Subject: [malloc] MALLOC MIB

From: "Dave Thaler" <[email-masked]>
Date: Wed, 15 May 2002 19:26:09 -0700

I have addressed all but one of the comments of the "MIB 
doctor", and the last comment made me think a bit.
We have an "exclusion" table in the MIB right now, that
I believe originated from AAP.  I'd like to propose removing
the table.

As far as I can tell, nothing in the MALLOC architecture
(RFC 2908) or the MADCAP protocol (RFC 2730) requires
implementing any such concept, and those are what this MIB
instruments.

As a reminder, the MIB currently contains 3 tables that are
relevant to this question:
Scope Table : contains the scope ranges known (e.g. 
		  Global, LinkLocal, IPv4 Local Scope, etc.)
Allocation Range Table : contains the subranges legal
		  to allocate from (e.g. the piece of LinkLocal
		  Erik Guttman asked IANA for, all of IPv4 Local
		  Scope except the scope-relative addresses,
	        your own GLOP range, etc).
Exclusion Table : "contains sub-ranges which are excluded
		  from being allocated".  The wording implies
		  these are subranges of the scope, disjoint
	   	  from subranges in the allocation range table.
		  The description also used to say entries may
		  be dynamically discovered via some protocol
		  such as AAP (which we already removed from the 
		  MIB).

I believe that the Exclusion Table should have been removed
when AAP was removed, and that for today's uses, exclusions
are unnecessary (since the Allocation Ranges are manually
configured without needing to have a concept of exclusions, 
or are acquired as part of experimental protocols outside 
the scope of this MIB).

Any objections?  (Positive acknowledgements from any of 
Mark, Steve, and Pavlin would be greatly appreciated :)

-Dave
_______________________________________________
malloc mailing list
[email-masked]
http://catarina.usc.edu/mailman/listinfo/malloc

---

From: Pavlin Radoslavov <[email-masked]>
Date: Thu, 16 May 2002 10:22:17 -0700

> Mark, Steve, and Pavlin would be greatly appreciated :)

It seems to me that the allocatable address ranges can be expressed
only by the information in the "Allocation Range Table" instead of
(AllocRangeTable - ExclTable).
If we have both AllocRangeTable and ExclTable, it may be easier
for practical purpose to express the allocatable range(s); it may
also make simpler the interfacing with protocols/mechanisms that
originate/create those ranges (I guess the simplicity of such
interface was probably the primary motivation to have the
ExclTable added to the MIB).
However, my guess is that the MIB doesn't have to deal with
such practical issues. Further, having ExclTable adds the complexity
that anyone who reads the MIB MUST take into account the ExclTable
as well to figure-out the address ranges that are valid for
allocation.

Now that the AAP has been removed, I don't see a reason to keep the
Exclusion Table, so removing it is fine with me.

Pavlin

P.S. FWIW, MASC doesn't have the equivalent of excluding
sub-ranges.
_______________________________________________
malloc mailing list
[email-masked]
http://catarina.usc.edu/mailman/listinfo/malloc

---

From: Steve Hanna <[email-masked]>
Date: Thu, 16 May 2002 13:35:59 -0400

If people use some protocol or technique to coordinate the
efforts of several MAAS's allocating from a single address
range, each MAAS will need to exclude addresses allocated
by the other MAAS's (and maybe some addresses reserved for
future allocations by the other MAAS's).

This could be done by dividing each allocation range into
several allocation ranges and ensuring that each MAAS only
knows about one of these. But this will prevent the ability
for a MAAS to report (via the Allocation Range Table) on
the overall status of an allocation range: how full is
scope X? and are requests being met? Instead, the status
will be fragmented into separate allocation ranges for
each MAAS. If the MAAS's aren't communicating, then this is
probably the best thing to do. But if they are communicating
(through a directory, an experimental protocol, or whatever),
then I think we want to retain the ability for a MAAS to say
"I'm allocating out of this range, but excluding these
subranges."

So I think we should leave the Exclusion table in the MIB.
People who don't use it can always leave it empty. I welcome
any further discussion, though.

Thanks,

Steve