[Snow-users-list] [gambit-list] AWS, Termite, and Snow

Joe Hosteny jhosteny at gmail.com
Wed Jan 30 08:00:10 EST 2008

On Jan 30, 2008, at 12:05 AM, Marc Feeley wrote:

> On 29-Jan-08, at 11:29 PM, Joe Hosteny wrote:
>> Hi all,
>> 	First of all, let me preface this email with a disclaimer. I'm  
>> fairly
>> new (again) to Scheme (last exposure was 10+ years ago in college).
>> I'm still feeling my way around a bit, and have settled on Gambit,
>> Chicken, and PLT, to a lesser extent. What I'm trying to say is -  
>> dumb
>> questions may follow!
>> 	I recently wrote a library to manage a cluster of machines in
>> Amazon's EC2. I'm looking to totally rewrite it, and port it to  
>> Scheme
>> in the process. I was also looking at having some facility for
>> managing the cluster from within, with event monitoring via SQS or
>> Termite. Currently, the library does that via polling from a machine
>> external to the cluster. It's not ideal, but was sufficient to get my
>> application working.
>> 	As a start, I wrote a simple Snow package to do MD5 and SHA1 HMAC
>> calculations (the AWS query string API uses SHA1 signatures).
> The "digest" Snow package does MD5, SHA1, and other digests:
>  http://snow.iro.umontreal.ca/?viewpkg=digest

Yes, actually I only wrote the HMAC part, and am using the digests  
from this package.

>> I
>> started to look around for some utilities for URI parsing and  
>> encoding
>> for use in Gambit, but didn't seem to find anything. So, first
>> question - is anyone aware of a suitable package for this?
> Check examples/web-server/http.scm in the Gambit distribution.

Will do.

>> Second
>> question - if one doesn't exist, what do people do for regular
>> expression parsing in Gambit?
> I normally use pregexp: http://www.ccs.neu.edu/home/dorai/pregexp/pregexp.html 
>  .
> It is well written and portable, so it shouldn't be hard to turn it  
> into a Snow module.
>> 	Since I haven't really fleshed out the new architecture, I'm not  
>> sure
>> it's a requirement that I host code to both communicate events across
>> the cluster and issue AWS API calls from within the same executable.
>> So I guess an option would be to use Chicken for the HTTP stuff, and
>> Gambit for Termite and making calls to the code written with Chicken
>> (though at that point, it may make sense to just use one of the Ruby
>> or Java libs for that part). I'd prefer not to, if for nothing more
>> than to be able to contribute the AWS portion as a Chicken or Snow
>> package.
>> 	So, a few general questions follow. From recent mailing list
>> discussions, it sounds like Termite will be targeted towards Gambit
>> only, for the time being at least. Guillaume, is that correct? If  
>> not,
>> do you have an idea of when it might be seen on other Schemes
>> (specifically, Chicken or PLT)?
>> 	Also, does anyone have a feel for what is going on with Snow? It
>> seems like the traffic on the mailing list is a bit slow, and the
>> number of packages is still relatively few.
> I'm still very much interested in continuing to develop Snow.   
> However I've been busy with other things recently and hope to get  
> back to maintaining Snow more actively soon.  To ease the workload  
> I'm also looking for someone to take on some of the maintenance  
> tasks.  Is anyone interested in getting involved?

I may be able to help some. Feel free to contact me off list if you'd  
like to discuss.

> Marc

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