4 ms·
Replication lag can make that pretty tricky - you never know if the client doing the reading has seen a state further in the future than the replica
by zinodaur 5y ago
Replication lag can make that pretty tricky - you never know if the client doing the reading has seen a state further in the future than the replica
- daneel_w 5y agoThat's not a concern unless your application is broken. An application should stick to one DB instance for one and the same isolated task, not open multiple parallel connections to interact with.
- evanelias 5y agoYou're trivializing read-after-write consistency. It's actually quite a challenging problem for most applications, especially for anything web-based. Let's say you add a comment to a piece of content and then refresh the page. With a naively-implemented CRUD app, your comment disappears if your request's read query was routed to a lagging replica. This gets even trickier when multiple datacenters in different geographic regions are involved.