Re: [atomic-devel] rpm-ostree equivalent of fastest mirror and parallel downloads

[Colin Walters <walters verbum org>]

On Thu, May 17, 2018, at 8:24 PM, Muayyad AlSadi wrote:
> Hi,
> 
> in /etc/dnf/dnf.conf I have
> 
> fastestmirror=1
> max_parallel_downloads=20
> 
> what is the of that in rpm-ostree?

So...this is an interesting topic.  As the name implies, rpm-ostree
glues together two fundamentally different "engines" - ostree and libdnf.

Theoretically, those config options would apply when downloading
layered packages with libdnf.  Except today, libdnf doesn't parse the
global dnf.conf file, which is (kind of) a bug.

Now if you're talking about what the ostree equivalents of those are:
they don't exist today.  For `fastestmirror` my opinion is
that's a lot of complexity that's better handled by CDNs.  Which
we have configured today for the FAH/Silverblue content, but
it's somewhat neutered by https://github.com/ostreedev/ostree/issues/1541

As far as `max_parallel_downloads` - libostree today already uses
a lot higher number than the default dnf value of `3`.  Big picture
the biggest efficiency win for things like this using HTTP/2 which I hope we can re-enable
for Fedora soon.

Now of course with https://github.com/projectatomic/rpm-ostree/issues/1081
things get a lot easier to understand/manage, as content is fetched in a single way.
But the libdnf-vs-dnf.conf issue would still apply.  And today librepo doesn't enable
HTTP/2 unfortunately, but that shouldn't be too hard to fix.