[erlang-questions] What's the status of erl_com, the Erlang-t o-COM bridge?

David Mitchell <>
Fri Oct 17 03:53:44 CEST 2008


Hmm, thanks Dale - you've definitely given me another approach worth
thinking about.  Time to make a list of the pros and cons of Flash vs.
COMET.  To be honest, I've never even considered using Flash for
something like this, but I can see it's got a lot going for it.

Hmm...

Thanks and regards

Dave M.

2008/10/17 Dale Harvey <>:
> the xiff library can connect to ejabberd using flash sockets, writing a
> custom client
> with flash sockets is also possible, and writing a proxy / gateway that
> connects to
> xmpp on the server and can serve comet or flash would be straightforward.
>
> websockets are also coming natively to browsers but not yet supported.
> (they would need a proxy / gateway to xmpp, incompatible protocol)
>
> as for comet 'scaling' its used for facebook and meebo chat, both serve a
> fair
> amount of people with realtime information. flash sockets havent gained
> the same popularity as far as ive seen, although I dont see an obvious
> reason
> why, apart from the flash plugin dependancy
>
> 2008/10/16 David Mitchell <>
>>
>> I'd LOVE to replace MQ and Tibco - about they only things they have in
>> their favor is "vendor support", and being already entrenched in the
>> environment.  I quite like the functionality of both, but trying to do
>> something with them that the vendors didn't consider (i.e. hook Erlang
>> to them) is painful.  For an open-source app, there would either be a
>> generic API (e.g. REST) that would be language independent, or I could
>> pull apart the source and extend it.
>>
>> Actually, MQ has a "sort of like REST" API, but it's an optional extra
>> i.e. costs money.  It's not enough like REST to make it a no-brainer
>> though, and then there's the question of how it's gonna impact the
>> existing infrastructure since it has to run on the MQ server.
>>
>> As far as the data distribution goes, I need to build a
>> "dashboard"-type Web page that I can use to see the state of all the
>> various interfaces.  COMET gives me the ability to have the server
>> update each interface's status as new info becomes available without
>> having the user refresh the Web page (at least, that's the theory -
>> whether it's gonna scale is another matter...).  Do you know of a way
>> I could duplicate that with XMPP and ejabberd?  I don't really want an
>> AJAX interface except as a last resort, as that's going to be a "pull"
>> interface; I'd really like a "push" interface if it's practical, so I
>> can get something approaching real-time updates.
>>
>> Thanks for your response
>>
>> Dave M.
>>
>> 2008/10/16 French, Mike <>:
>> >
>> > How about using XMPP and ejabberd for the data distribution ?
>> > COMET over HTTP is always an unnatural contortion,
>> > but Jabber is pub/sub push by nature.
>> >
>> > Then you could always replace MQ and Tibco with XMPP later on :)
>> >
>> > Mike
>> >
>> >> -----Original Message-----
>> >> From: 
>> >> [mailto:]On Behalf Of
>> >> David Mitchell
>> >> Sent: 15 October 2008 21:34
>> >> To: 
>> >> Subject: Re: [erlang-questions] What's the status of erl_com, the
>> >> Erlang-to-COM bridge?
>> >>
>> >>
>> >> My reason for choosing Erlang in the first place was for scalability -
>> >> I need to be able to read/write/monitor upwards of 1000 MQ and Tibco
>> >> queues simultaneously, and drive them all and present status plus
>> >> drill-down info from a central point via a Web interface.  I've got
>> >> access to lots of Intel servers (if necessary) to build this.  With
>> >> Erlang, the ease of scaling horizontally makes it relatively
>> >> straightforward to handle that quantity of interfaces (ignoring the
>> >> fact that they're MQ and Tibco specifically), and using Yaws would
>> >> mean that I won't have issues with scalability in data presentation.
>> >> Finally, and I haven't thought this next part through thoroughly yet,
>> >> I would also lean towards using COMET (not the COM interface project;
>> >> the Web push interface project) to push updates out to my Web clients.
>> >>
>> >> Finally the app is such that it needs to be 100% reliable during
>> >> extended periods of high load, and OTP gives me the capability to
>> >> build that in fairly easily.
>> >>
>> >> Bottom line is that I know Erlang would be a good fit (again, ignoring
>> >> the fact that the interfaces are MQ and Tibco), whereas I think it
>> >> would take me longer to produce a less-reliable solution in Java.
>> >>
>> >> Regards
>> >>
>> >> Dave M.
>> >>
>> >> 2008/10/15 Rapsey <>:
>> >> > I'm sure Java has what you need, so why not go through jinterface?
>> >> >
>> >> >
>> >> > Sergej
>> >> >
>> >> > On Wed, Oct 15, 2008 at 11:31 AM, Robert Raschke
>> >> <>
>> >> > wrote:
>> >> >>
>> >> >> On Wed, Oct 15, 2008 at 5:52 AM, David Mitchell
>> >> <>
>> >> >> wrote:
>> >> >> > Thanks Jakob and Kenneth for your responses.
>> >> >> >
>> >> >> > I need to hook Erlang to a variety of external
>> >> applications (MQ, Tibco
>> >> >> > Rendezvous, Oracle), none of which have "native" Erlang
>> >> interfaces but
>> >> >> > all have COM interfaces available.  Comet looked like a good fit
>> >> >> > (assuming I ran Erlang on a Windows box), but based on
>> >> your comments
>> >> >> > I'll look elsewhere.  That probably means building a C
>> >> port for MQ and
>> >> >> > Tibco, and I may be able to get away with using ODBC for Oracle.
>> >> >> >
>> >> >> > If you need any votes of support to revive COMET within Ericsson,
>> >> >> > please let me know ;->
>> >> >>
>> >> >> If you don't want to use something like C#, then I can
>> >> recommend Lua
>> >> >> together with LuaCOM for interfacing to COM. I would guess
>> >> that it's
>> >> >> not very hard to wrap a COM interface with this and expose it to
>> >> >> Erlang through a port. Still, a little bit of work would
>> >> be required.
>> >> >>
>> >> >> Robby
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