Tracy Reed <[email protected]> writes:
> On Thu, Apr 22, 2010 at 07:25:43AM +1000, Daniel Pittman spake thusly:
>
>> At work we are running into a need to deal with message passing in more
>> places, and I have a general policy of picking up existing, standard tools
>> rather than letting the developers invent their own messaging-on-HTTP
>> layer.
>
> This is an area I've sometimes wondered about ever since I heard about
> midleware years ago but never really understood what it did... What is
> message passing used for?
>
> Can you give me some general or generic examples of what sort of application
> would use message passing and how it is architected?
Andrew gave a good answer to some of this, but the things that I want to avoid
having to build ourselves are:
Message routing: having the developer stick something an address on their
message, or subscript to an address, rather than having to know which machine
is handling the content.
Message efficiency: for broadcast or publish/subscribe messages, aside from
the cost of having to implement that at all, being able to use the middleware
to send one copy of the message across the WAN rather than one-per-subscriber.
Message reliability: being able to provide a strong, well defined assurance
about what the reliability of a message will be, and when it is persistent,
avoid developers best-guessing their own implementation.
Logging and metrics: being able to know what messages are moving, what volume,
how long they are in flight, or in the queue for processing, in a *standard*
way makes it easier for me to spot problems.
...and which applications benefit from this? Anything that needs to
communicate between two or more machines *can* benefit from this, because they
don't have to invent their own mechanism, they just use the standard one.
Daniel
Don't mistake a message queue system like this for something more than a low
level message passing tool, though: you can't deploy one and get a "batch
processing system" for free or anything like that.
--
✣ Daniel Pittman ✉ [email protected] ☎ +61 401 155 707
♽ made with 100 percent post-consumer electrons
_______________________________________________
Tech mailing list
[email protected]
http://lopsa.org/cgi-bin/mailman/listinfo/tech
This list provided by the League of Professional System Administrators
http://lopsa.org/
