[erlang-questions] cost of integrating 3rd party SW

[Ben Hood]

Ulf,

On 24 May 2008, at 13:55, Ulf Wiger wrote:

> Perhaps somewhat related to the "RPC is bad" thread,
> do any of you know of any reasonably systematic
> discussions about whether or not Erlang is good or
> bad at interfacing with 3rd party components?

I think it depends what you mean by being good at interfacing with  
foreign language components.

I don't think this is a Erlang specific issue.

Some runtimes can interpret foreign opcodes, e.g. JRuby or compile to  
a multitude of target languages, e.g. CLR,  but a lot of the time you  
are communicating via sockets.

And when you have socket communication, it just comes down to the  
serialization protocol between the two runtimes.

>
> It's something that pops up every once in a while,
> e.g. in the Facebook chat server article: that combining
> Erlang with components written in other languages is
> hard.

I don't think so. I think it's just as hard from any language. The  
gist of the Thrift is they've defined a cross-language serialization  
format.

>
> I know that sometimes, decisions have been made to
> rather write a component from scratch in Erlang, rather
> than interfacing with some COTS component, based on
> the assumption that it will be both cheaper and better
> to do this than to deal with the 3rd party component.
> This is always a hard sell, and usually meets with the
> exclamation: "aha! Erlang is bad at interfacing with other
> software."

What I would find really cool is to be able to embed a VM for a  
foreign language inside an Erlang runtime.

That way you could re-use 3rd party components in foreign instruction  
sets in the same address space as the Erlang code.

HTH,

Ben