Re: [tarantool-patches] [PATCH v2 4/4] Introduce replica local spaces

[Vladislav Shpilevoy <v.shpilevoy@tarantool.org>]

On 09/07/2018 18:40, Vladimir Davydov wrote:
> This patch introduces a new space option, group_id, which defines how
> the space is replicated. If it is 0 (default), the space is replicated
> throughout the entire cluster. If it is 1, the space is replica local,
> i.e. all changes made to it are invisible to other replicas in the
> cluster. Currently, no other value is permitted, but in future we will
> use this option for setting up arbitrary replication groups in a
> cluster. The option can only be set on space creation and cannot be
> altered.
> 
> Technically, to support this feature, we introduce a new header key,
> IPROTO_GROUP_ID, which is set to the space group id for all rows
> corresponding to a space, both in xlog and in snap. Relay won't send
> snapshot rows whose group_id is 1. As for xlog rows, they are
> transformed to IPROTO_NOP so as to promote vclock on replicas without
> any actual data modification.
> 
> The feature is currently supported for memtx spaces only, but it should
> be easy to implement it for vinyl spaces as well.
> 
> @TarantoolBot document
> Title: Document new space option - group_id
> Group identifier defines how the space is replicated. Currently, only
> two values are permitted: 0 and 1. If space.group_id is 0, changes made
> to the space are replicated throughout the entire cluster. If it is 1,
> then the space is replica local, i.e. changes made to it are invisible
> to other replicas in the cluster.

Please, put the doc request after 'Closes'. The request must be at the
very end of the commit message.

> 
> Closes #3443
> ---