From 98ac25743bd502db2c9e6419518c3143bb584118 Mon Sep 17 00:00:00 2001
From: James Campbell <james@shh-dot-com.org>
Date: Sat, 19 Apr 2025 02:33:48 -0400
Subject: [PATCH] Add queries for replication slot monitoring

---
 sample-config/pgmon-metrics.yml | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/sample-config/pgmon-metrics.yml b/sample-config/pgmon-metrics.yml
index 3c38391..c72c786 100644
--- a/sample-config/pgmon-metrics.yml
+++ b/sample-config/pgmon-metrics.yml
@@ -8,6 +8,10 @@ metrics:
     type: set
     query:
       0: SELECT client_addr || '_' || regexp_replace(application_name, '[ ,]', '_', 'g') AS repid, client_addr, state FROM pg_stat_replication
+  discover_slots:
+    type: set
+    query:
+      0: SELECT slot_name, plugin, slot_type, database, temporary, active FROM pg_replication_slots
 
   # cluster-wide metrics
   version:
@@ -43,3 +47,9 @@ metrics:
     type: value
     query:
       0: SELECT now(), pg_sleep(5);
+
+  # Per-slot metrics
+  slot_stats:
+    type: row
+    query:
+      0: SELECT active_pid, xmin, pg_wal_lsn_diff(pg_current_wal_lsn(), restart_lsn) AS restart_bytes, pg_wal_lsn_diff(pg_current_wal_lsn(), confirmed_flush_lsn) AS confirmed_flush_bytes FROM pg_replication_slots WHERE slot_name = '{slot}'