Re: [9fans] p9p factotum available for plan 9

[tlaronde@polynum.com]

On Fri, Nov 12, 2010 at 02:20:35PM -0800, ron minnich wrote:
> On Fri, Nov 12, 2010 at 2:15 PM, Eric Van Hensbergen <ericvh@gmail.com> wrote:
> 
> > No, that's true.  I think this is actually a huge open issue for
> > existing distributed file systems in general and I'm not sure of a
> > good way around.
> 
> yeah, we had lots of discussion of this about 8 years ago with 9grid
> and never worked it out. What's your global identify? How do you name
> it? How do you map it to a local identity? I have no clue.

The problem with strings is that they are human oriented and human
dependent, on mood and/or trend. Numbers are agnostic.

Isn't a solution à la IP network numbers possible? I mean, a user,
whatever string is locally associated to it (and this may change), is
uniquely identified by a number that could encode a domain (with some
numbers being absolutely local), the conversion between string to number
being local (I'm called "god" on my personal systems, and may be called
"dummy" elsewhere; well, in fact "god" is "root" on Unices, and this 
"god" is only a local thing, with external systems don't believing in it
at all), and negociation being only with numbers.

And separate logical user from physical user: a physical user can be,
depending on the task, several distinct logical users; but the reverse
is true: several distinct physical users can be an uniq logical user.

This changes the way one thinks about the sharing of randomly writable
files: only "the" (logical) user of a file can randomly write 
(by randomly, I mean not append) a file; but there can be several 
concurrent instances of "the" user writing to the file (an instance
of a user is called a terminal; and a terminal is a temporary view
of the data).

And there are group writable files that are only append writable so long
as a new record doesn't invalidate the previous ones [partition]
(hence distinct logical users sharing a group writable file don't
care about other writes when reading; when writing, an identifier
is returned, and if the record already exists, added by another user,
the existing identifier is returned, else it is added and the new
identifier is returned).

The use of numbers mapping to a string that can change is the principle
I have adopted with my CVS: the "projects" are only numbers, and if the
mood (or the "marketing") change, only the string associated changes,
the hierarchy is left alone since the numbers are fixed from start.
-- 
        Thierry Laronde <tlaronde +AT+ polynum +dot+ com>
                      http://www.kergis.com/
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