RE: Re: Look ma, no hub?

["Ian Lowe" <ianlowe@xxxxxxxxxxxxxxxxx>]

> Please explain what you can do with a hub that you couldn't do
perfectly
well without one

NO! *YOU* explain what is to be gained by making a drastic change to how
things are done. The fact that a given OS supports a method doesn't mean
that we should automatically adopt it: especially when the benefits in
doing
so seem pretty nebulous.

Jean Paul is asking us to leave things they they are, please, and you are
asking for a change - justify your change, don't demand that users defend
the status quo!

"> The application just has to:"

And what happens if an application *doesn't* do this? If you bind to 3865,
then another app is broken, unless it also implements your method.

There are a variety of linux implementations of xPL so far, and to my
knowledge *none* of them use the SO_REUSEADDR option. To my mind that says
that this is not a well known technique. Come to think of it, I'm
struggling
to think of any other situation where multiple instances of an application
share a port in common usage.

> Personally I'd not have a problem requiring applications (and hubs) to
perform this test on all platforms.

Hmm. I would, because it's complexity for it's own sake!

> Sorry to cause trouble here, but I think it is important to justify
having
single points of failure.

Sorry Mark, but this is an argument that we have already had, and expended
a
lot of effort on - one of the most prolific developers walked away from the
xPL project because of these same arguments sapping away at development
effort.

What the project needs is more useful applications, not more and more
tinkering with the basics which already work!Seriously - if you want to
help
the project, release cool new apps, interesting and useful home automation
tools. The basic architecture is doing fine, it doesn't need more refining
just yet.

As an aside, the SPOF argument also made an appearance during the Windows
hub discussions. Despite the use of a windows mutex allowing multiple apps
to act as a hub, therefore "removing a SPOF", it actually caused
apps to
fail, fight over the xPL port, race conditions to emerge etc etc.

My opinion: It ain't broke. We don't need to fix it.

Ian.