perf/app/influx.go - build - Git at Google

 // Copyright 2022 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.

 package app

 import (
 	"bytes"
 	"context"
 	"fmt"
 	"io"
 	"log"
 	"net/http"
 	"strings"
 	"time"

 	"cloud.google.com/go/compute/metadata"
 	secretmanager "cloud.google.com/go/secretmanager/apiv1"
 	"cloud.google.com/go/secretmanager/apiv1/secretmanagerpb"
 	influxdb2 "github.com/influxdata/influxdb-client-go/v2"
 	"golang.org/x/build/internal/influx"
 	"golang.org/x/build/perfdata"
 	"golang.org/x/perf/benchfmt"
 	"golang.org/x/perf/benchseries"
 	"google.golang.org/api/idtoken"
 )

 const (
 	backfillWindow = 30 * 24 * time.Hour // 30 days.
 )

 func (a *App) influxClient(ctx context.Context) (influxdb2.Client, error) {
 	if a.InfluxHost == "" {
 		return nil, fmt.Errorf("Influx host unknown (set INFLUX_HOST?)")
 	}

 	token, err := a.findInfluxToken(ctx)
 	if err != nil {
 		return nil, fmt.Errorf("error finding Influx token: %w", err)
 	}

 	return influxdb2.NewClient(a.InfluxHost, token), nil
 }

 // syncInflux handles /cron/syncinflux, which updates an InfluxDB instance with
 // the latest data from perfdata.golang.org (i.e. storage), or backfills it.
 func (a *App) syncInflux(w http.ResponseWriter, r *http.Request) {
 	ctx := r.Context()

 	if a.AuthCronEmail != "" {
 		if err := checkCronAuth(ctx, r, a.AuthCronEmail); err != nil {
 			log.Printf("Dropping invalid request to /cron/syncinflux: %v", err)
 			http.Error(w, err.Error(), 403)
 			return
 		}
 	}

 	ifxc, err := a.influxClient(ctx)
 	if err != nil {
 		log.Printf("Error getting Influx client: %v", err)
 		http.Error(w, err.Error(), 500)
 		return
 	}
 	defer ifxc.Close()

 	log.Printf("Connecting to influx...")

 	lastPush, err := latestInfluxTimestamp(ctx, ifxc)
 	if err != nil {
 		http.Error(w, err.Error(), 500)
 		return
 	}
 	if lastPush.IsZero() {
 		// Pick the backfill window.
 		lastPush = time.Now().Add(-backfillWindow)
 	}

 	log.Printf("Last push to influx: %v", lastPush)

 	uploads, err := a.uploadsSince(ctx, lastPush)
 	if err != nil {
 		http.Error(w, err.Error(), 500)
 		return
 	}

 	log.Printf("Uploads since last push: %d", len(uploads))

 	var errs []error
 	for _, u := range uploads {
 		log.Printf("Processing upload %s...", u.UploadID)
 		if err := a.pushRunToInflux(ctx, ifxc, u); err != nil {
 			errs = append(errs, err)
 			log.Printf("Error processing upload %s: %v", u.UploadID, err)
 		}
 	}
 	if len(errs) > 0 {
 		var failures strings.Builder
 		for _, err := range errs {
 			failures.WriteString(err.Error())
 			failures.WriteString("\n")
 		}
 		http.Error(w, failures.String(), 500)
 	}
 }

 func checkCronAuth(ctx context.Context, r *http.Request, wantEmail string) error {
 	const audience = "/cron/syncinflux"

 	const authHeaderPrefix = "Bearer "
 	authHeader := r.Header.Get("Authorization")
 	if !strings.HasPrefix(authHeader, authHeaderPrefix) {
 		return fmt.Errorf("missing Authorization header")
 	}
 	token := authHeader[len(authHeaderPrefix):]

 	p, err := idtoken.Validate(ctx, token, audience)
 	if err != nil {
 		return err
 	}

 	if p.Issuer != "https://accounts.google.com" {
 		return fmt.Errorf("issuer must be https://accounts.google.com, but is %s", p.Issuer)
 	}

 	e, ok := p.Claims["email"]
 	if !ok {
 		return fmt.Errorf("email missing from token")
 	}
 	email, ok := e.(string)
 	if !ok {
 		return fmt.Errorf("email unexpected type %T", e)
 	}

 	if email != wantEmail {
 		return fmt.Errorf("email got %s want %s", email, wantEmail)
 	}

 	return nil
 }

 func (a *App) findInfluxToken(ctx context.Context) (string, error) {
 	if a.InfluxToken != "" {
 		return a.InfluxToken, nil
 	}

 	var project string
 	if a.InfluxProject != "" {
 		project = a.InfluxProject
 	} else {
 		var err error
 		project, err = metadata.ProjectID()
 		if err != nil {
 			return "", fmt.Errorf("error determining GCP project ID (set INFLUX_TOKEN or INFLUX_PROJECT?): %w", err)
 		}
 	}

 	log.Printf("Fetching Influx token from %s...", project)

 	token, err := fetchInfluxToken(ctx, project)
 	if err != nil {
 		return "", fmt.Errorf("error fetching Influx token: %w", err)
 	}

 	return token, nil
 }

 func fetchInfluxToken(ctx context.Context, project string) (string, error) {
 	client, err := secretmanager.NewClient(ctx)
 	if err != nil {
 		return "", fmt.Errorf("error creating secret manager client: %w", err)
 	}
 	defer client.Close()

 	req := &secretmanagerpb.AccessSecretVersionRequest{
 		Name: "projects/" + project + "/secrets/" + influx.AdminTokenSecretName + "/versions/latest",
 	}

 	result, err := client.AccessSecretVersion(ctx, req)
 	if err != nil {
 		return "", fmt.Errorf("failed to access secret version: %w", err)
 	}

 	return string(result.Payload.Data), nil
 }

 func latestInfluxTimestamp(ctx context.Context, ifxc influxdb2.Client) (time.Time, error) {
 	qc := ifxc.QueryAPI(influx.Org)
 	// Find the latest upload in the last month.
 	q := fmt.Sprintf(`from(bucket:%q)
 		|> range(start: -%dh)
 		|> filter(fn: (r) => r["_measurement"] == "benchmark-result")
 		|> filter(fn: (r) => r["_field"] == "upload-time")
 		|> group()
 		|> sort(columns: ["_value"], desc: true)
 		|> limit(n: 1)`, influx.Bucket, backfillWindow/time.Hour)
 	result, err := influxQuery(ctx, qc, q)
 	if err != nil {
 		return time.Time{}, err
 	}
 	for result.Next() {
 		// Except for the point timestamp, all other timestamps are stored as strings, specifically
 		// as the RFC3339Nano format.
 		//
 		// We only care about the first result, and there should be just one.
 		return time.Parse(time.RFC3339Nano, result.Record().Value().(string))
 	}
 	return time.Time{}, result.Err()
 }

 func (a *App) uploadsSince(ctx context.Context, since time.Time) ([]perfdata.UploadInfo, error) {
 	query := strings.Join([]string{
 		// Limit results to the window from since to now.
 		"upload-time>" + since.UTC().Format(time.RFC3339),
 		// Only take results generated by the coordinator. This ensures that nobody can
 		// just upload data to perfdata.golang.org and spoof us (accidentally or intentionally).
 		"by:public-worker-builder@golang-ci-luci.iam.gserviceaccount.com",
 		// Only take results that were generated from post-submit runs, not trybots.
 		"post-submit:true",
 	}, " ")
 	uploadList := a.StorageClient.ListUploads(
 		ctx,
 		query,
 		nil,
 		500, // TODO(mknyszek): page results if this isn't enough.
 	)
 	defer uploadList.Close()

 	var uploads []perfdata.UploadInfo
 	for uploadList.Next() {
 		uploads = append(uploads, uploadList.Info())
 	}
 	if err := uploadList.Err(); err != nil {
 		return nil, err
 	}
 	return uploads, nil
 }

 func (a *App) pushRunToInflux(ctx context.Context, ifxc influxdb2.Client, u perfdata.UploadInfo) error {
 	s, err := a.StorageClient.Query(ctx, fmt.Sprintf("upload:%s", u.UploadID))
 	if err != nil {
 		return err
 	}

 	// We need to read the upload multiple times via benchfmt.Reader, so
 	// copy to a buffer we can seek back to the beginning.
 	var buf bytes.Buffer
 	if _, err := io.Copy(&buf, s); err != nil {
 		return fmt.Errorf("error reading upload: %w", err)
 	}
 	if err := s.Close(); err != nil {
 		return fmt.Errorf("error closing upload: %w", err)
 	}

 	comparisons := []struct {
 		suffix      string
 		compare     string
 		numerator   string
 		denominator string
 		filter      string
 	}{
 		{
 			// Default: toolchain:baseline vs experiment without PGO
 			compare:     "toolchain",
 			numerator:   "experiment",
 			denominator: "baseline",
 			filter:      "-pgo:on", // "off" or unset (bent doesn't set pgo).
 		},
 		{
 			// toolchain:baseline vs experiment with PGO
 			suffix:      "/pgo=on,toolchain:baseline-vs-experiment",
 			compare:     "toolchain",
 			numerator:   "experiment",
 			denominator: "baseline",
 			filter:      "pgo:on",
 		},
 		{
 			// pgo:off vs on with experiment toolchain (impact of enabling PGO)
 			suffix:      "/toolchain:experiment,pgo=off-vs-on",
 			compare:     "pgo",
 			numerator:   "on",
 			denominator: "off",
 			filter:      "toolchain:experiment",
 		},
 	}
 	for _, c := range comparisons {
 		r := bytes.NewReader(buf.Bytes())
 		fmtr := benchfmt.NewReader(r, u.UploadID)

 		// Use the default comparisons. Namely:
 		// 1. Build a series out of commit dates (in our case, this is length 1).
 		// 2. Split out comparisons by benchmark name (unit we get for free).
 		//
 		// Copy the options for mutation.
 		opts := *benchseries.DefaultBuilderOptions()
 		opts.Compare = c.compare
 		opts.Numerator = c.numerator
 		opts.Denominator = c.denominator
 		if opts.Filter == "" {
 			opts.Filter = c.filter
 		} else {
 			opts.Filter += " " + c.filter
 		}

 		if err := a.compareAndPush(ctx, ifxc, fmtr, &opts, c.suffix); err != nil {
 			return fmt.Errorf("error in compareAndPush(%s): %w", c.suffix, err)
 		}
 	}

 	return nil
 }

 func (a *App) compareAndPush(ctx context.Context, ifxc influxdb2.Client, r *benchfmt.Reader, opts *benchseries.BuilderOptions, suffix string) error {
 	// Scan the results into a benchseries builder.
 	builder, err := benchseries.NewBuilder(opts)
 	if err != nil {
 		return fmt.Errorf("failed to create benchseries builder: %v", err)
 	}
 	for r.Scan() {
 		rec := r.Result()
 		if err, ok := rec.(*benchfmt.SyntaxError); ok {
 			// Non-fatal result parse error. Warn
 			// but keep going.
 			log.Printf("Parse error: %v", err)
 			continue
 		}
 		res := rec.(*benchfmt.Result)
 		builder.Add(res)
 	}
 	if err := r.Err(); err != nil {
 		return err
 	}

 	// Run the comparison. We don't have any existing results so our
 	// duplicate policy doesn't matter here. Just pick replacement.
 	comparisons, err := builder.AllComparisonSeries(nil, benchseries.DUPE_REPLACE)
 	if err != nil {
 		return fmt.Errorf("failed to creation comparison series: %w", err)
 	}

 	const (
 		confidence = 0.95
 		bootstrap  = 1000
 	)

 	// Iterate over the comparisons, extract the results, and push them to Influx.
 	wapi := ifxc.WriteAPIBlocking(influx.Org, influx.Bucket)
 comparisonLoop:
 	for _, cs := range comparisons {
 		cs.AddSummaries(confidence, bootstrap)

 		summaries := cs.Summaries

 		// Build a map of residues with single values. Our benchmark pipeline enforces
 		// that the only key that has a differing value across benchmark runs of the same
 		// name and unit is "toolchain."
 		//
 		// Most other keys are singular for *all* benchmarks in a run (like "goos") but
 		// even those that are not (like "pkg") remain the same even if "toolchain" differs.
 		//
 		// We build a map instead of just using them because we need to decide at upload
 		// time whether the key is an Influx tag or field.
 		residues := make(map[string]string)
 		for _, r := range cs.Residues {
 			if len(r.Slice) > 1 {
 				log.Printf("found non-singular key %q with values %v; comparison may be invalid, skipping...", r.S, r.Slice)
 				continue comparisonLoop
 			}
 			residues[r.S] = r.Slice[0]
 		}

 		// N.B. In our case Series should have length 1, because we're processing
 		// a single result here. By default the string value here is the commit date.
 		for i, series := range cs.Series {
 			for j, benchmarkName := range cs.Benchmarks {
 				sum := summaries[i][j]
 				if !sum.Defined() {
 					log.Printf("Summary not defined for %s %s", series, benchmarkName)
 					continue
 				}

 				measurement := "benchmark-result"                  // measurement
 				benchmarkName = benchmarkName + suffix             // tag
 				series = series                                    // time
 				center, low, high := sum.Center, sum.Low, sum.High // fields
 				unit := cs.Unit                                    // tag
 				uploadTime := residues["upload-time"]              // field
 				cpu := residues["cpu"]                             // tag
 				goarch := residues["goarch"]                       // tag
 				goos := residues["goos"]                           // tag
 				benchmarksCommit := residues["benchmarks-commit"]  // field
 				baselineCommit := cs.HashPairs[series].DenHash     // field
 				experimentCommit := cs.HashPairs[series].NumHash   // field
 				repository := residues["repository"]               // tag
 				branch := residues["branch"]                       // tag

 				// cmd/bench didn't set repository prior to
 				// CL 413915. Older runs are all against go.
 				if repository == "" {
 					repository = "go"
 				}

 				// Push to influx.
 				t, err := benchseries.ParseNormalizedDateString(series)
 				if err != nil {
 					return fmt.Errorf("error parsing normalized date: %w", err)
 				}
 				fields := map[string]interface{}{
 					"center":            center,
 					"low":               low,
 					"high":              high,
 					"upload-time":       uploadTime,
 					"benchmarks-commit": benchmarksCommit,
 					"baseline-commit":   baselineCommit,
 					"experiment-commit": experimentCommit,
 				}
 				tags := map[string]string{
 					"name":       benchmarkName,
 					"unit":       unit,
 					"cpu":        cpu,
 					"goarch":     goarch,
 					"goos":       goos,
 					"repository": repository,
 					"branch":     branch,
 					// TODO(prattmic): Add pkg, which
 					// benchseries currently can't handle.
 				}
 				p := influxdb2.NewPoint(measurement, tags, fields, t)
 				if err := wapi.WritePoint(ctx, p); err != nil {
 					return fmt.Errorf("error writing point: %w", err)
 				}
 			}
 		}
 	}
 	return nil
 }
	// Copyright 2022 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.

	package app

	import (
	"bytes"
	"context"
	"fmt"
	"io"
	"log"
	"net/http"
	"strings"
	"time"

	"cloud.google.com/go/compute/metadata"
	secretmanager "cloud.google.com/go/secretmanager/apiv1"
	"cloud.google.com/go/secretmanager/apiv1/secretmanagerpb"
	influxdb2 "github.com/influxdata/influxdb-client-go/v2"
	"golang.org/x/build/internal/influx"
	"golang.org/x/build/perfdata"
	"golang.org/x/perf/benchfmt"
	"golang.org/x/perf/benchseries"
	"google.golang.org/api/idtoken"
	)

	const (
	backfillWindow = 30 * 24 * time.Hour // 30 days.
	)

	func (a *App) influxClient(ctx context.Context) (influxdb2.Client, error) {
	if a.InfluxHost == "" {
	return nil, fmt.Errorf("Influx host unknown (set INFLUX_HOST?)")
	}

	token, err := a.findInfluxToken(ctx)
	if err != nil {
	return nil, fmt.Errorf("error finding Influx token: %w", err)
	}

	return influxdb2.NewClient(a.InfluxHost, token), nil
	}

	// syncInflux handles /cron/syncinflux, which updates an InfluxDB instance with
	// the latest data from perfdata.golang.org (i.e. storage), or backfills it.
	func (a App) syncInflux(w http.ResponseWriter, r http.Request) {
	ctx := r.Context()

	if a.AuthCronEmail != "" {
	if err := checkCronAuth(ctx, r, a.AuthCronEmail); err != nil {
	log.Printf("Dropping invalid request to /cron/syncinflux: %v", err)
	http.Error(w, err.Error(), 403)
	return
	}
	}

	ifxc, err := a.influxClient(ctx)
	if err != nil {
	log.Printf("Error getting Influx client: %v", err)
	http.Error(w, err.Error(), 500)
	return
	}
	defer ifxc.Close()

	log.Printf("Connecting to influx...")

	lastPush, err := latestInfluxTimestamp(ctx, ifxc)
	if err != nil {
	http.Error(w, err.Error(), 500)
	return
	}
	if lastPush.IsZero() {
	// Pick the backfill window.
	lastPush = time.Now().Add(-backfillWindow)
	}

	log.Printf("Last push to influx: %v", lastPush)

	uploads, err := a.uploadsSince(ctx, lastPush)
	if err != nil {
	http.Error(w, err.Error(), 500)
	return
	}

	log.Printf("Uploads since last push: %d", len(uploads))

	var errs []error
	for _, u := range uploads {
	log.Printf("Processing upload %s...", u.UploadID)
	if err := a.pushRunToInflux(ctx, ifxc, u); err != nil {
	errs = append(errs, err)
	log.Printf("Error processing upload %s: %v", u.UploadID, err)
	}
	}
	if len(errs) > 0 {
	var failures strings.Builder
	for _, err := range errs {
	failures.WriteString(err.Error())
	failures.WriteString("\n")
	}
	http.Error(w, failures.String(), 500)
	}
	}

	func checkCronAuth(ctx context.Context, r *http.Request, wantEmail string) error {
	const audience = "/cron/syncinflux"

	const authHeaderPrefix = "Bearer "
	authHeader := r.Header.Get("Authorization")
	if !strings.HasPrefix(authHeader, authHeaderPrefix) {
	return fmt.Errorf("missing Authorization header")
	}
	token := authHeader[len(authHeaderPrefix):]

	p, err := idtoken.Validate(ctx, token, audience)
	if err != nil {
	return err
	}

	if p.Issuer != "https://accounts.google.com" {
	return fmt.Errorf("issuer must be https://accounts.google.com, but is %s", p.Issuer)
	}

	e, ok := p.Claims["email"]
	if !ok {
	return fmt.Errorf("email missing from token")
	}
	email, ok := e.(string)
	if !ok {
	return fmt.Errorf("email unexpected type %T", e)
	}

	if email != wantEmail {
	return fmt.Errorf("email got %s want %s", email, wantEmail)
	}

	return nil
	}

	func (a *App) findInfluxToken(ctx context.Context) (string, error) {
	if a.InfluxToken != "" {
	return a.InfluxToken, nil
	}

	var project string
	if a.InfluxProject != "" {
	project = a.InfluxProject
	} else {
	var err error
	project, err = metadata.ProjectID()
	if err != nil {
	return "", fmt.Errorf("error determining GCP project ID (set INFLUX_TOKEN or INFLUX_PROJECT?): %w", err)
	}
	}

	log.Printf("Fetching Influx token from %s...", project)

	token, err := fetchInfluxToken(ctx, project)
	if err != nil {
	return "", fmt.Errorf("error fetching Influx token: %w", err)
	}

	return token, nil
	}

	func fetchInfluxToken(ctx context.Context, project string) (string, error) {
	client, err := secretmanager.NewClient(ctx)
	if err != nil {
	return "", fmt.Errorf("error creating secret manager client: %w", err)
	}
	defer client.Close()

	req := &secretmanagerpb.AccessSecretVersionRequest{
	Name: "projects/" + project + "/secrets/" + influx.AdminTokenSecretName + "/versions/latest",
	}

	result, err := client.AccessSecretVersion(ctx, req)
	if err != nil {
	return "", fmt.Errorf("failed to access secret version: %w", err)
	}

	return string(result.Payload.Data), nil
	}

	func latestInfluxTimestamp(ctx context.Context, ifxc influxdb2.Client) (time.Time, error) {
	qc := ifxc.QueryAPI(influx.Org)
	// Find the latest upload in the last month.
	q := fmt.Sprintf(`from(bucket:%q)
	\|> range(start: -%dh)
	\|> filter(fn: (r) => r["_measurement"] == "benchmark-result")
	\|> filter(fn: (r) => r["_field"] == "upload-time")
	\|> group()
	\|> sort(columns: ["_value"], desc: true)
	\|> limit(n: 1)`, influx.Bucket, backfillWindow/time.Hour)
	result, err := influxQuery(ctx, qc, q)
	if err != nil {
	return time.Time{}, err
	}
	for result.Next() {
	// Except for the point timestamp, all other timestamps are stored as strings, specifically
	// as the RFC3339Nano format.
	//
	// We only care about the first result, and there should be just one.
	return time.Parse(time.RFC3339Nano, result.Record().Value().(string))
	}
	return time.Time{}, result.Err()
	}

	func (a *App) uploadsSince(ctx context.Context, since time.Time) ([]perfdata.UploadInfo, error) {
	query := strings.Join([]string{
	// Limit results to the window from since to now.
	"upload-time>" + since.UTC().Format(time.RFC3339),
	// Only take results generated by the coordinator. This ensures that nobody can
	// just upload data to perfdata.golang.org and spoof us (accidentally or intentionally).
	"by:public-worker-builder@golang-ci-luci.iam.gserviceaccount.com",
	// Only take results that were generated from post-submit runs, not trybots.
	"post-submit:true",
	}, " ")
	uploadList := a.StorageClient.ListUploads(
	ctx,
	query,
	nil,
	500, // TODO(mknyszek): page results if this isn't enough.
	)
	defer uploadList.Close()

	var uploads []perfdata.UploadInfo
	for uploadList.Next() {
	uploads = append(uploads, uploadList.Info())
	}
	if err := uploadList.Err(); err != nil {
	return nil, err
	}
	return uploads, nil
	}

	func (a *App) pushRunToInflux(ctx context.Context, ifxc influxdb2.Client, u perfdata.UploadInfo) error {
	s, err := a.StorageClient.Query(ctx, fmt.Sprintf("upload:%s", u.UploadID))
	if err != nil {
	return err
	}

	// We need to read the upload multiple times via benchfmt.Reader, so
	// copy to a buffer we can seek back to the beginning.
	var buf bytes.Buffer
	if _, err := io.Copy(&buf, s); err != nil {
	return fmt.Errorf("error reading upload: %w", err)
	}
	if err := s.Close(); err != nil {
	return fmt.Errorf("error closing upload: %w", err)
	}

	comparisons := []struct {
	suffix string
	compare string
	numerator string
	denominator string
	filter string
	}{
	{
	// Default: toolchain:baseline vs experiment without PGO
	compare: "toolchain",
	numerator: "experiment",
	denominator: "baseline",
	filter: "-pgo:on", // "off" or unset (bent doesn't set pgo).
	},
	{
	// toolchain:baseline vs experiment with PGO
	suffix: "/pgo=on,toolchain:baseline-vs-experiment",
	compare: "toolchain",
	numerator: "experiment",
	denominator: "baseline",
	filter: "pgo:on",
	},
	{
	// pgo:off vs on with experiment toolchain (impact of enabling PGO)
	suffix: "/toolchain:experiment,pgo=off-vs-on",
	compare: "pgo",
	numerator: "on",
	denominator: "off",
	filter: "toolchain:experiment",
	},
	}
	for _, c := range comparisons {
	r := bytes.NewReader(buf.Bytes())
	fmtr := benchfmt.NewReader(r, u.UploadID)

	// Use the default comparisons. Namely:
	// 1. Build a series out of commit dates (in our case, this is length 1).
	// 2. Split out comparisons by benchmark name (unit we get for free).
	//
	// Copy the options for mutation.
	opts := *benchseries.DefaultBuilderOptions()
	opts.Compare = c.compare
	opts.Numerator = c.numerator
	opts.Denominator = c.denominator
	if opts.Filter == "" {
	opts.Filter = c.filter
	} else {
	opts.Filter += " " + c.filter
	}

	if err := a.compareAndPush(ctx, ifxc, fmtr, &opts, c.suffix); err != nil {
	return fmt.Errorf("error in compareAndPush(%s): %w", c.suffix, err)
	}
	}

	return nil
	}

	func (a App) compareAndPush(ctx context.Context, ifxc influxdb2.Client, r benchfmt.Reader, opts *benchseries.BuilderOptions, suffix string) error {
	// Scan the results into a benchseries builder.
	builder, err := benchseries.NewBuilder(opts)
	if err != nil {
	return fmt.Errorf("failed to create benchseries builder: %v", err)
	}
	for r.Scan() {
	rec := r.Result()
	if err, ok := rec.(*benchfmt.SyntaxError); ok {
	// Non-fatal result parse error. Warn
	// but keep going.
	log.Printf("Parse error: %v", err)
	continue
	}
	res := rec.(*benchfmt.Result)
	builder.Add(res)
	}
	if err := r.Err(); err != nil {
	return err
	}

	// Run the comparison. We don't have any existing results so our
	// duplicate policy doesn't matter here. Just pick replacement.
	comparisons, err := builder.AllComparisonSeries(nil, benchseries.DUPE_REPLACE)
	if err != nil {
	return fmt.Errorf("failed to creation comparison series: %w", err)
	}

	const (
	confidence = 0.95
	bootstrap = 1000
	)

	// Iterate over the comparisons, extract the results, and push them to Influx.
	wapi := ifxc.WriteAPIBlocking(influx.Org, influx.Bucket)
	comparisonLoop:
	for _, cs := range comparisons {
	cs.AddSummaries(confidence, bootstrap)

	summaries := cs.Summaries

	// Build a map of residues with single values. Our benchmark pipeline enforces
	// that the only key that has a differing value across benchmark runs of the same
	// name and unit is "toolchain."
	//
	// Most other keys are singular for all benchmarks in a run (like "goos") but
	// even those that are not (like "pkg") remain the same even if "toolchain" differs.
	//
	// We build a map instead of just using them because we need to decide at upload
	// time whether the key is an Influx tag or field.
	residues := make(map[string]string)
	for _, r := range cs.Residues {
	if len(r.Slice) > 1 {
	log.Printf("found non-singular key %q with values %v; comparison may be invalid, skipping...", r.S, r.Slice)
	continue comparisonLoop
	}
	residues[r.S] = r.Slice[0]
	}

	// N.B. In our case Series should have length 1, because we're processing
	// a single result here. By default the string value here is the commit date.
	for i, series := range cs.Series {
	for j, benchmarkName := range cs.Benchmarks {
	sum := summaries[i][j]
	if !sum.Defined() {
	log.Printf("Summary not defined for %s %s", series, benchmarkName)
	continue
	}

	measurement := "benchmark-result" // measurement
	benchmarkName = benchmarkName + suffix // tag
	series = series // time
	center, low, high := sum.Center, sum.Low, sum.High // fields
	unit := cs.Unit // tag
	uploadTime := residues["upload-time"] // field
	cpu := residues["cpu"] // tag
	goarch := residues["goarch"] // tag
	goos := residues["goos"] // tag
	benchmarksCommit := residues["benchmarks-commit"] // field
	baselineCommit := cs.HashPairs[series].DenHash // field
	experimentCommit := cs.HashPairs[series].NumHash // field
	repository := residues["repository"] // tag
	branch := residues["branch"] // tag

	// cmd/bench didn't set repository prior to
	// CL 413915. Older runs are all against go.
	if repository == "" {
	repository = "go"
	}

	// Push to influx.
	t, err := benchseries.ParseNormalizedDateString(series)
	if err != nil {
	return fmt.Errorf("error parsing normalized date: %w", err)
	}
	fields := map[string]interface{}{
	"center": center,
	"low": low,
	"high": high,
	"upload-time": uploadTime,
	"benchmarks-commit": benchmarksCommit,
	"baseline-commit": baselineCommit,
	"experiment-commit": experimentCommit,
	}
	tags := map[string]string{
	"name": benchmarkName,
	"unit": unit,
	"cpu": cpu,
	"goarch": goarch,
	"goos": goos,
	"repository": repository,
	"branch": branch,
	// TODO(prattmic): Add pkg, which
	// benchseries currently can't handle.
	}
	p := influxdb2.NewPoint(measurement, tags, fields, t)
	if err := wapi.WritePoint(ctx, p); err != nil {
	return fmt.Errorf("error writing point: %w", err)
	}
	}
	}
	}
	return nil
	}