Description of problem:
I'm on a 1Gb/s network with private Fedora mirrors. All the packages are usually downloaded in a matter of seconds. Yet, with dnf, the first package to download suffers a "random" delay of 2-60? seconds, before the downloading really starts. This is different to yum, which started downloading immediately after confirming the transaction.

With dnf, I see "Downloading packages:" line and then a blinking cursor with no other feedback for some time. After the random wait, all packages are downloaded immediately.

My theory is that dnf is trying to contact some mirrors before the download operation starts, and some mirrors are slow from time to time. However, this seems to happen always, even when all metalinks are up-to-date (for example when I had performed other dnf operations in the last few minutes). dnf seems to try to contact the mirrors always, not just when needed, and waits until it is done, which slows down every operation. But that's just my theory.

mluscon on #yum asked me to try to identify the long operation in /var/log/dnf.librepo.log, so I attach a part of that log with a few comments inside roughly where the wait occurred. However, this is really hard to reproduce reliably (the 30+ sec timeout occurs just sometimes, usually it is just a few seconds), so it's very approximate. I can try harder if needed.

Maybe there is a reason why dnf is waiting for something to happen, before the downloading starts. But if that operation takes more than 5-10 seconds, it should give users some feedback. (Even when I run it with -v, there is *no* feedback what it is waiting for). Otherwise it just seems like stuck and it contributes to a poor user experience and perceived slowness.


Version-Release number of selected component (if applicable):
dnf-1.0.1-2.fc22.noarch
hawkey-0.5.7-1.fc22.x86_64
librepo-1.7.16-1.fc22.x86_64
libsolv-0.6.10-1.fc22.x86_64

How reproducible:
random

Steps to Reproduce:
1. run something like dnf makecache or dnf install foo to make sure all your repo metadata is up to date
2. run dnf install bar and confirm Y to run the operation
3. see that after "Downloading packages:" is printed out, you stare at a blinking cursor for a random delay (sometimes very long), before the packages start to be really downloaded. See no feedback during that time that would explain why nothing is happening.