Re: LCUP and PSearch on Sync-And-Persist

["Kurt D. Zeilenga" <Kurt@xxxxxxxxxxxx>]

At 09:07 AM 2002-04-04, Rich Megginson wrote:
>"Kurt D. Zeilenga" wrote:
>
>> There are many clients which need to know they are 'in sync'.
>> I note that this is not just after the initial 'sync up' phase,
>> but subsequently.  Also, there are cases where the server
>> needs to update the cookie without sending an update (in the
>> 'persist' phase.
>>
>> I suggest that we add a 'in sync' notification to LCUP.  Basically,
>> just a (intermediate) response PDU which says "you're in sync"
>> and, OPTIONALLY, provides a new cookie.
>>
>> The server should send one when it has sent all changes necessary
>> to 'sync' the client.  The server may send them subsequently to
>> again notify the client it is 'in sync'.
>
>But what exactly does 'sync' mean?

It means that the server has sent all the messages necessary for
the client to have a complete and accurate copy of the requested
(and provided) information.

>Does this mean 'all changes between the time I last connected and the time I connected for this
>session'?

It means all the changes necessary to have a complete and accurate
copy of the requested (and provided) information.

>Because changes may come in to the server during the sync phase.

The server may send them or queue them or possible use other
approaches.

>What should happen to these changes?  Or should those
>entries be included?  What if the server is under a heavy update load and never gets to the end of the sync phase?

If it never reaches the 'in sync' condition, it never should sent
the 'in sync' message.

I think we should get away from this 'sync'/'persist' phase
business and look at this simply as a sequence up messages which
'updates' entries of interest.  When the sequence of updates
sent is known to reflect the server's current state (for all
entries of interest), the server sends an 'in sync' message
notifying the client of this.

The initial 'in sync' message should be sent as soon as the
all the changes necessary to be 'in sync' have be sent.
Subsequent 'in sync' messages can be sent whenever the
server desires to send them.

Kurt
Kurt