I am currently noticing an issue with yum. There are a bunch of new updates for FC4. Each time I run yum, it adds and then the next time deletes the new packages. It also gives inconsistent results, like the new packages showing up in 'yum list extras'. I assume that some of the mirrors haven't yet pulled down the updates and are returning the old version of the metadata. I think it would be good to add some detection in yum for out-of-date mirrors to prevent weird results. The repomd.xml file seems to include a timestamp for each metadata file. The solution would be to not allow the timestamp to go backwards. If a newer timestamp has already been downloaded, then an older timestamp would cause that mirror to be skipped. This does require that the timestamp does not legitimately go backwards in the metadata. This requires that the system which does createrepo has a good clock. It would also be good if the mirrors do not rebuild the metadata because their newer metadata would override all the other mirrors. - Ian
