It depends on many factors. We need to know how much resources do you have and how much is being consumed by the pods. To do so you need to setup a Metrics-server.

Metrics Server is a cluster-wide aggregator of resource usage data.

Next step is to setup HPA.

The Horizontal Pod Autoscaler automatically scales the number of pods in a replication controller, deployment or replica set based on observed CPU utilization or other custom metrics. HPA normally fetches metrics from a series of aggregated APIs:

• metrics.k8s.io
• custom.metrics.k8s.io
• external.metrics.k8s.io

How to make it work?

HPA is being supported by kubectl by default:

• kubectl create - creates a new autoscaler
• kubectl get hpa - lists your autoscalers
• kubectl describe hpa - gets a detailed description of autoscalers
• kubectl delete - deletes an autoscaler

Example: kubectl autoscale rs foo --min=2 --max=5 --cpu-percent=80 creates an autoscaler for replication set foo, with target CPU utilization set to 80% and the number of replicas between 2 and 5. You can and should adjust all values to your needs.

Here is a detailed documentation of how to use kubectl autoscale command.

Please let me know if you find that useful.