ws-rx message
[Date Prev]
| [Thread Prev]
| [Thread Next]
| [Date Next]
--
[Date Index]
| [Thread Index]
| [List Home]
Subject: RE: [ws-rx] State Tables - First June 27 version
- From: Doug Davis <dug@us.ibm.com>
- To: ws-rx@lists.oasis-open.org
- Date: Thu, 29 Jun 2006 12:56:09 -0400
Bob,
I like the idea of leaving it
blank (unspecified bad thing) :-)
As for Xmit, could we not just
use the term "generate" like most WS specs since the actual handling
of the fault itself depends on may factors.
thanks,
-Doug
"Bob Freund-Hitachi"
<bob.freund@hitachisoftware.com>
06/29/2006 12:47 PM
|
To
| Doug Davis/Raleigh/IBM@IBMUS, <ws-rx@lists.oasis-open.org>
|
cc
|
|
Subject
| RE: [ws-rx] State Tables - First June
27 version |
|
Doug
I don’t think that it is the
wsa layer, since although it might be our intent that CSR be related to
its corresponding CS via wsa:RelatesTo, there is nothing that I know that
might prevent a message destined to the RM Source endpoint arriving without
such a relation. I agree that it is weird and perhaps my choice might
have been wrong. I picked unknown sequence fault since the CSR contains
a sequence identifier, which is unknown, on the other hand it might be
better to use Sequence Terminated fault. An alternative is to leave
it blank which is an unspecified bad thing.
Yes, Reply:to of anon would
have the response return on the back channel, Should I use “respond”
instead of “Xmit”? I used Transmit since it is in the Glossary
which says “The act of writing a message to a network connection” which
I supposed applied to a response that might be sync or async with respect
to the nature of the underlying wire transport. Perhaps “Respond”
should be defined in the glossary
Comments?
Thanks
-bob
From: Doug Davis [mailto:dug@us.ibm.com]
Sent: Thursday, June 29, 2006 8:39 AM
To: ws-rx@lists.oasis-open.org
Subject: RE: [ws-rx] State Tables - First June 27 version
Bob,
still reviewing but I was thinking about the CSR event/msg and the
RMS being in the None state situation, and I'm not comfortable with it
transmitting an UnknownSeq Fault. I agree that it is an incorrect
thing to have happen but by saying that someone must generate an UnknownSeq
Fault may be asking a bit much. In situations like this we can not
be sure which part of the soap stack will catch this bad situation - the
state table is assuming that RM will be the one. However, it may
not be because there are actually two bad things going on here - one for
RM and one for WSA. Its possible that the WS-Addressing layer could
look at the message, notice the wsa:RelatesTo, try to find a waiting request
message to match it up, and finding none just ignores the message - or
generates some other kind of fault. I'd prefer if we put something
else in that box, like N/A. Not a show-stopper, just don't like the
implication on soap stacks that the current entry implies.
The other part of this that worries me is that the state table says
"Xmit" the fault - and if the CSR came back on a back-channel
then it can't do that. This may go back to the issue of Xmit vs Generate
for all Xmits in the table.
I think this concern would apply to the other events/msgs that are
related to Respone messages.
thanks,
-Doug
"Bob Freund-Hitachi"
<bob.freund@hitachisoftware.com>
06/28/2006 06:50 PM
|
To
| Doug Davis/Raleigh/IBM@IBMUS,
<ws-rx@lists.oasis-open.org>
|
cc
|
|
Subject
| RE: [ws-rx] State Tables - First June
27 version |
|
Doug.
It was very hard for me to make the state table reflect the text that I
found and not what I thought the protocol should do.
I made a distinction between blank which I thought to be unspecified or
invalid behavior, and N/A which is internal behavior inconsistent in the
given state. The state table is not a general state table for a machine
capable of processing wsrm messages, but rather it is a state table that
describes behavior with respect to the lifetime of a sequence. N/A
in general represents combinations that I thought to be impossible or self
inconsistent. An example of this is the Create Sequence event from
an unspecified motivator that starts the ball rolling. Perhaps in
incorrect implementation of an RMS might have this event occur to a sequence
that already exists, but it is not an event that has any external appearance
on the wire and thus has meaning to the RMS state table only while in the
None state.
To illustrate this distinction take the case of receipt of a CSR while
in the None state. In the None state, there is no knowledge of the
sequence, it does not yet exist, thus I chose to apply the unknown sequence
fault due to its description in Section 4.3, unless message in its context
has some sort of special meaning. In the closed state, the sequence
is known, but there is no text I can find that expresses what should be
done. Perhaps, since this might be an unrecoverable state or protocol
error, a Sequence Terminated fault as described in Sec 4.2 might be appropriate,
but the definition of protocol error exists in only its plain reading but
does not otherwise what messages received at what time constitute such
an error.
The CreateSequenceRefused fault’s reception while in the none state was
a close call. Note that I specified that the fault is dropped with
a reference of unspecified which roughly means that I made it up (my bad).
Strictly speaking, I am not sure that the CSRefused fault contains
a sequence identifier or not since its detail element is only defined as
xs:any, so I could not make up my mind if it was targeted to a sequence
or not (*maybe there is a new issue here*).
If it is not sequence targeted, then in the none state it could by N/A,
but since it is a potential message from the other side of the wire it
could be a sequence Terminated fault. My error was not leaving this
cell as blank since I don’t this the spec says what should happen here.
One problem for me as I worked to construct these tables is that we are
not very good at making the distinction of generating a fault and transmitting
a fault message. Many of these ought to be transmitted as fault messages
since efficient state recovery depends to some degree on these fault messages
to be used as signals from one side of the wire to the other. I opened
an issue for more precise statements of source and action for each fault
partially due to this lack of clarity. Perhaps there ought to be
a flavor or two of faults that might be generated but not transmitted for
local purposes that can be used for such circumstances.
-For Send message in the rollover state the spec does not specify when
message rollover occurs precisely. That is why there a Reached max msg
number internally sourced event. I imagined that if the RMS was in
rollover state for whatever reason, the sequence was going to have to wind
down. We know that the transfer of some prior message was faulted
by the RMD or that the RMS itself determined that the message about to
be sent generated a MessageNumber too high. Anyway, I did not include
a section reference here since there is none describing this situation.
We also do not have a fault that is used to convey such a situation.
Perhaps I should have left this cell blank too and not attempted
to make an unreferenced guess about correct operation. The fix for
this cell is to make some text somewhere state what it should do or to
point me to where I missed it which is a distinct possibility.
-Close Sequence event. The motivator for close sequence is not specified;
indeed it is an optional concept as indicated by its MAY language from
whence I derived its definition. I think that you caught an error
of mine. The cells should be N/A in Closed and Terminated. I agree
that is something that I should fix. I have some difficulty with
this event in the connecting state, since it is conceivable that the RMS
might to close the sequence at any time and indeed that includes the connecting
state where the RMS has not yet created the sequence (since it is not created
until the CSR is successfully processed and the Sequence ID in known. I
think that No Action [None] might be applied here although it might leave
an orphaned sequence for the RMD to clean up some day. As for CloseSequence
re-transmissions, there is nothing that describes re-transmissions in any
specific way. I don’t think it should be the re-triggering of the
close sequence event. I suspect that especially dur to the new polling
stuff that I might enjoy construction a “MEP” engine that might operate
underneath the Sequence State machine to handle re-transmission and polling.
Re-transmission behavior probably should be moved entirely to that
new state table when we decide it is warranted.
-Terminate Sequence[int] none state: You there is a problem with
this row Should be N/A | No Action[none] | STET | STET | STET | N/A
In the connecting state although the RMS may have sent a sequenceID, the
RMS has not yet processed it. It is a valid condition, but the correct
next state is None with no action since there is no sequence yet to terminate.
Spec text might be tightened here. Can you suggest where? *
Perhaps some words that define Sequence Lifetime ought to be included in
Sec 3.4*.
-TernSeqRed event well in the None and Connecting State I guess it ought
to be the unknown seq fault I will fix In the other states
other than Terminating I left it blank since the behavior is unspecified
as far as I can determine. Perhaps this is a good use of SequenceTerminated
fault transmission to the RMS.
-Expires: you are correct, but the spec doesn’t say. I opened an
issue on this one
The last row is an event raised by the receipt of an invalid acknowledgment
range (see section 4.4) Its tribber is the receipt of any ack range
that is invalid
RMD
-CloseSeq message, I disagree, according to sec 4.7, the attempt to close
a sequence that is already closed results in this fault.
-Expires: Yup, where does the spec say what it should do? (issue proposed
on this one)
-Non-RM message: you are correct, I will fix
Thanks for reviewing
-bob
From: Doug Davis [mailto:dug@us.ibm.com]
Sent: Wednesday, June 28, 2006 12:23 PM
To: ws-rx@lists.oasis-open.org
Subject: Re: [ws-rx] State Tables - First June 27 version
Bob,
comments about the state tables:
RMS:
- not sure I see the diff between "blank" and "N/A".
In both cases its abnormal behavior. Take for example the receipt
of a CSR w/o sending a CS - why would being the "none" state
be any different from being in a "closed" state. Both would
require the rejection of the message and no change in the state.
- On CreateSeqRefused fault - I would think the action wouldn't be "none"
- something more like generate fault since something needs to tell the
AS (or the admin) that the sequence was refused. But this gets a bit close
to leaving our scope.
- For the "Send message" event, in the "Rollover" state,
I wouldn't have said "No action" in that case I would have said
"generate fault" or something - since I believe you're assuming
that the msg numbers got too high, right?
- I think the same is true for the max msg num reached event too - seem
like some fault should be generated instead of "no action"
- CloseSeq event - Closing state - I think it should resend the Close message
instead of "n/a" since it may need to resend it.
- CloseSeq event - Closed or Terminating states - I think those should
be blank or N/A since that should never happen
- Terminate Seq [int] event - None state - I think that should be blank
since it shouldn't ever happen
- Terminate Seq [int] event - Connecting state - I don't think you want
to generate a fault since its an internal event - instead we should just
move to the terminating state
- TermSeqRes event - I would think that all states (except terminating)
would either generate some fault or be blank (since it should never happen)
- don't understand why "none" state is different or why it doesn't
generate an UnknownSeq fault.
- Expires - shouldn't this cause some action for some states? Like
terminate the seq?
- InvalidAck [msg] event - I think this highlights some of the inconsistencies
I think are in the table - in the first two states we generate an unkownSeqFault
but in other spots in the table we have either "no action" or
blank for similar "never should happen" cases. We need to be
consistent.
- Actually, what is the last row/event? is that meant to be InvalidAck
Fault? We don't have an invalid Ack msg just a fault. If its
supposed to be a fault msg then I don't see why we would generate an invalid
ack fault by receiving this msg.
RMD:
- CloseSeq msg, Closed state -> should be no action, not xmit SeqClosed
fault
- Expires - shouldn't this cause some action for some states? Like
terminate the seq?
- Non-RM msg event - should be "WSRM Required Fault" instead
of just "WSRM Fault"
thanks,
-Doug
"Bob Freund-Hitachi"
<bob.freund@hitachisoftware.com>
06/27/2006 09:52 AM
|
To
| "[WS-RX]" <ws-rx@lists.oasis-open.org>
|
cc
|
|
Subject
| [ws-rx] State Tables - First June 27
version |
|
Added references, removed gratuitously applied protocol fault responses
to change them to unspecified.
Corrected a few cells[attachment "wsrm-1.1-spec-wd-15-ith-ST-Edits.doc"
deleted by Doug Davis/Raleigh/IBM]
[Date Prev]
| [Thread Prev]
| [Thread Next]
| [Date Next]
--
[Date Index]
| [Thread Index]
| [List Home]