168.0.100
}
}
virtual_server 192.168.0.100 80 {
delay_loop 6
lb_algo rr
lb_kind NAT
protocol TCP
real_server 192.168.0.10 80 {
weight 100
TCP_CHECK {
connect_timeout 3
}
}
real_server 192.168.0.11 80 {
weight 100
TCP_CHECK {
connect_timeout 3
}
}
}
|
