metrics: add prometheus-based libp2p and awl-specific metrics

README.md

@@ -200,6 +200,12 @@ Tip: you can force using config file in the same directory with executable by cr
 
 It is not recommended to amend config file while application is still running.
 
+## Monitoring
+
+AWL includes built-in Prometheus metrics support. You can access the metrics endpoint at `http://localhost:8639/metrics`.
+
+A pre-packaged monitoring stack with Prometheus and Grafana dashboards is available in the [monitoring/](monitoring/) directory. See [monitoring/README.md](monitoring/README.md) for setup instructions.
+
 ## Terminal based client
 
 Both `awl` and `awl-tray` versions have CLI to communicate with vpn server.
@@ -262,12 +268,6 @@ systemctl restart awl
 
 As alternative, on Desktop/Server you can download new version from [releases page](https://github.com/anywherelan/awl/releases) and manually replace old files with new ones.
 
-# Roadmap
-
-- performance improvements for vpn tunnel protocol
-- exit nodes - let you route all internet traffic through other peers
-- add support for awl dns for android ([#17](https://github.com/anywherelan/awl/issues/17))
-
 # Contributing
 
 Contributions to this repository are very welcome.

api/api.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/go-playground/validator/v10"
 	"github.com/ipfs/go-log/v2"
+	"github.com/labstack/echo-contrib/echoprometheus"
 	"github.com/labstack/echo/v4"
 	"github.com/labstack/echo/v4/middleware"
 
@@ -79,6 +80,15 @@ func (h *Handler) SetupAPI() error {
 	return nil
 }
 
+// use global to register metric only once
+var metricsMiddleware = echoprometheus.NewMiddlewareWithConfig(
+	echoprometheus.MiddlewareConfig{
+		Namespace: "awl",
+		Subsystem: "api",
+	},
+)
+var metricsHandler = echoprometheus.NewHandler()
+
 func (h *Handler) setupRouter(address string) (*echo.Echo, error) {
 	e := echo.New()
 	e.HideBanner = true
@@ -98,6 +108,10 @@ func (h *Handler) setupRouter(address string) (*echo.Echo, error) {
 
 	// Routes
 
+	// Metrics
+	e.Use(metricsMiddleware)
+	e.GET("/metrics", metricsHandler)
+
 	// Peers
 	e.GET(GetKnownPeersPath, h.GetKnownPeers)
 	e.POST(GetKnownPeerSettingsPath, h.GetKnownPeerSettings)

application.go

@@ -19,9 +19,11 @@ import (
 	dssync "github.com/ipfs/go-datastore/sync"
 	"github.com/ipfs/go-log/v2"
 	"github.com/libp2p/go-libp2p"
+	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/libp2p/go-libp2p/p2p/host/eventbus"
 	"github.com/libp2p/go-libp2p/p2p/host/peerstore/pstoremem"
 	rcmgr "github.com/libp2p/go-libp2p/p2p/host/resource-manager"
+	"github.com/prometheus/client_golang/prometheus"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
 	"golang.zx2c4.com/wireguard/tun"
@@ -30,6 +32,7 @@ import (
 	"github.com/anywherelan/awl/awldns"
 	"github.com/anywherelan/awl/awlevent"
 	"github.com/anywherelan/awl/config"
+	"github.com/anywherelan/awl/metrics"
 	"github.com/anywherelan/awl/p2p"
 	"github.com/anywherelan/awl/protocol"
 	"github.com/anywherelan/awl/ringbuffer"
@@ -160,6 +163,11 @@ func (a *Application) Init(ctx context.Context, tunDevice tun.Device) error {
 		}
 	}
 
+	// Metrics
+	metrics.SetNodeInfo(config.Version, p2pHost.ID().String())
+	cma := &configMetricsAdapter{conf: a.Conf, authStatus: a.AuthStatus, p2p: a.P2p}
+	go metrics.StartBackgroundUpdater(a.ctx, cma, a.P2p)
+
 	a.logger.Info("Application initialized successfully")
 
 	return nil
@@ -288,6 +296,7 @@ func (a *Application) makeP2pHostConfig() p2p.HostConfig {
 			libp2p.ResourceManager(mgr),
 			libp2p.EnableHolePunching(),
 			libp2p.NATPortMap(),
+			libp2p.PrometheusRegisterer(prometheus.DefaultRegisterer),
 		}, a.ExtraLibp2pOpts...),
 		ConnManager: struct {
 			LowWater    int
@@ -414,3 +423,38 @@ func (a *DNSService) AwlDNSAddress() string {
 func (a *DNSService) IsAwlDNSSetAsSystem() bool {
 	return a.isAwlDNSSetAsSystem
 }
+
+// configMetricsAdapter implements metrics.ConfigMetrics by combining Config and AuthStatus.
+type configMetricsAdapter struct {
+	conf       *config.Config
+	authStatus *service.AuthStatus
+	p2p        *p2p.P2p
+}
+
+func (a *configMetricsAdapter) GetKnownPeersSnapshot() (total, confirmed, connected int, peerIDs []peer.ID) {
+	a.conf.RLock()
+	defer a.conf.RUnlock()
+	total = len(a.conf.KnownPeers)
+	peerIDs = make([]peer.ID, 0, total)
+	for _, kp := range a.conf.KnownPeers {
+		pid := kp.PeerId()
+		peerIDs = append(peerIDs, pid)
+		if kp.Confirmed {
+			confirmed++
+		}
+		if a.p2p.IsConnected(pid) {
+			connected++
+		}
+	}
+	return
+}
+
+func (a *configMetricsAdapter) GetBlockedPeersCount() int {
+	a.conf.RLock()
+	defer a.conf.RUnlock()
+	return len(a.conf.BlockedPeers)
+}
+
+func (a *configMetricsAdapter) GetAuthRequestCounts() (ingoing, outgoing int) {
+	return a.authStatus.GetAuthRequestCounts()
+}

application_test.go

@@ -881,3 +881,36 @@ func BenchmarkTunnelPackets(b *testing.B) {
 		})
 	}
 }
+
+func TestMetricsEndpoint(t *testing.T) {
+	// NOTE: all tests use the same metrics register - so we can't rely on metrics values here
+	ts := NewTestSuite(t)
+
+	peer1 := ts.NewTestPeer(true)
+
+	// Make some API requests first so counter metrics get populated
+	_, _ = peer1.api.PeerInfo()
+
+	// Query the /metrics endpoint
+	metricsURL := fmt.Sprintf("http://%s/metrics", peer1.app.Api.Address())
+	resp, err := http.Get(metricsURL) //nolint:gosec
+	ts.NoError(err)
+	defer resp.Body.Close()
+
+	ts.Equal(http.StatusOK, resp.StatusCode)
+
+	body, err := io.ReadAll(resp.Body)
+	ts.NoError(err)
+
+	metricsOutput := string(body)
+
+	// Verify AWL-specific metrics are present
+	ts.Contains(metricsOutput, "awl_node_info")
+	ts.Contains(metricsOutput, "awl_node_start_timestamp")
+	ts.Contains(metricsOutput, "awl_node_uptime_seconds")
+	ts.Contains(metricsOutput, "awl_peers_known_total")
+	ts.Contains(metricsOutput, "awl_api_request_duration_seconds_bucket")
+
+	// Verify libp2p built-in metrics are present
+	ts.Contains(metricsOutput, "libp2p_")
+}

awldns/awldns.go

@@ -9,6 +9,8 @@ import (
 
 	"github.com/ipfs/go-log/v2"
 	"github.com/miekg/dns"
+
+	"github.com/anywherelan/awl/metrics"
 )
 
 const (
@@ -142,6 +144,12 @@ func (r *Resolver) Close() {
 }
 
 func (r *Resolver) dnsLocalDomainHandler(resp dns.ResponseWriter, req *dns.Msg) {
+	metrics.DNSQueriesTotal.WithLabelValues("awl").Inc()
+	start := time.Now()
+	defer func() {
+		metrics.DNSQueryDurationSeconds.Observe(time.Since(start).Seconds())
+	}()
+
 	if len(req.Question) == 0 {
 		return
 	}
@@ -183,6 +191,12 @@ func (r *Resolver) dnsLocalDomainHandler(resp dns.ResponseWriter, req *dns.Msg)
 }
 
 func (r *Resolver) ptrv4Handler(resp dns.ResponseWriter, req *dns.Msg) {
+	metrics.DNSQueriesTotal.WithLabelValues("awl_ptr").Inc()
+	start := time.Now()
+	defer func() {
+		metrics.DNSQueryDurationSeconds.Observe(time.Since(start).Seconds())
+	}()
+
 	if len(req.Question) == 0 || req.Question[0].Qtype != dns.TypePTR {
 		r.dnsProxyHandler(resp, req)
 		return
@@ -222,6 +236,12 @@ func (r *Resolver) ptrv4Handler(resp dns.ResponseWriter, req *dns.Msg) {
 }
 
 func (r *Resolver) dnsProxyHandler(resp dns.ResponseWriter, req *dns.Msg) {
+	metrics.DNSQueriesTotal.WithLabelValues("proxy").Inc()
+	start := time.Now()
+	defer func() {
+		metrics.DNSQueryDurationSeconds.Observe(time.Since(start).Seconds())
+	}()
+
 	cfg := r.loadConfig()
 
 	dnsClient := r.udpClient
@@ -231,6 +251,7 @@ func (r *Resolver) dnsProxyHandler(resp dns.ResponseWriter, req *dns.Msg) {
 
 	upstreamResp, _, err := dnsClient.Exchange(req, cfg.upstreamDNS)
 	if err != nil {
+		metrics.DNSQueryErrorsTotal.Inc()
 		r.logger.Warnf("send request to upstream dns: %v", err)
 		m := new(dns.Msg)
 		m.SetRcode(req, dns.RcodeServerFailure)

cmd/awl-tray/go.mod

@@ -66,7 +66,8 @@ require (
 	github.com/josharian/native v1.1.1-0.20230202152459-5c7d0dd6ab86 // indirect
 	github.com/klauspost/cpuid/v2 v2.3.0 // indirect
 	github.com/koron/go-ssdp v0.0.6 // indirect
-	github.com/labstack/echo/v4 v4.14.0 // indirect
+	github.com/labstack/echo-contrib v0.50.1 // indirect
+	github.com/labstack/echo/v4 v4.15.0 // indirect
 	github.com/labstack/gommon v0.4.2 // indirect
 	github.com/leodido/go-urn v1.4.0 // indirect
 	github.com/libp2p/go-buffer-pool v0.1.0 // indirect
@@ -128,8 +129,8 @@ require (
 	github.com/polydawn/refmt v0.89.0 // indirect
 	github.com/prometheus/client_golang v1.23.2 // indirect
 	github.com/prometheus/client_model v0.6.2 // indirect
-	github.com/prometheus/common v0.66.1 // indirect
-	github.com/prometheus/procfs v0.17.0 // indirect
+	github.com/prometheus/common v0.67.5 // indirect
+	github.com/prometheus/procfs v0.19.2 // indirect
 	github.com/quic-go/qpack v0.6.0 // indirect
 	github.com/quic-go/quic-go v0.59.0 // indirect
 	github.com/quic-go/webtransport-go v0.10.0 // indirect

cmd/awl-tray/go.sum

@@ -122,6 +122,8 @@ github.com/josharian/native v1.1.1-0.20230202152459-5c7d0dd6ab86 h1:elKwZS1OcdQ0
 github.com/josharian/native v1.1.1-0.20230202152459-5c7d0dd6ab86/go.mod h1:aFAMtuldEgx/4q7iSGazk22+IcgvtiC+HIimFO9XlS8=
 github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
 github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
+github.com/klauspost/compress v1.18.0 h1:c/Cqfb0r+Yi+JtIEq73FWXVkRonBlf0CRNYc8Zttxdo=
+github.com/klauspost/compress v1.18.0/go.mod h1:2Pp+KzxcywXVXMr50+X0Q/Lsb43OQHYWRCY2AiWywWQ=
 github.com/klauspost/cpuid/v2 v2.3.0 h1:S4CRMLnYUhGeDFDqkGriYKdfoFlDnMtqTiI/sFzhA9Y=
 github.com/klauspost/cpuid/v2 v2.3.0/go.mod h1:hqwkgyIinND0mEev00jJYCxPNVRVXFQeu1XKlok6oO0=
 github.com/koron/go-ssdp v0.0.6 h1:Jb0h04599eq/CY7rB5YEqPS83HmRfHP2azkxMN2rFtU=
@@ -133,8 +135,12 @@ github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
-github.com/labstack/echo/v4 v4.14.0 h1:+tiMrDLxwv6u0oKtD03mv+V1vXXB3wCqPHJqPuIe+7M=
-github.com/labstack/echo/v4 v4.14.0/go.mod h1:xmw1clThob0BSVRX1CRQkGQ/vjwcpOMjQZSZa9fKA/c=
+github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
+github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
+github.com/labstack/echo-contrib v0.50.1 h1:W9cZZ9viA4TDdFtm8cuA+XGFwOcnfbjJpl7VgfsRLHE=
+github.com/labstack/echo-contrib v0.50.1/go.mod h1:8r/++U/Fw/QniApFnzunLanKaviPfBX7fX7/2QX0qOk=
+github.com/labstack/echo/v4 v4.15.0 h1:hoRTKWcnR5STXZFe9BmYun9AMTNeSbjHi2vtDuADJ24=
+github.com/labstack/echo/v4 v4.15.0/go.mod h1:xmw1clThob0BSVRX1CRQkGQ/vjwcpOMjQZSZa9fKA/c=
 github.com/labstack/gommon v0.4.2 h1:F8qTUNXgG1+6WQmqoUWnz8WiEU60mXVVw0P4ht1WRA0=
 github.com/labstack/gommon v0.4.2/go.mod h1:QlUFxVM+SNXhDL/Z7YhocGIBYOiwB0mXm1+1bAPHPyU=
 github.com/leodido/go-urn v1.4.0 h1:WT9HwE9SGECu3lg4d/dIA+jxlljEa1/ffXKmRjqdmIQ=
@@ -277,10 +283,10 @@ github.com/prometheus/client_golang v1.23.2 h1:Je96obch5RDVy3FDMndoUsjAhG5Edi49h
 github.com/prometheus/client_golang v1.23.2/go.mod h1:Tb1a6LWHB3/SPIzCoaDXI4I8UHKeFTEQ1YCr+0Gyqmg=
 github.com/prometheus/client_model v0.6.2 h1:oBsgwpGs7iVziMvrGhE53c/GrLUsZdHnqNwqPLxwZyk=
 github.com/prometheus/client_model v0.6.2/go.mod h1:y3m2F6Gdpfy6Ut/GBsUqTWZqCUvMVzSfMLjcu6wAwpE=
-github.com/prometheus/common v0.66.1 h1:h5E0h5/Y8niHc5DlaLlWLArTQI7tMrsfQjHV+d9ZoGs=
-github.com/prometheus/common v0.66.1/go.mod h1:gcaUsgf3KfRSwHY4dIMXLPV0K/Wg1oZ8+SbZk/HH/dA=
-github.com/prometheus/procfs v0.17.0 h1:FuLQ+05u4ZI+SS/w9+BWEM2TXiHKsUQ9TADiRH7DuK0=
-github.com/prometheus/procfs v0.17.0/go.mod h1:oPQLaDAMRbA+u8H5Pbfq+dl3VDAvHxMUOVhe0wYB2zw=
+github.com/prometheus/common v0.67.5 h1:pIgK94WWlQt1WLwAC5j2ynLaBRDiinoAb86HZHTUGI4=
+github.com/prometheus/common v0.67.5/go.mod h1:SjE/0MzDEEAyrdr5Gqc6G+sXI67maCxzaT3A2+HqjUw=
+github.com/prometheus/procfs v0.19.2 h1:zUMhqEW66Ex7OXIiDkll3tl9a1ZdilUOd/F6ZXw4Vws=
+github.com/prometheus/procfs v0.19.2/go.mod h1:M0aotyiemPhBCM0z5w87kL22CxfcH05ZpYlu+b4J7mw=
 github.com/pymq/zenity v0.0.0-20230509161854-c117c448544d h1:vrhQkfRgAGr/dUCtJ3bUg16FbHjw6Yl8CKz0eF9NdeM=
 github.com/pymq/zenity v0.0.0-20230509161854-c117c448544d/go.mod h1:FzjqP1loicusCFJTdIt5Oqbmoj2zySHpM0RsgJeeCbk=
 github.com/quic-go/qpack v0.6.0 h1:g7W+BMYynC1LbYLSqRt8PBg5Tgwxn214ZZR34VIOjz8=

go.mod

@@ -15,7 +15,8 @@ require (
 	github.com/haxii/socks5 v1.0.0
 	github.com/ipfs/go-datastore v0.9.0
 	github.com/ipfs/go-log/v2 v2.9.1
-	github.com/labstack/echo/v4 v4.14.0
+	github.com/labstack/echo-contrib v0.50.1
+	github.com/labstack/echo/v4 v4.15.0
 	github.com/libp2p/go-libp2p v0.47.0
 	github.com/libp2p/go-libp2p-kad-dht v0.37.1
 	github.com/libp2p/go-libp2p-kbucket v0.8.0
@@ -27,6 +28,7 @@ require (
 	github.com/multiformats/go-multiaddr v0.16.1
 	github.com/multiformats/go-multistream v0.6.1
 	github.com/olekukonko/tablewriter v0.0.5
+	github.com/prometheus/client_golang v1.23.2
 	github.com/quic-go/quic-go v0.59.0
 	github.com/stretchr/testify v1.11.1
 	github.com/urfave/cli/v2 v2.27.7
@@ -123,10 +125,9 @@ require (
 	github.com/pion/webrtc/v4 v4.1.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/polydawn/refmt v0.89.0 // indirect
-	github.com/prometheus/client_golang v1.23.2 // indirect
 	github.com/prometheus/client_model v0.6.2 // indirect
-	github.com/prometheus/common v0.66.1 // indirect
-	github.com/prometheus/procfs v0.17.0 // indirect
+	github.com/prometheus/common v0.67.5 // indirect
+	github.com/prometheus/procfs v0.19.2 // indirect
 	github.com/quic-go/qpack v0.6.0 // indirect
 	github.com/quic-go/webtransport-go v0.10.0 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect

go.sum

@@ -101,6 +101,8 @@ github.com/josharian/native v1.1.1-0.20230202152459-5c7d0dd6ab86 h1:elKwZS1OcdQ0
 github.com/josharian/native v1.1.1-0.20230202152459-5c7d0dd6ab86/go.mod h1:aFAMtuldEgx/4q7iSGazk22+IcgvtiC+HIimFO9XlS8=
 github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
 github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
+github.com/klauspost/compress v1.18.0 h1:c/Cqfb0r+Yi+JtIEq73FWXVkRonBlf0CRNYc8Zttxdo=
+github.com/klauspost/compress v1.18.0/go.mod h1:2Pp+KzxcywXVXMr50+X0Q/Lsb43OQHYWRCY2AiWywWQ=
 github.com/klauspost/cpuid/v2 v2.3.0 h1:S4CRMLnYUhGeDFDqkGriYKdfoFlDnMtqTiI/sFzhA9Y=
 github.com/klauspost/cpuid/v2 v2.3.0/go.mod h1:hqwkgyIinND0mEev00jJYCxPNVRVXFQeu1XKlok6oO0=
 github.com/koron/go-ssdp v0.0.6 h1:Jb0h04599eq/CY7rB5YEqPS83HmRfHP2azkxMN2rFtU=
@@ -112,8 +114,12 @@ github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
-github.com/labstack/echo/v4 v4.14.0 h1:+tiMrDLxwv6u0oKtD03mv+V1vXXB3wCqPHJqPuIe+7M=
-github.com/labstack/echo/v4 v4.14.0/go.mod h1:xmw1clThob0BSVRX1CRQkGQ/vjwcpOMjQZSZa9fKA/c=
+github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
+github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
+github.com/labstack/echo-contrib v0.50.1 h1:W9cZZ9viA4TDdFtm8cuA+XGFwOcnfbjJpl7VgfsRLHE=
+github.com/labstack/echo-contrib v0.50.1/go.mod h1:8r/++U/Fw/QniApFnzunLanKaviPfBX7fX7/2QX0qOk=
+github.com/labstack/echo/v4 v4.15.0 h1:hoRTKWcnR5STXZFe9BmYun9AMTNeSbjHi2vtDuADJ24=
+github.com/labstack/echo/v4 v4.15.0/go.mod h1:xmw1clThob0BSVRX1CRQkGQ/vjwcpOMjQZSZa9fKA/c=
 github.com/labstack/gommon v0.4.2 h1:F8qTUNXgG1+6WQmqoUWnz8WiEU60mXVVw0P4ht1WRA0=
 github.com/labstack/gommon v0.4.2/go.mod h1:QlUFxVM+SNXhDL/Z7YhocGIBYOiwB0mXm1+1bAPHPyU=
 github.com/leodido/go-urn v1.4.0 h1:WT9HwE9SGECu3lg4d/dIA+jxlljEa1/ffXKmRjqdmIQ=
@@ -254,10 +260,10 @@ github.com/prometheus/client_golang v1.23.2 h1:Je96obch5RDVy3FDMndoUsjAhG5Edi49h
 github.com/prometheus/client_golang v1.23.2/go.mod h1:Tb1a6LWHB3/SPIzCoaDXI4I8UHKeFTEQ1YCr+0Gyqmg=
 github.com/prometheus/client_model v0.6.2 h1:oBsgwpGs7iVziMvrGhE53c/GrLUsZdHnqNwqPLxwZyk=
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metrics/dns.go

@@ -0,0 +1,30 @@
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var (
+	DNSQueriesTotal = promauto.NewCounterVec(prometheus.CounterOpts{
+		Namespace: namespace,
+		Subsystem: "dns",
+		Name:      "queries_total",
+		Help:      "Total DNS queries handled.",
+	}, []string{"handler"})
+
+	DNSQueryErrorsTotal = promauto.NewCounter(prometheus.CounterOpts{
+		Namespace: namespace,
+		Subsystem: "dns",
+		Name:      "query_errors_total",
+		Help:      "Total DNS query errors (upstream failures).",
+	})
+
+	DNSQueryDurationSeconds = promauto.NewHistogram(prometheus.HistogramOpts{
+		Namespace: namespace,
+		Subsystem: "dns",
+		Name:      "query_duration_seconds",
+		Help:      "DNS query duration in seconds.",
+		Buckets:   []float64{0.001, 0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 10},
+	})
+)