Re: [Evolution] Sync or share....do multiple instances work?

[Not Zed <notzed ximian com>]

On Wed, 2002-06-05 at 06:13, Jeffrey Stedfast wrote:
> On Sat, 2002-06-01 at 05:09, Joshua Rochester wrote:
> > I'm looking to run Evolution on multiple systems simultaneously, and I 
> > want to make sure what I'm doing won't corrupt the databases for 
> > contacts, tasks, and calendars. Do any (all) of these configurations 
> > work without conflict?

In short - no.

Of course, if you're contacts are in an ldap backend, etc etc things
like that work.  But even stuff like imap doesn't support multiple
clients (yet).

> > 1) Running multiple instances of Evolution on differnt X displays (vnc 
> > clients, etc) from the same user account at the same time?
>
> can't do this mostly because of the way oafd works. Another problem
> would be that the config databases might not be safe, I'm not really
> sure.

Hrm, I thought it was supposed to work?  Its more a problem with
gdk/gtk+ i'd have thought anyway because it only handles a single
display.  At best, oaf could run another whole instance of the objects,
but this is precisely what you dont want it to do.

Anyway i just tested it.  Logged into the same box, with a different
display and re-ran evolution.  All I got was another copy on the same
display as the first one.

> > 2) Sharing the ~/evolution directory (nfs, smb, afs!?) on multiple 
> > systems and running simultaneous Evolution clients at the same time?
>
> The mailer does proper file locking on mailboxes, but like I said above
> I don't think that bonobo-conf (the config database engine) does. I'm
> not sure about the rest of Evolution either, I doubt ETable locks it's
> spec-files for example. I'm not sure that wombat does file locking
> either, although it probably should? Maybe libdb3 handles that for you,
> I'm not really sure.

Although the mailer locks the mailboxes you cannot share mail.  Other
files like the index and summary files are not locked or written to work
with multiple separate processes.

The config database loads things into memory and then works off that -
all changes would be lost on different systems (the last to exit would
write its data out?  it could also get corrupted entirely it two write
at the same time).

I presume the contacts db files dont work across multiple accessors
either, and yeah libdb may have some smarts for this.

> > 3) Running a file synchronization utility on live data files to allow 
> > disconnected clients to share the same profile?
>
> I'd be wary of this approach. I can't say that it won't work, but I
> can't say that it will either - I'd say it depends on the answers for
> the above question. I'd also make sure that your sync utility uses file
> locking.

You could:
 end up with stale data (e.g. config changed, not committed to disk)
 end up with corrupt data (the file changes while you're reading it)
 end up with good data, sometimes.

You really just have to logout of one first and login to another one for
this to work.

> > 4) Somehow wiring a remote evolution station to interoperate through 
> > corba with the bonobo data store on a different machine?
>
> I don't think oafd is capable of doing this, but I could be wrong?

It might be, but i doubt it'll work with the current codebase.