問題文
An architect reviews an app before enabling horizontal scaling of its web process. Which properties must hold for adding dynos to be safe and effective? (Select two.)
選択肢
- Any singleton process type, such as a scheduler, must stay at one dyno, because additional dynos of a singleton produce duplicate work.
- Every process type must run the same number of dynos, and the platform refuses a formation in which the counts differ.
- The web framework must be single-threaded, because the platform assumes one request per dyno and distributes the load evenly only when each dyno handles exactly one request at a time throughout the whole lifetime of that dyno.
- The processes must be stateless, so anything that has to outlive a request lives in a backing service rather than in the dyno's memory or file system.
- The application must enable session affinity, because horizontal scaling is only supported for applications whose requests are pinned by the router to a single dyno and held there for the whole of a user's session.