Configure load balancing

This section describes a simple load balancing configuration. As an example, we use a topology for balancing the traffic between two HTTP servers listening on port 80. The example topology includes the following parameters:

• Back-end servers 10.10.0.4 and 10.10.0.3 in the private-subnet subnet run an HTTP application that listens on the TCP port 80.

• The public-subnet subnet is a shared external subnet created by the cloud operator and accessible from the Internet.

• The created load balancer is accessible through an IP address from the public subnet that will distribute web requests between the back-end servers.

To configure load balancing:

1. Log in to a keystone-client pod.

2. Create a load balancer:

   openstack loadbalancer create --vip-subnet-id=private-subnet --name test-lb
   

   Note

   By default, MOSK uses the Octavia Tungsten Fabric load balancing. Since 23.1, you can explicitly specify amphorav2 as a provider when creating a load balancer using the provider argument:

   openstack loadbalancer create --provider amphorav2
   

   Octavia Amphora load balancing is available as a Technology Preview feature. For details, refer to Octavia Amphora load balancing.

3. Create an HTTP listener:

   openstack loadbalancer listener create --name test-listener \
   --protocol HTTP --protocol-port 80 test-lb
   

4. Create a LBaaS pool that will be used by default for test-listener:

   openstack loadbalancer pool create  --protocol HTTP \
   --lb-algorithm ROUND_ROBIN --name test-pool --listener test-listener
   

5. Create a health monitor that ensures health of the pool members:

   openstack loadbalancer healthmonitor create --delay 5 --name test-hm \
   --timeout 3 --max-retries 3 --type HTTP test-pool
   

6. Add back-end servers to the pool. The following example adds the 10.10.0.3 and 10.10.0.4 back-end servers:

   openstack loadbalancer member create --address 10.10.0.3 --protocol-port 80 test-pool
   openstack loadbalancer member create --address 10.10.0.4 --protocol-port 80 test-pool
   

7. Create a floating IP address in a public network and associate it with a port of the load balancer VIP:

   vip_port_id=$(openstack loadbalancer show test-lb -c vip_port_id \
   -f value)
   fip_id=$openstack floating ip create public -c floating_ip_address \
   -f value)
   openstack floating ip set --port $vip_port_id $fip_id
   

8. Optionally, enable security groups using the Tungsten Fabric web UI:

   1. Navigate to Configure > Networking > Ports.

   2. Find the load balancer ports.

   3. In the Device column, find the VIP port.

   4. Using the gear icon menu of the VIP port, enable Security Groups.

9. Access the VIP floating IP address and verify that requests are distributed between the two servers. For example:

   curl http://10.11.12.103:80
   Welcome to addr:10.10.10.4
   
   curl http://10.11.12.103:80
   Welcome to addr:10.10.10.3
   

   In the example above, an HTTP application that runs on the back-end servers returns an IP address of the host on which it runs.