SCALING: Changing the number of replicas in a Deployment.
The Deployment only created one Pod to run our application, and that just won't do. We need more when traffic increases.
When you scale, you make sure new Pods are created and scheduled to Nodes who have the resources.
Scaling in will "reduce the number of Pods to the new desired state".
"Can we do this automatically?" Yes! But not now.
Running multiple application instances require a way to distribute traffic to them all. There is an integrated load-balancers with Services to do so, and they will continuously monitor the running Pods with endpoints, ensuring the traffic is sent only to available Pods.
(It’s still kubernetes-bootcamp, and is has one (1) Pod)
Now the tutorial wants to talk about what the columns mean.
DESIRED: Configured # of replicas.
CURRENT: How many replicas are running.
UP-TO-DATE: Replicas updated to match the configured state.
AVAILABLE: How many replicas can users actually make use of?
All of these columns have the number 1 in them.
Now, let’s replicate. How does four sound?
After get deployments, our numbers have increased from 1 to 4.
So have our Pods!