metrics: use VictoriaMetrics instead of prometheus/client_golang

Most notably:
* the syntax is much simpler (no Register, less verbose calls)
* now we can Get metrics (concurrent-safe, along with Set), so:
  * data/ipfs/metrics.go now uses Set and Get instead of atomic.Float64
  * vochaininfo also uses Set and Get for most metrics, out of vi.lock.Lock()

Additional changes:
* drop metric vochain_vote_tree_increase_last_minute
* drop package `go.vocdoni.io/dvote/metrics` altogether
* unify types of vochaininfo to uint64
* drop vs.MetricsAgent field

api/api_types.go

@@ -198,7 +198,7 @@ type GenericTransactionWithInfo struct {
 
 type ChainInfo struct {
 	ID                      string    `json:"chainId" example:"azeno"`
-	BlockTime               [5]int32  `json:"blockTime" example:"12000,11580,11000,11100,11100"`
+	BlockTime               [5]uint64 `json:"blockTime" example:"12000,11580,11000,11100,11100"`
 	ElectionCount           uint64    `json:"electionCount" example:"120"`
 	OrganizationCount       uint64    `json:"organizationCount" example:"20"`
 	GenesisTime             time.Time `json:"genesisTime"  format:"date-time" example:"2022-11-17T18:00:57.379551614Z"`

cmd/node/main.go

@@ -16,6 +16,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/VictoriaMetrics/metrics"
 	"github.com/google/uuid"
 	flag "github.com/spf13/pflag"
 	"github.com/spf13/viper"
@@ -30,7 +31,6 @@ import (
 	"go.vocdoni.io/dvote/httprouter"
 	"go.vocdoni.io/dvote/internal"
 	"go.vocdoni.io/dvote/log"
-	"go.vocdoni.io/dvote/metrics"
 	"go.vocdoni.io/dvote/service"
 	"go.vocdoni.io/dvote/types"
 	"go.vocdoni.io/dvote/vochain"
@@ -507,8 +507,14 @@ func main() {
 		}
 		// Enable metrics via proxy
 		if conf.Metrics.Enabled {
-			srv.MetricsAgent = metrics.NewAgent("/metrics",
-				time.Duration(conf.Metrics.RefreshInterval)*time.Second, srv.Router)
+			// This flag will eventually be passed to CometBFT to report metrics as well
+			srv.Config.TendermintMetrics = true
+
+			path := "/metrics"
+			srv.Router.AddRawHTTPHandler(path, "GET", func(w http.ResponseWriter, req *http.Request) {
+				metrics.WritePrometheus(w, true)
+			})
+			log.Infof("prometheus metrics ready at: %s", path)
 		}
 	}
 

cmd/voconed/voconed.go

@@ -3,6 +3,7 @@ package main
 import (
 	"encoding/hex"
 	"fmt"
+	"net/http"
 	"os"
 	"os/signal"
 	"path/filepath"
@@ -11,6 +12,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/VictoriaMetrics/metrics"
 	"github.com/ethereum/go-ethereum/common"
 	flag "github.com/spf13/pflag"
 	"github.com/spf13/viper"
@@ -19,7 +21,6 @@ import (
 	"go.vocdoni.io/dvote/crypto/zk/circuit"
 	"go.vocdoni.io/dvote/internal"
 	"go.vocdoni.io/dvote/log"
-	"go.vocdoni.io/dvote/metrics"
 	"go.vocdoni.io/dvote/vochain/state"
 	"go.vocdoni.io/dvote/vocone"
 	"go.vocdoni.io/proto/build/go/models"
@@ -232,8 +233,11 @@ func main() {
 		log.Fatal(err)
 	}
 
-	vc.MetricsAgent = metrics.NewAgent("/metrics",
-		time.Duration(10)*time.Second, vc.Router)
+	path := "/metrics"
+	vc.Router.AddRawHTTPHandler(path, "GET", func(w http.ResponseWriter, req *http.Request) {
+		metrics.WritePrometheus(w, true)
+	})
+	log.Infof("prometheus metrics ready at: %s", path)
 
 	// enable faucet if requested, this will create a new account and attach the faucet API to the vocone API
 	if config.enableFaucetWithAmount > 0 {

data/ipfs/ipfs.go

@@ -132,7 +132,6 @@ func (i *Handler) Init(d *types.DataStore) error {
 	}
 
 	go i.updateStats(time.Minute)
-	i.registerMetrics()
 
 	return nil
 }
@@ -211,7 +210,7 @@ func (i *Handler) Unpin(ctx context.Context, path string) error {
 
 // Stats returns stats about the IPFS node.
 func (i *Handler) Stats() map[string]any {
-	return map[string]any{"peers": stats.Peers.Load(), "addresses": stats.KnownAddrs.Load(), "pins": stats.Pins.Load()}
+	return map[string]any{"peers": stats.Peers.Get(), "addresses": stats.KnownAddrs.Get(), "pins": stats.Pins.Get()}
 }
 
 func (i *Handler) countPins(ctx context.Context) (int, error) {

data/ipfs/metrics.go

@@ -5,40 +5,17 @@ import (
 	"sync"
 	"time"
 
-	"github.com/prometheus/client_golang/prometheus"
-	"go.uber.org/atomic"
-
-	"go.vocdoni.io/dvote/metrics"
+	"github.com/VictoriaMetrics/metrics"
 )
 
-var stats struct {
-	Peers      atomic.Float64
-	KnownAddrs atomic.Float64
-	Pins       atomic.Float64
-}
-
-// registerMetrics registers prometheus metrics
-func (i *Handler) registerMetrics() {
-	metrics.Register(prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-		Namespace: "file",
-		Name:      "peers",
-		Help:      "The number of connected peers",
-	},
-		stats.Peers.Load))
-
-	metrics.Register(prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-		Namespace: "file",
-		Name:      "addresses",
-		Help:      "The number of registered addresses",
-	},
-		stats.KnownAddrs.Load))
-
-	metrics.Register(prometheus.NewGaugeFunc(prometheus.GaugeOpts{
-		Namespace: "file",
-		Name:      "pins",
-		Help:      "The number of pinned files",
-	},
-		stats.Pins.Load))
+var stats = struct {
+	Peers      *metrics.Counter
+	KnownAddrs *metrics.Counter
+	Pins       *metrics.Counter
+}{
+	Peers:      metrics.NewCounter("file_peers"),
+	KnownAddrs: metrics.NewCounter("file_addresses"),
+	Pins:       metrics.NewCounter("file_pins"),
 }
 
 // updateStats constantly updates the ipfs stats (Peers, KnownAddrs, Pins)
@@ -55,7 +32,7 @@ func (i *Handler) updateStats(interval time.Duration) {
 		go func() {
 			list, err := i.CoreAPI.Swarm().Peers(ctx)
 			if err == nil {
-				stats.Peers.Store(float64(len(list)))
+				stats.Peers.Set(uint64(len(list)))
 			}
 			wg.Done()
 		}()
@@ -64,7 +41,7 @@ func (i *Handler) updateStats(interval time.Duration) {
 		go func() {
 			list, err := i.CoreAPI.Swarm().KnownAddrs(ctx)
 			if err == nil {
-				stats.KnownAddrs.Store(float64(len(list)))
+				stats.KnownAddrs.Set(uint64(len(list)))
 			}
 			wg.Done()
 		}()
@@ -73,7 +50,7 @@ func (i *Handler) updateStats(interval time.Duration) {
 		go func() {
 			count, err := i.countPins(ctx)
 			if err == nil {
-				stats.Pins.Store(float64(count))
+				stats.Pins.Set(uint64(count))
 			}
 			wg.Done()
 		}()

go.mod

@@ -12,6 +12,7 @@ go 1.21
 require (
 	git.sr.ht/~sircmpwn/go-bare v0.0.0-20210406120253-ab86bc2846d9
 	github.com/766b/chi-prometheus v0.0.0-20211217152057-87afa9aa2ca8
+	github.com/VictoriaMetrics/metrics v1.24.0
 	github.com/arnaucube/go-blindsecp256k1 v0.0.0-20211204171003-644e7408753f
 	github.com/cockroachdb/pebble v0.0.0-20230620232302-06034ff014e0
 	github.com/cometbft/cometbft v0.38.0
@@ -50,15 +51,13 @@ require (
 	github.com/multiformats/go-multicodec v0.9.0
 	github.com/multiformats/go-multihash v0.2.3
 	github.com/pressly/goose/v3 v3.10.0
-	github.com/prometheus/client_golang v1.16.0
 	github.com/rs/zerolog v1.30.0
 	github.com/spf13/pflag v1.0.5
 	github.com/spf13/viper v1.16.0
 	github.com/syndtr/goleveldb v1.0.1-0.20220614013038-64ee5596c38a
 	github.com/vocdoni/go-snark v0.0.0-20210709152824-f6e4c27d7319
 	github.com/vocdoni/storage-proofs-eth-go v0.1.6
 	go.mongodb.org/mongo-driver v1.12.1
-	go.uber.org/atomic v1.11.0
 	go.vocdoni.io/proto v1.15.4-0.20231023165811-02adcc48142a
 	golang.org/x/crypto v0.14.0
 	golang.org/x/exp v0.0.0-20230905200255-921286631fa9
@@ -245,6 +244,7 @@ require (
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/polydawn/refmt v0.89.0 // indirect
+	github.com/prometheus/client_golang v1.16.0 // indirect
 	github.com/prometheus/client_model v0.4.0 // indirect
 	github.com/prometheus/common v0.44.0 // indirect
 	github.com/prometheus/procfs v0.11.1 // indirect
@@ -270,6 +270,8 @@ require (
 	github.com/tklauser/go-sysconf v0.3.10 // indirect
 	github.com/tklauser/numcpus v0.4.0 // indirect
 	github.com/ucarion/urlpath v0.0.0-20200424170820-7ccc79b76bbb // indirect
+	github.com/valyala/fastrand v1.1.0 // indirect
+	github.com/valyala/histogram v1.2.0 // indirect
 	github.com/wasmerio/wasmer-go v1.0.4 // indirect
 	github.com/whyrusleeping/base32 v0.0.0-20170828182744-c30ac30633cc // indirect
 	github.com/whyrusleeping/cbor v0.0.0-20171005072247-63513f603b11 // indirect
@@ -298,6 +300,7 @@ require (
 	go.opentelemetry.io/otel/sdk v1.16.0 // indirect
 	go.opentelemetry.io/otel/trace v1.16.0 // indirect
 	go.opentelemetry.io/proto/otlp v0.19.0 // indirect
+	go.uber.org/atomic v1.11.0 // indirect
 	go.uber.org/dig v1.17.0 // indirect
 	go.uber.org/fx v1.20.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect

go.sum

@@ -101,6 +101,8 @@ github.com/VictoriaMetrics/fastcache v1.5.3/go.mod h1:+jv9Ckb+za/P1ZRg/sulP5Ni1v
 github.com/VictoriaMetrics/fastcache v1.5.7/go.mod h1:ptDBkNMQI4RtmVo8VS/XwRY6RoTu1dAWCbrk+6WsEM8=
 github.com/VictoriaMetrics/fastcache v1.6.0 h1:C/3Oi3EiBCqufydp1neRZkqcwmEiuRT9c3fqvvgKm5o=
 github.com/VictoriaMetrics/fastcache v1.6.0/go.mod h1:0qHz5QP0GMX4pfmMA/zt5RgfNuXJrTP0zS7DqpHGGTw=
+github.com/VictoriaMetrics/metrics v1.24.0 h1:ILavebReOjYctAGY5QU2F9X0MYvkcrG3aEn2RKa1Zkw=
+github.com/VictoriaMetrics/metrics v1.24.0/go.mod h1:eFT25kvsTidQFHb6U0oa0rTrDRdz4xTYjpL8+UPohys=
 github.com/VividCortex/gohistogram v1.0.0 h1:6+hBz+qvs0JOrrNhhmR7lFxo5sINxBCGXrdtl/UvroE=
 github.com/VividCortex/gohistogram v1.0.0/go.mod h1:Pf5mBqqDxYaXu3hDrrU+w6nw50o/4+TcAqDqk/vUH7g=
 github.com/adlio/schema v1.3.3 h1:oBJn8I02PyTB466pZO1UZEn1TV5XLlifBSyMrmHl/1I=
@@ -1504,8 +1506,12 @@ github.com/urfave/cli/v2 v2.17.2-0.20221006022127-8f469abc00aa/go.mod h1:1CNUng3
 github.com/urfave/negroni v1.0.0/go.mod h1:Meg73S6kFm/4PpbYdq35yYWoCZ9mS/YSx+lKnmiohz4=
 github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
 github.com/valyala/fasthttp v1.6.0/go.mod h1:FstJa9V+Pj9vQ7OJie2qMHdwemEDaDiSdBnvPM1Su9w=
+github.com/valyala/fastrand v1.1.0 h1:f+5HkLW4rsgzdNoleUOB69hyT9IlD2ZQh9GyDMfb5G8=
+github.com/valyala/fastrand v1.1.0/go.mod h1:HWqCzkrkg6QXT8V2EXWvXCoow7vLwOFN002oeRzjapQ=
 github.com/valyala/fasttemplate v1.0.1/go.mod h1:UQGH1tvbgY+Nz5t2n7tXsz52dQxojPUpymEIMZ47gx8=
 github.com/valyala/fasttemplate v1.2.1/go.mod h1:KHLXt3tVN2HBp8eijSv/kGJopbvo7S+qRAEEKiv+SiQ=
+github.com/valyala/histogram v1.2.0 h1:wyYGAZZt3CpwUiIb9AU/Zbllg1llXyrtApRS815OLoQ=
+github.com/valyala/histogram v1.2.0/go.mod h1:Hb4kBwb4UxsaNbbbh+RRz8ZR6pdodR57tzWUS3BUzXY=
 github.com/valyala/tcplisten v0.0.0-20161114210144-ceec8f93295a/go.mod h1:v3UYOV9WzVtRmSR+PDvWpU/qWl4Wa5LApYYX4ZtKbio=
 github.com/viant/assertly v0.4.8/go.mod h1:aGifi++jvCrUaklKEKT0BU95igDNaqkvz+49uaYMPRU=
 github.com/viant/toolbox v0.24.0/go.mod h1:OxMCG57V0PXuIP2HNQrtJf2CjqdmbrOx5EkMILuUhzM=

service/service.go

@@ -7,7 +7,6 @@ import (
 	"go.vocdoni.io/dvote/data"
 	"go.vocdoni.io/dvote/data/downloader"
 	"go.vocdoni.io/dvote/httprouter"
-	"go.vocdoni.io/dvote/metrics"
 	"go.vocdoni.io/dvote/vochain"
 	"go.vocdoni.io/dvote/vochain/indexer"
 	"go.vocdoni.io/dvote/vochain/keykeeper"
@@ -20,7 +19,6 @@ type VocdoniService struct {
 	Config         *config.VochainCfg
 	App            *vochain.BaseApplication
 	Router         *httprouter.HTTProuter
-	MetricsAgent   *metrics.Agent
 	OffChainData   *offchaindatahandler.OffChainDataHandler
 	DataDownloader *downloader.Downloader
 	CensusDB       *censusdb.CensusDB

service/vochain.go

@@ -97,11 +97,6 @@ func (vs *VocdoniService) Vochain() error {
 		}
 	}
 
-	// Metrics agent (Prometheus)
-	if vs.MetricsAgent != nil {
-		vs.Config.TendermintMetrics = true
-	}
-
 	// Create the vochain node
 	vs.App = vochain.NewVochain(vs.Config, genesisBytes)
 
@@ -171,10 +166,10 @@ func (vs *VocdoniService) Start() error {
 
 // VochainPrintInfo initializes the Vochain statistics recollection.
 func VochainPrintInfo(interval time.Duration, vi *vochaininfo.VochainInfo) {
-	var a *[5]int32
+	var a *[5]uint64
 	var h int64
 	var p, v uint64
-	var m, vc, vxm int
+	var m, vc, vxm uint64
 	var b strings.Builder
 	for {
 		b.Reset()

subpub/discovery.go

@@ -4,24 +4,20 @@ import (
 	"context"
 	"time"
 
+	"github.com/VictoriaMetrics/metrics"
 	corediscovery "github.com/libp2p/go-libp2p/core/discovery"
 	libpeer "github.com/libp2p/go-libp2p/core/peer"
 	"github.com/libp2p/go-libp2p/core/protocol"
 	discrouting "github.com/libp2p/go-libp2p/p2p/discovery/routing"
 	discutil "github.com/libp2p/go-libp2p/p2p/discovery/util"
 	multiaddr "github.com/multiformats/go-multiaddr"
-	"github.com/prometheus/client_golang/prometheus"
 	"go.vocdoni.io/dvote/log"
-	"go.vocdoni.io/dvote/metrics"
 )
 
 // Metrics exported via prometheus
 var (
-	dhtLatency = prometheus.NewHistogram(prometheus.HistogramOpts{
-		Namespace: "file",
-		Name:      "peers_dht_latency",
-		Help:      "The time it takes FindPeers to discover peers",
-	})
+	// The time it takes FindPeers to discover peers
+	dhtLatency = metrics.NewHistogram("file_peers_dht_latency")
 )
 
 // setupDiscovery creates a DHT discovery service and attaches it to the libp2p Host.
@@ -39,8 +35,6 @@ func (s *SubPub) setupDiscovery(ctx context.Context) {
 	s.routing = discrouting.NewRoutingDiscovery(s.node.DHT)
 	discutil.Advertise(ctx, s.routing, s.Topic)
 
-	metrics.Register(dhtLatency)
-
 	// Discover new peers periodically
 	go func() { // this spawns a single background task per instance
 		for {
@@ -58,7 +52,8 @@ func (s *SubPub) setupDiscovery(ctx context.Context) {
 }
 
 func (s *SubPub) discover(ctx context.Context) {
-	dhtLatencyTimer := prometheus.NewTimer(dhtLatency)
+	startTime := time.Now()
+
 	// Now, look for others who have announced.
 	// This is like your friend telling you the location to meet you.
 	log.Debugf("looking for peers in topic %s", s.Topic)
@@ -83,7 +78,7 @@ func (s *SubPub) discover(ctx context.Context) {
 		}
 		// new peer; let's connect to it
 		// first update the latency metrics
-		dhtLatencyTimer.ObserveDuration()
+		dhtLatency.UpdateDuration(startTime)
 		connectCtx, cancel := context.WithTimeout(ctx, time.Second*10)
 		if err := s.node.PeerHost.Connect(connectCtx, peer); err != nil {
 			cancel()