On 2022-08-04 07:43:28 +0000, Sacheen Birhade wrote: > I have a very basic question about streaming replication feature of Postgres. > Let’s assume I have servers A, B, C, D, & E with postgres installed with > streaming replication as follow: > A à B ( sync replication ) > A à C ( async replication ) > A à D ( async replication ) > A à E ( async replication ) > A is master & rest are slaves. > > Now my question is: > Assume replication link between A & B may/may not stable. Using sync replication on an unstable link is probably not a good idea. Every time the link goes down, A freezes. Is this what you want? > If A goes down, how will I choose my new master from slaves? What are > criteria to choose new master? I would prefer B over the others because it is in sync with A, so you don't lose data. All the other ones might. Otherwise: For the same reason I would prefer B, I would prefer the one with the most up-to-date data. But there might be other considerations, e.g. the network connections (bandwidth and delays) between the surviving members and the clients. hp -- _ | Peter J. Holzer | Story must make more sense than reality. |_|_) | | | | | hjp@xxxxxx | -- Charles Stross, "Creative writing __/ | http://www.hjp.at/ | challenge!"
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