[Dmozrdf] checkupdates program re-enabled

[Ciaran Hamilton]

Hi,

It seems that the problem with the RDFs is that DMOZ has been putting new
servers into place, and presumably the bad effect with the RDF
notifications is caused by mirroring from one server to another without
properly preserving the timestamps.

I've made a couple of changes to the checkupdates program to resolve this:

1. Previously, checkupdates would send a message whenever it detected that
a date had changed. Now, it'll only do so if the date it finds is later
than the date of the RDF the last time it checked. At the very worst this
will reduce the emails to two, and not sent a long string of emails back
and forth to the list.

However...

2. I've also introduced a change whereby a notification is only sent if
the date of both the RDFs is more than one hour from the last ones it
recorded. This should mean two things:

  * No more false double notifications like we've been having on the list
where one RDF had updated but not the other; now notifications will only
be sent when both RDFs are updated.

  * Elimination of the problem where two notifications might be sent in
the case of the mirroring problem above. In very rare cases, when the
mirroring takes longer than an hour, there may be two emails sent to the
list - but only two, no more.

If you have any questions about this, please feel free to email me at
dmozrdf-owner at theblob.org . The checkupdates program has now been
re-enabled, and the next email will be the notification of the new RDFs
which will be sent in about 6-7 minutes.

Thanks for bearing with me on this.

 - Ciaran.