4 ms·

You're thinking too qualitatively; imagine the spikes they get... Also most apps are I/O restricted, not CPU... Also, all these proposed messaging architectur

You're thinking too qualitatively; imagine the spikes they get... Also most apps are I/O restricted, not CPU... Also, all these proposed messaging architectures are somewhat flawed. Twitter isn't really "sending" messages to other people. It's more like a person's message history is bound to their account, and appropriate privileges are applied. Then, when people try to "read," privileges are obeyed and information is produced... Am I the only one who believes the solution to Twitter does not involve a massive distributed system? Twitter is inherently centralized... people don't see that.

tptacek 18y ago
The most popular messaging systems are all centralized, too.
Retric 18y ago
Ok I can't edit the old post but they are basically just reinventing mailing lists. Anyway, poling is fine if it's initiated by a user action or it's a vary limited number of systems but if you have a few million users you can't uses it per user. As to reading old log's that's a trivially parallizable problem see database replication for some hints. So you separate the active messaging that automatically adds new Tweets to a user’s cell phone from the way users read old messages with the webpage and your home free. PS: Text is cheep EX: Slashdot is running off of ~4 computers. And bandwidth is not a scaling issue until you need a single system to handle more than ~1GB of bandwidth per second. (Saturating an OC-3 line costs a lot of money but you don't need to change your architecture to do so.)