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:

Instance
Virtual Host Name
Internal TCP Load Balancer
Frontend IP Address
HDB00 sps-hana ilb-sps-hana 10.20.0.5

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.
Name
ilb-sps-ascs-ers
Create Load Balancer
Resource Group LK-QSG
Name ilb-sps-hana
Region (same as the Virtual Machines)
Type Internal
SKU Standard (select Standard as the workload is distributed across Availability Zones)
Tier Regional
Frontend IP Configuration
Name SPSHANAFrontEnd
Virtual Network LK-VNET
Subnet LK-subnet (10.20.0.0/22)
Assignment Static
IP address 10.20.0.5
Availability zone Zone-redundant
Backend Pool
Name backend-sps-hana
Backend Pool Configuration NIC
IP Version IPv4
Virtual machines node-a, node-b
Health Probe
Name probe-sps-hana
Protocol TCP
Port 50098 (This must agree with the corresponding LifeKeeper LB Health Check resource created later)
Interval 5 seconds
Unhealthy threshold 2 consecutive failures
Load Balancing Rule
Name ilb-rule-sps-hana
IP Version IPv4
Frontend IP address SPSHANAFrontEnd (10.20.0.5)
HA Ports Click (allow forwarding to all ports for simplicity of evaluation deployment)
Backend pool backend-sps-hana
Health probe probe-sps-hana (TCP:50098)
Session persistence None
Idle timeout 4 minutes
TCP reset Disabled
Floating IP Enabled

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

  1. Following the steps in Responding to Load Balancer Health Checks, create a LifeKeeper LB Health Check 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
Reply daemon Port 50098
Reply daemon message None (Empty)
LB Health Check Resource Tag ilb-sps-hana
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-hana

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

  1. 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.

  1. 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.

  1. 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

  1. Test switchover and failover of the LB Health Check resource hierarchy 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 check as required to achieve successful operation.

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