Re: [ws-rx] Presence of an wsa:relatesTo part within an acknowledgementmessage

[Doug Davis <dug@us.ibm.com>]

Acks are not replies and therefore the
presence, or absence, of a wsa:relatesTo in a message
is not influences by it at all.  When
an AckRequested is sent there is no guarantee that an Ack will
be sent back on any kind of response
flow - it just asks the RMD to send an Ack - it doesn't say
anything about when or where that ack
goes.  The Ack will be sent to the AcksTo EPR which 
may be totally different from the replyTo
EPR that carried the AckRequested.  In cases where
the Ack is not piggy-backed on another
message, the Ack message is just a new one-way message.
Does that help?
thanks,
-Doug

Chamikara Jayalath <chamikara@wso2.com>

02/08/2006 12:09 PM

Please respond to
chamikara

To	ws-rx@lists.oasis-open.org
cc
Subject	[ws-rx] Presence of an wsa:relatesTo part within an acknowledgement message

Hi All,

I have a question regarding the relationship between an sequence
acknowledgement message and the corresponding request message. I think
I
missed a part of the discussion that happened through this list. Pardon
me if this issue was discussed previously.

The problem is weather an wsa:RelatesTo tag should be present in an
acknowledgement message. The presence of an wsa:RelatesTo part will make
implementation issues such as dispatching easy. I.e. an web service
framework will be able to identify the relationship between an ack
message and the original application message that asked for this and it
will be able to easily relate them (without going to the RM level).

But to my knowledge,having a wsa:relatesTo value without the
wsa:relationshipType attribute imply that the second message is an
'reply'. But an acknowledment is not an application level reply to the
original message and it might be better to have an different value for
the wsa:relationshipType attribute.

On the other hand somebody could argue that the wsa:relatesTo header
should not be present in an ack message since it is an RM control
message and since it may have no direct connection with the original
application message (even though it trigured the RM destination to send
this ack).

What should be the convention ?

Thank you,
Chamikara