snax

Seth Thomas Rasmussen says (March 13, 2009):

Any chance the audio will be available anywhere at some point?

Jim Greer says (March 13, 2009):

+1 for audio!

Lucas Rockwell says (March 13, 2009):

So why are so few, to no, startups using LDAP? I would think LDAP would be a perfect short and long-term solution for twitter. They could put all of their users in LDAP, and then all of the people they are following into a group (each user gets a group). Now, when you want to know who someone is following, that is one query (no joins like in a DB!), and then if you want to know who is following them, again, it is one query.

LDAP (like Sun's LDAP which is free) scales beautifully (it was designed for this, just ask the telcos), and you can easily put all of this info in memory. Sun's 6.3 version handles large groups like this very well. (I do not work for Sun.) And if you want open source, they could use OpenDS or Fedora DS (but I don't know how well Fedora would do with huge groups).

Looking at those slides makes my head spin in terms of what they have tired to engineer with memcache, etc. It just seems like they are trying to fit square pegs into round holes.

Giles Bowkett says (March 13, 2009):

Style isn't everything!

antirez says (March 13, 2009):

Implementing a scalable Twitter is the "Hello World" application of Redis: http://code.google.com/p/redis/wiki/TwitterAlikeExample

(here "Hello World" does not mean the simplest, but the one that is non obvious and exploits many important features to understand the system).

Nick Kallen says (March 13, 2009):

I know London is dreary evan but please don't commit suicide.

Koz says (March 14, 2009):

Why don't you just use X, X works on my blog. Amateurs.

Good slides man, and don't let the london weather (or locals) get you down :)

Chris Farnham says (June 29, 2009):

Great presentation!

On slide 40 of your presentation, you state that, "network memory, at web scale, is lower latency than local computation." Could you elaborate on that? What do you mean by web scale and what qualities of "web scale" changes the traditional latency ordering?

Josh Margulis says (June 18, 2009):

@Chris Farnham: I was not at the presentation and did not hear the audio, but from looking through these slides, my assumption is that it is faster to get the cached results from the network memory than the recompute them locally. Once you have computed something locally, you want to cache it on the network, so that other nodes can pick it up, rather than recompute the same result.

Ranjith Kilari says (June 28, 2009):

I would like to hear some views on the use of LDAP as proposed by Lucas Rockwell .

Charlie says (July 02, 2009):

What does Twitter use the Comet Server for?