Setting up the Otel Collector - OpenTelemetry NodeJS

The OpenTelemetry Collector is a crucial component for managing and exporting telemetry data. It acts as a central point to receive, process, and export traces, metrics, and logs from various services, enhancing the observability of your microservices architecture.

Understand why and when to use the collector in the following article

Use the OpenTelemetry Collector When:

• Centralized Management: You need a central point to manage, process, and export telemetry data from multiple services.
• Data Enrichment and Processing: You need to batch, filter, or enrich data before exporting it.
• Protocol Translation: Your services emit telemetry data in different formats or protocols.
• Scalability and High Availability: You need to distribute the load and ensure high availability.
• Security and Compliance: You have stringent security or compliance requirements.

Send Data Directly When:

• Simplicity: Your setup is small-scale or simple.

• Low Latency: Minimizing latency is critical.

• Minimal Processing Needed: Your telemetry data doesn't require additional processing.

• Fewer Services: You have only a few services emitting telemetry data.

• Centralized Management: You need a central point to manage, process, and export telemetry data from multiple services.

• Data Enrichment and Processing: You need to batch, filter, or enrich data before exporting it.

• Protocol Translation: Your services emit telemetry data in different formats or protocols.

• Scalability and High Availability: You need to distribute the load and ensure high availability.

• Security and Compliance: You have stringent security or compliance requirements.

Send Data Directly When:

• Simplicity: Your setup is small-scale or simple.
• Low Latency: Minimizing latency is critical.
• Minimal Processing Needed: Your telemetry data doesn't require additional processing.
• Fewer Services: You have only a few services emitting telemetry data.

Setting Up the OpenTelemetry Collector

Prerequisites and Requirements

Before setting up the OpenTelemetry Collector, ensure you have the following:

• Basic understanding of Docker and Docker Compose.
• Access to your SigNoz account and the ingestion key.

Creating the Collector Configuration File

First, create a otel-collector-config.yaml file in the same folder as your docker-compose.yml with the following content. Make sure SIGNOZ_INGESTION_KEY and OTEL_EXPORTER_OTLP_ENDPOINT exists in your .env file

receivers:
  otlp:
    protocols:
      grpc:
        endpoint: 0.0.0.0:4317
      http:
        endpoint: 0.0.0.0:4318
  hostmetrics:
    collection_interval: 60s
    scrapers:
      cpu: {}
      disk: {}
      load: {}
      filesystem: {}
      memory: {}
      network: {}
      paging: {}
      process:
        mute_process_name_error: true
        mute_process_exe_error: true
        mute_process_io_error: true
      processes: {}
  prometheus:
    config:
      global:
        scrape_interval: 60s
      scrape_configs:
        - job_name: otel-collector-binary
          static_configs:
            - targets:
processors:
  batch:
    send_batch_size: 1000
    timeout: 10s
  resourcedetection:
    detectors: [env, system]
    timeout: 2s
    system:
      hostname_sources: [os]
extensions:
  health_check: {}
  zpages: {}
exporters:
  otlp:
    endpoint: ${OTEL_EXPORTER_OTLP_ENDPOINT}
    tls:
      insecure: false
    headers:
      "signoz-ingestion-key": ${SIGNOZ_INGESTION_KEY}
  logging:
    verbosity: normal
service:
  telemetry:
    metrics:
      address: 0.0.0.0:8888
  extensions: [health_check, zpages]
  pipelines:
    metrics:
      receivers: [otlp]
      processors: [batch]
      exporters: [otlp]
    metrics/internal:
      receivers: [prometheus, hostmetrics]
      processors: [resourcedetection, batch]
      exporters: [otlp]
    traces:
      receivers: [otlp]
      processors: [batch]
      exporters: [otlp]
    logs:
      receivers: [otlp]
      processors: [batch]
      exporters: [otlp]

Adding the Collector to Docker Compose

We will add the OpenTelemetry Collector as a service in our existing docker-compose.yml

Modify docker-compose.yml

version: '3.8'
services:
  mongodb:
    image: mongo:latest
    ports:
      - "27017:27017"
    volumes:
      - mongo-data:/data/db
    networks:
      - myapp-network

  order:
    build: ./order-service
    ports:
      - "3001:3001"
    environment:
      - OTEL_TRACES_EXPORTER=otlp
      - OTEL_EXPORTER_OTLP_ENDPOINT=http://otel-collector:4318
      - OTEL_NODE_RESOURCE_DETECTORS=env,host,os
      - OTEL_SERVICE_NAME=order-service
      - NODE_OPTIONS=--require @opentelemetry/auto-instrumentations-node/register
    depends_on:
      - mongodb
      - otel-collector
    networks:
      - myapp-network

  payment:
    build: ./payment-service
    ports:
      - "3002:3002"
    environment:
      - OTEL_TRACES_EXPORTER=otlp
      - OTEL_EXPORTER_OTLP_ENDPOINT=http://otel-collector:4318
      - OTEL_NODE_RESOURCE_DETECTORS=env,host,os
      - OTEL_SERVICE_NAME=payment-service
      - NODE_OPTIONS=--require @opentelemetry/auto-instrumentations-node/register
    depends_on:
      - mongodb
      - otel-collector
    networks:
      - myapp-network

  product:
    build: ./product-service
    ports:
      - "3003:3003"
    environment:
      - OTEL_TRACES_EXPORTER=otlp
      - OTEL_EXPORTER_OTLP_ENDPOINT=http://otel-collector:4318
      - OTEL_NODE_RESOURCE_DETECTORS=env,host,os
      - OTEL_SERVICE_NAME=product-service
      - NODE_OPTIONS=--require @opentelemetry/auto-instrumentations-node/register
    depends_on:
      - mongodb
      - otel-collector
    networks:
      - myapp-network

  user:
    build: ./user-service
    ports:
      - "3004:3004"
    environment:
      - OTEL_TRACES_EXPORTER=otlp
      - OTEL_EXPORTER_OTLP_ENDPOINT=http://otel-collector:4318
      - OTEL_NODE_RESOURCE_DETECTORS=env,host,os
      - OTEL_SERVICE_NAME=user-service
      - NODE_OPTIONS=--require @opentelemetry/auto-instrumentations-node/register
    depends_on:
      - mongodb
      - otel-collector
    networks:
      - myapp-network

  otel-collector:
    image: otel/opentelemetry-collector-contrib:latest
    command: ["--config", "/etc/otel-collector-config.yaml"]
    volumes:
      - ./otel-collector-config.yaml:/etc/otel-collector-config.yaml:ro
    ports:
      - "4317:4317"
      - "4318:4318"
      - "8888:8888"
    environment:
      - OTEL_EXPORTER_OTLP_ENDPOINT=${OTEL_EXPORTER_OTLP_ENDPOINT}
      - SIGNOZ_INGESTION_KEY=${SIGNOZ_INGESTION_KEY}
    networks:
      - myapp-network

networks:
  myapp-network:

volumes:
  mongo-data:

Running the Services

Now, start all the services using Docker Compose:

docker-compose up --build

Verifying the Setup

Once the services are running, you should see telemetry data being sent to SigNoz. Check the SigNoz dashboard to visualize the collected traces, metrics, and logs.

Common Issues and Troubleshooting

• Missing Traces: Ensure that the environment variables are correctly set and that the OpenTelemetry Collector is reachable.

• Collector Connectivity Issues: Verify that the collector is running and the endpoints are correctly configured.

• Port not mentioned in the endpoint: Ensure you add the port to the SigNoz endpoint URL as follow:

  OTEL_EXPORTER_OTLP_ENDPOINT="ingest.{region}.signoz.cloud:443"
  

• Connection Issue: OpenTelemetry traces are not being exported correctly, and errors like Parse Error: Expected HTTP/ appear in the logs.

  Solution:

  Verify that the OpenTelemetry environment variables are set correctly. Ensure that the OTEL_EXPORTER_OTLP_ENDPOINT is set to the correct endpoint. Change the OTLP endpoint port from 4317 (gRPC) to 4318 (HTTP) if you're facing connection issues. This change resolved the issue in our setup:

  - OTEL_EXPORTER_OTLP_ENDPOINT=http://otel-collector:4318
  

• Unauthorized Error with Signoz Ingest: When trying to send traces to Signoz, you encounter a 401 Unauthorized error.

  Solution:

  Ensure that the signoz-ingestion-key is correctly set in your environment variables.

  Verify that the token has not expired or been revoke. You can test the token using a curl command:

  curl -v -H "signoz-ingestion-key: YOUR_ACCESS_TOKEN" https://ingest.in.signoz.cloud:443
  

Conclusion

• Centralized Telemetry Management: The OpenTelemetry Collector centralizes the management and export of telemetry data, enhancing observability in microservices architectures.
• Configuration and Setup: Properly configuring the collector and ensuring correct environment variables are crucial for successful telemetry data export.
• Endpoint and Port Configuration: Understanding the importance of using the correct OTLP endpoint and port (switching from 4317 for gRPC to 4318 for HTTP) can resolve common connectivity issues.
• Authentication and Authorization: Ensuring the correct usage of authentication tokens when sending data to external services like SigNoz to avoid unauthorized access issues.

By setting up the OpenTelemetry Collector within Docker, you've centralized the management and export of telemetry data, enhancing the observability of your microservices. This setup allows you to capture detailed traces, metrics, and logs, providing valuable insights into your application's performance.

Next steps include exploring more advanced configurations and custom metrics to fully leverage the capabilities of OpenTelemetry and SigNoz.