Scaling strategies differ for a stateful vs a stateless service. Currently, it is not possible to scale a Stateful Service automatically. A Scaling policy is applicable only for a stateless Service.
A Scaling Policy defines the CPU and Memory thresholds beyond which the Service must automatically scale up.
What are Replicas ?
Replicas are identical instances of a Service deployment. All the replicas carry the same set of configurations like Container definitions and Policies, except for the Persistent Volume mounts. In a stateful Service, each replica can mount the same static volume or a separate instance of a volume which is dynamically provisioned at the time of creating the replica.
The CPU and Memory consumption is the average consumption of all the replicas within a Service. For each replica, their utilisation is calculated as the average utilisation of all the sidecar containers within the Service.
Minimum Number of replicas to be maintained when a Service scales down.
Maximum Number of replicas that can be created when a Service scales up.
Steps to create a Scaling Policy
- In the left panel, navigate to Service Policies and choose Scaling Policies
- Click on Create new policy to open the creation wizard.
- Choose the scaling attributes and click Create to create new policy.