The Replication metrics group provides details on:
Which nodes are Replicas
The Replication Slot metrics group provides details on:
Last LSN Sent to each replica
Current LSN & Last LSN Received
The Log Sequence Number (LSN) indicates the insert position of transactions in the Write Ahead Log (WAL). The Current LSN metric shows the position of the latest transaction for the cluster.
Shows the latest LSN received by each replica in the cluster. Ideally, this value should closely follow the Current LSN metric.
Provides historical data on which nodes are acting as replicas. A value of “1” indicates that a node is a replica, whereas a value of “0” indicates that the node is not in recovery mode (e.g. it may be acting as the master).
Last LSN Sent
Provides historical data on the last transaction sent by the master to a replica. Ideally, this should closely follow the Current LSN metric.