7 ms·

Skittr, a Twitter clone that scales easily, written in 170 lines of Scala and lift

31 points by jorgeortiz85 19y ago

cstejerean 19y ago
Well, I didn't read the entire article, so maybe there was an answer to this but I'm a bit weary of claims like "can be modified to scale linearly with the number of machines with 1 week of coding".
- henning 19y ago
  You're perfectly justified in being skeptical, but if anyone could code such a piece of software, David Pollak could. He was a mature developer when I was an infant.
- deleted 19y ago
  [deleted]
- dpp 19y ago
  There are some folks working on the code and we'll be testing it on an Amazon EC2 cluster. Once there's stuff to share, I'll share it.
  - cstejerean 19y ago
    Excellent, please do.
- yariv 19y ago
  The main difference in effort between a Scala/lift and Erlang/ErlyWeb implementation is that making the Erlang app distributed and linearly scalable doesn't require any coding. Just store the process IDs in Mnesia and when you add more nodes add those nodes to the Mnesia schema and you're done. Not having to restart your Erlang server (and therefore lose your client connections) to do code updates is also pretty cool.
  - michaelneale 19y ago
    So the app writes itself? wow.
    - yariv 19y ago
      It doesn't write itself. Mnesia is a distributed database. When you use it you get distribution for free.
      - michaelneale 19y ago
        I was making a joke ;) However, looking at the scala code it doesn't look like it is written to scale at all. I can't really see any thing in it that indicates it was written in a certain way. Its more a pattern to follow I guess.
- ntoshev 19y ago
  This whole thread smells of lack of understanding of software. Hackers should know how inefficient an SQL server would be to handle Twitter-type tasks, versus specialized code. This is supposed to be hacker's news, not small business news. news.YC is a good example of an efficient architecture. If it was written in Ruby/MySQL, pg would need at least 20 servers to keep up with the current traffic, versus a single box now. And the latency would never be as good as it is now.
michaelneale 19y ago
Wow, scala really is pretty when David shows it like that. I like the new "point free" style syntax (I think that i fairly new). messageViewers = messageViewers.remove(_ == who) (so it creates a new list excluding items that are == to "who"). Nice.
hello_moto 19y ago
Impressive but I dislike the title because it tries make other looks bad. Please don't be like the Rails cult.
mickt 19y ago
With a name like Skittr, picking a name can be tough, Skitter is Irish slang for diarrhoea (or a wee kid). As Twitter is a form of verbal diarrhoea, then SKittr is as good a name as any for a competitor! ;) http://books.google.com/books?id=5GpLcC4a5fAC&pg=PA1295&lpg=PA1295&dq=skitter+irish+slang&source=web&ots=2wmST3hmA9&sig=oVoVZSG1tPDIj3GzZWse7FEPz-w http://books.google.com/books?id=5GpLcC4a5fAC&pg=PA1295&... http://www.bbc.co.uk/northernireland/voices/atilazed/s.shtml http://www.bbc.co.uk/northernireland/voices/atilazed/s.shtml
- michaelneale 19y ago
  I remember the "Pikey" which was a USB key with PKI stuff built in. Hilarious.
sbh 19y ago
I don't want to be arrogant, but from the technology point of view Twitter is nothing. Write it in a way that scales better, write it in 170 lines of Scala or 10 lines of Lisp, you still haven't done anything. Come up with the idea before anyone else, get millions of users, that's the difficult part.
- vikram 19y ago
  I think he's trying to advertise his framework and scala. He doesn't care about the idea.
tlrobinson 19y ago
First of all, I'll say that this (really neat sounding) project doesn't necessarily fall into the following category, the title just reminded me of a pet peeve of mine... I'm always skeptical of the claims of "do this amazing thing in x lines of code" where x is some ridiculously small number. For example, the prototypical 10 minute Ruby on Rails blog, or the 1 line of code WebKit-based web browser. The problem with these things is they make great whiz bang demos, but they really don't take any less code, it's just that you don't have to write that code because it's already written for you and hidden behind a layer of abstraction... which is great, as long as it can also be applied to real world problems, not just little toy demos.
helptheworld 19y ago
Here are 4 twitter-like sites - built with php and mysql. I guess they won't scale all that well, we'll see :) I just wanted to get them out there, like, quick.. so, people could, like, use them. www.HelpWorldClimate.com www.HelpWorldPoverty.com www.HelpWorldPeace.com www.HelpWorldWildlife.com

31 points by jorgeortiz85 19y ago

Well, I didn't read the entire article, so maybe there was an answer to this but I'm a bit weary of claims like "can be modified to scale linearly with the number of machines with 1 week of coding".

henning 19y ago
You're perfectly justified in being skeptical, but if anyone could code such a piece of software, David Pollak could. He was a mature developer when I was an infant.
deleted 19y ago
[deleted]
dpp 19y ago
There are some folks working on the code and we'll be testing it on an Amazon EC2 cluster. Once there's stuff to share, I'll share it.
- cstejerean 19y ago
  Excellent, please do.
yariv 19y ago
The main difference in effort between a Scala/lift and Erlang/ErlyWeb implementation is that making the Erlang app distributed and linearly scalable doesn't require any coding. Just store the process IDs in Mnesia and when you add more nodes add those nodes to the Mnesia schema and you're done. Not having to restart your Erlang server (and therefore lose your client connections) to do code updates is also pretty cool.
- michaelneale 19y ago
  So the app writes itself? wow.
  - yariv 19y ago
    It doesn't write itself. Mnesia is a distributed database. When you use it you get distribution for free.
    - michaelneale 19y ago
      I was making a joke ;) However, looking at the scala code it doesn't look like it is written to scale at all. I can't really see any thing in it that indicates it was written in a certain way. Its more a pattern to follow I guess.
ntoshev 19y ago
This whole thread smells of lack of understanding of software. Hackers should know how inefficient an SQL server would be to handle Twitter-type tasks, versus specialized code. This is supposed to be hacker's news, not small business news. news.YC is a good example of an efficient architecture. If it was written in Ruby/MySQL, pg would need at least 20 servers to keep up with the current traffic, versus a single box now. And the latency would never be as good as it is now.

michaelneale 19y ago

Wow, scala really is pretty when David shows it like that. I like the new "point free" style syntax (I think that i fairly new). messageViewers = messageViewers.remove(_ == who) (so it creates a new list excluding items that are == to "who"). Nice.

hello_moto 19y ago

Impressive but I dislike the title because it tries make other looks bad. Please don't be like the Rails cult.

mickt 19y ago

With a name like Skittr, picking a name can be tough, Skitter is Irish slang for diarrhoea (or a wee kid). As Twitter is a form of verbal diarrhoea, then SKittr is as good a name as any for a competitor! ;) http://books.google.com/books?id=5GpLcC4a5fAC&pg=PA1295&lpg=PA1295&dq=skitter+irish+slang&source=web&ots=2wmST3hmA9&sig=oVoVZSG1tPDIj3GzZWse7FEPz-w http://books.google.com/books?id=5GpLcC4a5fAC&pg=PA1295&... http://www.bbc.co.uk/northernireland/voices/atilazed/s.shtml http://www.bbc.co.uk/northernireland/voices/atilazed/s.shtml

michaelneale 19y ago
I remember the "Pikey" which was a USB key with PKI stuff built in. Hilarious.

sbh 19y ago

I don't want to be arrogant, but from the technology point of view Twitter is nothing. Write it in a way that scales better, write it in 170 lines of Scala or 10 lines of Lisp, you still haven't done anything. Come up with the idea before anyone else, get millions of users, that's the difficult part.

vikram 19y ago
I think he's trying to advertise his framework and scala. He doesn't care about the idea.

tlrobinson 19y ago

First of all, I'll say that this (really neat sounding) project doesn't necessarily fall into the following category, the title just reminded me of a pet peeve of mine... I'm always skeptical of the claims of "do this amazing thing in x lines of code" where x is some ridiculously small number. For example, the prototypical 10 minute Ruby on Rails blog, or the 1 line of code WebKit-based web browser. The problem with these things is they make great whiz bang demos, but they really don't take any less code, it's just that you don't have to write that code because it's already written for you and hidden behind a layer of abstraction... which is great, as long as it can also be applied to real world problems, not just little toy demos.

helptheworld 19y ago

Here are 4 twitter-like sites - built with php and mysql. I guess they won't scale all that well, we'll see :) I just wanted to get them out there, like, quick.. so, people could, like, use them. www.HelpWorldClimate.com www.HelpWorldPoverty.com www.HelpWorldPeace.com www.HelpWorldWildlife.com