Question about yum metadata transfer

[Megh Parikh]

XML Diff and Patch tools:

https://github.com/amouat/diffxml : Apache2
http://diffxml.sourceforge.net/ :GPL2

The above tools are from same author under different license

Other not so popular tools:
http://xmlpatch.sourceforge.net/

Regards,
Megh

On Tue, Dec 30, 2014 at 8:28 PM, Megh Parikh <meghprkh at gmail.com> wrote:
> Well I read in the YumFuture page that repo meta delta was a goal.
>
> I wish to contribute but first I need your review on what I have to say.
>
> So here are my two cents:
>
> -> Repos should create patches (there are xml patch tools listed below
> for diff and patch are not so suitable for XML files)
> -> Patches should be organized by timestamps.
> -> The current state of metadata should be saved as an xml file which
> is served to any new user.
> -> An old user requests a list of patches from the server
> -> Preferably certain amount of patches should be compressed as HTTP
> requests take certain time. (Lets say 25. This maybe added to the
> .repo file)
> -> The list contains list of timestamps of patch files
>     - The first line of this list contains the timestamp of the
> starting point (more on this later)
> -> If this list has a timestamp newer than what the user has the user
> downloads the patch files
>     - If the timestamp of the starting point is newer than the users
> timestamp than the user has to redownload the repo metadata
>     - Yum would know the count of compressed files from the .repo file
> and would request the gzipped file instead of each file if yum has to
> download more than 25 files. Else It would individually download each
> file.
> -> If the amount of patch files exceeds a big amount, (eg 250) old
> patch files should be deleted and the starting point updated
> .   - This means that 100 of the 250 patches would be deleted while
> the rest deleted so that the list doesnot swell much in size nor does
> a very old user have to download much.
>
> Tell me your ideas and as I am a newbie tell me if this can be
> implemented as a plugin
>
> Regards,
> Megh
>
> On Tue, Dec 30, 2014 at 7:44 PM, Megh Parikh <meghprkh at gmail.com> wrote:
>> Hello,
>>
>> I donot no much about the internals of yum but is repository metadata
>> downloaded in whole everytime it gets autoupdated?
>>
>> Especially the updates and the Fedora repos take a long time to download and
>> use about 30 MB of download.
>>
>> If not can it not be supplied as patches to existing xml data. (There are
>> several xml diff utilities)
>>
>> (I donot know if this should have been posted in the yum list instead of
>> yum-devel. If so pls redirect me)
>>
>> Regards,
>> Megh Parikh