Re: [PATCH 10/16] Introduce the concept that wal has a 'origin' node

On Mon, Jun 18, 2012 at 8:50 AM, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:

>> * Size of field. 16 bits is enough for 32,000 master nodes, which is
>> quite a lot. Do we need that many? I think we may have need for a few
>> flag bits, so I'd like to reserve at least 4 bits for flag bits, maybe
>> 8 bits. Even if we don't need them in this release, I'd like to have
>> them. If they remain unused after a few releases, we may choose to
>> redeploy some of them as additional nodeids in future. I don't foresee
>> complaints that 256 master nodes is too few anytime soon, so we can
>> defer that decision.
> I wished we had some flag bits available before as well. I find 256 nodes a
> pretty low value to start with though, 4096 sounds better though, so I would
> be happy with 4 flag bits. I think for cascading setups and such you want to
> add node ids for every node, not only masters...
>
> Any opinions from others on this?

What's the cost of going a lot higher? Because if one makes enough
numerical space available, one can assign node identities without a
coordinator, a massive decrease in complexity.

--
fdr