Subject Re: [Firebird-Architect] Remote Shadows (again...)
Author Jim Starkey
Alex Peshkov wrote:
> NFS is a special case when engine checks for ability to create DB shadow
> at some path. It's not very interesting, how is it done in engine - code
> is trivial, and it's very easy to let it create shadows for any other
> file sharing protocol. The interesting question is why this was done
> only for NFS.
Again, this is an area where a superserver solution would be simple,
elegant, robust, and fast, but a classic version difficult.

Here's the idea: Create a dedicated protocol and server to propagate
pages images to a shadow on a different system rather than using a
remote file system. The advantages are:

1. Careful write is preserved.
2. The data stream is buffered so the server doesn't wait.
3. Only the significant part of the part need be sent
4. The data can be streamed since acknowledgment isn't required, so
there are no "round trips"
5. If the shadow server were temporarily available, the data stream
could be redirected to a file

I haven't a clue as to how to do it in classic. The superserver version
would probably take less than a week to implement included the server.


Jim Starkey
Netfrastructure, Inc.
978 526-1376