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Re: snmpconf PM MIB Issue #9

>>>>> Jon Saperia writes:

Steve> This adapts to multiple strategies, including: 1) Write to
Steve> nvram immediately on activating the target row (sync is a
Steve> no-op) 2) Every N seconds, look for unwritten rows and write
Steve> them (sync only writes rows that have been modified since last
Steve> interval) 3) Delay writes until sync button is pushed

>>  Option 3) is a bit problematic with the current StorageType. Right
>> now, applications assume that setting the StorageType to
>> nonVolatile is enough to put the configuration information into
>> stable storage, even though it is right now implementation specific
>> when this actually happens. But it should happen at some point in
>> time. So only relying on the sync button might confuse existing
>> applications that do not know about sync buttons. So if 3) is an
>> option we want, then we probably need to have a new StorageType
>> kind of TC.

Jon> Option three is an important sematic. To what applications do you
Jon> refer?

Lets take a management application which configures SNMPv3 users or
access control. Such an application (which I assume exists) will set
the relevant RowStatus objects to nonVolatile and it will be done.

If now someone implements StorageType objects (e.g. SNMPv3 user and
access control tables) which are never written to stable storage
unless you press a magic new sync button, then the manager I was
talking about will screw up since it can not know that it has to press
a sync button.

So if we continue with the existing StorageType TC (which has some
value since several of our MIBs already use it), then the behaviour
described in option 3) above does not work - at least for the set of
already published MIBs.

(In fact, we probably need a requirement that StorageType descriptions
 must clearly say how managers can identify sync buttons.)


Juergen Schoenwaelder      Technical University Braunschweig
<schoenw@ibr.cs.tu-bs.de>  Dept. Operating Systems & Computer Networks
Phone: +49 531 391 3289    Bueltenweg 74/75, 38106 Braunschweig, Germany
Fax:   +49 531 391 5936    <URL:http://www.ibr.cs.tu-bs.de/~schoenw/>