GCP – Creating 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:

• ASCS10 instance virtual host:
  • Virtual hostname: sps-ascs
  • Internal TCP load balancer: ilb-sps-ascs
  • IP address: 10.20.0.10

• ERS20 instance virtual host:
  • Virtual hostname: sps-ers
  • Internal TCP load balancer: ilb-sps-ers
  • IP address: 10.20.0.11

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

• 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 GenLB resource created later)
Proxy protocol	NONE
Request	Leave empty
Response	Leave empty
Check interval	2 seconds
Timeout	2 seconds
Healthy threshold	2 consecutive successes
Unhealthy threshold	3 consecutive failures
Connection draining timeout	10 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	51098 (This must agree with the corresponding LifeKeeper GenLB resource created later)
Proxy protocol	NONE
Request	Leave empty
Response	Leave empty
Check interval	2 seconds
Timeout	2 seconds
Healthy threshold	2 consecutive successes
Unhealthy threshold	3 consecutive failures
Connection draining timeout	10 seconds
Frontend configuration
Name	fe-sps-ers
Subnetwork	lk-subnet
Purpose	Non-shared
IP address	Ephemeral (Custom)
Custom ephemeral IP address	10.20.0.11
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. Implement the startup script workaround described in the Enabling Load Balancer Traffic from Backend Servers section of GCP – 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 in Responding to Load Balancer Health Checks, install the LifeKeeper Generic Application Recovery Kit for Load Balancer Health Checks (“GenLB Recovery Kit”) and create two LifeKeeper GenLB 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
Restore Script	/opt/LifeKeeper/SIOS_Hotfixes/Gen-LB-PL-7172/restore.pl
Remove Script	/opt/LifeKeeper/SIOS_Hotfixes/Gen-LB-PL-7172/remove.pl
QuickCheck Script	/opt/LifeKeeper/SIOS_Hotfixes/Gen-LB-PL-7172/quickCheck
Local Recovery Script	None (Empty)
Application Info	51098
Bring Resource In Service	Yes
Resource Tag	ilb-sps-ascs
Pre-Extend Wizard
Target Server	node-b
Switchback Type	intelligent
Template Priority	1
Target Priority	10
Extend gen/app Resource Hierarchy Wizard
Resource Tag	ilb-sps-ascs
Application Info	51098

Field	Value
Create Resource Wizard
Switchback Type	intelligent
Server	node-b
Restore Script	/opt/LifeKeeper/SIOS_Hotfixes/Gen-LB-PL-7172/restore.pl
Remove Script	/opt/LifeKeeper/SIOS_Hotfixes/Gen-LB-PL-7172/remove.pl
QuickCheck Script	/opt/LifeKeeper/SIOS_Hotfixes/Gen-LB-PL-7172/quickCheck
Local Recovery Script	None (Empty)
Application Info	52098
Bring Resource In Service	Yes
Resource Tag	ilb-sps-ers
Pre-Extend Wizard
Target Server	node-a
Switchback Type	intelligent
Template Priority	1
Target Priority	10
Extend gen/app Resource Hierarchy Wizard
Resource Tag	ilb-sps-ers
Application Info	52098

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

5. 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
10.20.0.11 sps-ers

6. Test switchover and failover of the GenLB resources as described in the Test GenLB 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.