Tom,
I am surprised that you think reliability is the issue - I thought we could
make it quite reliable by having multiple redundant servers.
I expected the criticism to be complexity - to make it work you need
something along the lines of the following:
1. A 'master' which maintains a database of the available servers, whether
they are alive or not, and how fast they are.
2. Some 'deputies' which synchronise themselves with the master and take
over its duty if the master dies (the 'take over' bit is the bit I don't
know how to do - will have to do something with DNS I suppose...).
3. When a request comes in the current master decides which sever to send
the request to and passes it on.
Therefore I think the main issue is that this is rather complicated and may
be difficult to maintain, rather than a reliability issue as such?
There is of course the additional processing step of choosing a server,
which could slow things down, but I suppose it is just a scan through the
bounding boxes of the various servers to see which ones can meet this
request, so it might not add much onto the overall request.
Graham.
On Sep 8, 2009 8:46pm, Tom Hughes <t...@compton.nu> wrote:
On 08/09/09 19:41, Graham Jones wrote:
This would work for a single 'main' server, but I like the idea of it
being distributed with lots of little ones (for example the computer in
my attic could serve Northern England, someone else could do Belgium
etc.). I don't know how to deal with re-directing the requests without
a central main server though...any ideas?
That kind of distribution is, in my opinion, a terrible idea. Such a
system will just never be reliable.
Tom
--
Tom Hughes (t...@compton.nu)
http://www.compton.nu/
_______________________________________________
dev mailing list
dev@openstreetmap.org
http://lists.openstreetmap.org/listinfo/dev
