New remote backend (was Re: [Xapian-discuss] Remote databases slower than local?)

[Olly Betts]

On Wed, Jun 28, 2006 at 03:32:33AM +0100, Olly Betts wrote:
> But I have a mostly complete reworked remote backend which removes
> unnecessary layers of classes in various places and simplifies how
> the matcher interfaces with the remote backend so it might be better
> for you to look at that than the current code.

OK, I've tied up the loose ends and have just committed this to SVN
(revision 7142).  There are bootstrapped snapshot tarballs here:

http://www.oligarchy.co.uk/xapian/trunk/

The remote protocol has been rebuilt from scratch, so you'll need to
upgrade clients and servers together.

Most things are now supported (including writing to remote databases
if the server was run with --writable).  You can't currently open
postlists, and you can't use replace_document or delete_document with a
termname - not for any good reason, I've just not implemented these
yet.

I've implemented a new "remotetcp" testsuite backend which gives us
rather better test coverage for the remote backend.  This is currently a
little temperamental - e.g.  tests occassionally fail because the server
from the previous test hasn't had quite enough time to shut down.

The "prog" variant of the remote backend is now useful outside the
testsuite.  For example, you can run it across ssh to provide
authenticated and encrypted connections to remote databases.

All the testsuite passes when run under the remote backend (tests which 
would try to use unimplemented features are just rigged up to "SKIP")
but it's not had any real world use.  So if you use the remote backend,
it would be useful if you could give it a try.

I'm going to be away from regular (or at least daily) email for the next
month, but I'll be checking in when I can.

Cheers,
    Olly