Scaling

Horizontal scaling

Horizontal scaling changes the number of running replicas for a supported resource. It is most relevant to resources using the master-node or Docker Swarm deployment path.

Before adding replicas:

• Confirm the application can run more than one instance.
• Move session state and shared files to appropriate backing services.
• Confirm workers do not process the same job twice.

Vertical scaling

Vertical scaling changes the compute plan or CPU and memory assigned to a resource.

Use metrics to determine whether the workload is CPU-bound or memory-bound. A scale operation can require an infrastructure update or process restart.

Storage scaling

Supported resource plans can expose storage scaling. Storage limits and extra-storage billing are plan-specific.

See Data transfer and storage for the per-plan storage verification note.

Scaling controls require runtime credits and are restricted during the free trial.