nntp-extensions feedback on draft-ietf-nntpext-dynfeed-00.txt

[Jeff Garzik]

> 
> 
> > Just a couple thoughts after a quick reading. While I think the idea of
> > adding a dynamic feed control method to the protocol is long overdue,
> > I'm not sure this is the way to do it. Maybe the draft just needs to be
> > clarified.
> 
> Could be.  Maybe I should start by saying that I wasn't trying to
> solve the whole dynamic feed control problem.  I was just responding
> to a problem that I as a news admin see, which is that many of my
> downstream sites believe, deep in their souls, that the way to not
> carry a group is "ctlinnd rmgroup".  My attempts to educate them to
> the contrary have not been successful.  So I was just trying to deal
> with the ugliness of having to send lots of /dev/null fodder, because
> I have no good way to know what groups my downstream sites are
> bitbucketing.  

It's a problem, but if you are going to update the official spec, may I
suggest that solving the *whole* dynamic feed control problem is a
better approach than fixing "point" problems with domain-specific
solutions.

However, there is one point implied in your solution that should be
recognized as very important:

There are inherent security problems with being able to ADD groups to
a feed.  Because once your customers gain the capability to request
new groups from your feed, your customers also gain the ability to
define how much of YOUR resoruces (bandwidth, CPU, backlog disk, etc.)
they consume.

The current dynafeed proposal only allows the downstream to REMOVE
groups from their feed, not add them, which is good.

Another point:  Dynafeed controls define NOTHING about upstream server
state.

What I mean by this is the upstream (receiving the dynafeed commands) 
may store the feed update permanently, just for the current session,
until server restart...  the point is, you don't know how long it is
stored.  You may want to put some language into the spec addressing
that.

-- 
Jeff Garzik			    Typhoon, Cyclone, Diablo, and INN
http://www.spinne.com/usenet/	           News tuning and consulting