[Metrics] Give visibility into indexing

go.mod

@@ -7,9 +7,14 @@ require (
 	github.com/go-git/go-git/v5 v5.19.1
 	github.com/google/go-cmp v0.7.0
 	github.com/gorilla/mux v1.8.1
+	github.com/prometheus/client_golang v1.23.2
 	github.com/transparency-dev/formats v0.1.0
 	github.com/transparency-dev/merkle v0.0.2
 	github.com/transparency-dev/tessera v1.0.3-0.20260318145621-a1e0ccb4adf4
+	go.opentelemetry.io/otel v1.44.0
+	go.opentelemetry.io/otel/exporters/prometheus v0.66.0
+	go.opentelemetry.io/otel/metric v1.44.0
+	go.opentelemetry.io/otel/sdk/metric v1.44.0
 	golang.org/x/mod v0.36.0
 	golang.org/x/sync v0.20.0
 	k8s.io/klog/v2 v2.140.0
@@ -39,34 +44,34 @@ require (
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8 // indirect
-	github.com/golang/protobuf v1.5.4 // indirect
 	github.com/golang/snappy v0.0.4 // indirect
+	github.com/google/uuid v1.6.0 // indirect
 	github.com/hashicorp/golang-lru/v2 v2.0.7 // indirect
 	github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 // indirect
 	github.com/kevinburke/ssh_config v1.2.0 // indirect
 	github.com/klauspost/compress v1.18.0 // indirect
 	github.com/klauspost/cpuid/v2 v2.3.0 // indirect
 	github.com/kr/pretty v0.3.1 // indirect
 	github.com/kr/text v0.2.0 // indirect
-	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/pjbgf/sha1cd v0.6.0 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
-	github.com/prometheus/client_golang v1.15.0 // indirect
-	github.com/prometheus/client_model v0.3.0 // indirect
-	github.com/prometheus/common v0.42.0 // indirect
-	github.com/prometheus/procfs v0.9.0 // indirect
+	github.com/prometheus/client_model v0.6.2 // indirect
+	github.com/prometheus/common v0.67.5 // indirect
+	github.com/prometheus/otlptranslator v1.0.0 // indirect
+	github.com/prometheus/procfs v0.20.1 // indirect
 	github.com/rogpeppe/go-internal v1.14.1 // indirect
 	github.com/sergi/go-diff v1.3.2-0.20230802210424-5b0b94c5c0d3 // indirect
 	github.com/skeema/knownhosts v1.3.1 // indirect
 	github.com/xanzy/ssh-agent v0.3.3 // indirect
 	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
-	go.opentelemetry.io/otel v1.42.0 // indirect
-	go.opentelemetry.io/otel/metric v1.42.0 // indirect
-	go.opentelemetry.io/otel/trace v1.42.0 // indirect
+	go.opentelemetry.io/otel/sdk v1.44.0 // indirect
+	go.opentelemetry.io/otel/trace v1.44.0 // indirect
+	go.yaml.in/yaml/v2 v2.4.4 // indirect
 	golang.org/x/crypto v0.50.0 // indirect
 	golang.org/x/exp v0.0.0-20260410095643-746e56fc9e2f // indirect
 	golang.org/x/net v0.53.0 // indirect
-	golang.org/x/sys v0.43.0 // indirect
+	golang.org/x/sys v0.45.0 // indirect
 	golang.org/x/text v0.36.0 // indirect
 	google.golang.org/protobuf v1.36.11 // indirect
 	gopkg.in/warnings.v0 v0.1.2 // indirect

go.sum

@@ -66,14 +66,12 @@ github.com/gogo/protobuf v1.3.2 h1:Ov1cvc58UF3b5XjBnZv7+opcTcQFZebYjWzi34vdm4Q=
 github.com/gogo/protobuf v1.3.2/go.mod h1:P1XiOD3dCwIKUDQYPy72D8LYyHL2YPYrpS2s69NZV8Q=
 github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8 h1:f+oWsMOmNPc8JmEHVZIycC7hBoQxHH9pNKQORJNozsQ=
 github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8/go.mod h1:wcDNUvekVysuuOpQKo3191zZyTpiI6se1N1ULghS0sw=
-github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
-github.com/golang/protobuf v1.3.5/go.mod h1:6O5/vntMXwX2lRkT1hjjk0nAC1IDOTvTlVgjlRvqsdk=
-github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
-github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
 github.com/golang/snappy v0.0.4 h1:yAGX7huGHXlcLOEtBnF4w7FQwA26wojNCwOYAEhLjQM=
 github.com/golang/snappy v0.0.4/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
 github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
 github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/gorilla/mux v1.8.1 h1:TuBL49tXwgrFYWhqrNgrUNEY92u81SPhu7sTdzQEiWY=
 github.com/gorilla/mux v1.8.1/go.mod h1:AKf9I4AEqPTmMytcMc0KkNouC66V3BtZ4qD5fmWSiMQ=
 github.com/hashicorp/golang-lru/v2 v2.0.7 h1:a+bsQ5rvGLjzHuww6tVxozPZFVghXaHOwFs4luLUK2k=
@@ -95,8 +93,10 @@ 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/matttproud/golang_protobuf_extensions v1.0.4 h1:mmDVorXM7PCGKw94cs5zkfA9PSy5pEvNWRP0ET0TIVo=
-github.com/matttproud/golang_protobuf_extensions v1.0.4/go.mod h1:BSXmuO+STAnVfrANrmjBb36TMTDstsz7MSK+HVaYKv4=
+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/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
 github.com/onsi/gomega v1.34.1 h1:EUMJIKUjM8sKjYbtxQI9A4z2o+rruxnzNvpknOXie6k=
 github.com/onsi/gomega v1.34.1/go.mod h1:kU1QgUvBDLXBJq618Xvm2LUX6rSAfRaFRTcdOeDLwwY=
 github.com/pingcap/errors v0.11.4 h1:lFuQV/oaUMGcD2tqt+01ROSmJs75VG1ToEOkZIZ4nE4=
@@ -108,14 +108,16 @@ github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/prometheus/client_golang v1.15.0 h1:5fCgGYogn0hFdhyhLbw7hEsWxufKtY9klyvdNfFlFhM=
-github.com/prometheus/client_golang v1.15.0/go.mod h1:e9yaBhRPU2pPNsZwE+JdQl0KEt1N9XgF6zxWmaC0xOk=
-github.com/prometheus/client_model v0.3.0 h1:UBgGFHqYdG/TPFD1B1ogZywDqEkwp3fBMvqdiQ7Xew4=
-github.com/prometheus/client_model v0.3.0/go.mod h1:LDGWKZIo7rky3hgvBe+caln+Dr3dPggB5dvjtD7w9+w=
-github.com/prometheus/common v0.42.0 h1:EKsfXEYo4JpWMHH5cg+KOUWeuJSov1Id8zGR8eeI1YM=
-github.com/prometheus/common v0.42.0/go.mod h1:xBwqVerjNdUDjgODMpudtOMwlOwf2SaTr1yjz4b7Zbc=
-github.com/prometheus/procfs v0.9.0 h1:wzCHvIvM5SxWqYvwgVL7yJY8Lz3PKn49KQtpgMYJfhI=
-github.com/prometheus/procfs v0.9.0/go.mod h1:+pB4zwohETzFnmlpe6yd2lSc+0/46IYZRB/chUwxUZY=
+github.com/prometheus/client_golang v1.23.2 h1:Je96obch5RDVy3FDMndoUsjAhG5Edi49h0RJWRi/o0o=
+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 v0.67.5 h1:pIgK94WWlQt1WLwAC5j2ynLaBRDiinoAb86HZHTUGI4=
+github.com/prometheus/common v0.67.5/go.mod h1:SjE/0MzDEEAyrdr5Gqc6G+sXI67maCxzaT3A2+HqjUw=
+github.com/prometheus/otlptranslator v1.0.0 h1:s0LJW/iN9dkIH+EnhiD3BlkkP5QVIUVEoIwkU+A6qos=
+github.com/prometheus/otlptranslator v1.0.0/go.mod h1:vRYWnXvI6aWGpsdY/mOT/cbeVRBlPWtBNDb7kGR3uKM=
+github.com/prometheus/procfs v0.20.1 h1:XwbrGOIplXW/AU3YhIhLODXMJYyC1isLFfYCsTEycfc=
+github.com/prometheus/procfs v0.20.1/go.mod h1:o9EMBZGRyvDrSPH1RqdxhojkuXstoe4UlK79eF5TGGo=
 github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
 github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
@@ -141,12 +143,24 @@ github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9de
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
 go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
-go.opentelemetry.io/otel v1.42.0 h1:lSQGzTgVR3+sgJDAU/7/ZMjN9Z+vUip7leaqBKy4sho=
-go.opentelemetry.io/otel v1.42.0/go.mod h1:lJNsdRMxCUIWuMlVJWzecSMuNjE7dOYyWlqOXWkdqCc=
-go.opentelemetry.io/otel/metric v1.42.0 h1:2jXG+3oZLNXEPfNmnpxKDeZsFI5o4J+nz6xUlaFdF/4=
-go.opentelemetry.io/otel/metric v1.42.0/go.mod h1:RlUN/7vTU7Ao/diDkEpQpnz3/92J9ko05BIwxYa2SSI=
-go.opentelemetry.io/otel/trace v1.42.0 h1:OUCgIPt+mzOnaUTpOQcBiM/PLQ/Op7oq6g4LenLmOYY=
-go.opentelemetry.io/otel/trace v1.42.0/go.mod h1:f3K9S+IFqnumBkKhRJMeaZeNk9epyhnCmQh/EysQCdc=
+go.opentelemetry.io/otel v1.44.0 h1:JjwHmHpA4iZ3wBxluu2fbbE7j4kqlE8jXyAyPXH7HqU=
+go.opentelemetry.io/otel v1.44.0/go.mod h1:BMgjTHL9WPRlRjL2oZCBTL4whCGtXch2H4BhOPIAyYc=
+go.opentelemetry.io/otel/exporters/prometheus v0.66.0 h1:vkrK8PAznv2NKt2r+kdu252ccGzkEqLc2aSXbQIALYQ=
+go.opentelemetry.io/otel/exporters/prometheus v0.66.0/go.mod h1:V/UB6D3vMF/UBOL5igAsAYnk1nG/bzYYTzvsB16cy7o=
+go.opentelemetry.io/otel/metric v1.44.0 h1:1w0gILTcHdr3YI+ixLyjemwrVnsMURbTZFrSYCdDdmc=
+go.opentelemetry.io/otel/metric v1.44.0/go.mod h1:8O7hanEPBNgEMmybD3s2VBKcgWOCsA6tzHBPODAiquo=
+go.opentelemetry.io/otel/metric/x v0.66.0 h1:YkCrx1zLOChi9ZcZ6euupOcsgzbVlec7D/xoEU1+cTA=
+go.opentelemetry.io/otel/metric/x v0.66.0/go.mod h1:d1+BDj9t96do0/1LoU1ayfCv79ZgNE41qbhBvnMOBZk=
+go.opentelemetry.io/otel/sdk v1.44.0 h1:nHYwb9lK+fJPU/dnT6s7W7Z8itMWyqrnVfbheVYrZ58=
+go.opentelemetry.io/otel/sdk v1.44.0/go.mod h1:Osuydd3Se74nqjAKxid74N5eC+jfEqfTegHRnq58oK0=
+go.opentelemetry.io/otel/sdk/metric v1.44.0 h1:3LlKgI+VjbVsjNRFZJZAJ30WjXC5VkNRks6si09iEfI=
+go.opentelemetry.io/otel/sdk/metric v1.44.0/go.mod h1:5B5pMARnXxKhltooO4xUuCBorl65a4EpnTalObqOigA=
+go.opentelemetry.io/otel/trace v1.44.0 h1:jxF5CsGYCe74MCRx2X4g7WsY/VBKRqqpNvXlX/6gtIk=
+go.opentelemetry.io/otel/trace v1.44.0/go.mod h1:oLl1jrMQAVo6v3GAggN+1VH9VIz9iUSvW53sW1Q8PIE=
+go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
+go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
+go.yaml.in/yaml/v2 v2.4.4 h1:tuyd0P+2Ont/d6e2rl3be67goVK4R6deVxCUX5vyPaQ=
+go.yaml.in/yaml/v2 v2.4.4/go.mod h1:gMZqIpDtDqOfM0uNfy0SkpRhvUryYH0Z6wdMYcacYXQ=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
@@ -166,7 +180,6 @@ golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwY
 golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.53.0 h1:d+qAbo5L0orcWAr0a9JweQpjXF19LMXJE8Ey7hwOdUA=
 golang.org/x/net v0.53.0/go.mod h1:JvMuJH7rrdiCfbeHoo3fCQU24Lf5JJwT9W3sJFulfgs=
-golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -181,8 +194,8 @@ golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.43.0 h1:Rlag2XtaFTxp19wS8MXlJwTvoh8ArU6ezoyFsMyCTNI=
-golang.org/x/sys v0.43.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/sys v0.45.0 h1:dO4czNzziLiiXplLQgBCEpCvXQ3dnkn0SdaZSYdQ+FY=
+golang.org/x/sys v0.45.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.42.0 h1:UiKe+zDFmJobeJ5ggPwOshJIVt6/Ft0rcfrXZDLWAWY=
 golang.org/x/term v0.42.0/go.mod h1:Dq/D+snpsbazcBG5+F9Q1n2rXV8Ma+71xEjTRufARgY=

vindex/cmd/logandmap/README.md

@@ -41,6 +41,7 @@ Running the above will run a web server hosting the following URLs:
  - `/inputlog/` - the [tlog-tiles][] base URL for the input log
  - `/vindex/lookup` - the provisional [vindex lookup API](./api/api.go)
  - `/outputlog/` - the [tlog-tiles][] base URL for the output log
+ - `/metrics` - Prometheus metrics endpoint
 
 The input log has entries for packages in the set {`foo`, `bar`, `baz`, `splat`}.
 To inspect the log, you can use the woodpecker tool (using the corresponding public key to the private key used above):
@@ -60,3 +61,14 @@ This log is processed into a verifiable map which can be looked up using the fol
 ```shell
 go run ./vindex/cmd/client --vindex_base_url http://localhost:8088/vindex/ --in_log_base_url http://localhost:8088/inputlog/ --out_log_pub_key=example.com/outputlog+07392c46+AWyS8y8ZsRmQnTr6Fr2knaa8+t6CPYFh5Ho3wJEr14B8 --in_log_pub_key=example.com/inputlog+bd6268fb+AWdGkrHKBm+pOubTrcBTV8JMDLFlF1Y8WUH1nrtLNXDr --lookup=foo
 ```
+
+## Monitoring
+
+The server exports metrics via Prometheus on the `/metrics` endpoint.
+
+Key areas covered by the metrics include:
+- **Map Function Keys**: Tracks the number of keys returned by the `MapFn` for each leaf (`vindex_map_fn_keys`).
+- **Sync Performance**: Histograms tracking the duration of fetching, mapping, and processing leaves during the synchronization phase (under `vindex_sync_*`).
+- **Build Performance**: Histograms tracking the duration of various steps in the build process, including WAL processing, MPT updates, publishing to the Output Log, and total build time (under `vindex_build_*`).
+
+

vindex/cmd/logandmap/main.go

@@ -30,6 +30,7 @@ import (
 	"fmt"
 	"iter"
 	"math/rand"
+	"net"
 	"net/http"
 	"os"
 	"os/signal"
@@ -45,6 +46,8 @@ import (
 	"github.com/transparency-dev/tessera/api"
 	"github.com/transparency-dev/tessera/client"
 	"github.com/transparency-dev/tessera/storage/posix"
+	"go.opentelemetry.io/otel/exporters/prometheus"
+	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
 	"golang.org/x/mod/sumdb/note"
 	"k8s.io/klog/v2"
 )
@@ -80,6 +83,20 @@ func run(ctx context.Context) error {
 	if *storageDir == "" {
 		return errors.New("storage_dir must be set")
 	}
+
+	exporter, err := prometheus.New()
+	if err != nil {
+		return fmt.Errorf("failed to create prometheus exporter: %v", err)
+	}
+	provider := sdkmetric.NewMeterProvider(sdkmetric.WithReader(exporter))
+	defer func() {
+		shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		if err := provider.Shutdown(shutdownCtx); err != nil {
+			klog.Errorf("failed to shutdown meter provider: %v", err)
+		}
+	}()
+
 	inputLogDir := path.Join(*storageDir, "inputlog")
 	outputLogDir := path.Join(*storageDir, "outputlog")
 	mapRoot := path.Join(*storageDir, "vindex")
@@ -97,29 +114,54 @@ func run(ctx context.Context) error {
 	// Create the input log, output log, and verifiable index.
 	// The input log is continuously getting new leaves written to it.
 	inputLog, inputCloser := inputLogOrDie(ctx, inputLogDir)
-	defer inputCloser()
+	defer func() {
+		shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		inputCloser(shutdownCtx)
+	}()
 
 	outputLog, outputCloser := outputLogOrDie(ctx, outputLogDir)
-	defer outputCloser()
+	defer func() {
+		shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		outputCloser(shutdownCtx)
+	}()
 
 	vi, err := vindex.NewVerifiableIndex(ctx, inputLog, mapFnFromFlags(), outputLog, mapRoot, vindex.Options{
-		PersistIndex: *persistIndex,
+		PersistIndex:  *persistIndex,
+		MeterProvider: provider,
 	})
 	if err != nil {
 		return fmt.Errorf("failed to create vindex: %v", err)
 	}
+	defer func() {
+		if err := vi.Close(); err != nil {
+			klog.Errorf("failed to close vindex: %v", err)
+		}
+	}()
 
 	// Keeps the map synced with the latest published input log state.
 	go maintainMap(ctx, vi)
 
 	// Run a web server to serve the input log, index, and output log.
-	go runWebServer(vi, inputLogDir, outputLogDir)
+	webShutdown, err := runWebServer(vi, inputLogDir, outputLogDir)
+	if err != nil {
+		return fmt.Errorf("failed to start web server: %v", err)
+	}
+	defer func() {
+		shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		if err := webShutdown(shutdownCtx); err != nil {
+			klog.Errorf("failed to shutdown web server: %v", err)
+		}
+	}()
+
 	<-ctx.Done()
 	return nil
 }
 
 // inputLogOrDie returns an input log that is being updated periodically.
-func inputLogOrDie(ctx context.Context, inputLogDir string) (log logReaderSource, closer func()) {
+func inputLogOrDie(ctx context.Context, inputLogDir string) (log logReaderSource, closer func(context.Context)) {
 	// Gather the info needed for reading/writing checkpoints
 	ils, ilv := getInputLogSignerVerifierOrDie()
 
@@ -145,7 +187,7 @@ func inputLogOrDie(ctx context.Context, inputLogDir string) (log logReaderSource
 	// Submits new entries to the log in the background.
 	go submitEntries(ctx, inputAppender)
 
-	return inputLog, func() {
+	return inputLog, func(ctx context.Context) {
 		if err := inputShutdown(ctx); err != nil {
 			klog.Warningf("Error shutting down Input Log appender: %v", err)
 		}
@@ -197,7 +239,7 @@ func (s logReaderSource) Leaves(ctx context.Context, start, end uint64) iter.Seq
 }
 
 // outputLogOrDie returns an output log using a POSIX log in the given directory.
-func outputLogOrDie(ctx context.Context, outputLogDir string) (log vindex.OutputLog, closer func()) {
+func outputLogOrDie(ctx context.Context, outputLogDir string) (log vindex.OutputLog, closer func(context.Context)) {
 	s, v := getOutputLogSignerVerifierOrDie()
 
 	l, c, err := vindex.NewOutputLog(ctx, outputLogDir, s, v, vindex.OutputLogOpts{})
@@ -262,7 +304,7 @@ func submitEntries(ctx context.Context, appender *tessera.Appender) {
 	}
 }
 
-func runWebServer(vi *vindex.VerifiableIndex, inLogDir, outLogDir string) {
+func runWebServer(vi *vindex.VerifiableIndex, inLogDir, outLogDir string) (func(context.Context) error, error) {
 	web := NewServer(vi.Lookup)
 
 	ilfs := http.FileServer(http.Dir(inLogDir))
@@ -271,14 +313,23 @@ func runWebServer(vi *vindex.VerifiableIndex, inLogDir, outLogDir string) {
 	r.PathPrefix("/inputlog/").Handler(http.StripPrefix("/inputlog/", ilfs))
 	r.PathPrefix("/outputlog/").Handler(http.StripPrefix("/outputlog/", olfs))
 	web.registerHandlers(r)
+
+	listener, err := net.Listen("tcp", *listen)
+	if err != nil {
+		return nil, err
+	}
+
 	hServer := &http.Server{
-		Addr:    *listen,
 		Handler: r,
 	}
 	go func() {
-		_ = hServer.ListenAndServe()
+		if err := hServer.Serve(listener); err != http.ErrServerClosed {
+			klog.Errorf("HTTP server Serve: %v", err)
+		}
 	}()
 	klog.Infof("Started HTTP server listening on %s", *listen)
+
+	return hServer.Shutdown, nil
 }
 
 // Read input log private key from file or environment variable and generate the

vindex/cmd/logandmap/web.go

@@ -24,6 +24,7 @@ import (
 	"net/http"
 
 	"github.com/gorilla/mux"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/transparency-dev/incubator/vindex/api"
 	"k8s.io/klog/v2"
 )
@@ -73,4 +74,5 @@ func (s Server) handleLookup(w http.ResponseWriter, r *http.Request) {
 
 func (s Server) registerHandlers(r *mux.Router) {
 	r.HandleFunc("/vindex/lookup/{hash}", s.handleLookup).Methods("GET")
+	r.Handle("/metrics", promhttp.Handler())
 }