これは、なにをしたくて書いたもの？
Telemetry generator for OpenTelemetry（telemetrygen）を使うと、OpenTelemetryの各種シグナルをテストなどの用途向けに
生成できるようです。
軽く使い方は見ておいた方がいいのかなと思ったので、試してみます。
Telemetry generator for OpenTelemetry（telemetrygen）
Telemetry generator for OpenTelemetry（telemetrygen）は、OpenTelemetry Collector ContribのGitHubリポジトリーの
一部に含まれています。
https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/cmd/telemetrygen
用途としてはテストやデモ用のシミュレーターです。
This utility simulates a client generating traces, metrics, and logs. It is useful for testing and demonstration purposes.
telemetrygenを使うと、トレース、メトリクス、ログの各種シグナルを生成してOpenTelemetry Collectorのテストができます。
実際に、OpenTelemetryのドキュメント内でtelemetrygenが出てくるのは、OpenTelemetry CollectorのQuick startですからね。
Quick start | OpenTelemetry
では、少し試してみましょう。
環境
今回の環境はこちら。Ubuntu Linux 24.04 LTSです。
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 24.04.5 LTS
Release: 24.04
Codename: noble
$ uname -srvmpio
Linux 6.8.0-139-generic
またGoも必要になります。
$ go version
go version go1.26.8 linux/amd64
テレメトリーデータの受信確認には、Grafana LGTMを使うことにします。
$ docker container run -it --rm --name lgtm \
-p 3000:3000 -p 4040:4040 -p 4317:4317 -p 4318:4318 -p 9090:9090 \
-e GF_PATHS_DATA=/data/grafana \
grafana/otel-lgtm:0.33.1
telemetrygenを使ってみる
では、telemetrygenを使ってみましょう。
インストール。
$ go install github.com/open-telemetry/opentelemetry-collector-contrib/cmd/telemetrygen@latest
今回は0.161.0がインストールされました。
go: downloading github.com/open-telemetry/opentelemetry-collector-contrib/cmd/telemetrygen v0.161.0
ちなみに、Dockerイメージでも提供されているようです。
Package opentelemetry-collector-contrib/telemetrygen · GitHub
ヘルプを見てみます。
$ telemetrygen --help
Telemetrygen simulates a client generating traces, metrics, and logs
Usage:
telemetrygen [command]
Examples:
telemetrygen metrics --otlp-insecure --metrics 1
telemetrygen traces --otlp-insecure --traces 1
telemetrygen logs --otlp-insecure --logs 1
Available Commands:
help Help about any command
logs Simulates a client generating logs. (Stability level: alpha)
metrics Simulates a client generating metrics. (Stability level: alpha)
traces Simulates a client generating traces. (Stability level: alpha)
Flags:
-h, --help help for telemetrygen
Use "telemetrygen [command] --help" for more information about a command.
各種シグナルを送信するにはサブコマンドを利用するようですが、それぞれにもヘルプがあるようです。
使い方のイメージはこんな感じみたいです。それぞれ、各種シグナルを1回送信するコマンドです。
$ telemetrygen traces --otlp-insecure --traces 1
$ telemetrygen metrics --otlp-insecure --metrics 1
$ telemetrygen logs --otlp-insecure --logs 1
トレースを送信する
トレースから見ていくことにします。こちらのコマンドを実行してみましょう。
$ telemetrygen traces --otlp-insecure --traces 1
こんな感じに標準出力に書き出されるのですが
2026-09-21T12:51:30.684+0900 INFO traces/traces.go:53 starting gRPC exporter
2026-09-21T12:51:30.684+0900 INFO grpclog/component.go:69 [core] original dial target is: "localhost:4317" {"grpc_log": true}
2026-09-21T12:51:30.684+0900 INFO channelz/trace.go:200 [core] [Channel #1] Channel created for target "localhost:4317" {"grpc_log": true}
2026-09-21T12:51:30.684+0900 INFO channelz/trace.go:200 [core] [Channel #1] parsed dial target is: resolver.Target{URL:url.URL{Scheme:"dns", Opaque:"", User:(*url.Userinfo)(nil), Host:"", Path:"/localhost:4317", Fragment:"", RawQuery:"", RawPath:"", RawFragment:"", ForceQuery:false, OmitHost:false}} {"grpc_log": true}
2026-09-21T12:51:30.684+0900 INFO channelz/trace.go:200 [core] [Channel #1] Channel authority set to "localhost:4317" {"grpc_log": true}
2026-09-21T12:51:30.684+0900 INFO traces/traces.go:125 generation of traces is limited {"per-second": 1}
2026-09-21T12:51:31.685+0900 INFO traces/worker.go:180 traces generated {"worker": 0, "traces": 1}
2026-09-21T12:51:31.686+0900 INFO traces/traces.go:75 stop the batch span processor
2026-09-21T12:51:31.686+0900 INFO channelz/trace.go:200 [core] [Channel #1] Channel Connectivity change to CONNECTING {"grpc_log": true}
2026-09-21T12:51:31.687+0900 INFO channelz/trace.go:200 [core] [Channel #1] Channel exiting idle mode {"grpc_log": true}
2026-09-21T12:51:31.688+0900 INFO channelz/trace.go:200 [core] [Channel #1] Resolver state updated: {
"Addresses": [
{
"Addr": "127.0.0.1:4317",
"ServerName": "",
"Attributes": null,
"BalancerAttributes": null,
"Metadata": null
}
],
"Endpoints": [
{
"Addresses": [
{
"Addr": "127.0.0.1:4317",
"ServerName": "",
"Attributes": null,
"BalancerAttributes": null,
"Metadata": null
}
],
"Attributes": null
}
],
"ServiceConfig": null,
"Attributes": null
} (resolver returned new addresses) {"grpc_log": true}
2026-09-21T12:51:31.688+0900 INFO channelz/trace.go:200 [core] [Channel #1] Channel switches to new LB policy "pick_first" {"grpc_log": true}
2026-09-21T12:51:31.688+0900 INFO grpclog/prefix_logger.go:42 [pick-first-leaf-lb] [pick-first-leaf-lb 0xecf47ae8000] Received new config {
"shuffleAddressList": false
}, resolver state {
"Addresses": [
{
"Addr": "127.0.0.1:4317",
"ServerName": "",
"Attributes": null,
"BalancerAttributes": null,
"Metadata": null
}
],
"Endpoints": [
{
"Addresses": [
{
"Addr": "127.0.0.1:4317",
"ServerName": "",
"Attributes": null,
"BalancerAttributes": null,
"Metadata": null
}
],
"Attributes": null
}
],
"ServiceConfig": null,
"Attributes": null
} {"grpc_log": true}
2026-09-21T12:51:31.688+0900 INFO channelz/trace.go:200 [core] [Channel #1 SubChannel #2] Subchannel created {"grpc_log": true}
2026-09-21T12:51:31.688+0900 INFO channelz/trace.go:200 [core] [Channel #1 SubChannel #2] Subchannel Connectivity change to CONNECTING {"grpc_log": true}
2026-09-21T12:51:31.688+0900 INFO channelz/trace.go:200 [core] [Channel #1 SubChannel #2] Subchannel picks a new address "127.0.0.1:4317" to connect {"grpc_log": true}
2026-09-21T12:51:31.689+0900 INFO channelz/trace.go:200 [core] [Channel #1 SubChannel #2] Subchannel Connectivity change to READY {"grpc_log": true}
2026-09-21T12:51:31.689+0900 INFO grpclog/prefix_logger.go:42 [pick-first-leaf-lb] [pick-first-leaf-lb 0xecf47ae8000] SubConn 0xecf47aa0190 reported connectivity state READY and the health listener is disabled. Transitioning SubConn to READY. {"grpc_log": true}
2026-09-21T12:51:31.689+0900 INFO channelz/trace.go:200 [core] [Channel #1] Channel Connectivity change to READY {"grpc_log": true}
2026-09-21T12:51:31.690+0900 INFO channelz/trace.go:200 [core] [Channel #1] Channel Connectivity change to SHUTDOWN {"grpc_log": true}
2026-09-21T12:51:31.690+0900 INFO channelz/trace.go:200 [core] [Channel #1] Closing the name resolver {"grpc_log": true}
2026-09-21T12:51:31.690+0900 INFO channelz/trace.go:200 [core] [Channel #1] ccBalancerWrapper: closing {"grpc_log": true}
2026-09-21T12:51:31.690+0900 INFO channelz/trace.go:200 [core] [Channel #1 SubChannel #2] Subchannel Connectivity change to SHUTDOWN {"grpc_log": true}
2026-09-21T12:51:31.690+0900 INFO channelz/trace.go:200 [core] [Channel #1 SubChannel #2] Subchannel deleted {"grpc_log": true}
2026-09-21T12:51:31.690+0900 INFO grpclog/prefix_logger.go:42 [transport] [client-transport 0xecf47af8008] Closing: rpc error: code = Canceled desc = grpc: the client connection is closing {"grpc_log": true}
2026-09-21T12:51:31.690+0900 INFO grpclog/prefix_logger.go:42 [transport] [client-transport 0xecf47af8008] loopyWriter exiting with error: rpc error: code = Canceled desc = grpc: the client connection is closing {"grpc_log": true}
2026-09-21T12:51:31.690+0900 INFO channelz/trace.go:200 [core] [Channel #1] Channel deleted {"grpc_log": true}
2026-09-21T12:51:31.690+0900 INFO traces/traces.go:65 stopping the exporter
Grafana LGTMで見た方がわかりやすいですね。
実行には--tracesまたは--durationオプションが必須のようです。生成個数で指定するか実行時間で指定するかですね。
Error: either `traces` or `duration` must be greater than 0
オプションをいろいろ試してみましょう。
$ telemetrygen traces --otlp-insecure --traces 10
$ telemetrygen traces --otlp-insecure --duration 5s
$ telemetrygen traces --otlp-insecure --duration inf
$ telemetrygen traces --otlp-insecure --duration 10s --interval 5s
$ telemetrygen traces --otlp-insecure --traces 1 --service myapp
$ telemetrygen traces --otlp-insecure --otlp-endpoint localhost:4317 --traces 1
$ telemetrygen traces --otlp-insecure --traces 1 --telemetry-attributes 'foo1="bar1"' --telemetry-attributes 'foo2=100'
$ telemetrygen traces --otlp-insecure --traces 1 --otlp-attributes 'service.name="myapp"'
このあたりの使い方は、オプション（フラグ）の説明を見るとなんとなくわかる気がします。
Flags:
--allow-export-failures Whether to continue running when export operations fail (instead of terminating)
--batch Whether to batch telemetry records before sending (default true)
--batch-size int Number of telemetry records to batch before sending (default 100)
--ca-cert string Trusted Certificate Authority to verify server certificate
--child-spans int Number of child spans to generate for each trace (default 1)
--client-cert string Client certificate file
--client-key string Client private key file
--duration duration|inf For how long to run the test. Use 'inf' for infinite duration. (default 0s)
-h, --help help for traces
--interval duration Reporting interval (default 1s)
--marshal Whether to marshal trace context via HTTP headers
--mtls Whether to require client authentication for mTLS
--otlp-attributes map[string]any Custom resource attributes, describing the entity that produces the telemetry. They are set once on the OTLP resource and are shared by every span, metric data point and log record emitted by this run, e.g. --otlp-attributes service.name="my-service" overrides --service. The value is expected in one of the following formats: key="value", key=true, key=false, key=<integer>, or key=["value1", "value2", ...]. Note you may need to escape the quotes when using the tool from a cli. Flag may be repeated to set multiple attributes (e.g --otlp-attributes key1=\"value1\" --otlp-attributes key2=\"value2\" --otlp-attributes key3=true --otlp-attributes key4=123 --otlp-attributes key5=[1,2,3])
--otlp-endpoint string Destination endpoint for exporting logs, metrics and traces
--otlp-header map[string]any Custom header to be passed along with each OTLP request. The value is expected in the format key="value". Note you may need to escape the quotes when using the tool from a cli. Flag may be repeated to set multiple headers (e.g --otlp-header key1=\"value1\" --otlp-header key2=\"value2\")
--otlp-http Whether to use HTTP exporter rather than a gRPC one
--otlp-http-url-path string Which URL path to write to (default "/v1/traces")
--otlp-insecure Whether to enable client transport security for the exporter's grpc or http connection
--otlp-insecure-skip-verify Whether a client verifies the server's certificate chain and host name
--rate float Approximately how many metrics/spans/logs per second each worker should generate. Zero means no throttling. (default 1)
--service string Service name to use (default "telemetrygen")
--size int Desired minimum size in MB of string data for each generated telemetry record
--span-duration duration The duration of each generated span. (default 123µs)
--span-links int Number of span links to generate for each span
--status-code string Status code to use for the spans, one of (Unset, Error, Ok) or the equivalent integer (0,1,2) (default "0")
--telemetry-attributes map[string]any Custom attributes describing an individual telemetry item. They are set on every generated span, metric data point and log record rather than on the resource, e.g. --telemetry-attributes http.response.status_code=200. The value is expected in one of the following formats: key="value", key=true, key=false, or key=<integer>, or key=["value1", "value2", ...]. Note you may need to escape the quotes when using the tool from a cli. Flag may be repeated to set multiple attributes (e.g --telemetry-attributes key1=\"value1\" --telemetry-attributes key2=\"value2\" --telemetry-attributes key3=true --telemetry-attributes key4=123 --telemetry-attributes key5=[1,2,3])
--timeout duration Maximum time to wait for the signals to reach destination. (default 10s)
--traces int Number of traces to generate in each worker (ignored if duration is provided)
--workers int Number of workers (goroutines) to run (default 1)
デフォルト値や例も書いていますし。
--duration duration|inf For how long to run the test. Use 'inf' for infinite duration. (default 0s)
--interval duration Reporting interval (default 1s)
--service string Service name to use (default "telemetrygen")
--telemetry-attributes map[string]any Custom attributes describing an individual telemetry item. They are set on every generated span, metric data point and log record rather than on the resource, e.g. --telemetry-attributes http.response.status_code=200. The value is expected in one of the following formats: key="value", key=true, key=false, or key=<integer>, or key=["value1", "value2", ...]. Note you may need to escape the quotes when using the tool from a cli. Flag may be repeated to set multiple attributes (e.g --telemetry-attributes key1=\"value1\" --telemetry-attributes key2=\"value2\" --telemetry-attributes key3=true --telemetry-attributes key4=123 --telemetry-attributes key5=[1,2,3])
--traces int Number of traces to generate in each worker (ignored if duration is provided)
メトリクスを送信する
次はメトリクスを見ていきましょう。
$ telemetrygen metrics --otlp-insecure --metrics 1
こんな感じのメトリクスが送信されています。
メトリクスのオプションで気になるところはこのあたりかなと。
--aggregation-temporality temporality aggregation-temporality for metrics. Must be one of 'delta' or 'cumulative' (default )
--metric-type MetricType Metric type enum. must be one of 'Gauge', 'Sum', 'Histogram', or 'ExponentialHistogram' (default Gauge)
--otlp-metric-name string Metric name of the exported metric (default "gen")
--span-id string SpanID to use as exemplar
--trace-id string TraceID to use as exemplar
--unique-timeseries Enforce unique timeseries within unique-timeseries-timelimit, performance impacting
--unique-timeseries-duration duration Time limit for unique timeseries generation, timeseries generated within this time will be unique (default 1s)
他のオプションはトレースと似たようなものなので省略します。
ログを送信する
最後はログです。
$ telemetrygen logs --otlp-insecure --logs 1
オプションを試してみます。
$ telemetrygen logs --otlp-insecure --logs 1 --body 'my log'
$ telemetrygen logs --otlp-insecure --logs 1 --severity-number 17 --severity-text ERROR
Severity（重要度）でどのような値を指定すればよいのかは、こちらを参照するとよいでしょう。
Logs Data Model / Log and Event Record Definition / Severity Fields
ログのオプションで気になるものはこのあたりでしょうか。
--body string Body of the log (default "the message")
--severity-number int32 Severity number of the log, range from 1 to 24 (inclusive) (default 9)
--severity-text string Severity text of the log (default "Info")
--span-id string SpanID of the log
--trace-id string TraceID of the log
おわりに
テスト用にトレース、メトリクス、ログシグナルを生成できるTelemetry generator for OpenTelemetry（telemetrygen）を
試してみました。
ローカルにインストールしようと思うとGo言語が必要になりますが、インストールできれば意外と簡単に使えることが
わかりました。
どちらかというとCollectorなどの受信側の確認に使うものなので登場機会はあまり多くないかもしれませんが、ひとまず
テレメトリーデータを投入したいという時に覚えておくと便利なのかなと思います。
