Configuration

Pigsty uses IP address as the unique identifier for nodes. This IP should be the internal IP address on which the database instance listens and provides external services.

node-test:
  hosts:
    10.10.10.11: { nodename: node-test-1 }
    10.10.10.12: { nodename: node-test-2 }
    10.10.10.13: { nodename: node-test-3 }
  vars:
    node_cluster: node-test

This IP address must be the address on which the database instance listens and provides external services, but should not be a public IP address. That said, you don’t necessarily have to connect to the database via this IP. For example, managing target nodes indirectly through SSH tunnels or jump hosts is also feasible. However, when identifying database nodes, the primary IPv4 address remains the node’s core identifier. This is critical, and you should ensure this during configuration.

The IP address is the inventory_hostname in the inventory, represented as the key in the <cluster>.hosts object. In addition, each node has two optional identity parameters:

The parameters nodename and node_cluster are optional. If not provided, the node’s existing hostname and the fixed value nodes will be used as defaults. In Pigsty’s monitoring system, these two will be used as the node’s cluster identifier (cls) and instance identifier (ins).

For PGSQL nodes, because Pigsty defaults to a 1:1 exclusive deployment of PG to node, you can use the node_id_from_pg parameter to borrow the PostgreSQL instance’s identity parameters (pg_cluster and pg_seq) for the node’s ins and cls labels. This allows database and node monitoring metrics to share the same labels for cross-analysis.

#nodename:                # [instance] # node instance identity, uses existing hostname if missing, optional
node_cluster: nodes       # [cluster] # node cluster identity, uses 'nodes' if missing, optional
nodename_overwrite: true          # overwrite node's hostname with nodename?
nodename_exchange: false          # exchange nodename among play hosts?
node_id_from_pg: true             # borrow postgres identity as node identity if applicable?

You can also configure rich functionality for host clusters. For example, use HAProxy on the node cluster for load balancing and service exposure, or bind an L2 VIP to the cluster.