Google Cloud – Create ASCS and ERS Internal Load Balancers

In Google Cloud, TCP Internal Load Balancers are used to facilitate failover of the ASCS and ERS virtual IP’s. The frontend of each load balancer is assigned an ephemeral IP from the subnet that it operates in. In this example, we will be using the following IP addresses for load balancers corresponding to each virtual host:

Following the steps provided in Google Cloud – Using an Internal Load Balancer and Responding to Load Balancer Health Checks, create and configure the following Google Cloud and LifeKeeper resources.

1. Create two unmanaged instance groups: ig-sps-ascs-zone1, containing node-a, and ig-sps-ascs-zone2, containing node-b.

2. Create two TCP Internal Load Balancers, ilb-sps-ascs and ilb-sps-ers, with the following properties. The icon indicates that the default option is chosen.

Name	ilb-sps-ascs
Backend configuration
Region	<Deployment region> (e.g., us-east1)
Network	lk-vpc
Backends	ig-sps-ascs-zone1 ig-sps-ascs-zone2
Health Check
Name	hc-sps-ascs
Protocol	TCP
Port	51098 (This must agree with the corresponding LifeKeeper LB Health Check resource created later)
Proxy protocol	NONE
Request	Leave empty
Response	Leave empty
Check interval	5 seconds
Timeout	5 seconds
Healthy threshold	2 consecutive successes
Unhealthy threshold	2 consecutive failures
Connection draining timeout	15 seconds
Frontend configuration
Name	fe-sps-ascs
Subnetwork	lk-subnet
Purpose	Non-shared
IP address	Ephemeral (Custom)
Custom ephemeral IP address	10.20.0.10
Ports	All
Global access	Disable
Service label	Leave empty

Name	ilb-sps-ers
Backend configuration
Region	<Deployment region> (e.g., us-west1)
Network	lk-vpc
Backends	ig-sps-ascs-zone1 ig-sps-ascs-zone2
Health Check
Name	hc-sps-ers
Protocol	TCP
Port	52098 (This must agree with the corresponding LifeKeeper GenLB resource created later)
Proxy protocol	NONE
Request	Leave empty
Response	Leave empty
Check interval	5 seconds
Timeout	5 seconds
Healthy threshold	2 consecutive successes
Unhealthy threshold	2 consecutive failures
Connection draining timeout	15 seconds
Frontend configuration
Name	fe-sps-ers
Subnetwork	lk-subnet
Purpose	Non-shared
IP address	Ephemeral (Custom)
Custom ephemeral IP address	10.20.0.20
Ports	All
Global access	Disable
Service label	Leave empty

Once created, the Network services → Load balancing page in the Google Cloud Console will show the two load balancers.

3. Follow the steps described in the Disable IP Forwarding section of Google Cloud – Using an Internal Load Balancer to allow node-a and node-b to communicate through the frontend IP addresses of the load balancers. Reboot node-a and node-b for the changes to take effect.

4. Following the steps described in Creating an IP Resource, use the following parameters to create and extend two LifeKeeper IP resources (ip-sps-ascs and ip-sps-ers), each with net mask 255.255.255.255, to protect the ASCS and ERS virtual IP addresses on node-a and node-b. Notice that ip-sps-ascs is created on node-a and extended to node-b, while ip-sps-ers is created on node-b and extended to node-a. Also note that the resulting resources should not be extended to node-c, the witness node. The icon indicates that the default option is chosen.

!The use of 255.255.255.255 as the value of the Netmask parameter (both during create and extend) is important. Be careful not to select “Accept Defaults” during the extend process as this will typically cause 255.255.255.0 to be incorrectly used as the network mask on the standby node, which may lead to unexpected networking issues.

Field	Value
Create Resource Wizard
Switchback Type	intelligent
Server	node-a
IP Resource	10.20.0.10
Netmask	255.255.255.255
Network Interface	eth0
IP Resource Tag	ip-sps-ascs
Pre-Extend Wizard
Target Server	node-b
Switchback Type	intelligent
Template Priority	1
Target Priority	10
Extend comm/ip Resource Hierarchy Wizard
IP Resource	10.20.0.10
Netmask	255.255.255.255
Network Interface	eth0
IP Resource Tag	ip-sps-ascs

Field	Value
Create Resource Wizard
Switchback Type	intelligent
Server	node-b
IP Resource	10.20.0.20
Netmask	255.255.255.255
Network Interface	eth0
IP Resource Tag	ip-sps-ers
Pre-Extend Wizard
Target Server	node-a
Switchback Type	intelligent
Template Priority	1
Target Priority	10
Extend comm/ip Resource Hierarchy Wizard
IP Resource	10.20.0.20
Netmask	255.255.255.255
Network Interface	eth0
IP Resource Tag	ip-sps-ers

Once the IP resources have been created successfully, the LifeKeeper GUI should resemble the following image.

5. Following the steps in Responding to Load Balancer Health Checks, create two LifeKeeper LB Health Check resources, ilb-sps-ascs and ilb-sps-ers, with the following properties. Notice that ilb-sps-ascs is created on node-a and extended to node-b, while ilb-sps-ers is created on node-b and extended to node-a. The icon indicates that the default option is chosen.

Field	Value
Create Resource Wizard
Switchback Type	intelligent
Server	node-a
Reply daemon Port	51098
Reply daemon message	None (Empty)
LB Health Check Resource Tag	ilb-sps-ascs
Pre-Extend Wizard
Target Server	node-b
Switchback Type	intelligent
Template Priority	1
Target Priority	10
Extend LB Health Check Resource Hierarchy Wizard
LB Health Check Resource Tag	ilb-sps-ascs

Field	Value
Create Resource Wizard
Switchback Type	intelligent
Server	node-b
Reply daemon Port	52098
Reply daemon message	None (Emply)
LB Health Check Resource Tag	ilb-sps-ers
Pre-Extend Wizard
Target Server	node-a
Switchback Type	intelligent
Template Priority	1
Target Priority	10
Extend LB Health Check Resource Hierarchy Wizard
LB Health Check Resource Tag	ilb-sps-ers

The resources will appear in the LifeKeeper GUI resource pane once they have been created and extended successfully.

6. Right-click the ilb-sps-ascs resource on node-a and click “Create Dependency…” Specify ip-sps-ascs as the Child Resource Tag and click Create Dependency.

7. Right-click the ilb-sps-ers resource on node-b and click “Create Dependency…” Specify ip-sps-ers as the Child Resource Tag and click Create Dependency.

Once both dependencies have been created, the LifeKeeper GUI should resemble the following image.

8. Add the following entries to /etc/hosts on node-a and node-b to allow resolution of each virtual hostname to the frontend IP address of the corresponding load balancer:

10.20.0.10 sps-ascs
10.20.0.20 sps-ers

9. Test switchover and failover of the LB Health Check resources as described in the Test LB Health Check Resource Switchover and Failover section of Responding to Load Balancer Health Checks. Correct any issues found or tune the parameters of the load balancer health checks as required to achieve successful operation.