Node Identity and Identity Parameters

Each node has identity parameters that are configured by parameters in <cluster>.hosts and <cluster>.vars.

There are two important node identity parameters: nodename and node_cluster, which will be used as the node’s instance identity (ins) and cluster identity (cls) in the monitoring system. nodename and node_cluster are NOT REQUIRED since they all have proper default values: Hostname and constant nodes.

Besides, Pigsty uses an IP address as a unique node identifier, too. Which is the inventory_hostname reflected as the key in the <cluster>.hosts object. A node may have multiple interfaces & IP addresses. But you must explicitly designate one as the PRIMARY IP ADDRESS. Which should be an intranet IP for service access. It’s not mandatory to use that same IP address to ssh from the meta node, you can use ssh tunnel & jump server with Ansible Connect parameters.

Name Type Level Attribute Description
inventory_hostname ip - REQUIRED Node IP
nodename string I Optional Node Name
node_cluster string C Optional Node Cluster Name

The following cluster configuration declares a three-node cluster.

  hosts: { nodename: node-test-1 } { pg_hostname: true } # Borrowed identity pg-test-2 {  } # Use the original hostname: node-3
    node_cluster: node-test
host node_cluster nodename instance node-test node-test-1 pg-test-1 node-test pg-test-2 pg-test-2 node-test node-3 pg-test-3

IIn the monitoring system, the time-series monitoring data are labeled as follows.

node_load1{cls="pg-meta", ins="pg-meta-1", ip="", job="nodes"}
node_load1{cls="pg-test", ins="pg-test-1", ip="", job="nodes"}
node_load1{cls="pg-test", ins="pg-test-2", ip="", job="nodes"}
node_load1{cls="pg-test", ins="pg-test-3", ip="", job="nodes"}

Last modified 2022-06-04: fii en docs batch 2 (61bf601)