Resource relationships in Managed Service for PostgreSQL

The main entity used in the Managed Service for PostgreSQL service is a database cluster.

Each cluster consists of one or more database hosts, which are virtual machines with DBMS servers deployed on them. Cluster hosts may reside in different availability zones. You can learn more about Yandex Cloud availability zones here.

• A cluster with multiple hosts features automatic failover: one of the replica hosts becomes master if the current master host is down.

  A replica that has an explicitly specified replication thread source cannot take the master role. To learn more, see Replication.

• The cost of a single-host cluster is lower, but it does not guarantee fault tolerance.

• The minimum number of hosts in a cluster depends on the selected disk type.

A cluster's computing capacity depends on its host class, which is the virtual machine template used to deploy the cluster's hosts. For a list of available host classes and their specs, see Host classes.

To manage connections and balance the cluster load, the service architecture features the Odyssey connection pooler. For more information, see Managing connections.

A cluster created in a folder can be accessed by all VMs connected to the same cloud network. For more information about networking, see the Virtual Private Cloud documentation.