[bind10-dev] MSQ-NG requirements

[Michal 'vorner' Vaner]

Hello

On Mon, Apr 09, 2012 at 01:54:48PM +0000, Steven Meyer wrote:
> The design of the msgq is not supportive of synchronous, point-to-point communications (i.e. RPC).  Sending large messages through such a centralized resource has negative impacts on many fronts. Therefore either the applications have to change to make use of the asynchronous, multi-point, queuing model or they should not be going thorough the msgq!  There is nothing to preclude using both a point-to-point model and a message queuing model for different types of messaging.

I don't want to argue, but I never said that the RPC should be synchronous. I
explicitly state that we should move to as much asynchronous as possible, with
callbacks. And we don't need large messages often, just sometimes ‒ for example
retrieving configuration on startup. If there's configuration with many ACLs or
zones, we can't avoid sending large messages ‒ therefore the system must be able
to cope with them. And I don't think it is such a big problem, to asynchronously
read it, then route and write it (asynchronously again).

I don't know what you don't like with RPC or what is wrong with it in relation
to MSGQ. What is the difference between sending an event to 5 connected clients
and sending a command to one connected client?

Maybe the MSGQ name is wrong, but it is used as rpc/signalling bus. And it is
used for point to point communication.

> I see many assumptions implicit in the discussion so far, some of which may be wrong. Perhaps you should take a step back and elaborate on the application messaging requirements (the 'what') before you consider how to implement the solution? 

The assumptions arise from the fact we already use the message bus heavily and
we would have a very hard time changing the system too much. So I want to aim to
make it functional without too much rewriting all we have written in the past 3
years.

With regards

-- 
I'm reading your disk
		-- General Failure

Michal 'vorner' Vaner
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