What is Postgres replication?
What Is PostgreSQL Replication? The process of copying data from a PostgreSQL database server to another server is called PostgreSQL Replication. The source database server is usually called the Master server, whereas the database server receiving the copied data is called the Replica server.
How does Postgres replication work?
Understanding replication in PostgreSQL Streaming replication in PostgreSQL works on log shipping. Every transaction in postgres is written to a transaction log called WAL (write-ahead log) to achieve durability. A slave uses these WAL segments to continuously replicate changes from its master.
How are replication parameters set on a server?
These parameters can be set on any server that is to send replication data to one or more standby servers. The master is always a sending server, so these parameters must always be set on the master. The role and meaning of these parameters does not change after a standby becomes the master.
Where can I find the availability of replication slots?
You can see the WAL availability of replication slots in pg_replication_slots. Terminate replication connections that are inactive for longer than this amount of time. This is useful for the sending server to detect a standby crash or network outage. If this value is specified without units, it is taken as milliseconds.
When to use a standby server in cascading replication?
When cascading replication (see Section 26.2.7) is used, Standby server (s) can also be senders, as well as receivers. Parameters are mainly for Sending and Standby servers, though some parameters have meaning only on the Master server. Settings may vary across the cluster without problems if that is required.
What are the settings for streaming replication in PostgreSQL?
These settings control the behavior of the built-in streaming replication feature (see Section 26.2.5 ). Servers will be either a master or a standby server. Masters can send data, while standbys are always receivers of replicated data.