OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.

 


Help: OASIS Mailing Lists Help | MarkMail Help

wsdm message

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]


Subject: RE: [wsdm] Groups - OperationMetricsProposal (MowsOpMetrics.doc) uploaded


I don't know about starting and stopping operations but I do believe it is reasonable to report whether a particular operation is available or not. Let's say one web service is really an aggregation of many other web services. If one of those back-end services is down, only some of the operations of the front end web service will be unavailable. Even with Bryan's analogy of a service being a resource and operations being actions to take on that resource, its possible that same actions may not be performed at any given time.
 
Tony


From: David E Cox [mailto:decox@us.ibm.com]
Sent: Monday, October 24, 2005 1:16 PM
To: wsdm@lists.oasis-open.org
Subject: RE: [wsdm] Groups - OperationMetricsProposal (MowsOpMetrics.doc) uploaded


I do not agree that Start and Stop don't make sense on an operation by operation basis.  In most app servers, Start and Stop aren't going to be directly implementable at the service level.  Web services in j2ee containers (for example) are probably stateless session beans that are not "running" but are rather driven when a request comes in.  Therefore Start and Stop are probably implemented not by stopping some long-running process (because there is none), but rather by blocking the messages.  Therefore it is perfectly possible and reasonable to allow blocking messages at the operation granularity.

Similarly, as my examples below illustrated, a Web service is not a monolithic resource.  There can and will be cases where one operation is available and another is not.  One operation may have a dependency is that is unavailable, and other operations may not have that dependency.  In that case, you can state that the entire Web service is unavailable, which is incorrect because maybe every operation except one is available.  Otherwise, you state that if any operation is Available, then the Web service is Available.  In that case, you may have Service Level Agreements that are failing due to a particular operation not working, because your management tool doesn't have granular visibility to the state of the operations.  You may even have the case where some operations are processed in a completely different container than other operations (probably on a port-type boundary).  

Another example is that  one business process might use one operation on a service, and a different business process might use another operation on the same service.  Without status granularity to the operation, in the case where one operation is unavailable and the other is available, the management tool will have to conclude that both business processes are impacted or not without being able to tell that one is impacted and the other is not.

In summary,  I think that start, stop, state, status, and relationships do have meaning for operations within a Web service.  I also believe that providing this level of manageability will be critical to actually isolating and diagnosing problems in Web services.


Regards,
David E Cox



"Murray, Bryan P." <bryan.murray@hp.com>

10/24/2005 03:58 PM

To
David E Cox/Raleigh/IBM@IBMUS, <wsdm@lists.oasis-open.org>
cc
Subject
RE: [wsdm] Groups - OperationMetricsProposal (MowsOpMetrics.doc) uploaded





I do not know what it means to have a Start resource, or a Stop or Reset resource. To me, operations are the actions that can be done to a resource, not resources in themselves. I do not know of other models that define resources for the actions to be taken on a resource - CIM does not.
 
To get back to the original subject, I agree with Kirk about State and Status not really making sense on a per operation basis. A resource is in a particular state. Some operations are designed to change that state. Sometimes the state changes for some resource-specific reason. I don't see State as inherently being different just because a certain operation is being processed (except for those operations designed to change a state).
 
We are defining metrics on a per operation basis, not because metrics are inherently different for different operations, but to report more detailed data than the resource-wide metrics are able to do. The resource-wide metric incorporates all of the data that the individual per operation metrics do as a summary, but sometimes a management application wants to have more detailed information about some critical operation than is available with the original set of metrics.
 
Bryan


From: David E Cox [mailto:decox@us.ibm.com]
Sent:
Monday, October 24, 2005 12:38 PM
To:
wsdm@lists.oasis-open.org
Subject:
RE: [wsdm] Groups - OperationMetricsProposal (MowsOpMetrics.doc) uploaded



Hi Kirk,


 I agree that if the service is Unavailable, quite likely all of the operations are unavailable.  The reverse, however, may not be true.  The operations in a service may vary widely in what they require in order to accomplish their function.  For example, reading a record may work whereas writing a record may not (due to locking issues, etc).  Another example is that some operations may be simple, self-contained operations that always work, but other operations may call out to other web services or non-web services dependencies (such as a database) that may or may not be up.  Operations that access one table in a databsae that has performance problems or poor tuning may show a degraded or unacceptable response time, while other operations work fine.


 From that perspective, I would have to get out a great big can opener and open a can of worms.  Just about (but not quite) everything in the MOWS spec can be different from one operation to the next within a web service.  The metrics, state, and status, plus the relationships can certainly be different.  Message processing state can be different.  Would it make sense to model operations as resources, rather than trying to qualify most but not everything in MOWS with operation qualifiers?  This would be in addition to the model of a Web service as a whole, not a replacement for it.  Let's discuss first whether it might or might not make sense academically, before we reject it out of hand because it seems "hard" or too much trouble.



Regards,
David E Cox


"Wilson, Kirk D" <Kirk.Wilson@ca.com>

10/24/2005 03:02 PM


To
David E Cox/Raleigh/IBM@IBMUS, <fred.carter@amberpoint.com>
cc
<wsdm@lists.oasis-open.org>
Subject
RE: [wsdm] Groups - OperationMetricsProposal (MowsOpMetrics.doc) uploaded







On second thought:  I’m not sure what value per-operation status and state will have.  If the service is Available or Unavailable, that would apply generally to the operations within the service.  Perhaps if the service is Partially Aavailable we might what to drill down to see what operations are available or not—does anyone have any opinions on this??  I believe that state model used for operational state is pretty much defined for the service-level state.

 
On the other hand, I think we should include the operationName/portTypeName attributes that are part of the OperationMetric capability as part of the RequestProcessingStateType so that notification consumer can know what process is being talked about.  (I assume what is meant by “operation” in the OperationMetric is the same thing that is being talked about as a “request” in the RequestProcessingState.  If so, then we should probably use of consistent vocabulary and talk about a RequestMetric and Request metric properties.  Opinions on this??)

 
Kirk Wilson

Architect, Development

Office of the CTO

802 765-4337

 
-----Original Message-----
From:
Wilson, Kirk D
Sent:
Friday, October 21, 2005 4:59 PM
To:
'David E Cox'; fred.carter@amberpoint.com
Cc:
wsdm@lists.oasis-open.org
Subject:
RE: [wsdm] Groups - OperationMetricsProposal (MowsOpMetrics.doc) uploaded

 
Dave, yes I agree.  I already brought up about an operation processing state (and, correspondingly) notifications.  I think the general consensus was that it would be more difficult.  I agree that this issue should be revisited.

 
Kirk Wilson

Architect, Development

Office of the CTO

802 765-4337

 
-----Original Message-----
From:
David E Cox [mailto:decox@us.ibm.com]
Sent:
Friday, October 21, 2005 8:05 AM
To:
fred.carter@amberpoint.com
Cc:
wsdm@lists.oasis-open.org
Subject:
Re: [wsdm] Groups - OperationMetricsProposal (MowsOpMetrics.doc) uploaded

 

I think this will be very useful, and thanks for the Proposal, Fred.  But metrics is only part of the story.  Are we going to do per-operation state and status?  Are we going to do per-operation message processing state and notifications?  (The last item may be possible already, if you specify the operation in your xpath).  I know those weren't explicitely in the action item, so I am asking if we can add them to the action item, or write a new action item.


Regards,
David E Cox

Fred Carter <fred.carter@amberpoint.com>

10/17/2005 01:21 PM


Please respond to
fred.carter


To
wsdm@lists.oasis-open.org
cc
 
Subject
Re: [wsdm] Groups - OperationMetricsProposal (MowsOpMetrics.doc) uploaded


 


   





Good catch.  Operation + ${metric} it is

Thus quoth Wilson, Kirk D (~ 10/15/2005 11:24 AM ~)...

I think there might be a processing problem in the proposal as it current stands.  When encountering a <NumberOfRequests> element, the client parser would have to check the attributes to determine whether the data is at the service level or the operation level.  That might produce a backwards compatibility problem for current implementations.


I would recommend that the OperationMetrics properties also be prefaced with “Operation”, i.e. <OperationNumberOfRequests>, etc.


Kirk Wilson

Architect, Development

Office of the CTO

802 765-4337


-----Original Message-----
From:
Fred Carter [mailto:
fred.carter@amberpoint.com]
Sent:
Friday, October 14, 2005 2:27 PM
To:
wsdm@lists.oasis-open.org
Subject:
Re: [wsdm] Groups - OperationMetricsProposal (MowsOpMetrics.doc) uploaded


Thus quoth Wilson, Kirk D (~ 10/14/2005 11:16 AM ~)...

I haven’t had time to read Fred’s proposal yet (weekend reading), but isn’t another alternative just to handle OperationMetrics as an “empty” capability (extension of MOWS metrics) and allow the designer to specify GEDs as part of an service specific extension for each metric property for each operation of interest within that service (a bit ugly and tedious)?

indeed it is.  That's effectively, albeit with even fewer restrictions, the alternative mentioned below  the query resource properties.  It would require each new manageable endpoint to specify their own schema, I think, or run entirely within the extensibility rules.  Then, though, I think you need to figure out how to link them back to this capability...  By type?  By some other, still-to-be-named attribute?

I thought about this.  We could do it using, say, the operationName attribute as a key meaning that this is an operation metric.  Or use the mows:operation{integer,duration}  type, I suppose.  That would work as well.  Difference is that they caller will have to examine the schema to 1) figure out if there are op metrics, and 2) to figure out what their names are.  In this case, the names are known, the operation's names come from the wsdl, but you either have to get the whole prop doc and mung or rely on the server to do it (its having implemented queryResourceProps).  Unclear to me which is preferred...



Any thoughts on this?  (Just as a conceptual possibility if not a practical one.)


Kirk Wilson

Architect, Development

Office of the CTO

802 765-4337


-----Original Message-----
From:
Tony Gullotta [
mailto:tony.gullotta@soa.com]
Sent:
Friday, October 14, 2005 1:59 PM
To:
wsdm@lists.oasis-open.org
Subject:
RE: [wsdm] Groups - OperationMetricsProposal (MowsOpMetrics.doc) uploaded


I see. So we have to use QueryResourceProperties because GetResourceProperty won't be able to distinguish between operations.

 



 




From:
Fred Carter [
mailto:fred.carter@amberpoint.com]
Sent:
Friday, October 14, 2005 10:52 AM
To:
Tony Gullotta
Cc:
wsdm@lists.oasis-open.org
Subject:
Re: [wsdm] Groups - OperationMetricsProposal (MowsOpMetrics.doc) uploaded

Well, it's just a properties document.  So whatever query mechanism for that would have to do -- that's a WSDM limit, I think.  So this would use the QueryResourceProperties optional call with a query expression (dialect XPath) of
 *[namespace-uri()="this capability's namespace" and ./@operationName="desiredOperation"]
(or something like that)

An alternative, where the query function isn't required, would be to name the operation metrics with the operation name.  However, I think we'd have a hard time coming up with a schema then (we'd need a meta schema :-) ), since we wouldn't have the metric names at spec time (since the operations vary quite a bit, obviously).

At a higher level, the choice at some level, was either individual metrics or a more general property document element for the operation -- that would contain all the stuff  about an operation.  This seemed counter to how we've done capabilities, so I separated it this way.

The other choice involves a capability (or some combination thereof) that instituted a subdocument for operation properties.  I wasn't quite sure if that was easily representable, so...

Thus quoth Tony Gullotta (~ 10/14/2005 10:34 AM ~)...

How would I request the NumberOfRequests metric for just one operation?


-----Original Message-----

From:
fred.carter@amberpoint.com [mailto:fred.carter@amberpoint.com]
Sent: Friday, October 14, 2005 10:22 AM

To:
wsdm@lists.oasis-open.org
Subject: [wsdm] Groups - OperationMetricsProposal (MowsOpMetrics.doc)

uploaded


This document proposes to extend the MUWS metrics capability, adding an

operation name &, optionally, portType, attributes to the current set of

MOWS metrics.  As an example, we could report number of requests for the

sample operation as

  <NumberOfRequests operationName="sample" ...>34</NumberOfRequests>

  <NumberOfRequests operationName="anotherSample"

...>3</NumberOfRequests>


In this environment, any number of numberOfRequests is permitted, though

they must have different operationNames, or, if the same, different

portTypes, as these are the distinguishing characteristics.


Document current shows changes based on the MOWS Metrics capability

since it's pretty analogous.


It occurred to me that this is not all that hard, so we may be able to

fit it in (as was some folks recollection of the plan).  My apologies to

Bryan as I think we were supposed to collaborate, but he's out of town

now, and I'll be out much of next week.


Feel free to shoot away on the list!


/fred


-- fred carter


The document named OperationMetricsProposal (MowsOpMetrics.doc) has been

submitted by fred carter to the OASIS Web Services Distributed

Management

(WSDM) TC document repository.


Document Description:

Operation Metrics Proposed Text


View Document Details:

http://www.oasis-open.org/apps/org/workgroup/wsdm/document.php?document_
id=14904


Download Document:  

http://www.oasis-open.org/apps/org/workgroup/wsdm/download.php/14904/Mow
sOpMetrics.doc



PLEASE NOTE:  If the above links do not work for you, your email

application may be breaking the link into two pieces.  You may be able

to copy and paste the entire link address into the address field of your

web browser.


-OASIS Open Administration





--
Fred Carter / AmberPoint, Inc.


mailto:fred.carter@amberpoint.com
tel:+1.510.433.6525 fax:+1.510.663.6301




--
Fred Carter / AmberPoint, Inc.


mailto:fred.carter@amberpoint.com
tel:+1.510.433.6525 fax:+1.510.663.6301



--
Fred Carter / AmberPoint, Inc.


mailto:fred.carter@amberpoint.com
tel:+1.510.433.6525 fax:+1.510.663.6301



[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]