Cyrus News Daemon as poor man's replication engine

[Ken Murchison]

Michael Fair wrote:
> My apologies in advance for not being subscribed to the list but I had a
> quick inquiry.
> 
> I've read in the docs that the Cyrus NNTP daemon can export shared folders
> via NNTP and receive an NNTP feed.  Can the same be done for user mailboxes?
> 
> I've always wondered if a group of Cyrus Servers could use their NNTP
> daemons to provide fairly robust asynchronous replication for user
> mailboxes.  A poor man's replication engine if you will.  Aside from the
> geographic redundancy this could provide, it would be handy for users who
> travel among many branch offices so their email access is to the "local"
> server rather than across the WAN link. 
> 
> I envisioned that the only allowed "subscribers" to these "groups" would be
> the servers themselves to feed each other changes in the user's folders.
> 
> Could this be done?

Sure.

> Would there be many technical challenges to use NNTP as a poor man's
> replication tool?

You'd need to remove the code in nntpd.c which check for and prohibits 
user.* mailboxes from being exported.  Aside from that there may be 
other changes needed for the kind of replication you're looking for. 
Why not try the replication code in Cyrus 2.3?

> Is there a technical reason that the NNTP engine is limited to shared
> folders?

No.  It just didn't seem to make much sense at the time.

-- 
Kenneth Murchison
Systems Programmer
Project Cyrus Developer/Maintainer
Carnegie Mellon University