Thanks for your inputs Laurenz Albe. Would you please explain single-master failover solution.
Suppose we have promoted standby (replica) as master after the h/w issue at Master. If after few hours we recovered the h/w then how we can switchback on the old primary. . As in Oracle we have switchover method for Dataguard. How we can do in Postgres. Thanks, -----Original Message----- From: Laurenz Albe <laurenz.a...@cybertec.at> Sent: Thursday, March 5, 2020 5:37 PM To: Daulat Ram <daulat....@exponential.com>; pgsql-general@lists.postgresql.org Subject: Re: Real application clustering in postgres. On Thu, 2020-03-05 at 07:45 +0000, Daulat Ram wrote: > Is there any possibility/options to setup a real application clustering in > Postgres as in Oracle we have a RAC feature. No, and as far as I know nobody feels interested in providing it. RAC is a complicated architecture that doesn't do much good, so most people feel that it would be a waste of time and effort. RAC ist not really a scaling solution: because of the shared storage, you can only scale for more CPUs; I/O remains the bottleneck. RAC is not really a high availability solution: because of the shared storage, it has a sibgle point of failure. Today, people use shared-nothing architectures for high avaliability, like Patroni. > What about multi-master replication in Postgres. would you please suggest how > it is useful and how can setup it. There is no support for that in core PostgreSQL. There is a closed-source implementation that you can buy: https://www.2ndquadrant.com/en/resources/postgres-bdr-2ndquadrant/ But multi-master replication is complicated to get right, and an applicatoin that uses it has to be specifically designed for that. Very often a single-master failover solution is a better solution. Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com
