nova team mailing list archive

[Michael Gundlach <michael.gundlach@xxxxxxxxxxxxx>]

On Tue, Oct 5, 2010 at 2:43 PM, Jay Pipes <jaypipes@xxxxxxxxx> wrote:

> keys) across multiple nodes.  A random 32-bit integer would be fine as
> long as the generating algorithm produced acceptable collision rates.
>

I'm using randint(0, 2^32) atm.  The chance of collision is intuitively
something less than 1 in 1000 after adding a million instances.  Ed, I don't
see the need for a 128-bit ID when 32 bits almost suffices.

This would be bikeshedding, except that I don't know how to make a
larger-than-32-bit integer work in sqlalchemy without becoming
implementation-specific.  I think I read that sqlalchemy has a BIGINT type
that's only usable with mysql, for example.  If someone knows how to make an
internal_id column that is 128 bits and happily stores itself in any mysql
backend, I'm fine with 128 bits (and you can argue with Soren about it :)

Michael


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