18.2. Scaling clusters for application traffic by using Octavia

OpenShift Container Platform clusters that run on Red Hat OpenStack Platform (RHOSP) can use the Octavia load balancing service to distribute traffic across multiple virtual machines (VMs) or floating IP addresses. This feature mitigates the bottleneck that single machines or addresses create.

If your cluster uses Kuryr, the Cluster Network Operator created an internal Octavia load balancer at deployment. You can use this load balancer for application network scaling.

If your cluster does not use Kuryr, you must create your own Octavia load balancer to use it for application network scaling.

18.2.1. Scaling clusters by using Octavia

If you want to use multiple API load balancers, or if your cluster does not use Kuryr, create an Octavia load balancer and then configure your cluster to use it.

Prerequisites

Octavia is available on your Red Hat OpenStack Platform (RHOSP) deployment.

Procedure

From a command line, create an Octavia load balancer that uses the Amphora driver:
```
$ openstack loadbalancer create --name API_OCP_CLUSTER --vip-subnet-id <id_of_worker_vms_subnet>
```
You can use a name of your choice instead of API_OCP_CLUSTER.
After the load balancer becomes active, create listeners:
```
$ openstack loadbalancer listener create --name API_OCP_CLUSTER_6443 --protocol HTTPS--protocol-port 6443 API_OCP_CLUSTER
```
注意
To view the status of the load balancer, enter openstack loadbalancer list.

Create a pool that uses the round robin algorithm and has session persistence enabled:

$ openstack loadbalancer pool create --name API_OCP_CLUSTER_pool_6443 --lb-algorithm ROUND_ROBIN --session-persistence type=<source_IP_address> --listener API_OCP_CLUSTER_6443 --protocol HTTPS

To ensure that control plane machines are available, create a health monitor:

$ openstack loadbalancer healthmonitor create --delay 5 --max-retries 4 --timeout 10 --type TCP API_OCP_CLUSTER_pool_6443

Add the control plane machines as members of the load balancer pool:

$ for SERVER in $(MASTER-0-IP MASTER-1-IP MASTER-2-IP)
do
  openstack loadbalancer member create --address $SERVER  --protocol-port 6443 API_OCP_CLUSTER_pool_6443
done

Optional: To reuse the cluster API floating IP address, unset it:
```
$ openstack floating ip unset $API_FIP
```

Add either the unset API_FIP or a new address to the created load balancer VIP:

$ openstack floating ip set  --port $(openstack loadbalancer show -c <vip_port_id> -f value API_OCP_CLUSTER) $API_FIP

Your cluster now uses Octavia for load balancing.

注意

If Kuryr uses the Octavia Amphora driver, all traffic is routed through a single Amphora virtual machine (VM).

You can repeat this procedure to create additional load balancers, which can alleviate the bottleneck.

18.2.2. Scaling clusters that use Kuryr by using Octavia

If your cluster uses Kuryr, associate the API floating IP address of your cluster with the pre-existing Octavia load balancer.