Add a HTTP server for prometheus metrics

Also add instrumentation for the load balancer module.

cmd/radiod/radiod.go

@@ -29,6 +29,7 @@ var (
 	httpPort      = flag.Int("http-port", 80, "HTTP port")
 	dnsPort       = flag.Int("dns-port", 53, "DNS port")
 	gossipPort    = flag.Int("gossip-port", 2323, "Gossip GRPC port")
+	metricsPort   = flag.Int("monitoring-port", 2424, "HTTP port for monitoring")
 	bwlimit       = flag.Int("bwlimit", 100, "Bandwidth usage limit (Mbps), for load-balancing")
 	maxClients    = flag.Int("max-clients", 1000, "Maximum number of connected clients, for load-balancing")
 	etcdEndpoints = flag.String("etcd", "http://localhost:2379", "Etcd endpoints (comma-separated list of URLs)")
@@ -136,7 +137,7 @@ func main() {
 	}
 
 	// Start all the network services.
-	srv := node.NewServer(n, *domain, strings.Split(*nameservers, ","), *publicIPs, *peerIP, *httpPort, *dnsPort, *gossipPort, autoradio.IcecastPort)
+	srv := node.NewServer(n, *domain, strings.Split(*nameservers, ","), *publicIPs, *peerIP, *httpPort, *dnsPort, *gossipPort, autoradio.IcecastPort, *metricsPort)
 
 	// Wait until the Node and the Server terminate. A failure in
 	// either the network services or the Node itself should cause

node/instrumentation.go

 package node
 
-import "github.com/prometheus/client_golang/prometheus"
+import (
+	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
 
 var (
 	streamSentBytes = prometheus.NewCounterVec(
@@ -24,6 +29,13 @@ var (
 		},
 		[]string{"stream"},
 	)
+	proxyConnectErrs = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "proxy_connect_errors",
+			Help: "Proxy connection errors (client-side).",
+		},
+		[]string{"stream", "upstream"},
+	)
 )
 
 func init() {
@@ -31,5 +43,12 @@ func init() {
 		streamSentBytes,
 		streamRcvdBytes,
 		streamListeners,
+		proxyConnectErrs,
 	)
 }
+
+func newMetricsHandler() http.Handler {
+	mux := http.NewServeMux()
+	mux.Handle("/metrics", promhttp.Handler())
+	return mux
+}

node/lbv2/debug.go

@@ -47,7 +47,7 @@ type costAndUtil struct {
 
 func (l *LoadBalancer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	// Build a view of the cost/utilization data.
-	l.lock.Lock()
+	l.lock.RLock()
 	var nodes []nodeDebugData
 	for i := 0; i < l.nodes.Len(); i++ {
 		n := l.nodes.Get(i)
@@ -67,7 +67,7 @@ func (l *LoadBalancer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	for dim := range l.predictors {
 		dimensions = append(dimensions, dim)
 	}
-	l.lock.Unlock()
+	l.lock.RUnlock()
 
 	ctx := struct {
 		Nodes         []nodeDebugData

node/lbv2/instrumentation.go

+package lbv2
+
+import (
+	"strconv"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	requestsDesc = prometheus.NewDesc(
+		"lbv2_requests",
+		"Number of requests sent to each upstream.",
+		[]string{"upstream", "dimension"}, nil,
+	)
+	reportedUtilDesc = prometheus.NewDesc(
+		"lbv2_reported_utilization",
+		"Utilization (reported).",
+		[]string{"upstream", "dimension"}, nil,
+	)
+	predictedUtilDesc = prometheus.NewDesc(
+		"lbv2_predicted_utilization",
+		"Utilization (predicted).",
+		[]string{"upstream", "dimension"}, nil,
+	)
+	costDesc = prometheus.NewDesc(
+		"lbv2_cost",
+		"Estimated query cost.",
+		[]string{"upstream", "dimension"}, nil,
+	)
+)
+
+// Generating lb metrics is a relatively expensive operation, so we
+// only do it at scraping time by implementing our own custom
+// prometheus.Collector.
+type loadBalancerCollector struct {
+	*LoadBalancer
+}
+
+func (lc loadBalancerCollector) Describe(ch chan<- *prometheus.Desc) {
+	ch <- requestsDesc
+	ch <- reportedUtilDesc
+	ch <- predictedUtilDesc
+	ch <- costDesc
+}
+
+type nodeMetrics struct {
+	name      string
+	dimension int
+	requests  int
+	util      float64
+	pred      float64
+	cost      float64
+}
+
+func (lc loadBalancerCollector) Collect(ch chan<- prometheus.Metric) {
+	lc.LoadBalancer.lock.RLock()
+	data := make([]nodeMetrics, 0, lc.LoadBalancer.nodes.Len())
+	for i := 0; i < lc.LoadBalancer.nodes.Len(); i++ {
+		n := lc.LoadBalancer.nodes.Get(i)
+		for dim, pred := range lc.LoadBalancer.predictors {
+			util := n.Utilization(dim)
+			data = append(data, nodeMetrics{
+				name:      n.Name(),
+				dimension: dim,
+				requests:  util.Requests,
+				util:      util.Utilization,
+				pred:      pred.Utilization(n),
+				cost:      float64(pred.cost[n.Name()]),
+			})
+		}
+	}
+	lc.LoadBalancer.lock.RUnlock()
+
+	for _, d := range data {
+		dimLabel := strconv.Itoa(d.dimension)
+		ch <- prometheus.MustNewConstMetric(
+			requestsDesc,
+			prometheus.CounterValue,
+			float64(d.requests),
+			d.name,
+			dimLabel,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			reportedUtilDesc,
+			prometheus.GaugeValue,
+			d.util,
+			d.name,
+			dimLabel,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			predictedUtilDesc,
+			prometheus.GaugeValue,
+			d.pred,
+			d.name,
+			dimLabel,
+		)
+		ch <- prometheus.MustNewConstMetric(
+			costDesc,
+			prometheus.GaugeValue,
+			d.cost,
+			d.name,
+			dimLabel,
+		)
+	}
+}

node/lbv2/lbv2.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/jmcvetta/randutil"
+	"github.com/prometheus/client_golang/prometheus"
 )
 
 // Node utilization along a specific dimension. Utilization is treated
@@ -156,7 +157,7 @@ type NodeList interface {
 // receives an equal share of incoming traffic.
 //
 type LoadBalancer struct {
-	lock       sync.Mutex
+	lock       sync.RWMutex
 	nodes      NodeList
 	predictors map[int]*costPredictor
 	filters    []NodeFilter
@@ -168,9 +169,14 @@ type LoadBalancer struct {
 
 // New returns a new LoadBalancer with no filters or policy set.
 func New() *LoadBalancer {
-	return &LoadBalancer{
+	lb := &LoadBalancer{
 		predictors: make(map[int]*costPredictor),
 	}
+
+	lc := loadBalancerCollector{lb}
+	prometheus.MustRegister(lc)
+
+	return lb
 }
 
 // AddFilters appends a filter to the filter list.
@@ -212,8 +218,8 @@ func (l *LoadBalancer) Update(nodes NodeList) {
 
 // Choose a node according to the specified policies.
 func (l *LoadBalancer) Choose(ctx RequestContext) Node {
-	l.lock.Lock()
-	defer l.lock.Unlock()
+	l.lock.RLock()
+	defer l.lock.RUnlock()
 	if l.nodes == nil || l.nodes.Len() == 0 {
 		return nil
 	}

node/proxy.go

@@ -100,12 +100,14 @@ func doIcecastProxy(rw http.ResponseWriter, req *http.Request, target *url.URL,
 	if err != nil {
 		log.Printf("http: proxy dial error: %v", err)
 		rw.WriteHeader(http.StatusInternalServerError)
+		proxyConnectErrs.WithLabelValues(streamName, target.Host).Inc()
 		return
 	}
 	defer upstream.Close()
 	if err := outreq.Write(upstream); err != nil {
 		log.Printf("http: proxy request write error: %v", err)
 		rw.WriteHeader(http.StatusInternalServerError)
+		proxyConnectErrs.WithLabelValues(streamName, target.Host).Inc()
 		return
 	}
 

node/server.go

 package node
 
 import (
+	"fmt"
 	"net"
 	"strconv"
 	"sync"
@@ -71,12 +72,13 @@ func (s *Server) Wait() error {
 
 // NewServer creates a new Server. Will use publicAddrs / peerAddr to
 // build all the necessary addr/port combinations.
-func NewServer(n *Node, domain string, nameservers []string, publicAddrs []net.IP, peerAddr net.IP, httpPort, dnsPort, gossipPort, icecastPort int) *Server {
+func NewServer(n *Node, domain string, nameservers []string, publicAddrs []net.IP, peerAddr net.IP, httpPort, dnsPort, gossipPort, icecastPort, metricsPort int) *Server {
 	httpHandler := newHTTPHandler(n, icecastPort, domain)
 	dnsHandler := newDNSHandler(n, domain, nameservers)
 
 	servers := []genericServer{
 		newStatusServer(mkaddr(peerAddr, gossipPort), n.statusMgr),
+		newHTTPServer(fmt.Sprintf(":%d", metricsPort), newMetricsHandler()),
 	}
 	for _, ip := range publicAddrs {
 		servers = append(servers,

vendor/github.com/golang/protobuf/ptypes/duration.go

@@ -82,7 +82,7 @@ func Duration(p *durpb.Duration) (time.Duration, error) {
 		return 0, fmt.Errorf("duration: %v is out of range for time.Duration", p)
 	}
 	if p.Nanos != 0 {
-		d += time.Duration(p.Nanos)
+		d += time.Duration(p.Nanos) * time.Nanosecond
 		if (d < 0) != (p.Nanos < 0) {
 			return 0, fmt.Errorf("duration: %v is out of range for time.Duration", p)
 		}

vendor/github.com/golang/protobuf/ptypes/timestamp.go

@@ -111,11 +111,9 @@ func TimestampNow() *tspb.Timestamp {
 // TimestampProto converts the time.Time to a google.protobuf.Timestamp proto.
 // It returns an error if the resulting Timestamp is invalid.
 func TimestampProto(t time.Time) (*tspb.Timestamp, error) {
-	seconds := t.Unix()
-	nanos := int32(t.Sub(time.Unix(seconds, 0)))
 	ts := &tspb.Timestamp{
-		Seconds: seconds,
-		Nanos:   nanos,
+		Seconds: t.Unix(),
+		Nanos:   int32(t.Nanosecond()),
 	}
 	if err := validateTimestamp(ts); err != nil {
 		return nil, err

vendor/golang.org/x/sys/unix/mkasm_darwin.go

-// Copyright 2018 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build ignore
-
-// mkasm_darwin.go generates assembly trampolines to call libSystem routines from Go.
-//This program must be run after mksyscall.go.
-package main
-
-import (
-	"bytes"
-	"fmt"
-	"io/ioutil"
-	"log"
-	"os"
-	"strings"
-)
-
-func main() {
-	in1, err := ioutil.ReadFile("syscall_darwin.go")
-	if err != nil {
-		log.Fatalf("can't open syscall_darwin.go: %s", err)
-	}
-	arch := os.Args[1]
-	in2, err := ioutil.ReadFile(fmt.Sprintf("syscall_darwin_%s.go", arch))
-	if err != nil {
-		log.Fatalf("can't open syscall_darwin_%s.go: %s", arch, err)
-	}
-	in3, err := ioutil.ReadFile(fmt.Sprintf("zsyscall_darwin_%s.go", arch))
-	if err != nil {
-		log.Fatalf("can't open zsyscall_darwin_%s.go: %s", arch, err)
-	}
-	in := string(in1) + string(in2) + string(in3)
-
-	trampolines := map[string]bool{}
-
-	var out bytes.Buffer
-
-	fmt.Fprintf(&out, "// go run mkasm_darwin.go %s\n", strings.Join(os.Args[1:], " "))
-	fmt.Fprintf(&out, "// Code generated by the command above; DO NOT EDIT.\n")
-	fmt.Fprintf(&out, "\n")
-	fmt.Fprintf(&out, "// +build go1.12\n")
-	fmt.Fprintf(&out, "\n")
-	fmt.Fprintf(&out, "#include \"textflag.h\"\n")
-	for _, line := range strings.Split(in, "\n") {
-		if !strings.HasPrefix(line, "func ") || !strings.HasSuffix(line, "_trampoline()") {
-			continue
-		}
-		fn := line[5 : len(line)-13]
-		if !trampolines[fn] {
-			trampolines[fn] = true
-			fmt.Fprintf(&out, "TEXT ·%s_trampoline(SB),NOSPLIT,$0-0\n", fn)
-			fmt.Fprintf(&out, "\tJMP\t%s(SB)\n", fn)
-		}
-	}
-	err = ioutil.WriteFile(fmt.Sprintf("zsyscall_darwin_%s.s", arch), out.Bytes(), 0644)
-	if err != nil {
-		log.Fatalf("can't write zsyscall_darwin_%s.s: %s", arch, err)
-	}
-}

vendor/golang.org/x/sys/unix/mkpost.go

-// Copyright 2016 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build ignore
-
-// mkpost processes the output of cgo -godefs to
-// modify the generated types. It is used to clean up
-// the sys API in an architecture specific manner.
-//
-// mkpost is run after cgo -godefs; see README.md.
-package main
-
-import (
-	"bytes"
-	"fmt"
-	"go/format"
-	"io/ioutil"
-	"log"
-	"os"
-	"regexp"
-)
-
-func main() {
-	// Get the OS and architecture (using GOARCH_TARGET if it exists)
-	goos := os.Getenv("GOOS")
-	goarch := os.Getenv("GOARCH_TARGET")
-	if goarch == "" {
-		goarch = os.Getenv("GOARCH")
-	}
-	// Check that we are using the Docker-based build system if we should be.
-	if goos == "linux" {
-		if os.Getenv("GOLANG_SYS_BUILD") != "docker" {
-			os.Stderr.WriteString("In the Docker-based build system, mkpost should not be called directly.\n")
-			os.Stderr.WriteString("See README.md\n")
-			os.Exit(1)
-		}
-	}
-
-	b, err := ioutil.ReadAll(os.Stdin)
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	// Intentionally export __val fields in Fsid and Sigset_t
-	valRegex := regexp.MustCompile(`type (Fsid|Sigset_t) struct {(\s+)X__val(\s+\S+\s+)}`)
-	b = valRegex.ReplaceAll(b, []byte("type $1 struct {${2}Val$3}"))
-
-	// Intentionally export __fds_bits field in FdSet
-	fdSetRegex := regexp.MustCompile(`type (FdSet) struct {(\s+)X__fds_bits(\s+\S+\s+)}`)
-	b = fdSetRegex.ReplaceAll(b, []byte("type $1 struct {${2}Bits$3}"))
-
-	// If we have empty Ptrace structs, we should delete them. Only s390x emits
-	// nonempty Ptrace structs.
-	ptraceRexexp := regexp.MustCompile(`type Ptrace((Psw|Fpregs|Per) struct {\s*})`)
-	b = ptraceRexexp.ReplaceAll(b, nil)
-
-	// Replace the control_regs union with a blank identifier for now.
-	controlRegsRegex := regexp.MustCompile(`(Control_regs)\s+\[0\]uint64`)
-	b = controlRegsRegex.ReplaceAll(b, []byte("_ [0]uint64"))
-
-	// Remove fields that are added by glibc
-	// Note that this is unstable as the identifers are private.
-	removeFieldsRegex := regexp.MustCompile(`X__glibc\S*`)
-	b = removeFieldsRegex.ReplaceAll(b, []byte("_"))
-
-	// Convert [65]int8 to [65]byte in Utsname members to simplify
-	// conversion to string; see golang.org/issue/20753
-	convertUtsnameRegex := regexp.MustCompile(`((Sys|Node|Domain)name|Release|Version|Machine)(\s+)\[(\d+)\]u?int8`)
-	b = convertUtsnameRegex.ReplaceAll(b, []byte("$1$3[$4]byte"))
-
-	// Convert [1024]int8 to [1024]byte in Ptmget members
-	convertPtmget := regexp.MustCompile(`([SC]n)(\s+)\[(\d+)\]u?int8`)
-	b = convertPtmget.ReplaceAll(b, []byte("$1[$3]byte"))
-
-	// Remove spare fields (e.g. in Statx_t)
-	spareFieldsRegex := regexp.MustCompile(`X__spare\S*`)
-	b = spareFieldsRegex.ReplaceAll(b, []byte("_"))
-
-	// Remove cgo padding fields
-	removePaddingFieldsRegex := regexp.MustCompile(`Pad_cgo_\d+`)
-	b = removePaddingFieldsRegex.ReplaceAll(b, []byte("_"))
-
-	// Remove padding, hidden, or unused fields
-	removeFieldsRegex = regexp.MustCompile(`\b(X_\S+|Padding)`)
-	b = removeFieldsRegex.ReplaceAll(b, []byte("_"))
-
-	// Remove the first line of warning from cgo
-	b = b[bytes.IndexByte(b, '\n')+1:]
-	// Modify the command in the header to include:
-	//  mkpost, our own warning, and a build tag.
-	replacement := fmt.Sprintf(`$1 | go run mkpost.go
-// Code generated by the command above; see README.md. DO NOT EDIT.
-
-// +build %s,%s`, goarch, goos)
-	cgoCommandRegex := regexp.MustCompile(`(cgo -godefs .*)`)
-	b = cgoCommandRegex.ReplaceAll(b, []byte(replacement))
-
-	// gofmt
-	b, err = format.Source(b)
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	os.Stdout.Write(b)
-}

vendor/golang.org/x/sys/unix/mksyscall.go

-// Copyright 2018 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build ignore
-
-/*
-This program reads a file containing function prototypes
-(like syscall_darwin.go) and generates system call bodies.
-The prototypes are marked by lines beginning with "//sys"
-and read like func declarations if //sys is replaced by func, but:
-	* The parameter lists must give a name for each argument.
-	  This includes return parameters.
-	* The parameter lists must give a type for each argument:
-	  the (x, y, z int) shorthand is not allowed.
-	* If the return parameter is an error number, it must be named errno.
-
-A line beginning with //sysnb is like //sys, except that the
-goroutine will not be suspended during the execution of the system
-call.  This must only be used for system calls which can never
-block, as otherwise the system call could cause all goroutines to
-hang.
-*/
-package main
-
-import (
-	"bufio"
-	"flag"
-	"fmt"
-	"os"
-	"regexp"
-	"strings"
-)
-
-var (
-	b32       = flag.Bool("b32", false, "32bit big-endian")
-	l32       = flag.Bool("l32", false, "32bit little-endian")
-	plan9     = flag.Bool("plan9", false, "plan9")
-	openbsd   = flag.Bool("openbsd", false, "openbsd")
-	netbsd    = flag.Bool("netbsd", false, "netbsd")
-	dragonfly = flag.Bool("dragonfly", false, "dragonfly")
-	arm       = flag.Bool("arm", false, "arm") // 64-bit value should use (even, odd)-pair
-	tags      = flag.String("tags", "", "build tags")
-	filename  = flag.String("output", "", "output file name (standard output if omitted)")
-)
-
-// cmdLine returns this programs's commandline arguments
-func cmdLine() string {
-	return "go run mksyscall.go " + strings.Join(os.Args[1:], " ")
-}
-
-// buildTags returns build tags
-func buildTags() string {
-	return *tags
-}
-
-// Param is function parameter
-type Param struct {
-	Name string
-	Type string
-}
-
-// usage prints the program usage
-func usage() {
-	fmt.Fprintf(os.Stderr, "usage: go run mksyscall.go [-b32 | -l32] [-tags x,y] [file ...]\n")
-	os.Exit(1)
-}
-
-// parseParamList parses parameter list and returns a slice of parameters
-func parseParamList(list string) []string {
-	list = strings.TrimSpace(list)
-	if list == "" {
-		return []string{}
-	}
-	return regexp.MustCompile(`\s*,\s*`).Split(list, -1)
-}
-
-// parseParam splits a parameter into name and type
-func parseParam(p string) Param {
-	ps := regexp.MustCompile(`^(\S*) (\S*)$`).FindStringSubmatch(p)
-	if ps == nil {
-		fmt.Fprintf(os.Stderr, "malformed parameter: %s\n", p)
-		os.Exit(1)
-	}
-	return Param{ps[1], ps[2]}
-}
-
-func main() {
-	// Get the OS and architecture (using GOARCH_TARGET if it exists)
-	goos := os.Getenv("GOOS")
-	if goos == "" {
-		fmt.Fprintln(os.Stderr, "GOOS not defined in environment")
-		os.Exit(1)
-	}
-	goarch := os.Getenv("GOARCH_TARGET")
-	if goarch == "" {
-		goarch = os.Getenv("GOARCH")
-	}
-
-	// Check that we are using the Docker-based build system if we should
-	if goos == "linux" {
-		if os.Getenv("GOLANG_SYS_BUILD") != "docker" {
-			fmt.Fprintf(os.Stderr, "In the Docker-based build system, mksyscall should not be called directly.\n")
-			fmt.Fprintf(os.Stderr, "See README.md\n")
-			os.Exit(1)
-		}
-	}
-
-	flag.Usage = usage
-	flag.Parse()
-	if len(flag.Args()) <= 0 {
-		fmt.Fprintf(os.Stderr, "no files to parse provided\n")
-		usage()
-	}
-
-	endianness := ""
-	if *b32 {
-		endianness = "big-endian"
-	} else if *l32 {
-		endianness = "little-endian"
-	}
-
-	libc := false
-	if goos == "darwin" && strings.Contains(buildTags(), ",go1.12") {
-		libc = true
-	}
-	trampolines := map[string]bool{}
-
-	text := ""
-	for _, path := range flag.Args() {
-		file, err := os.Open(path)
-		if err != nil {
-			fmt.Fprintf(os.Stderr, err.Error())
-			os.Exit(1)
-		}
-		s := bufio.NewScanner(file)
-		for s.Scan() {
-			t := s.Text()
-			t = strings.TrimSpace(t)
-			t = regexp.MustCompile(`\s+`).ReplaceAllString(t, ` `)
-			nonblock := regexp.MustCompile(`^\/\/sysnb `).FindStringSubmatch(t)
-			if regexp.MustCompile(`^\/\/sys `).FindStringSubmatch(t) == nil && nonblock == nil {
-				continue
-			}
-
-			// Line must be of the form
-			//	func Open(path string, mode int, perm int) (fd int, errno error)
-			// Split into name, in params, out params.
-			f := regexp.MustCompile(`^\/\/sys(nb)? (\w+)\(([^()]*)\)\s*(?:\(([^()]+)\))?\s*(?:=\s*((?i)SYS_[A-Z0-9_]+))?$`).FindStringSubmatch(t)
-			if f == nil {
-				fmt.Fprintf(os.Stderr, "%s:%s\nmalformed //sys declaration\n", path, t)
-				os.Exit(1)
-			}
-			funct, inps, outps, sysname := f[2], f[3], f[4], f[5]
-
-			// Split argument lists on comma.
-			in := parseParamList(inps)
-			out := parseParamList(outps)
-
-			// Try in vain to keep people from editing this file.
-			// The theory is that they jump into the middle of the file
-			// without reading the header.
-			text += "// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT\n\n"
-
-			// Go function header.
-			outDecl := ""