Re: [netconf] Current activities on RESTCONF/NETCONF to support paging

[Douglas Hubler <[e-mail]>]

On Thu, Mar 14, 2019 at 5:24 AM Wisotzky, Sven (Nokia - DE/Stuttgart) <
[e-mail]> wrote:

> There was some discussion in earlier days (back in 2012/2014) to support
> paging for extra-long lists. The main use-case is clearly to improve
> support for interactive user-frontends, as loading entire lists with
> potentially more than 100.000’s objects easily can become a nightmare:
> loading time, memory consumption, crashes, …
>

speaking from experience, RESTCONF is very usable straight from interactive
user-frontends and this is one of the key things missing.  I did add a
custom parameter to FreeCONF's RESTCONF implementation to support this.
Maybe I took this took far, but I decided that because data is in a
hierarchy you might have multiple lists you need to page thru so I came up
this this parameter

   range=b/c!N-M

returns rows N thru M inclusive in list under path b/c.  And that you can
specify multiple ranges for multiple paths.  Front ends usually have no
problem remembering what number they are on to track N and M.

As brought-up, for lists that are highly dynamic, this strategy is bit
naive and maybe etags can help the clients that need to know when list has
changed and they might need to start over.  For my backend, I could start
iteration at row N without have to manage a cursor.


I did not found any active DRAFT or RFC for this. That said, we can see
> various vendors implementing proprietary solutions for this in their
> RESTCONF stacks.
>
> Would really like to see an IETF defined approach for this, to avoid
> multi-vendor clients need to deal various vendors implementations.
>

+1