Basic and manual scaling

As with automatic scaling, basic scaling allows App Engine to create and destroy service instances as needed. Basic scaling differs from automatic scaling in that services are directly scaled in relation to user requests. If an instance goes longer than idle_timeout, that instance is destroyed:

basic_scaling:
  max_instances: 10
  idle_timeout: 5m

Compared to automatic scaling, basic scaling has slightly more relaxed constraints on application behavior, including support for background threading and longer request timeouts. Basic scaling is only available for the standard environment. When considering basic scaling for long running tasks, evaluate whether task queues provide a better solution.

The simplest form of scaling on App Engine is manual scaling, where developers simply specify the desired number of instances. Should a service become unhealthy, App Engine will replace it to maintain the target instance count:

manual_scaling:
  instances: 3