pg-replication-cluster-exporter

Postgres Replication Cluster Exporter

This repository houses pgrc_exporter, a small utility that will connect to all the nodes in a Postgres replication cluster and exports replication lag metrics of each node (Prometheus format).

Inspired by: https://github.com/Qarik-Group/pg-replication-tester - thanks 👍

Metrics

• pgrc_build_info: Program build info
• pgrc_cluster_node_info: Cluster node info
• pgrc_reconnects_count_total: Cluster node reconnects total count
• pgrc_queries_count_total: All queries total count
• pgrc_last_query_seconds: Cluster node last query seconds
• pgrc_current_wal_lsn_bytes: The current write-ahead log write location - SELECT pg_current_wal_lsn()
• pgrc_last_wal_receive_lsn_bytes: The last write-ahead log location that has been received and synced to disk by streaming replication - SELECT pg_last_wal_receive_lsn()
• pgrc_last_wal_replay_lsn_bytes: The last write-ahead log location that has been replayed during recovery - SELECT pg_last_wal_replay_lsn()
• pgrc_receive_lag_bytes: Cluster node receive lag bytes: pg_current_wal_lsn() - pg_last_wal_receive_lsn()
• pgrc_replay_lag_bytes: Cluster node replay lag bytes: pg_last_wal_receive_lsn() - pg_last_wal_reply_lsn()

Options

-A, --address, Address to listens on the TCP network. Default: :9188
-P, --path, Path under which to expose metrics. Default: /metrics
-C, --cluster-name, Cluster name. Default: cluster-hash(nodes)
-n, --node, Replication cluster nodes. May be specified more than once.
-p, --port, TCP port that Postgres listens on. Default: 6432 
-u, --user, User to connect as.
-s, --password, Password to connect with.
-i, --interval, Collecting metrics interval in seconds. Default: 15 
-V, --verbosity, Verbosity level (0 errors, 1 +warnings, 2 +infos, 3 +debugs). Default: 2 
-v, --version, Output version information, then exit.
-h, --help, Show this help, then exit.

Building

GOOS=linux GOARCH=amd64 go build -o pgrc_exporter