[tahoe-dev] Questions

[Zooko O'Whielacronx]

On Wed, May 12, 2010 at 12:33 PM, Brian Warner <warner at lothar.com> wrote:
>
> This is great for long-term servers, but can be a bit surprising in the
> short-term: if you've just started your client and upload a file before
> it has a chance to connect to all of the servers, your file may be
> stored on a small subset of the servers, with less reliability than you
> wanted. We're still working on a good way to prevent this while still
> retaining the dynamic server discovery properties (probably in the form
> of a client-side configuration statement that lists all the servers that
> you expect to connect to, so it can refuse to do an upload until it's
> connected to at least those). A list like that might require a client
> restart when you wanted to add to this "required" list, but we could
> implement such a feature without a restart requirement too.

Actually the "servers of happiness" feature which is hopefully going
to be included in the imminent Tahoe-LAFS v1.7 beta release should fix
this problem:

http://tahoe-lafs.org/trac/tahoe-lafs/ticket/778#comment:186

If this patch get sufficiently reviewed to go into v1.7 beta, then if
you start your client and upload a file before it has connected (or if
all but a couple of your servers happen to be disconnected from the
Internet when you upload) then you'll get a failure message from your
attempt to upload, that says something like:

"UploadUnhappinessError: shares could be placed or found only 2
server(s). We were asked to place shares on at least 7 server(s) such
that any 3 of them have enough shares to recover the file."

http://tahoe-lafs.org/trac/tahoe-lafs-ticket778/browser/src/allmydata/util/happinessutil.py?rev=4293#L6

Regards,

Zooko