RE: Review of EXI

Comments inline.

> -----Original Message-----
> From: noah_mendelsohn@us.ibm.com [mailto:noah_mendelsohn@us.ibm.com] 
> Sent: Friday, October 26, 2007 3:29 PM
> To: David Orchard
> Cc: W3C-TAG Group WG; shh@us.ibm.com; haggar@us.ibm.com; 
> klawrenc@us.ibm.com
> Subject: Re: Review of EXI
> 
> Dave:
> 
> Speaking as a TAG member:
> Thank you for doing this.  I think there's a lot of good 
> stuff here.  My overall impression, FWIW, is that this would 
> have more impact if we went into just a bit less detail, and 
> focussed a slightly shorter note on some key points.  Don't 
> take this is a significant criticism.  I think the core of 
> this is very good, just that a bit of tightening would make 
> it more effective.  If that means a few details fall out of 
> it, I'm not sure that's all bad.
> 
> Speaking as an IBMer:
> 
> > - IBM's withdrawal [4] from the Working Group shows their 
> detailed and
> specific disagreement with the benefits of EXI and remains 
> unaddressed. 
> 
> Thank you for referencing this note; we're very glad that our 
> concerns are 
> viewed as significant for this discussion.  I do note that, 
> like several 
> other references from your note, the link is to 
> member-confidential email. 
>  I doubt that anyone in IBM would object to having a copy posted in a 
> public archive, and if you'd like I could in principle check 
> with my IBM 
> colleagues.  I say in principle because our note also refers to some 
> correspondence among a smaller group of individuals in the 
> W3C.  It was 
> originally written as input to the chairs and W3C staff, and 
> I think we 
> would need the permission of this individuals as well.  Shall 
> we try and 
> ask all these folks whether they're OK with at least IBM's note being 
> posted in a public place?  If not, I think it will be 
> frustrating for your 
> readers to find the link and not be able to follow it.
> 

Let's get the IBM note into public space.

> > Just recently a working group member said "The same goes for 
> > IBM, if they really thought the result tells something 
> > important, they would have spent some more time establishing a 
> > case out the result against EXI. "[5]
> 
> Again, this is a member only link.  

It is indeed a shame that the EXI group is not doing their discussion in
the public domain.  

> I think you've taken a 
> small enough 
> bit that it's sort of out of context.  The quote appears to 
> imply that 
> surely IBM did not take its concerns about EXI seriously, as we would 
> otherwise have "spent more time establishing the 
> case...against EXI".  In 
> fact, our work on XML performance was done over several 
> years, and just 
> the comparison work we did on EXI involved several weeks of work in 
> particular.  Those comparisons were presented in a quite detailed 
> presentation to the EXI workgroup, and I happened to be there as an 
> observer that day.   I think it's only fair if you are going 
> to have a 
> quote like this that you ensure that the entire email at [5] 
> is publicly 
> accessible so that people can draw their own conclusions about it.
> 

Now I think that you are somewhat unfairly quoting out of context.
Reprising my note:
>>>>
It appears that the working group has presupposed a conclusion that
binary xml is necessary and no concerns by the TAG or member companies
on the technology and methodologies themselves or the integration with
the rest of XML (including DSig) need to be addressed directly.  Some
examples:
...
- IBM's withdrawal [4] from the Working Group shows their detailed and
specific disagreement with the benefits of EXI and remains unaddressed.
Just recently a working group member said "The same goes for IBM, if
they really thought the result tells something important, they would
have spent some more time establishing a case out the result against
EXI. "[5]
<<<<<

I mention member companies, and then IBM's withdrawal with detailed and
unaddressed concerns, followed by WG member quote that substantiates the
assertion that "no concerns by TAG or member companies .... need to be
addressed directly".  I don't think that it implies that IBM did not
take it's own concerns seriously.  

> I think it's fair to say that IBM believes that EXI offers 
> interesting 
> compression on XML, and some speed gains in many use cases;  
> we also think 
> that the speed gains over well optimized text implementations are not 
> nearly as great as might be inferred from the measurements 
> presented by 
> the EXI group.  The issues include many that you've put into 
> your note, 
> Dave (choice and weighting of test cases, use of Java, etc.) 
> 
> More to the point, I think you're trying to make the case 
> that the EXI 
> workgroup didn't take our concerns seriously (I offer no 
> opinion on that 
> -- while our concerns have not been satisfied, I wouldn't 
> want to accuse 
> anyone in the EXI group of not taking them seriously).  In 
> fact, the quote 
> more directly seems to imply that we in IBM did not take our 
> own concerns 
> seriously, and that I must  object to (though the author is surely 
> entitled to express that opinion).
> 
> Maybe it would be better to just point out that we were among 
> those who 
> raised concerns, possibly linking our note if we get it made 
> public, and 
> to indicate that we in IBM do not believe the performance 
> analysis in the 
> EXI drafts addresses our concerns.  If you want to 
> additionally say that 
> the authors of [5] think we did not take our own concerns 
> seriously enough 
> to give them force, of course you may do so, but I think we'd want a 
> chance to breifly and politely rebut that.
> 
> Sorry to make a fuss about this, but there's already a lot of 
> heat and 
> confusion around this whole issue, and I'm afraid that the current 
> fragmented quotes from member-only emails will make it worse and not 
> better.

I tend to agree, perhaps you can provide some specific alternative text.
I thought the assertion about member company concerns not needing to be
addressed followed by an example of not addressing the concerns was
pretty tight but I'm open to whatever you'd like.

> 
> Noah
> 
> [4] 
> http://lists.w3.org/Archives/Member/member-exi-wg/2007Mar/0014.html
> [5] 
> http://lists.w3.org/Archives/Member/member-exi-wg/2007Sep/0010.html
> 
> 
> 

Cheers,
Dave

Received on Tuesday, 30 October 2007 23:28:18 UTC