Merge pull request #1 from yanboer/release-v0.12.1

adjust pg_replication_slots metrics

Author: zlianzhuang

cmd/postgres_exporter/queries.go

@@ -112,8 +112,9 @@ var queryOverrides = map[string][]OverrideQuery{
 		{
 			semver.MustParseRange(">=10.0.0"),
 			`
-			SELECT slot_name, database, active, pg_wal_lsn_diff(pg_current_wal_lsn(), restart_lsn)
-			FROM pg_replication_slots
+			SELECT slot_name, database, active, 
+			       (case pg_is_in_recovery() when 't' then pg_last_wal_receive_lsn() - restart_lsn else pg_current_wal_lsn() - restart_lsn end) as pg_wal_lsn_diff
+			FROM pg_replication_slots;
 			`,
 		},
 	},

collector/replication_slots.go

@@ -53,9 +53,9 @@ var pgReplicationSlot = map[string]*prometheus.Desc{
 
 func (PGReplicationSlotCollector) Update(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	rows, err := db.QueryContext(ctx,
-		`SELECT
+		`SELECT 
 			slot_name,
-			pg_current_wal_lsn() - '0/0' AS current_wal_lsn,
+			(case pg_is_in_recovery() when 't' then pg_last_wal_receive_lsn() - '0/0' else pg_current_wal_lsn() - '0/0' end) as current_wal_lsn,
 			coalesce(confirmed_flush_lsn, '0/0') - '0/0',
 			active
 		FROM