middleware/metrics: log qtype as well

middleware/metrics/README.md

@@ -9,13 +9,17 @@ The following metrics are exported:
 * coredns_dns_request_duration_seconds
 * coredns_dns_request_size_bytes
 * coredns_dns_request_do_count_total
+* coredns_dns_request_type_count_total
 * coredns_dns_response_size_bytes
 * coredns_dns_response_rcode_count_total
 
 Each counter has a label `zone` which is the zonename used for the request/response. and a label
 `qtype` which old the query type. The `dns_request_count_total` has extra labels: `proto` which
 holds the transport of the response ("udp" or "tcp") and the address family of the transport (1
-= IP (IP version 4), 2 = IP6 (IP version 6)).
+= IP (IP version 4), 2 = IP6 (IP version 6)). And `type_count_total` hold a per RR type counter, it
+holds the most common ones (A, AAAA, MX, SOA, CNAME, PTR, TXT, NS, SRV, DS, DNSKEY, RRSIG, NSEC,
+NSEC3) and "other" which lumps together all other types.
+
 The `response_rcode_count_total` has an extra label `rcode` which holds the rcode of the response.
 The `*_size_bytes` counters also hold the protocol in the `proto` label ("udp" or "tcp").
 

middleware/metrics/handler.go

@@ -48,7 +48,32 @@ func Report(state middleware.State, zone, rcode string, size int, start time.Tim
 	if state.Do() {
 		requestDo.WithLabelValues(zone).Inc()
 	}
+	typ := state.QType()
+	if _, known := monitorType[typ]; known {
+		requestType.WithLabelValues(zone, dns.Type(typ).String())
+	} else {
+		requestType.WithLabelValues(zone, other)
+	}
 
 	responseSize.WithLabelValues(zone, net).Observe(float64(size))
 	responseRcode.WithLabelValues(zone, rcode).Inc()
 }
+
+var monitorType = map[uint16]bool{
+	dns.TypeAAAA:   true,
+	dns.TypeA:      true,
+	dns.TypeCNAME:  true,
+	dns.TypeDNSKEY: true,
+	dns.TypeDS:     true,
+	dns.TypeMX:     true,
+	dns.TypeNSEC3:  true,
+	dns.TypeNSEC:   true,
+	dns.TypeNS:     true,
+	dns.TypePTR:    true,
+	dns.TypeRRSIG:  true,
+	dns.TypeSOA:    true,
+	dns.TypeSRV:    true,
+	dns.TypeTXT:    true,
+}
+
+const other = "other"

middleware/metrics/metrics.go

@@ -16,6 +16,7 @@ var (
 	requestDuration *prometheus.HistogramVec
 	requestSize     *prometheus.HistogramVec
 	requestDo       *prometheus.CounterVec
+	requestType     *prometheus.CounterVec
 
 	responseSize  *prometheus.HistogramVec
 	responseRcode *prometheus.CounterVec
@@ -47,6 +48,8 @@ func (m *Metrics) Start() error {
 		prometheus.MustRegister(requestDuration)
 		prometheus.MustRegister(requestSize)
 		prometheus.MustRegister(requestDo)
+		prometheus.MustRegister(requestType)
+
 		prometheus.MustRegister(responseSize)
 		prometheus.MustRegister(responseRcode)
 
@@ -97,6 +100,13 @@ func define() {
 		Help:      "Counter of DNS requests with DO bit set per zone.",
 	}, []string{"zone"})
 
+	requestType = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: middleware.Namespace,
+		Subsystem: subsystem,
+		Name:      "request_type_count_total",
+		Help:      "Counter of DNS requests per type, per zone.",
+	}, []string{"zone", "type"})
+
 	responseSize = prometheus.NewHistogramVec(prometheus.HistogramOpts{
 		Namespace: middleware.Namespace,
 		Subsystem: subsystem,