[pmwiki-users] Sync of local pmwiki with remote pmwiki

[Patrick R. Michaud]

On Thu, Jul 21, 2005 at 06:34:33PM +0200, Joffrey Pannequin wrote:
> Hello,
> I am trying to setup a wiki server. I want it to be available offline
> through a local pmwiki for read/write.
> 
> I saw some threads about this in May and June 2004. It suggested to use
> unison to synchronize the files. So I tried it. It works fine when a
> file is modified by only one of the pmwiki. But I can't get it to work
> with modification on the same file on both pmwikis. Does anybody have a
> solution or an idea ?

Well, I don't have a solution but I have several ideas.  

Synchronizing updates between two active sites is a bit tricky,
but it can be done.  Essentially it's the same process as handling
simultaneous edits -- to add the changes made on site A to site B,
we have to tell site B which version of the page was there as
of the last time the two sites were in sync.  B can then merge
A's changes into its own copy of the page.  (We can then do the
same process in reverse to bring site B's changes into site A, or
we can consider site B to be the "master site" and tell site
A to get a direct copy of site B's version of the file.)

The problem and difficulty arises when there are conflicts -- when 
changes made independently on A and B directly interfere with each other.
For simultaneous edits, PmWiki handles this by merging the
two sets of changes and sending any conflicts back to the author
for review before saving them.  But this probably won't work
well if we're trying to synchronize more than a few pages 
between the two sites.

There's also a question of invocation -- i.e., what process does
a person go through to say "I want to synchronize this page (or site)
with this other page (or site)"?

So, it can be done, and PmWiki already has many of the needed
pieces in place, but we need some design work to get there.

Pm