Miscellaneous Metrics

The Miscellaneous metrics group provides details on following metrics:

• Connection stats
  • Number of connections against each node
  • Number of locks in each node
• Node role & state
  • Which nodes are running
  • Which node is master
  • Which nodes are replica

Some of the metrics will be hidden depends on types of cluster (single node, or multi node).

Connections stats

Number of connections against each node

This metric displays on all types of clusters. It provides the number of connections against each node in the cluster. Please note that a few of the connections are maintained by instaclustr to perform monitoring, replication and SLA checks.

Number of locks in each node

This metric displays on all types of clusters. It provides a count of the number of open locks across the database cluster.  To see more detailed information (e.g. what kinds of locks are active), open a psql terminal and run:

For further information on locks in Postgresql, see the official documentation.

Node role & state

Which nodes are running

This metric displays on all types of clusters. It provides historical data on which nodes are running. For example, if one of the Postgresql servers in the cluster was restarted as part of maintenance operations, it would return a value of “0” for the period that it was unavailable.

Which node is master

This metric displays on only multi node clusters. It provides historical data on which node is acting as the master for the cluster. In a streaming replication cluster, only one node can accept writes serving as the master and replicating those changes to replicas or standby leader.

For further information on replication, see the official documentation.

Which nodes are replica

This metric displays on only multi node clusters. It provides historical data on which nodes are acting as the replicas for the cluster. In a streaming replication cluster, only one node can accept writes serving as the master and replicating those changes to replicas or standby leader.

For further information on replication, see the official documentation.