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