Re: [PATCH v3 0/3] [RFC] Create 'core.featureAdoptionRate' setting to update config defaults

[Taylor Blau <me@ttaylorr.com>]

Hi Derrick,

I'm a little bit late to the part, but I think that this is a really
interesting feature with a lot of really interesting discussion so far.

I hope you don't mind me throwing in my $.02 as well :-).

On Mon, Jul 08, 2019 at 03:22:49PM -0400, Derrick Stolee wrote:
> On 7/1/2019 10:29 AM, Derrick Stolee via GitGitGadget wrote:
> > Here is a second run at this RFC, which aims to create a "meta" config
> > setting that automatically turns on other settings according to a user's
> > willingness to trade new Git behavior or new feature risk for performance
> > benefits. The new name for the setting is "core.featureAdoptionRate" and is
> > an integer scale from 0 to 10. There will be multiple "categories" of
> > settings, and the intention is to allow more granular levels as necessary.
>
> (Adding people who contributed feedback to CC line.)
>
> It seems that this "Feature Adoption Rate" idea was too simplistic, and
> had several issues. Time to take a different stab at this direction, but
> with these clear goals in mind:
>
>  1. We want intermediate users to be able to take advantage of new config
>     options without watching every release for new config options.
>
>  2. The config name should match the general effect of the implied
>     settings.
>
>  3. There are orthogonal settings that may not apply beneficially to
>     all repos.

I think that this is a clear representation of the initial reaction I
had to the 'core.featureAdoptionRate' idea. I had drafted a response to
advance these concerns before realizing that this subsequent RFC
existed, which does a nice job highlighting the concerns that I had.

> With this in mind, I propose instead a set of "feature.*" config settings
> that form groups of "community recommended" settings (with some caveats).
> In the space below, I'll list a set of possible feature names and the
> implied config options.

I think that 'feature.*' configuration settings are a good idea. They
address each of the above (3) concerns, since they are:

  1. Can be easily adopted by even novice-level users. Perhaps
     novice-users will not be setting 'feature.manyFiles = 1', but they
     can easily opt-in to organization-level features that have been
     defined to handle organization-specific concerns.

  2. This one is straightforward: I think that setting
     'feature.manyFiles = 1' is clearer than 'feature.adoptionRate = 3'.

  3. Right. Windows developers may have a different set of what features
     are interesting to adopt than, say, every-day users, and likewise
     for kernel developers, too.

> First, the main two categories we've discussed so far: many commits and
> many files. These two feature sets are for when your repo is large in
> one of these dimensions. Perhaps there are other settings to include
> in these?
>
> 	feature.manyFiles:
> 		index.version = 4
> 		index.threads = true
> 		core.untrackedCache = true
>
> 	feature.manyCommits:
> 		core.commitGraph = true
> 		gc.writeCommitGraph = true
> 		(future: fetch.writeSplitCommitGraph = true)

I think that for this *feature* (pun mostly unintended) to really shine,
we ought to adopt Junio's suggestion in [1] that we allow users to:

  * use pre-baked features that are defined within and shipped with
    Git itself.

  * define their own features and second-order features that can
    reference both pre-baked and user-defined feature groups.

I think that this will let, say, folks at Microsoft to define a set of
features that are interesting to Windows developers, that are separate
from the features that core Git thinks will be interesting to every-day
users.

>
> <snip>
>
> Thanks,
> -Stolee

Thanks,
Taylor

[1]: https://public-inbox.org/git/xmqqftonsr6a.fsf@gitster-ct.c.googlers.com/