Re: Scala paper: Actors that Unify Threads and Events

Terrance Sullivan wrote:
> As I recall from reading Philipp's early paper and the sense Erlang  the 
> language may have also possibly influenced his work on Scala  Actors 

Indeed, Scala's actors were influenced to a large extent by Erlang.

> (?), would suggest taking a look at YAWS (Yet Another Web  Server) done 
> in an Erlang/Actor style with interesting performance  and robustness 
> characteristics or YXA which is a similarly  implemented instance of 
> SIP. Certainly, the 15+ years Ericsson has  acquired using Erlang/OTP on 
> their production ATM switches would also  suggest that this is a well 
> founded technique.. Equally one could  back track to some of the 
> material at the Erlang.org site..

I agree. Existing Erlang work might be very helpful to look at. After
all, the programming models are very similar. I also recommend the
Erlang book ("Concurrent Programming in Erlang", 2nd ed. by Joe
Armstrong et al.). It contains a wealth of programming examples for
actor-style message passing concurrency. Most of them should be
straight-forward to write using Scala actors.

On the other hand, I fully agree with Warren that a comprehensive
example in Scala would be a very good thing.

Actually, some larger programs have been developed in our lab.
Unfortunately, they have to be re-written since the actor library has
been re-designed in the meantime. I'll take a look and see how much work
it is to update the old code.

Another point regarding "massive scalability". I think it is important
to note that large numbers of actors are not only interesting for
network applications such as web or Jabber servers (for connections/user
sessions).

Lightweight actors are also crucial if you intend to build general
abstractions on top of them. As a rather radical example, imagine
replacing all your normal objects with actors...

Cheers,
   Philipp



> /Terry
> 
> On 29-Jan-07, at 12:32 PM, Warren Henning wrote:
> 
>> On 1/29/07, Philipp Haller <philipp.haller@xxxxxxx> wrote:
>>
>>> Feedback is very welcome!
>>
>>
>> What would help me the most in understanding actors is a practical
>> example that clearly shows how the actor system can be used to create
>> real-world massively scalable systems. What would be nice is a
>> complete, realistic program, not too short but not too long, either,
>> that I can compile and run involving something, say, network-related,
>> that I can try out on my home machine and play around with.
>>
>> Apparently a tutorial of some kind is underway on the actors library
>> and I eagerly await it.
>>
>> Warren Henning
>>
>