Using OpenTelemetry Metrics
This guide explains how your Quarkus application can utilize OpenTelemetry (OTel) to provide metrics for interactive web applications.
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前提条件
このガイドを完成させるには、以下が必要です:
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約15分
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IDE
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JDK 17+がインストールされ、
JAVA_HOMEが適切に設定されていること -
Apache Maven 3.9.8
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Docker と Docker Compose、または Podman 、および Docker Compose
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使用したい場合は、 Quarkus CLI
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ネイティブ実行可能ファイルをビルドしたい場合、MandrelまたはGraalVM（あるいはネイティブなコンテナビルドを使用する場合はDocker）をインストールし、 適切に設定していること
ソリューション
次の章で紹介する手順に沿って、ステップを踏んでアプリを作成することをお勧めします。ただし、すぐに完成した例に飛んでも構いません。
Gitレポジトリをクローンするか git clone https://github.com/quarkusio/quarkus-quickstarts.git 、 アーカイブ をダウンロードします。
ソリューションは opentelemetry-quickstart ディレクトリ にあります。
Mavenプロジェクトの作成
まず、新しいプロジェクトが必要です。以下のコマンドで新規プロジェクトを作成します:
Windowsユーザーの場合:
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cmdを使用する場合、（バックスラッシュ
\を使用せず、すべてを同じ行に書かないでください）。 -
Powershellを使用する場合は、
-Dパラメータを二重引用符で囲んでください。例:"-DprojectArtifactId=opentelemetry-quickstart"
このコマンドはMavenプロジェクトを生成し、quarkus-opentelemetry エクステンションをインポートします。このエクステンションには、デフォルトのOpenTelemetryサポートと、https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/protocol/otlp.md[OTLP]のgRPC spanエクスポーターが含まれています。
Quarkusプロジェクトがすでに設定されている場合、プロジェクトのベースディレクトリで次のコマンドを実行することで、quarkus-opentelemetry エクステンションをプロジェクトに追加できます：
quarkus extension add opentelemetry./mvnw quarkus:add-extension -Dextensions='opentelemetry'./gradlew addExtension --extensions='opentelemetry'これにより、 pom.xml に以下が追加されます:
<dependency>
<groupId>io.quarkus</groupId>
<artifactId>quarkus-opentelemetry</artifactId>
</dependency>implementation("io.quarkus:quarkus-opentelemetry")Jakarta REST リソースの調査
Create a src/main/java/org/acme/opentelemetry/MetricResource.java file with the following content:
package org.acme;
import io.opentelemetry.api.metrics.LongCounter;
import io.opentelemetry.api.metrics.Meter;
import jakarta.ws.rs.GET;
import jakarta.ws.rs.Path;
import jakarta.ws.rs.Produces;
import jakarta.ws.rs.core.MediaType;
import org.jboss.logging.Logger;
@Path("/hello-metrics")
public class MetricResource {
private static final Logger LOG = Logger.getLogger(MetricResource.class);
private final LongCounter counter;
public MetricResource(Meter meter) { (1)
counter = meter.counterBuilder("hello-metrics") (2)
.setDescription("hello-metrics")
.setUnit("invocations")
.build();
}
@GET
@Produces(MediaType.TEXT_PLAIN)
public String hello() {
counter.add(1); (3)
LOG.info("hello-metrics");
return "hello-metrics";
}
}Quarkus is not currently producing metrics out of the box.
Here we are creating a counter for the number of invocations of the hello() method.
| 1 | Constructor injection of the Meter instance. |
| 2 | Create a LongCounter named hello-metrics with a description and unit. |
| 3 | Increment the counter by one for each invocation of the hello() method. |
コンフィグレーションの作成
エクステンションを動作させるために必須の設定はありません。
デフォルトのプロパティ値を変更する必要がある場合、 src/main/resources/application.properties ファイルを使用して、アプリケーション内でデフォルトの OTLP gRPC Exporter を設定する方法の例を以下に示します:
quarkus.application.name=myservice (1)
quarkus.otel.metrics.enabled=true (2)
quarkus.otel.exporter.otlp.metrics.endpoint=http://localhost:4317 (3)
quarkus.otel.exporter.otlp.metrics.headers=authorization=Bearer my_secret (4)| 1 | All metrics created from the application will include an OpenTelemetry Resource indicating the metrics was created by the myservice application.
If not set, it will default to the artifact id. |
| 2 | Enable the OpenTelemetry metrics. Must be set at build time. |
| 3 | gRPC endpoint to send the metrics.
If not set, it will default to http://localhost:4317. |
| 4 | Optional gRPC headers commonly used for authentication. |
To configure the connection using the same properties for all signals, please check the base configuration section of the OpenTelemetry guide.
To disable particular parts of OpenTelemetry, you can set the properties listed in this section of the OpenTelemetry guide.
アプリケーションの実行
First we need to start a system to visualise the OpenTelemetry data.
See the data
Grafana-OTel-LGTM Dev Service
You can use the Grafana-OTel-LGTM devservice.
This Dev service includes a Grafana for visualizing data, Loki to store logs, Tempo to store traces and Prometheus to store metrics. Also provides and OTel collector to receive the data.
Logging exporter
You can output all metrics to the console by setting the exporter to logging in the application.properties file:
quarkus.otel.metrics.exporter=logging (1)
quarkus.otel.metric.export.interval=10000ms (2)| 1 | Set the exporter to logging.
Normally you don’t need to set this.
The default is cdi. |
| 2 | Set the interval to export the metrics.
The default is 1m, which is too long for debugging. |
Start the application
これでアプリケーションを実行する準備が整いました。トレーサーの設定に application.properties を使用している場合:
quarkus dev./mvnw quarkus:dev./gradlew --console=plain quarkusDevまたは、JVM引数でOTLP gRPCエンドポイントを設定する場合:
quarkus dev -Djvm.args="-Dquarkus.otel.exporter.otlp.endpoint=http://localhost:4317"./mvnw quarkus:dev -Djvm.args="-Dquarkus.otel.exporter.otlp.endpoint=http://localhost:4317"./gradlew --console=plain quarkusDev -Djvm.args="-Dquarkus.otel.exporter.otlp.endpoint=http://localhost:4317"OpenTelemetry Collector、Jaegerシステム、アプリケーションが動作している状態で、提供されているエンドポイントにリクエストを出すことができます。
$ curl http://localhost:8080/hello-metrics
hello-metricsWhen using the logger exporter, metrics will be printed to the console. This is a pretty printed example:
{
"metric": "ImmutableMetricData",
"resource": {
"Resource": {
"schemaUrl": null,
"attributes": { (1)
"host.name": "myhost",
"service.name": "myservice ",
"service.version": "1.0.0-SNAPSHOT",
"telemetry.sdk.language": "java",
"telemetry.sdk.name": "opentelemetry",
"telemetry.sdk.version": "1.32.0",
"webengine.name": "Quarkus",
"webengine.version": "999-SNAPSHOT"
}
},
"instrumentationScopeInfo": {
"InstrumentationScopeInfo": { (2)
"name": "io.quarkus.opentelemetry",
"version": null,
"schemaUrl": null,
"attributes": {}
}
},
"name": "hello-metrics", (3)
"description": "hello-metrics",
"unit": "invocations",
"type": "LONG_SUM",
"data": {
"ImmutableSumData": {
"points": [
{
"ImmutableLongPointData": {
"startEpochNanos": 1720622136612378000,
"epochNanos": 1720622246618331000,
"attributes": {},
"value": 3, (4)
"exemplars": [ (5)
{
"ImmutableLongExemplarData": {
"filteredAttributes": {},
"epochNanos": 1720622239362357000,
"spanContext": {
"ImmutableSpanContext": {
"traceId": "d91951e50b0641552a76889c5356467c",
"spanId": "168af8b7102d0556",
"traceFlags": "01",
"traceState": "ArrayBasedTraceState",
"entries": [],
"remote": false,
"valid": true
},
"value": 1
}
}
}
]
}
}
],
"monotonic": true,
"aggregationTemporality": "CUMULATIVE"
}
}
}
}| 1 | Resource attributes common to all telemetry data. |
| 2 | Instrumentation scope is allways io.quarkus.opentelemetry |
| 3 | The name, description and unit of the metric you defined in the constructor of the MetricResource class. |
| 4 | The value of the metric. 3 invocations were made until now. |
| 5 | Exemplars additional tracing information about the metric. In this case, the traceId and spanId of one os the request that triggered the metric, since it was last sent. |
CTRL+C を押すか、 q と入力して、アプリケーションを停止してください。
独自のメトリクスの作成
OpenTelemetry Metrics vs Micrometer Metrics
Metrics are single numerical measurements, often have additional data captured with them. This ancillary data is used to group or aggregate metrics for analysis.
Pretty much like in the Quarkus Micrometer extension, you can create your own metrics using the OpenTelemetry API and the concepts are analogous.
The OpenTelemetry API provides a Meter interface to create metrics instead of a Registry.
The Meter interface is the entry point for creating metrics.
It provides methods to create counters, gauges, and histograms.
Attributes can be added to metrics to add dimensions, pretty much like tags in Micrometer.
Obtain a reference to the Meter
Use one of the following methods to obtain a reference to a Meter:
Use CDI Constructor injection
@Path("/hello-metrics")
public class MetricResource {
private final Meter meter;
public MetricResource(Meter meter) {
this.meter = meter;
}
}Pretty much like in the example above.
カウンター
Counters can be used to measure non-negative, increasing values.
LongCounter counter = meter.counterBuilder("hello-metrics") (1)
.setDescription("hello-metrics") // optional
.setUnit("invocations") // optional
.build();
counter.add(1, (2)
Attributes.of(AttributeKey.stringKey("attribute.name"), "attribute value")); // optional (3)| 1 | Create a LongCounter named hello-metrics with a description and unit. |
| 2 | Increment the counter by one. |
| 3 | Add an attribute to the counter.
This will create a dimension called attribute.name with value attribute value. |
| Each unique combination of metric name and dimension produces a unique time series. Using an unbounded set of dimensional data (many different values like a userId) can lead to a "cardinality explosion", an exponential increase in the creation of new time series. Avoid! |
OpenTelemetry provides many other types of Counters: LongUpDownCounter, DoubleCounter, DoubleUpDownCounter and also Observable, async counters like ObservableLongCounter, ObservableDoubleCounter, ObservableLongUpDownCounter and ObservableDoubleUpDownCounter.
For more details please refer to the OpenTelemetry Java documentation about Counters.
ゲージ
Observable Gauges should be used to measure non-additive values. A value that can increase or decrease over time, like the speedometer on a car. Gauges can be useful when monitoring the statistics for a cache or collection.
With this metric you provide a function to be periodically probed by a callback. The value returned by the function is the value of the gauge.
The default gauge records Double values, but if you want to record Long values, you can use
meter.gaugeBuilder("jvm.memory.total") (1)
.setDescription("Reports JVM memory usage.")
.setUnit("byte")
.ofLongs() (2)
.buildWithCallback( (3)
result -> result.record(
Runtime.getRuntime().totalMemory(), (4)
Attributes.empty())); // optional (5)| 1 | Create a Gauge named jvm.memory.total with a description and unit. |
| 2 | If you want to record Long values you need this builder method because the default gauge records Double values. |
| 3 | Build the gauge with a callback. An imperative builder is also available. |
| 4 | Register the function to call to get the value of the gauge. |
| 5 | No added attributes, this time. |
Histograms
Histograms are synchronous instruments used to measure a distribution of values over time. It is intended for statistics such as histograms, summaries, and percentile. The request duration and response payload size are good uses for a histogram.
On this section we have a new class, the HistogramResource that will create a LongHistogram.
package org.acme;
import io.opentelemetry.api.common.AttributeKey;
import io.opentelemetry.api.common.Attributes;
import io.opentelemetry.api.metrics.LongHistogram;
import io.opentelemetry.api.metrics.Meter;
import jakarta.ws.rs.GET;
import jakarta.ws.rs.Path;
import jakarta.ws.rs.Produces;
import jakarta.ws.rs.core.MediaType;
import org.jboss.logging.Logger;
import java.util.Arrays;
@Path("/roll-dice")
public class HistogramResource {
private static final Logger LOG = Logger.getLogger(HistogramResource.class);
private final LongHistogram rolls;
public HistogramResource(Meter meter) {
rolls = meter.histogramBuilder("hello.roll.dice") (1)
.ofLongs() (2)
.setDescription("A distribution of the value of the rolls.")
.setExplicitBucketBoundariesAdvice(Arrays.asList(1L, 2L, 3L, 4L, 5L, 6L, 7L)) (3)
.setUnit("points")
.build();
}
@GET
@Produces(MediaType.TEXT_PLAIN)
public String helloGauge() {
var roll = roll();
rolls.record(roll, (4)
Attributes.of(AttributeKey.stringKey("attribute.name"), "value")); (5)
LOG.info("roll-dice: " + roll);
return "" + roll;
}
public long roll() {
return (long) (Math.random() * 6) + 1;
}
}| 1 | Create a LongHistogram named hello.roll.dice with a description and unit. |
| 2 | If you want to record Long values you need this builder method because the default histogram records Double values. |
| 3 | Set the explicit bucket boundaries for the histogram. The boundaries are inclusive. |
| 4 | Record the value of the roll. |
| 5 | Add an attribute to the histogram.
This will create a dimension called attribute.name with value value. |
| Beware of cardinality explosion. |
We can invoke the endpoint with a curl command.
$ curl http://localhost:8080/roll-dice
2If we execute 4 consecutive requests, with results 2,2,3 and 4 this will produce the following output.
The Resource and InstrumentationScopeInfo data are ignored for brevity.
//...
name=hello.roll.dice,
description=A distribution of the value of the rolls., (1)
unit=points,
type=HISTOGRAM,
data=ImmutableHistogramData{
aggregationTemporality=CUMULATIVE, (2)
points=[
ImmutableHistogramPointData{
getStartEpochNanos=1720632058272341000,
getEpochNanos=1720632068279567000,
getAttributes={attribute.name="value"}, (3)
getSum=11.0, (4)
getCount=4, (5)
hasMin=true,
getMin=2.0, (6)
hasMax=true,
getMax=4.0, (7)
getBoundaries=[1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0], (8)
getCounts=[0, 2, 1, 1, 0, 0, 0, 0], (9)
getExemplars=[ (10)
ImmutableDoubleExemplarData{
filteredAttributes={},
epochNanos=1720632063049392000,
spanContext=ImmutableSpanContext{
traceId=a22b43a600682ca7320516081eca998b,
spanId=645aa49f219181d0,
traceFlags=01,
traceState=ArrayBasedTraceState{entries=[]},
remote=false,
valid=true
},
value=2.0 (11)
},
//... exemplars for values 3 and 4 omitted for brevity
]
}
]
}| 1 | The name, description and unit of the metric you defined in the constructor of the HistogramResource class. |
| 2 | The aggregation temporality of the histogram. |
| 3 | The attribute added to the histogram when the values were recorded. |
| 4 | The sum of the values recorded. |
| 5 | The number of values recorded. |
| 6 | The minimum value recorded. |
| 7 | The maximum value recorded. |
| 8 | The explicit bucket boundaries for the histogram. |
| 9 | The number of values recorded in each bucket. |
| 10 | The list of exemplars with tracing data for the values recorded. We only show 1 of 3 exemplars for brevity. |
| 11 | One of the 2 calls made with the value 2. |
Differences with the Micrometer API
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Timers and Distribution Summaries are not available in the OpenTelemetry API. Instead, use Histograms.
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The OpenTelemetry API does not define annotations for metrics like Micrometer’s
@Counted,@Timedor@MeterTag. You need to manually create the metrics. -
OpenTelemetry uses their own Semantic Conventions to name metrics and attributes.
リソース
See the main OpenTelemetry Guide resources section.
追加の計器
Automatic metrics are not yet provided by the Quarkus OpenTelemetry extension. We plan to bridge the existing Quarkus Micrometer extension metrics to OpenTelemetry in the future.
エクスポーター
See the main OpenTelemetry Guide exporters section.
OpenTelemetry 設定リファレンス
See the main OpenTelemetry Guide configuration reference.
