Re: [Ltru] Additional issues with 4646bis raised by an Apps Review Team review

[Alexey Melnikov <alexey.melnikov at isode.com>]

Alexey Melnikov wrote:

> Alexey Melnikov wrote:
>
> > This is the first batch. I received a fairly long list of comments 
> > and still deciding what to do with the rest.
>
> Sorry for the delay. This is the second batch. There would also be a
> third (and the last) batch, with about 6 issues.

Actually the last batch is down to 1 issue, but it is more serious.

14). Language Tag validity verification requires applications to keep 
up-to-date copies of the Language Tag registry. Such applications might 
be designed to automatically fetch new versions of the registry. This 
has three problems:
I). IANA is generally not happy about applications automatically 
downloading registries, unless data is located in DNS. This is primarily 
to scaling concerns.
II). There is also the issue of when application should be fetching the 
updated registry. I.e. what is the mechanism(s) for determining when to 
fetch.
III). The registry format is not designed for figuring out the minimal 
list of changes between any 2 versions. For example there is no way of 
only fetching changes since a given File-Date value.


BTW, are people aware of implementations that try to download Language 
Tag registry automatically?


While I don't expect this issue to be fully fixed at such a late stage, 
it needs to be discussed in the document. Some thoughts about what can 
be said on the topic:

Regarding I): application should be advised against frequent polling of 
the registry. For example:

 The registries specified in this document are not
 suitable for applications that require real-time access
 to, or retrieval, of the full registry contents.

It might be nice to have the File-Date value available as a separate 
short piece of data (a separate web page on IANA's website, a thing in 
DNS, etc.
But even with existing registry format it might be possible to minimize 
load on IANA's website by describing how HTTP/1.1 features can be used 
to only download necessary information, such as downloading the 
beginning of the registry which contains the File-Date field.

Regarding II): I think this needs some advice on which operations need 
and which don't need fetching of the registry.

Also this might mention that any application keeping a copy of the 
registry needs to preserve the File-Date value in some form.

Regarding III): I think it is Ok for now to explicitly acknowledge that 
this is an issue.

It might also be worth discussing how the registry format facilitates 
"diffing" 2 versions of the registry.