file meta information

[Anatoli Stoyanovski]

We are planning mogilefs reengeneering to implement the following features:

1) support webdav properties.
Since PUTting is done by client, it would be easy. Mogstored could be
replaced by any webdav-server, MogileFS.pm could be improved.
mofilefsd replication should be redesigned to use COPY method or copy
properties too.

2) try not to use fid'ed paths in storage servers. If key are real
unique paths (/x/y/x/file.gif), we prefer to use this path instead
/0/0000/0001.fid

3) device binding for domains.
Use preferred storage servers for replias.

Why is it all about? We think, mogilefs is good not as
application-level filesystem, but a good replication software. We want
to store files via mogilefs api, but access files locally on storage
servers via local posix filesystem (which is very fast comparing to
mogilefs). Application will try local read, then mogilefs read if no
local file found. Using this architecture, we want to combine fast
local disks with mogilefs failover features using cheap hardware and
software.

On 8/14/06, Mark Smith <junior at danga.com> wrote:
> > Is there are reliable method available to store metainformation about
> > files in mogilefs?
>
> There is not, yet.  This is something we want to do, though.
>
> > 2) store metainformation as ordinal file. For file with key
> > 'image:x.jpg' store small 'meta:x.jpg. Small size => fast rewrites.
>
> This is how we've thought about doing it.  Then you can restore a MogileFS
> database from a given set of storage disks, which would help if you had
> a critical database failure.  (Even though since you should have two
> databases, this shouldn't ever happen...)
>
> It's been talked about, but hasn't been done yet.  We will be getting
> around to it in the next few months, I know some big bosses here at 6A want
> the ability to restore from the storage disks.
>
>
> --
> Mark Smith
> junior at danga.com
>