Add gauges for CRL size in bytes and num entries (#8720)

Fixes #8716

Author: aarongable

crl/storer/storer.go

@@ -42,7 +42,6 @@ type crlStorer struct {
 	s3Bucket         string
 	issuers          map[issuance.NameID]*issuance.Certificate
 	uploadCount      *prometheus.CounterVec
-	sizeHistogram    *prometheus.HistogramVec
 	latencyHistogram *prometheus.HistogramVec
 	log              blog.Logger
 	clk              clock.Clock
@@ -68,12 +67,6 @@ func New(
 		Help: "A counter of the number of CRLs uploaded by crl-storer",
 	}, []string{"issuer", "result"})
 
-	sizeHistogram := promauto.With(stats).NewHistogramVec(prometheus.HistogramOpts{
-		Name:    "crl_storer_sizes",
-		Help:    "A histogram of the sizes (in bytes) of CRLs uploaded by crl-storer",
-		Buckets: []float64{0, 256, 1024, 4096, 16384, 65536},
-	}, []string{"issuer"})
-
 	latencyHistogram := promauto.With(stats).NewHistogramVec(prometheus.HistogramOpts{
 		Name:    "crl_storer_upload_times",
 		Help:    "A histogram of the time (in seconds) it took crl-storer to upload CRLs",
@@ -85,7 +78,6 @@ func New(
 		s3Client:         s3Client,
 		s3Bucket:         s3Bucket,
 		uploadCount:      uploadCount,
-		sizeHistogram:    sizeHistogram,
 		latencyHistogram: latencyHistogram,
 		log:              log,
 		clk:              clk,
@@ -149,8 +141,6 @@ func (cs *crlStorer) UploadCRL(stream grpc.ClientStreamingServer[cspb.UploadCRLR
 
 	crlId := crl.Id(issuer.NameID(), int(shardIdx), crlNumber)
 
-	cs.sizeHistogram.WithLabelValues(issuer.Subject.CommonName).Observe(float64(len(crlBytes)))
-
 	crl, err := x509.ParseRevocationList(crlBytes)
 	if err != nil {
 		return fmt.Errorf("parsing CRL for %s: %w", crlId, err)

crl/updater/updater.go

@@ -5,6 +5,7 @@ import (
 	"crypto/sha256"
 	"fmt"
 	"io"
+	"strconv"
 	"time"
 
 	"github.com/jmhodges/clock"
@@ -39,8 +40,10 @@ type crlUpdater struct {
 	ca capb.CRLGeneratorClient
 	cs cspb.CRLStorerClient
 
-	tickHistogram  *prometheus.HistogramVec
-	updatedCounter *prometheus.CounterVec
+	tickHistogram    *prometheus.HistogramVec
+	updatedCounter   *prometheus.CounterVec
+	sizeBytesGauge   *prometheus.GaugeVec
+	sizeEntriesGauge *prometheus.GaugeVec
 
 	log blog.Logger
 	clk clock.Clock
@@ -104,6 +107,16 @@ func NewUpdater(
 		Help: "A counter of CRL generation calls labeled by result",
 	}, []string{"issuer", "result"})
 
+	sizeBytesGauge := promauto.With(stats).NewGaugeVec(prometheus.GaugeOpts{
+		Name: "crl_updater_crl_size_bytes",
+		Help: "The size in bytes of each CRL, labeled by issuer and shard",
+	}, []string{"issuer", "shard"})
+
+	sizeEntriesGauge := promauto.With(stats).NewGaugeVec(prometheus.GaugeOpts{
+		Name: "crl_updater_crl_size_entries",
+		Help: "The number of entries in each CRL, labeled by issuer and shard",
+	}, []string{"issuer", "shard"})
+
 	return &crlUpdater{
 		issuersByNameID,
 		numShards,
@@ -120,6 +133,8 @@ func NewUpdater(
 		cs,
 		tickHistogram,
 		updatedCounter,
+		sizeBytesGauge,
+		sizeEntriesGauge,
 		log,
 		clk,
 	}, nil
@@ -324,6 +339,8 @@ func (cu *crlUpdater) updateShard(ctx context.Context, atTime time.Time, issuerN
 	cu.log.Infof(
 		"Generated CRL shard: id=[%s] size=[%d] hash=[%x]",
 		crlID, crlLen, crlHash.Sum(nil))
+	cu.sizeBytesGauge.WithLabelValues(cu.issuers[issuerNameID].Subject.CommonName, strconv.Itoa(shardIdx)).Set(float64(crlLen))
+	cu.sizeEntriesGauge.WithLabelValues(cu.issuers[issuerNameID].Subject.CommonName, strconv.Itoa(shardIdx)).Set(float64(len(crlEntries)))
 
 	return nil
 }