4 ms·

We know the java libraries are there for lots of things, but Node is all about async and handling thousands of connections. It does this by forcing the entire e

We know the java libraries are there for lots of things, but Node is all about async and handling thousands of connections. It does this by forcing the entire ecosystem to be async too (including things like database drivers). By using a Java JDBC database driver you're completely losing any async support. Same presumably goes for redis or Mongo drivers. You can do some of the work with threads and pooling, but it's still not the same, and makes this another useless micro benchmark.

tferris 14y ago
> It does this by forcing the entire ecosystem to be async too (including things like database drivers). Yes, that's exactly Node's main selling proposition everybody forgets when presenting their next Node.js
- soc88 14y ago
  I would call it "node.js's largest implementation issue". It is not that JavaScript gives you another choice, while you make it sound like it was a principled decision. Other platforms/languages have real concurrency constructs and don't suffer node's limitations.
  - drostie 14y ago
    Well, no, you could have done all of these things synchronously, and in fact JS would have preferred it because JS is intrinsically single-threaded. Ryan Dahl's stated inspiration for Node was that he struggled with a certain slowness in Ruby because it blocked for everything, so he tried to build an entire language that simply wouldn't let you sleep(). You can go listen to his talks; they're on YouTube. It was a principled decision. I don't know whether making JS single-threaded was a principled decision -- if anything it was presumably the KISS principle at work. However, it was actually a ridiculously nice choice to offer a single-threaded-asynchrony model. It sometimes gets in the way rather obtusely -- Firefox can still (if very rarely) fail to introspect and then crash when some ad script on your page goes into an infinite loop! -- but on the whole, it is very nice to always know that while I'm in this function, modifying this variable, nobody else can interfere. With that said, I also think that the lack of good concurrency planning is indeed missing, and that it will probably enter the language at a future time.
- batista 14y ago
  Actually that's not a "selling proposition". At best it's "making a virtue out of necessity".
deleted 14y ago
[deleted]
andrewvc 14y ago
The value of this is far overstated. You can think of your server as being composed of async queues and thread pools, even in node. About the only thing in a stack that truly is async is connection handling via epoll. Mysql itself is a big threadpool, bounded by the number of cores and table locking. The jvm has amazing threading support, doubly so if you use it with a language like scala or clojure. You can and should handle the connections asynchronously and use a thread pool for things like db access. It works well, people have done this with the jvm for years.
purplefox 14y ago
Vert.x has a hybrid model. It has both event loops and a background thread pool, so you can choose which to run your task on depending on what kind of thing it is. E.g. it's stupid to run long running or blocking actions on an event loop.
pron 14y ago
Node's API is async. Under the hood everything is done via threadpools, same as in Java or any other stack. Your hardware knows how to run threads; that's all. Whether or not that's what's exposed to you as a programmer is a different story. You don't actually get a performance boost from Node being "async". Node's async abilities simply give you transparent access to threads that are otherwise unavailable with javascript, and it's the threads giving you performance.
- ithkuil 14y ago
  I don't think this is true. Nodejs uses epoll/kqueue/select etc to multiplex access to multiple file descriptors from a single main thread. The async API is actually a price to pay (spaghettification). For example, the go language took a different approach: it created a cheap thread-like construct which doesn't incur in the biggest overhead of classical threading (namely pre-allocated linear stacks and context switching/sleeping requiring a systemcall; all this aided by the compiler), and a cheap mean of communication (channels). Then, the whole core IO library was written using a multiplexing async model (epoll...), which communicates with the user part of the library via channels). The result is a blocking like API which under the hood behaves like an async implementation. A similar goal is also met by http://www.neilmix.com/narrativejs/doc/ http://www.neilmix.com/narrativejs/doc/ and other javascript 'weavers' which convert "sequantial looking" code into callbacks.
  - pron 14y ago
    Yes, but at the end of the day, underneath it all, you gotta have threads because that's what the hardware understands. Even if you use hardware interrupts to detect IO, you still need a plain old thread to handle it. The only difference between various languages and runtimes is how you distribute tasks among the threads. Some environments provide green threads that have a partial stack, but even they are handed off to a thread pool (or a single thread) for execution. It's been found that if you employ only a single thread (that can run any number of tasks) you get a performance boost over using a larger threadpool under some conditions, but a single thread wouldn't let you scale by taking advantage of all processors.
pwpwp 14y ago
> forcing the entire ecosystem to be async too You say that like it's a good thing. I'd much rather have the choice between async and sync.
- baudehlo 14y ago
  The problem comes when you mix the two. Try it. Try scaling it (to a hundred thousand connections). I've done it and it doesn't mix. Sure programming-wise it's nice to have sync. No argument there.
soc88 14y ago
No, not really. You can happily run blocking and non-blocking code on the JVM without problems. The inability of JavaScript to do that created the need make everything asynchronous, not the other way around.
batista 14y ago
>We know the java libraries are there for lots of things, but Node is all about async and handling thousands of connections. It does this by forcing the entire ecosystem to be async too (including things like database drivers). By using a Java JDBC database driver you're completely losing any async support. Same presumably goes for redis or Mongo drivers. You can do some of the work with threads and pooling, but it's still not the same, and makes this another useless micro benchmark. Sounds like you're quoting from the "Node.js Is Bad Ass Rock Star Tech" satire video ( http://www.youtube.com/watch?v=bzkRVzciAZg http://www.youtube.com/watch?v=bzkRVzciAZg ). Nothing inherently special about "forcing the entire ecosystem to be async too", especially since Node is more or less FORCED to do that, because javascript is single threaded. Add the bad callback spaghetti implementation of async, and the main benefit of Node is easy deployment, and accessibility to the millions of javascript programmers. As an async environment it doesn't offer anything either new or too compelling.
- baudehlo 14y ago
  > As an async environment it doesn't offer anything either new or too compelling That isn't strictly true. If you focus on the traditional scripting languages as your competition: Ruby, Python, PHP, Perl: Then you start to realise that Node.js does offer a similar language structure (dynamic, no compilation, etc), with the benefits of thousands of concurrent connections (which those languages will do with certain modules) but while forcing all the libraries to also be async (which those languages DO NOT do). At my last job I had to build an SMTP server capable of scaling to 50k concurrent connections. Building this in Perl was fine, except for any library I wanted to use - all of the libraries were synchronous. So now I wrote Haraka, which Craigslist are now using as their incoming SMTP server. If you compare all that to Java you get slightly less performance but probably lower memory requirements. And that's OK. Different strokes for different folks.

tferris 14y ago

> It does this by forcing the entire ecosystem to be async too (including things like database drivers). Yes, that's exactly Node's main selling proposition everybody forgets when presenting their next Node.js

soc88 14y ago
I would call it "node.js's largest implementation issue". It is not that JavaScript gives you another choice, while you make it sound like it was a principled decision. Other platforms/languages have real concurrency constructs and don't suffer node's limitations.
- drostie 14y ago
  Well, no, you could have done all of these things synchronously, and in fact JS would have preferred it because JS is intrinsically single-threaded. Ryan Dahl's stated inspiration for Node was that he struggled with a certain slowness in Ruby because it blocked for everything, so he tried to build an entire language that simply wouldn't let you sleep(). You can go listen to his talks; they're on YouTube. It was a principled decision. I don't know whether making JS single-threaded was a principled decision -- if anything it was presumably the KISS principle at work. However, it was actually a ridiculously nice choice to offer a single-threaded-asynchrony model. It sometimes gets in the way rather obtusely -- Firefox can still (if very rarely) fail to introspect and then crash when some ad script on your page goes into an infinite loop! -- but on the whole, it is very nice to always know that while I'm in this function, modifying this variable, nobody else can interfere. With that said, I also think that the lack of good concurrency planning is indeed missing, and that it will probably enter the language at a future time.
batista 14y ago
Actually that's not a "selling proposition". At best it's "making a virtue out of necessity".

deleted 14y ago

[deleted]

andrewvc 14y ago

The value of this is far overstated. You can think of your server as being composed of async queues and thread pools, even in node. About the only thing in a stack that truly is async is connection handling via epoll. Mysql itself is a big threadpool, bounded by the number of cores and table locking. The jvm has amazing threading support, doubly so if you use it with a language like scala or clojure. You can and should handle the connections asynchronously and use a thread pool for things like db access. It works well, people have done this with the jvm for years.

purplefox 14y ago

Vert.x has a hybrid model. It has both event loops and a background thread pool, so you can choose which to run your task on depending on what kind of thing it is. E.g. it's stupid to run long running or blocking actions on an event loop.

pron 14y ago

Node's API is async. Under the hood everything is done via threadpools, same as in Java or any other stack. Your hardware knows how to run threads; that's all. Whether or not that's what's exposed to you as a programmer is a different story. You don't actually get a performance boost from Node being "async". Node's async abilities simply give you transparent access to threads that are otherwise unavailable with javascript, and it's the threads giving you performance.

ithkuil 14y ago
I don't think this is true. Nodejs uses epoll/kqueue/select etc to multiplex access to multiple file descriptors from a single main thread. The async API is actually a price to pay (spaghettification). For example, the go language took a different approach: it created a cheap thread-like construct which doesn't incur in the biggest overhead of classical threading (namely pre-allocated linear stacks and context switching/sleeping requiring a systemcall; all this aided by the compiler), and a cheap mean of communication (channels). Then, the whole core IO library was written using a multiplexing async model (epoll...), which communicates with the user part of the library via channels). The result is a blocking like API which under the hood behaves like an async implementation. A similar goal is also met by http://www.neilmix.com/narrativejs/doc/ http://www.neilmix.com/narrativejs/doc/ and other javascript 'weavers' which convert "sequantial looking" code into callbacks.
- pron 14y ago
  Yes, but at the end of the day, underneath it all, you gotta have threads because that's what the hardware understands. Even if you use hardware interrupts to detect IO, you still need a plain old thread to handle it. The only difference between various languages and runtimes is how you distribute tasks among the threads. Some environments provide green threads that have a partial stack, but even they are handed off to a thread pool (or a single thread) for execution. It's been found that if you employ only a single thread (that can run any number of tasks) you get a performance boost over using a larger threadpool under some conditions, but a single thread wouldn't let you scale by taking advantage of all processors.

pwpwp 14y ago

> forcing the entire ecosystem to be async too You say that like it's a good thing. I'd much rather have the choice between async and sync.

baudehlo 14y ago
The problem comes when you mix the two. Try it. Try scaling it (to a hundred thousand connections). I've done it and it doesn't mix. Sure programming-wise it's nice to have sync. No argument there.

soc88 14y ago

No, not really. You can happily run blocking and non-blocking code on the JVM without problems. The inability of JavaScript to do that created the need make everything asynchronous, not the other way around.

batista 14y ago

>We know the java libraries are there for lots of things, but Node is all about async and handling thousands of connections. It does this by forcing the entire ecosystem to be async too (including things like database drivers). By using a Java JDBC database driver you're completely losing any async support. Same presumably goes for redis or Mongo drivers. You can do some of the work with threads and pooling, but it's still not the same, and makes this another useless micro benchmark. Sounds like you're quoting from the "Node.js Is Bad Ass Rock Star Tech" satire video ( http://www.youtube.com/watch?v=bzkRVzciAZg http://www.youtube.com/watch?v=bzkRVzciAZg ). Nothing inherently special about "forcing the entire ecosystem to be async too", especially since Node is more or less FORCED to do that, because javascript is single threaded. Add the bad callback spaghetti implementation of async, and the main benefit of Node is easy deployment, and accessibility to the millions of javascript programmers. As an async environment it doesn't offer anything either new or too compelling.

baudehlo 14y ago
> As an async environment it doesn't offer anything either new or too compelling That isn't strictly true. If you focus on the traditional scripting languages as your competition: Ruby, Python, PHP, Perl: Then you start to realise that Node.js does offer a similar language structure (dynamic, no compilation, etc), with the benefits of thousands of concurrent connections (which those languages will do with certain modules) but while forcing all the libraries to also be async (which those languages DO NOT do). At my last job I had to build an SMTP server capable of scaling to 50k concurrent connections. Building this in Perl was fine, except for any library I wanted to use - all of the libraries were synchronous. So now I wrote Haraka, which Craigslist are now using as their incoming SMTP server. If you compare all that to Java you get slightly less performance but probably lower memory requirements. And that's OK. Different strokes for different folks.