[Nmc-wg] Mappings: old result codes -> new result codes

[Jason Zurawski]

Hi Roman;

Here are some additional comments to back up what we discussed on the call:

On 9/30/10 8:45 AM, Roman Łapacz wrote:
> Hi Jason, Aaron and others,
>
> I attached mapping text file and MS Word doc with small updates (just to
> have them together in one email).
>
> W dniu 2010-05-27 21:08, Jason Zurawski pisze:
>> Hi Roman/All;
>>
>> Some comments on the proposal:
>>
>> "Wrong structure of a request":
>>
>> Like Aaron, I think I am having a hard time with some of these as
>> being a purely 'structural' issue. For instance
>> 'error.ls.data_trigger' - I would assert there is some context to be
>> known about the content of the rest of the message before calling this
>> structural issue (for instance if there was a data/metadata pair
>> already).
>
> If there is such data/metadata pair in a message than I wouldn't expect
> to get error.ls.data_trigger. An example of xml message would help to
> analyse such case.


So the example I had in mind was something like this:

<message>
   <metadata id="m1">
     <!-- ... something ... -->
   </metadat>
   <data id="d1" metadataIdRef="m1" />

   <metadata id="m2">
     <!-- ... something ... -->
   </metadat>

   <!-- no trigger for m2, and m2 is not related to m1 or d1 -->
</message>

In this case m1 and d1 could be acted on, and m2 could not (it would get 
the error.ls_data_trigger response).  The pSPS would return the results 
for the first metadata/data pair and an error for the second in the same 
message.

My objection is related to the proposed 
"http://perfsonar.net/status/clienterror/wrong_message_structure/" 
eventType.  In this case the message structure is syntactically correct, 
the semantics are just wrong in one instance.


>> I think most of these are right, but we should be careful with the
>> context before calling all of them a pure xml structure violation.
>
> I still have the problem how much context should be included in the code
> (mainly datum element contains a description).


I forget what the outcome of the early discussion was (I am sure someone 
can correct me), but I believe that the description that will be 
returned in the datum does not need to be a 'standard' message.  The 
eventType code and instructions guiding its use (e.g. 'use this this 
code for errors that are related to ...') are the only thing we should 
make standard.  If someone wants to send back a datum that contains more 
than what the standard definition allows (e.g. a stack trace perhaps, or 
error logs) this seems fine to me.


>>
>> "EventType in a request is not supported":
>>
>> This also seems more context sensitive to me.
>>
>> "Request is not supported":
>>
>> I think 'message type unsupported' is different than 'no message type
>> specified'
>
> It just says ther's a problem with message type. Can we assume that if
> there's no message type then default type is considered (default type
> may be unspecified).


I dont think we should be assuming a default message type, because what 
would be the default?  Services like the LS use different messages than 
the MAs and MPs.  I would still favor having both 'type unsupported' and 
'no type specified'.


>>
>> "Elements of a request are not supported"
>>
>> I think we may need to be a bit more clear in the message. Instead of
>> 'wrong XXX' we may want to say 'unexpected XXX element' or something
>> similar. This will clear up of the content is wrong or the element is
>> wrong.
>
> Doesn't message_element_not_supported match here?


Good question.  I guess I can see this happening in one of two ways:

1) the element is unexpected semantically, but still schematically 
legal.  For example:

  <ns1:metadata>
     <ns:1subject />
     <ns1:eventType />
     <ns1:parameters />
     <ns2:parameters />
  </ns1:metadata>

2) The element is not semantically or schematically expected.  For example

  <ns1:metadata>
     <ns:1subject />
     <ns1:eventType />
     <ns1:parameters />
     <ns1:datum />
  </ns1:metadata>

I would say these are different errors.  In #1 the parser may choose to 
interpret the 'last' parameters element it saw, so things may still 
'work'.  We may owe the user a warning to say that something didnt look 
right though.  In #2 the element is unexpected and may be no-recoverable 
from a parsing standpoint.

Hope this helps;

-jason


> Roman
>
>>
>> Thanks;
>>
>> -jason
>>
>>
>> On 5/27/10 10:56 AM, romradz at man.poznan.pl wrote:
>>>
>>> Hi Aron,
>>>
>>> On Thu, 27 May 2010, Aaron Brown wrote:
>>>
>>>> One minor thing. I'd move the "No message type specified" to the
>>>> "wrong_message_structure" since the request is missing a required
>>>> element.
>>>> I'm curious what the "message_element_not_supported" event type is
>>>> for. From the error messages listed, It wasn't obvious to me why the
>>>> service threw
>>>> them.
>>>
>>> for example, if an element located in a request is not recognized (or
>>> the content of xml tag is wrong, eg. ip address)
>>>
>>> Roman
>>>
>>>
>>>>
>>>> Cheers,
>>>> Aaron
>>>>
>>>> On May 27, 2010, at 10:32 AM, Roman Lapacz wrote:
>>>>
>>>>
>>>> Hi,
>>>>
>>>> I've started preparing the mappings. So far I've focused only on RRD
>>>> MA, PSPS commons and PSPS LS. This is just the beginning for the
>>>> discussion (to check if this is a good direction for all interested).
>>>>
>>>> Cheers,
>>>> Roman
>>>> <proposal-of-mappings-20100527v1.txt>