Postgres replication repmgr notes

source/resources/apps/repmgr/README.md

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+# repmgr Postgres cluster
+
+https://repmgr.org/docs/repmgr.html
+
+Postgres 11 with streaming replication and backups.
+
+# Servers
+
+pg-oca             --- Master Postgres Server
+pg-oca-rep1        --- Standby Postgres Server
+pg-oca-hdd         --- Standby Postgres Server
+pg-oca-barman      --- Postgres Backup Server
+pg-oca-witness-1   --- Postgres Witness Server
+
+Each server has two ethernet interfaces. One for the VPN for ssh,
+and the second for database backend communication.
+
+# Install
+Add Postgres community repository to each server.
+
+Install Postgres 11 server.
+
+# System Configuration
+
+Configure firewall.
+
+Configure base Postgres 11 server.
+pg_hba.conf and tuning
+
+Configure ssh between nodes.
+Which users?
+
+# repmgr Cluster Configuration
+Set up nodes to communicate.
+
+Node pg-oca is master.
+Node pg-oca-rep1 does streaming replication of pg-oca.
+Node pg-oca-hdd does streaming replication of pg-oca-rep1 and stores to hard disk platters instead of NVMe drives.
+Node pg-oca-barman runs the Postgres barman backup system, and does backups of pg-oca-rep1.
+Node pg-oca-witness-1 is a Postgres witness server. It isn't needed at present.