Active/Standby Cluster

Configure the VRRP daemon on both instances

You must configure the VRRP daemon on both the active and the standby HAProxy ALOHA instances.

1. In the Services tab, make sure the syslogd service is up and running.

2. In the Services tab, click vrrp setup .

   

   Enter the following directives:

   Directive	Value
   group	Enable VRRP on group of network interfaces. Specify a single name or a space-separated list of interface names.
   track_svc	Check that the haproxy service is running.
   track_mgt	Check that the sshd and wui services are running.
   no autostart	Remove or comment out the line.

   service vrrp
     group eth0
     track_svc  haproxy
     track_mgt  sshd wui
     # no autostart

3. Restart the vrrp service.

   

Failover triggers

The following events can trigger a failover:

• The active instance lowers its weight below one of the backup instances due to a failed health check.

• A backup instance is reconfigured with a weight larger than the current active instance.

• The active instance stops emitting its heartbeat packet to the cluster.

Configure the active VRRP instance

1. In the Services tab, click network instance setup next to a network interface.

   

2. Add the following parameters to create a new VRRP instance:

   Directive	Value
   vrrp inst default id	The Virtual Router Identifier (VRID) can be any number between 1 and 255. It is a unique identifier that is the same on the active and standby instances. It allows the instances to share a virtual router and virtual IP address. To check if other VRIDs are currently in use, do one of the following: From the Tools tab, select capture from the drop-down, then enter the interface name where you will configure VRRP, and the vrrp keyword, then run the diagnostic. Run the following command from a terminal: admin@ALOHA1:~$ sudo tcpdump -vvvenns0 -c 5 -i eth0 vrrp | grep -o "vrid [0-9]*" [...] 5 packets captured 6 packets received by filter 0 packets dropped by kernel vrid 161 vrid 155
   vrrp inst default garp	Gratuitous ARP polling interval in seconds. 30.
   vrrp inst default prio	VRRP instance default priority. 101 or higher for master.
   vrrp inst default address	The Virtual IP.
   vrrp inst default password	VRRP instance authentication password. aloha (recommended).
   vrrp inst default no-address	Recommended. Deconfigures the primary virtual IPv4 address for the virtual router, to bypass the protocol limitation on the maximum of authorized VIPs.

   service network eth0
     ip address 172.16.24.238/24
     ip route default 172.16.24.1
     vrrp inst    default id        130
     vrrp inst    default garp      30
     vrrp inst    default prio      101
     vrrp inst    default address   172.16.24.235
     vrrp inst    default password  aloha
     vrrp inst    default no-address

3. Restart the network service.

Configure the standby VRRP instance

1. In the Services tab, click network instance setup next to a network interface.

   

2. Add the following parameters to create a new VRRP instance:

   Directive	Value
   vrrp inst default id	Same VRID as on the active HAProxy ALOHA instance.
   vrrp inst default garp	Gratuitous ARP polling interval in seconds. 30.
   vrrp inst default prio	VRRP instance default priority. 100 for backup.
   vrrp inst default address	The Virtual IP.
   vrrp inst default password	VRRP instance authentication password. aloha (recommended).
   vrrp inst default no-address	Recommended. Deconfigures the primary virtual IPv4 address for the virtual router, to bypass the protocol limitation on the maximum of authorized VIPs.

   service network eth0
     ip address 172.16.24.237/24
     ip route default 172.16.24.1
     vrrp inst    default id        130
     vrrp inst    default garp      30
     vrrp inst    default prio      100
     vrrp inst    default address   172.16.24.235
     vrrp inst    default password  aloha
     vrrp inst    default no-address

3. Restart the network service.

Save your configuration on both instances

1. Save your configuration from the Setup tab.

   

   The Configuration was successfully saved message displays.

   

Check that VRRP works

In the steps below, we shut down the active instance and then verify that the VIP was transferred to the standby instance by comparing the MAC addresses returned for the VIP.

From a Linux machine on the same network, check which MAC address is associated with the VIP by calling arping.

1. Check the MAC address on your HAProxy ALOHA instances.

   admin@ALOHA1:~$ arp -a

2. Check which MAC addresses are associated with the VIP and the HAProxy ALOHA instances' IP addresses.

   $ sudo arping -c 5 -I ens192 172.16.24.235 | cut -d " " -f 4
   00:50:56:8a:fc:52
   $ sudo arping -c 5 -I ens192 172.16.24.237 | cut -d " " -f 4
   00:50:56:8a:1a:78
   $ sudo arping -c 5 -I ens192 172.16.24.238 | cut -d " " -f 4
   00:50:56:8a:fc:52

   The MAC address associated with the VIP is the active HAProxy ALOHA instance's address.

3. Shut down your test HAProxy ALOHA instance, then check the MAC addresses.

   $ sudo arping -c 5 -I ens192 172.16.24.235 | cut -d " " -f 4
   00:50:56:8a:1a:78
   $ sudo arping -c 5 -I ens192 172.16.24.237 | cut -d " " -f 4
   00:50:56:8a:1a:78
   $ sudo arping -c 5 -I ens192 172.16.24.238
   Timeout

   The MAC address associated with the VIP is now the address of the previously standby HAProxy ALOHA instance.

Fail over to the standby instance

To manually fail over to the standby instance for doing routing maintenance on the active instance, reconfigure the backup instance a weight larger than the current active instance.

Troubleshooting