One of the NFR states “Consistency can take a hit (in the interest of availability), if a user doesn’t see a photo for a while, it should be fine.”. This sounds incorrect and should instead be “Availability can take a hit (in the interest of Consistency), if a user doesn’t see a photo for a while, it should be fine.”?
Consistency and Availability are discussed here in the context of the whole service and not individual photo. So this statement is essentially saying that the service should be available (showing photos to its users all the time) although some users might not be seeing some photos for some time (hence the service is inconsistent for all users).
In other words, the system should try its best to produce a timeline for every user (maximum availability), although some photos that should have been part of the timeline are not showing.
2 Likes