RE: [wsrm] Group Termination without group timing parameters - again

[Jacques Durand <JDurand@fsw.fujitsu.com>]

Title: RE: [wsrm] Group Termination without group timing parameters - again

Tom:

I would propose a very simple and bold solution to your problem,
when users do not care specifying GroupExpiryTime or MaxGroupIdleTime for
an ordered group:

- the sequence will be terminated as soon as there is an out-of-order message
on receiver side.

The Sender can avoid this very easily: always wait for previous Ack before
sending the next in-order message.

We can't rely on message ExpiryTime in any way here, if we agree that
ExpiryTime means nothing more than latest date an RMP can accept a message.
(no further semantics, once accepted.)

Regards,

jacques

-----Original Message-----
From: Tom Rutt [mailto:tom@coastin.com]
Sent: Friday, October 31, 2003 9:48 AM
To: wsrm
Subject: [wsrm] Group Termination without group timing parameters -
again

I picked the wrong example last time.

This is the troubesome example from the meeting

Ordered example 2

without GroupExpiryTime and without GroupIdleInterval

1 – exp4pm (start) sent at 0 pm –

2 – exp8pm (continue) sent at 0 pm –

3 – exp 4pm (end) sent at 0 pm

receive 1 - at 1pm ack, derived get=4pm then make avialable to user -

recieve 3 – 1.05 pm then ack – derived get=4pm, and buffered (not made
available yet, waiting for 2

4pm – group terminated, 3 removed from messageOrder queue, will not be
made available to use.

receive 2 – at 6:00 PM – acked and start new sequence. Derived get=8pm,
will be buffered waiting for 1

8pm – terminate new sequence, remove 2 from buffer will not be made
available to user.

Ordered example 2 has the problem that the sender has all three messages
acked, however 2 was not made available.

--

This is the one which could be avoided by having the sender ensure that
the expiry times
for messages in a sequence are monotonic increasing (i.e., greater or
equal the maxExpiryTimeOfReceivedMessegesInGroup). This could be the
corresponding check to
the one we already have for when groupExpiryTime is present (expiryTime
less or equal to GroupExpiryTime).

Tom Rutt

--
----------------------------------------------------
Tom Rutt                email: tom@coastin.com; trutt@fsw.fujitsu.com
Tel: +1 732 801 5744          Fax: +1 732 774 5133

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