Subject: Re: open issues in agentX MIB

From: "Matt White" <[email-masked]>
Date: Mon, 03 Aug 1998 23:53:47 -0400

--On Monday, August 03, 1998, 3:42 PM -0400 "Mike Daniele"
<[email-masked]> wrote: 

> Since we're moving toward refining h.SessionID to not be reused by the 
> master within the realm of 32-bit rollover, it seems like the non-reuse 
> requirements of the 2 are identical.

I haven't said much until now about this, but I am afraid that I'm missing
something here.  Why is this necessary?  The only reason I ask is that this
will break the current CMU implementation of AgentX and might take a little
time to fix.

I haven't been following the MIB discussions as closely as I might, so
perhaps I'm missing some motivation.  However, it seems to me that MIB
implementation should follow the protocol, not vice-versa.

> Note, currently it's legal to use a SessionID of 0.  If we're going to
> make agentxSessionIndex == h.SessionID, we may want to stipulate
> SessionIDs start at 1.

This seems somewhat reasonable in any case for debugging purposes.

-Matt

----------
Matt White
Network Systems Designer
Canegie Mellon Computing Services

---

From: Bob Natale <[email-masked]>
Date: Tue, 04 Aug 1998 01:28:04 -0400

>At 8/3/98 11:53 PM, Matt White wrote:

Hi Matt,

>something here.  Why is this necessary?

Avoiding re-use of small integer indices has simply become a matter
of "good practice" where other factors do not dictate otherwise.

(Note that, as has already been said, we can only do our best to
avoid re-use, not mandate it...given the (logically possible) case
of the long-running master that wraps...so far, we have not mandated
"monotonically increasing", but that is also a good idea in this case...
and, in any case, the active SessionID values in a given invocation
of the master agent must be globally unique.)

>The only reason I ask is that this will break the current CMU
>implementation of AgentX and might take a little time to fix.

At the bake-off, one implementation out of five under test (to the
best of my knowledge) had taken the approach of quickly re-using
SessionID values.  The developers were able to make the switch
to the "avoid re-use" model in a matter of minutes.  That's just
a single data point, I know; I realize that there may be many
valid reasons why anyone else's mileage may vary.

In any case, we'll be spending a little time fixing up one
thing or another in our AgentX implementations for a while
yet.  :-)

>implementation should follow the protocol, not vice-versa.

Yes, I don't think you'll see too much debate with that...the twist,
however, is that we are also refining the protocol spec in this process,
esp. in areas where possible multiple interpretations exist or where 
some things were left a bit looser than necessary or sufficient.

>This seems somewhat reasonable in any case for debugging purposes.

Right...good.

Cordially,

BobN
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