3 ms·
They measured their response time using average. Collecting metrics to look good. Since we can only speak in broad terms, those requests/updates aren't going t
by latch 9y ago
They measured their response time using average. Collecting metrics to look good.
Since we can only speak in broad terms, those requests/updates aren't going to be evenly distributed throughout the day and they might not be consistent from day to day so some over-provisioning is reasonable.
Since they're on EC2 a) they shouldn't be that over-provisioned though and b) are getting comparatively (to bare metal) awful performance (say 2x-8x depending on exactly what they're doing) and paying for the privilege.
I'd like to better understand why "Fanout-on-write" wasn't their go-to solution. All they said was that it was "expensive".
- tschellenbach 9y agoWe started out with fanout on write but it was tricky. Fanout on write can get incredibly expensive. Customers would implement things like featured accounts, or topics that you can follow. Basically feeds that are followed by a significant percentage of your userbase and update all the time. Companies like Twitter and Instagram control their product and can avoid some of these pitfalls. A full fanout on write approach means you need to enforce certain product limitations, have a large budget and accept that feed propagation is not always as fast.
- xstartup 9y agoHow does fan out write help?
- latch 9y agoLets you shard and makes your reads dead simple (1 table, 1 predicate, 1 sort)