Java Agent Error while sending Data to Open Telemetry Endpoint (OTEL Endpoint)

[ankitk-me]

Discussed in #1400

^{Originally posted by Gwydiyon February 13, 2025}
Hey guys, i am a bit lost. Following error occurs while I try sending Logs and Metrics to an OpenTelemetry Collector from my Zilla.

Error in Log: (

java.lang.NullPointerException: Cannot invoke "Object.hashCode()" because "pk" is null
	at java.base/java.util.ImmutableCollections$MapN.probe(ImmutableCollections.java:1328)
	at java.base/java.util.ImmutableCollections$MapN.get(ImmutableCollections.java:1242)
	at io.aklivity.zilla.runtime.exporter.otlp@0.9.125/io.aklivity.zilla.runtime.exporter.otlp.internal.serializer.OtlpMetricsSerializer$OtlpMetricsDescriptor.nameByBinding(OtlpMetricsSerializer.java:314)
	at io.aklivity.zilla.runtime.exporter.otlp@0.9.125/io.aklivity.zilla.runtime.exporter.otlp.internal.serializer.OtlpMetricsSerializer.serializeScalar(OtlpMetricsSerializer.java:161)
	at io.aklivity.zilla.runtime.exporter.otlp@0.9.125/io.aklivity.zilla.runtime.exporter.otlp.internal.serializer.OtlpMetricsSerializer.serialize(OtlpMetricsSerializer.java:120)
	at io.aklivity.zilla.runtime.exporter.otlp@0.9.125/io.aklivity.zilla.runtime.exporter.otlp.internal.serializer.OtlpMetricsSerializer.lambda$serializeAll$1(OtlpMetricsSerializer.java:92)
	at java.base/java.lang.Iterable.forEach(Iterable.java:75)
	at io.aklivity.zilla.runtime.exporter.otlp@0.9.125/io.aklivity.zilla.runtime.exporter.otlp.internal.serializer.OtlpMetricsSerializer.serializeAll(OtlpMetricsSerializer.java:92)
	at io.aklivity.zilla.runtime.exporter.otlp@0.9.125/io.aklivity.zilla.runtime.exporter.otlp.internal.OltpExporterHandler.exportMetrics(OltpExporterHandler.java:134)
	at io.aklivity.zilla.runtime.exporter.otlp@0.9.125/io.aklivity.zilla.runtime.exporter.otlp.internal.OltpExporterHandler.export(OltpExporterHandler.java:115)
	at io.aklivity.zilla.runtime.engine@0.9.125/io.aklivity.zilla.runtime.engine.internal.exporter.ExporterAgent.doWork(ExporterAgent.java:44)
	at org.agrona.core/org.agrona.concurrent.AgentRunner.doWork(AgentRunner.java:304)
	at org.agrona.core/org.agrona.concurrent.AgentRunner.workLoop(AgentRunner.java:296)
	at org.agrona.core/org.agrona.concurrent.AgentRunner.run(AgentRunner.java:162)
	at java.base/java.lang.Thread.run(Thread.java:1570)

zilla.yaml (Zilla-conf)
telemetry:
    # Desired metrics to track
    metrics:
      - http.request.size
      - http.response.size
      - http.active.requests
      - http.duration
      - stream.active.received
      - stream.active.sent
      - stream.opens.received
      - stream.opens.sent
      - stream.data.received
      - stream.data.sent
      - stream.errors.received
      - stream.errors.sent
      - stream.closes.received
      - stream.closes.sent

    exporters:
      otel_exporter_otlp:
        type: otlp
        options:
          interval: 5
          signals:
            - metrics
            - logs
          endpoint:
            protocol: http
            location: http://otel-gw-collector.esb:4318

  bindings:
    #### EVENT
    openapi_event_rest_server:
      type: openapi
      kind: server
      options:
        specs:
          diip_rest_spec:
            catalog:
              openapi_apicurio:
                subject: event
                version: "1"
            servers:
              - url: http://esb-zilla-event.esb:7114
      exit: event_openapi_asyncapi_mapping
      telemetry:
        metrics:
          - stream.*

otel-collector.conf:
   receivers:
      otlp:
        protocols:
          grpc:
            endpoint: 0.0.0.0:4317
          http:
            endpoint: 0.0.0.0:4318