what happens while node is decommissioning ?

[DE VITO Dominique <do...@thalesgroup.com>]

> > De : Tyler Hobbs [mailto:tyler@datastax.com]
> > Envoyé : mardi 16 octobre 2012 17:04
> > À : user@cassandra.apache.org
> > Objet : Re: what happens while node is bootstrapping?
> >
> > On Mon, Oct 15, 2012 at 3:50 PM, Andrey Ilinykh <ai...@gmail.com> wrote:
> > Does it mean that during bootstrapping process only replicas serve
> > read requests for new node range? In other words, replication factor
> > is RF-1?
>
> No.  The bootstrapping node will writes for its new range while bootstrapping as consistency optimization (more or less), but does not contribute to the replication factor or consistency level; all of the original replicas for that range still receive writes, serve reads, and are the nodes that count for consistency level.  Basically, the bootstrapping node has no effect on the existing replicas in terms of RF or CL until the bootstrap completes.
>
> --
> Tyler Hobbs
> DataStax

Is it symmetric for the decommission ?

Well, is it correct that:
- during a decommission, all of the original replicas for that range still receive writes, serve reads, and are the nodes that count for consistency level ?
- and so, basically, the decommissioning node has no effect on the existing replicas in terms of RF or CL until the end of decommission ?
- as a consistency optimization, all the new replicas will receive too the writes ?

Thanks.

Regards,
Dominique