Re: How does BDR replicate changes among nodes in a BDR group

Thanks for the clarification.

A follow up question, then, given *once joined all nodes are equal*, is that:

should the node A dies or taken out of the group, the remaining three node group (with B, C and D) would continue to function properly, correct?
[somewhere I saw the term "downstream" nodes was used, and I am not clear what that meant in the context of a mesh-connected group]

Thanks again

-----Original Message-----
From: Craig Ringer [mailto:craig(at)2ndquadrant(dot)com]
Sent: Wednesday, June 07, 2017 5:59 PM
To: Zhu, Joshua <jzhu(at)thalesesec(dot)net>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: [GENERAL] How does BDR replicate changes among nodes in a BDR group

On 8 June 2017 at 04:50, Zhu, Joshua <jzhu(at)vormetric(dot)com> wrote:

> How does BDR replicate a change delta on A to B, C, and D?

It's a mesh.

Once joined, it doesn't matter what the join node was, all nodes are equal.

> e.g., A
> replicates delta to B and D, and B to C, or some other way, or not
> statically determined?

Each node replicates to all other nodes in an undefined order determined by network timing etc.

--
Craig Ringer http://www.2ndQuadrant.com/
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