added index hits

Author: caarlos0

gauges/hits.go renamed to gauges/blocks.go

@@ -18,3 +18,33 @@ func (g *Gauges) UnusedIndexes() prometheus.Gauge {
 		`,
 	)
 }
+
+func (g *Gauges) IndexBlocksRead() prometheus.Gauge {
+	return g.new(
+		prometheus.GaugeOpts{
+			Name:        "postgresql_index_blks_read_sum",
+			Help:        "Sum of the number of disk blocks read from all public indexes",
+			ConstLabels: g.labels,
+		},
+		`
+			SELECT coalesce(sum(idx_blks_read), 0)
+			FROM pg_statio_all_indexes
+			WHERE schemaname = 'public'
+		`,
+	)
+}
+
+func (g *Gauges) IndexBlocksHit() prometheus.Gauge {
+	return g.new(
+		prometheus.GaugeOpts{
+			Name:        "postgresql_index_blks_hit_sum",
+			Help:        "Sum of the number of buffer hits on all public indexes",
+			ConstLabels: g.labels,
+		},
+		`
+			SELECT coalesce(sum(idx_blks_hit), 0)
+			FROM pg_statio_all_indexes
+			WHERE schemaname = 'public'
+		`,
+	)
+}

gauges/hits_test.go renamed to gauges/blocks_test.go

@@ -14,3 +14,21 @@ func TestUnusedIndexes(t *testing.T) {
 	assert.Len(metrics, 1)
 	assertGreaterThan(t, -1, metrics[0])
 }
+
+func TestIndexBlocksRead(t *testing.T) {
+	var assert = assert.New(t)
+	_, gauges, close := prepare(t)
+	defer close()
+	var metrics = evaluate(t, gauges.IndexBlocksRead())
+	assert.Len(metrics, 1)
+	assertGreaterThan(t, -1, metrics[0])
+}
+
+func TestIndexBlocksHit(t *testing.T) {
+	var assert = assert.New(t)
+	_, gauges, close := prepare(t)
+	defer close()
+	var metrics = evaluate(t, gauges.IndexBlocksHit())
+	assert.Len(metrics, 1)
+	assertGreaterThan(t, -1, metrics[0])
+}

gauges/indexes.go

@@ -80,6 +80,8 @@ func watch(db *sql.DB, reg prometheus.Registerer, name string) {
 	reg.MustRegister(gauges.ScheduledCheckpoints())
 	reg.MustRegister(gauges.HeapBlocksHit())
 	reg.MustRegister(gauges.HeapBlocksRead())
+	reg.MustRegister(gauges.IndexBlocksHit())
+	reg.MustRegister(gauges.IndexBlocksRead())
 	reg.MustRegister(gauges.DeadTuples())
 	reg.MustRegister(gauges.TempSize())
 	reg.MustRegister(gauges.TempFiles())