I am trying to integrate OpenTelemetry with a Spring Boot application and export metrics to VictoriaMetrics. Below is my setup:

Java Classes & Configurations

RestartMetrics.java

public class RestartMetrics {

    private static final String SERVICE_NAME = "springboot-service"; // Define service name

    private final LongCounter restartCounter;

    public RestartMetrics(MeterProvider meterProvider) {
        Meter meter = meterProvider.get(SERVICE_NAME + ".restart.metrics");
        this.restartCounter = meter.counterBuilder("service.restart.count")
                .setDescription("Tracks the number of service restarts")
                .build();
    }

    @PostConstruct
    public void init() {
        restartCounter.add(1, Attributes.of(AttributeKey.stringKey("service.name"), SERVICE_NAME));
    }
}

OpenTelemetryConfig.java

public class OpenTelemetryConfig {

    @Bean
    public MeterProvider meterProvider() {
        // Create an OTLP gRPC metric exporter
        OtlpGrpcMetricExporter metricExporter = OtlpGrpcMetricExporter.builder()
                .setEndpoint("http://localhost:4317") // OpenTelemetry Collector endpoint
                .build();

        // Create a PeriodicMetricReader to export metrics periodically
        PeriodicMetricReader metricReader = PeriodicMetricReader.builder(metricExporter)
                .setInterval(Duration.ofMillis(5000)) // Export interval as Duration
                .build();

        // Create and return a MeterProvider
        return SdkMeterProvider.builder()
                .registerMetricReader(metricReader)
                .build();
    }
}

otel-collector-config.yaml

receivers:
  otlp:
    protocols:
      grpc:
        endpoint: 0.0.0.0:4317
      http:
        endpoint: 0.0.0.0:4318

exporters:
  prometheusremotewrite:
    endpoint: http://localhost:8428/api/v1/write
    resource_to_telemetry_conversion:
      enabled: true

service:
  pipelines:
    metrics:
      receivers: [otlp]
      exporters: [prometheusremotewrite]

application.properties

otel.metrics.exporter=otlp
otel.exporter.otlp.endpoint=http://localhost:4317
otel.service.name=springboot-app
otel.exporter.otlp.protocol=http/protobuf

Dependencies (pom.xml)

<dependency>
    <groupId>io.opentelemetry</groupId>
    <artifactId>opentelemetry-api</artifactId>
    <version>1.37.0</version>
</dependency>

<dependency>
    <groupId>io.opentelemetry</groupId>
    <artifactId>opentelemetry-sdk</artifactId>
    <version>1.37.0</version>
</dependency>

<dependency>
    <groupId>io.opentelemetry</groupId>
    <artifactId>opentelemetry-exporter-otlp</artifactId>
    <version>1.36.0</version>
</dependency>

<dependency>
    <groupId>com.squareup.okhttp3</groupId>
    <artifactId>okhttp</artifactId>
    <version>4.11.0</version>
</dependency>

Running Services

VictoriaMetrics

docker run -d -p 8428:8428 --name victoriametrics victoriametrics/victoria-metrics

OpenTelemetry Collector

docker run -v /Users/smith/Documents/Workspace/otel-collector-config.yaml:/etc/otelcol/config.yml -p 4317:4317 otel/opentelemetry-collector

Logs from OpenTelemetry Collector

{"otelcolponent.id": "debug", "otelcolponent.kind": "Exporter", "otelcol.signal": "metrics"}
2025-03-17T07:22:47.997Z    info    Metrics 
{"otelcolponent.id": "debug", "otelcolponent.kind": "Exporter", "otelcol.signal": "metrics", "resource metrics": 1, "metrics": 1, "data points": 1}
2025-03-17T07:22:47.997Z    info    ResourceMetrics #0
Resource SchemaURL: 
Resource attributes:
     -> service.name: Str(unknown_service:java)
     -> telemetry.sdk.language: Str(java)
     -> telemetry.sdk.name: Str(opentelemetry)
     -> telemetry.sdk.version: Str(1.37.0)
ScopeMetrics #0
ScopeMetrics SchemaURL: 
InstrumentationScope springboot-service.restart.metrics 
Metric #0
Descriptor:
     -> Name: service.restart.count
     -> Description: Tracks the number of service restarts
     -> Unit: 
     -> DataType: Sum
     -> IsMonotonic: true
     -> AggregationTemporality: Cumulative
NumberDataPoints #0
Data point attributes:
     -> service.name: Str(springboot-service)
StartTimestamp: 2025-03-17 07:05:17.295034 +0000 UTC
Timestamp: 2025-03-17 07:22:47.899379 +0000 UTC
Value: 1

Issues

1. Metrics are not being sent to VictoriaMetrics. There are no logs related to export, and I verified that VictoriaMetrics is running on localhost:8428.
2. Service name appears as unknown_service:java instead of the expected springboot-app, even though it is specified in application.properties.

Questions

• Why are my metrics not being sent to VictoriaMetrics?
• How can I fix the unknown_service:java issue and correctly set the service name?

Any insights or suggestions would be appreciated. Thanks!