Microservices architecture allows you to isolate failures, thus enabling you to isolate the failures and get graceful degradation as failures are contained within the boundaries of the service and are not cascaded. For example, in social networking sites, the messaging service may go down, but that won't stop the end users from using social networks. They can still browse posts, share statuses, check-in locations, and so on. Services should be made such that they adhere to certain SLAs. If a microservice stops meeting its SLA, then that service should be restored to back up. Netflix's Hystrix is based on the same principle.