On Wed, Jul 18, 2018 at 6:02 PM Daniel P. Berrangé berrange@redhat.com wrote:
On Wed, Jul 18, 2018 at 03:24:54PM +0200, Daniel Mach wrote:
Hi everyone, The DNF team is currently reviewing DNF compatibility with YUM 3 and we'd like to get feedback on this one: https://bugzilla.redhat.com/show_bug.cgi?id=1120253
rpmdb checksum is a checksum of all installed RPMs It has no cryptographical value, it's just an unique ID of RPMs on a system before and after each transaction and it's used in dnf history info and dnf history list. If checksums of 2 following transactions do not match, DNF indicates that. This happens if a user installs an RPM by hand via rpm command.
Then `dnf history list` looks like: 2 | install bar | 2018-01-01 02:00 | Install | 2 < 1 | install foo | 2018-01-01 01:00 | Install | 7 > the "<" and ">" characters indicate discontinuity in rpmdb hashes
Here's the question: DNF computes the checksum from RPM N-E:V-R.A while YUM computed it from E:N-V-R.A
We'd like to change the behavior to be compatible with YUM again. This would create 1 discontinuity in rpmdb checksums in the history, because from that point a new algorithm will be used.
Are there any concerns about such change? I believe that >90% users wouldn't notice anything as it's related to the history database only.
What's the benefit in changing to be compatible with YUM as opposed to stickin with current alogorithm ?
Surely if we don't change it, even fewer users will notice that DNF's behaviour is different from YUM's, since DNF has been the default for many releases now.
I could understand the motiviation to stay compatible with YUM if we were only just about to switch Fedora from YUM to DNF, but time is way in the past now. Shouldn't we optimize for the fact that DNF is the more widely deployed & used tool, and thus not worry about YUM compatibility in respect of the history DB ?
From my point of view, I considered YUM's rendering of the NEVRA to be very weird. Personally, I'd rather see us keep the DNF behavior for rendering NEVRA rather than switch to YUM's ENVRA.