As a User, I want the system to remember that I read notifications when I go to the All Notifications page, so that I don't have to get notified of those messages again.

This is the other "write" function for the timestamps. When the user navigates to the Special:Notifications page, the server will reset the last-read timestamp, even though it is an HTTP GET request. In our multi-DC environment, we usually don't write to data storage on an HTTP GET, since POST, PUT, DELETE verbs will all be routed to the primary data centre. In this case, it can mean writing to data storage in a secondary data centre.

Priority: must have