Guys, following up from my
post earlier today on current proposals I realize the proposal 1 for i145 is
not current. Reading the below thread to see where this issue is the discussion
seems to have stopped here. Is there any agreement on this issue? Is there a
proposal available we could consider on today’s call?
From: Doug Davis
[mailto:dug@us.ibm.com]
Sent: Thursday, July 06, 2006 6:26 AM
To: ws-rx@lists.oasis-open.org
Subject: RE: [ws-rx] i145 - design: Implications of Sequence Expiration
not specified
The timer
started when the sequence is created - or in state table terms, when we move
from "none" state to "created" state. Why would we
need any finer granulatity than that?
Its interesting
that you think the lifetime of the Sequence should be longer on the RMS than
the RMD. I would think it would be the other way around. It seems
like it would worse for the RMS to think that a sequence lived longer than it
really did. Stopping early (for the RMS) wouldn't cause too much pain (at
least its in control over why it stopped using the sequence) but sending a
message and finding out that the sequence it wanted to use is no longer there
seems a bit scarier. Did it go away because it expired or because of some
internal error that now required some kind of admin help? It (the RMS)
just doesn't know and it would worry me if it made some kind of assumption.
It would be much safer to have the RMS expire before the RMD and let the
RMS have control over when to stop using a sequence.
re:MakeConnection
- I'm no so sure it belongs in the state table at all. Its more of a
transport level thing and doesn't really have 'state' per say. Either
there are messages waiting to be delivered or not - just 2 possible states.
Not very exciting :-)
thanks,
-Doug
Doug,
The
state table relies on definitions of events to advance from state to state.
It
looks pretty bad to say in the RMD state table that the sequence comes to life
at some implementation defined time and that it stays in the none state until
that time occurs. The state transitions are all very black and white
I
know of a community of potential users who are more than a bit concerned about
the security of the protocol. I believe that their opinion would be to
define expires to be fairly tight compared with the expected time for sequence
transmission. Others might feel fine leaving it at PT0S
One
aspect of the text I proposed that I like is defining expiry that way ensures
that the Sequence will expire at the RMS at the same time or later than at the
RMD (no fair discussing clock granularity at this juncture). This
provides at least known behavior and supports silent termination. The RMS
can be reasonably assured that it need not be concerned about what is going on
at the RMD.
As
for MakeConnection, I have been thinking a bit about its representation.
I am
drifting in the direction of defining an underlying “transfer engine” that
would deal with it independently of the sequence state tables. I think
that this also might take care of re-transmissions as well as the handling of
responses which are hard to find in the spec J.
Thanks
-bob
From: Doug Davis [mailto:dug@us.ibm.com]
Sent: Wednesday, July 05, 2006 12:29 PM
To: ws-rx@lists.oasis-open.org
Subject:
RE: [ws-rx] i145 - design: Implications of Sequence Expiration not specified
I had forgotten that I did have a version that fixed the start of the duration,
how about:
This element, if present, of type xs:duration specifies the duration of
time until the Sequence SHOULD be terminated, relative to its creation time.
The termination should probably be silent since we don't have a message for it.
Its not a fault, per say, so I'm not sure SeqTerminated Fault makes
sense.
My concern with the text you've proposed is that it mandates that the sequences
are created at a certain time and I'm not sure we can mandate that. For
example, you say the sequence starts (on the RMD) when the CSR is transmitted.
Is that before or after the MakeConnection is received? I would
prefer before, but the 'transmit' in there may imply something else to others.
I think leaving it as a generic "creation time" is best -
leaves it up to the impl to decide when that time is.
Likewise, as you asked, whether the Offered sequence is 'created' during the
generation of CS or during the processing of the CSR is an RMS detail that we
should not get into.
Overall, I'm not that concerned about the timing of this, and am ok with
leaving it a bit loose, because I don't think this timing is that critical.
If this timing were critical and every millisecond counted then I would
agree with you that we would need to be very precise and need more work in this
area, but I just don't think the expiry/lifetime of a sequence is mission
critical - it just needs to remain available 'as long as' the requested Expires
time - note it doesn't have to commit suicide at that time at all, it just
can't do it before that time.
thanks
-Doug
Doug,
Is that termination silent?
I think that you are correct, a new section is not really necessary.
Do we care what signals the start of that xs:duration?
I think that this may be tied to definition of the sequence lifetime which may
be better defined in Section 3.4 “Sequences”
My suggestion would be to insert in the first paragraph of 3.4, perhaps at the
end, something along the lines of:
“A Sequence exists at the RM Source from the processing of the
wsrm:CreateSequenceResponse until the earlier of the transmission of wsrm:TerminateSequence
or the Sequence expires (see section 3.1). A Sequence exists at the RM
Destination from the transmission of a wsrm:CreateSequenceResponse until the
earlier of the successful processing of a wsrm:TerminateSequence or the
Sequence expires (see Section 3.1).”
Once that is done, then in Section 3.3 “Sequence Termination” expiration
behavior could be stated as something like:
At the end of the first paragraph of 3.3
“Sequence are also implicitly terminated without further exchange of protocol
messages upon the expiration of the Sequence (see Section 3.1)”
Then in Section 3.1 something along the lines of:
Following the paragraph headed by the line:
/wsrm:CreateSequenceResponse/wsrm:Expires the following refining language:
“The Sequence is said to expire when wsrm:CreateSequenceResponse/wsrm:Expires
elapses from either the perspective of the sender or the receiver of this
element”
I am still a bit vague about the usage of the Expires within an Offer.
What does it mean to you?
Thanks
-non
From:
Doug Davis [mailto:dug@us.ibm.com]
Sent: Wednesday, July 05, 2006 10:38 AM
To: ws-rx@lists.oasis-open.org
Subject:
[ws-rx] i145 - design: Implications of Sequence Expiration not specified
http://lists.oasis-open.org/archives/ws-rx/200606/msg00216.html
Bob,
I think we can resolve this issue with a much smaller change - instead of
creating an entire new section why not just modify the description of the
Expires element like this:
This element, if present, of type xs:duration specified the duration of time
until the Sequence SHOULD be terminated.
It will need to be modified slightly based on the exact usage but you get the
idea.
thanks
-Doug