yum-deltarpm (Was Thread Hijack - Our package management GUI tools need improvement)

[Warren Togami]

Jonathan Dieter wrote:
> On Fri, 2007-03-09 at 20:01 -0500, Warren Togami wrote:
>> 1) Client wants to upgrade from foo-3.2-1 to foo-3.2-2 (Transition X)
>> 2) Client metadata sees that Transition X has a drpm available (from 
>> metadata or something).
> At the moment, it checks to see if a drpm is available from your
> deltarpm url that matches a filename.  If the file doesn't exist, then
> there is no drpm for this particular update.  I could code in a way of
> using metadata rather than filename checking, if that's what's
> preferred.  Are we talking a yum-style xml file?

Yes.  But this is only an optimization for later.  Checking for 
existence of the file and using 404 is a bit slow, so metadata would 
speed this up a bit.

>> 3) Client checks using rpm -V (or more likely the rpm API equivalent) to 
>> see if the local files are intact.  This step is a little time 
>> consuming, but it is worthwhile because we know that a drpm is available 
>> above the defined efficiency threshold.
> Should be easy to implement, and, yes, would be very important.  FYI,
> the current efficiency threshold is 50%.  It is very easy to adjust this
> level.

Could the efficiency threshold be > 50% and drpm is larger than a 
certain size?  This is because it is pointless to have drpms of tiny 
packages.  What exact threshold size however I don't know.

>> 4) All files are intact, except some files in /etc marked %config are 
>> changed.  This is OK.
> Yes.  Deltarpm stores %config files in the drpm no matter whether
> they've changed or not.
>> 5) drpm contains %config file data even if they did not change in 
>> Transition X.  This allows reconstruction of the original foo-3.2-2 RPM 
>> even if the local %config files are modified.
>>
>> deltarpm needs to put data within the drpm that is likely to change on 
>> the local systems.  This includes %config, but possibly other things 
>> like /var.  We can craft this predefined list to whatever our research 
>> finds is necessary.
> As far as I know, deltarpm doesn't have a way for the user to choose
> which files *must* get stored in the drpm.   

Not asking for users to choose which files must be stored in drpm.  Just 
indicating that it might be important for other non-%config files to be 
stored.  I might be wrong.  We'll see in testing.

Warren Togami
wtogami at redhat.com