Cluster Manager Internal Network for HA Communications

Earlier, SMI releases used the externally routable ssh-ip address to configure keepalived and DRBD communications between the active and standby CM HA nodes. This model left potential for a split-brain situation should the externally routable network become unstable or unavailable.

To reduce this potential, the CM HA nodes can now be configured to use the internal network for keepalived and DRBD communications. This is done using the following command in the CM configuration file:

nodes <node_name> 
cm ha-ip <internal_address> 

Below is an example of a configuration excerpt identifying the parameters for configuring internal and external addresses:


# The master-virtual-ip parameter contains the *internal* VIP address.
configuration master-virtual-ip 192.0.1.101 
configuration master-virtual-ip-cidr 24 
configuration master-virtual-ip-interface vlan1001
 
#
# The additional-master-virtual-ip parameter contains the details of the *externally* available VIP address.
configuration additional-master-virtual-ip 203.0.113.214 
configuration additional-master-virtual-ip-cidr 26 
configuration additional-master-virtual-ip-interface vlan3540 
#
#The additional cm ha-ip parameter needs to be added with the *internal* IP of the node.
# note: node-ip in a CM HA config points to the internal master-virtual-ip
nodes cm1 
ssh-ip 203.0.113.212
 type k8s
 k8s node-type control-plane 
k8s node-ip 192.0.1.101 
cm ha-ip 192.0.1.59 
...
initial-boot netplan vlans vlan3540 
addresses [ 203.0.113.212/26 ] 
exit 
os netplan-additions ethernets eno1 
addresses [ 192.200.0.29/8 ] 
exit 
os netplan-additions vlans vlan1001 
addresses [ 192.0.1.59/24 ] 
exit 
exit
 nodes cm2 
ssh-ip 203.0.113.213 
type k8s 
k8s node-type backup 
k8s node-ip 192.0.1.101 
cm ha-ip 192.0.1.60 
...
initial-boot netplan vlans vlan3540 
addresses [ 203.0.113.213/26 ] 
exit 
os netplan-additions ethernets eno1 
addresses [ 192.200.0.29/8 ] 
exit 
os netplan-additions vlans vlan1001 
addresses [ 192.0.1.60/24 ] 
exit
 exit