Azure – Create the SAP HANA Primary Database Load Balancer

In Microsoft Azure, a TCP Internal Load Balancer is used to facilitate failover of the virtual IP associated with the primary HANA database host. The frontend of the load balancer is assigned an IP address from the subnet that it operates in. In this example, we will be using the following IP address for load balancer corresponding to the virtual host name:

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

1. Create a Load Balancer in Azure, ilb-sps-hana, with the following properties.

Once created, the Load Balancing Services → Load Balancer page in the Microsoft Azure Console will show the newly created load balancer.

2. 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 a LifeKeeper GenLB resource, ilb-sps-hana, with the following properties. Notice that ilb-sps-hana is created on node-a and extended to node-b. 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 (Note: Although the quickCheck script may be optional for some ‘Generic Application’ resource types, it is required for GenLB resources.)
Local Recovery Script	None (Empty)
Application Info	50098
Bring Resource In Service	Yes
Resource Tag	ilb-sps-hana
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-hana
Application Info	50098

The resource will appear in the LifeKeeper GUI resource pane once it has been created and extended successfully.

3. Following the steps described in Creating an IP Resource, use the following parameters to create and extend a LifeKeeper IP resource (ip-sps-hana) to protect the HANA database virtual IP address on node-a and node-b. Notice that the IP resource is being created on node-a and extended to node-b. Also note that the resulting resource should not be extended to node-c, the witness node. The icon indicates that the default option is chosen.

Field	Value
Create Resource Wizard
Switchback Type	intelligent
Server	node-a
IP Resource	10.20.0.5
Netmask	255.255.252.0
Network Interface	eth0
IP Resource Tag	ip-sps-hana
Pre-Extend Wizard
Target Server	node-b
Switchback Type	intelligent
Template Priority	1
Target Priority	10
Extend comm/ip Resource Hierarchy Wizard
IP Resource	10.20.0.5
Netmask	255.255.252.0
Network Interface	eth0
IP Resource Tag	ip-sps-hana

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

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

Once the dependency has been created successfully, the LifeKeeper GUI should resemble the following image.

5. Add the following entry to /etc/hosts on node-a and node-b to allow resolution of the virtual host name to the frontend IP address of the corresponding load balancer:

10.20.0.5 sps-hana

6. Test switchover and failover of the GenLB resource hierarchy 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 check as required to achieve successful operation.