F21 downloads repository metadata in 3 places!

[Hedayat Vatankhah]

Hi!
I noticed that F21 can potentially download repository metadata 3 times: 
1. Yum cache 2. DNF cache 3. PackageKit cache! It really hurts to see 
how Fedora ignorance towards different kind of users is being increased 
as time passes. If Fedora is an international distro, it should try to 
consider condition of different users, not just a portion of them.
Fedora repository metadata format was already hostile, it wastes 
bandwidth considerably downloading mostly useless data repeatedly. 
Things got worse for DNF as it decides to also always download filelists.

Now, Fedora 21 contains yum, dnf and PackageKit (software center) with 
new backend. Surprisingly, PackageKit uses its own separate cache. DNF 
refreshes its cache automatically (without user's consent) every 3 hours 
by default (according to 'man dnf.conf'). PackageKit also does the same, 
but I don't know when it does (also without user's consent).

Now, if you are exclusively a 'yum' user, you'll end up with 3 
repository metadata downloads, two of which you are unaware of. 
Probably, it is OK for most of you having access to cheap, fast internet 
access. But not everybody in the world has such access. It was not long 
ago that dial-up internet access was a norm in my area (there are still 
some using it!). I'm not using dial-up, but still can't afford such a 
waste of bandwidth. I'm using a 'fast' internet access, which is 
512Kb/sec, and have 6GiB for 3 months (with free access at nights, which 
I use to update/install Fedora packages). As I've described at [1], DNF 
alone can potentially consume all my internet credit very soon; even if 
I don't want to use any package manager at all. This will make many 
users with conditions like me very angry when they realize that Fedora 
has eaten their money silently.

Another side of the story is how Fedora lacks any integration in this 
area. There are separate caches. Fedora doesn't tell you that it'll eat 
your internet. Also, there is nowhere you can tell Fedora 'Please don't 
eat my internet without my permission'. Even there is no single 
configuration option for it. You should manually disable automatic 
downloading for DNF, and then separately for gnome software using some 
obscure gsettings commands you should look for. Well, I've not tried 
other desktops, each one might have each own settings for that too! 
(though usually such ignorance is the worst in GNOME).

It's so unfortunate to see how Fedora lacks any integration (one of the 
main things that a distro is expected to provide) in its package 
management software (one of the main distro specific software, where you 
fairly expect an integrated experience as an 'internal' software).

As I was expecting, I've already seen how a user in our local community 
cried about Fedora 21 consuming his Internet credit the day after the 
release. The number of Fedora users around me were already low, and I 
expect it to become less if Fedora continues its ignorance trend.  I'm 
not annoyed that much yet, as I'm just considering switching to a 
different DE after suffering GNOMEs decisions for a long time hoping 
that 'things will be better soon'; and finding out that my needs are 
something that 'THEY see no reasons to support'.

P.S. sorry for the somewhat long email. I'm a little bit angry! :P

Regards,
Hedayat

[1] 
https://hedayatvk.wordpress.com/2014/07/26/the-shiny-new-dnf-and-why-i-prefer-yum/