distributed-tracing.md

Distributed Tracing

Easegress tracing is based on Zipkin. We can enable tracing in Traffic Gates, for example, in HTTPServer, we can do this by defining the tracing entry. Tracing creates spans containing the tracing service name (tracing.serviceName) and other information. The matched pipeline will start a child span, and its internal filters will start children spans according to their implementation and configuration. For example, the Proxy filter has a specific span implementation.

kind: HTTPServer
name: http-server-example
port: 10080
tracing:
  serviceName: httpServerExample
  zipkin:
    hostport: 0.0.0.0:10080
    serverURL: http:https://localhost:9412/api/v2/spans
    sampleRate: 1
    sameSpan: true
    id128Bit: false
rules:
  - paths:
    - pathPrefix: /pipeline
      backend: pipeline-example

Custom tags

Custom tags can help to further filter and debug tracing spans. Here's an example with custom tag customTagKey with value customTagValue:

kind: HTTPServer
name: http-server-example
port: 10080
tracing:
  serviceName: httpServerExample
  tags:                             # add "tags" entry and tags as key-value pairs
    customTagKey: customTagValue
  zipkin:
    hostport: 0.0.0.0:10080
    serverURL: http:https://localhost:9412/api/v2/spans
    sampleRate: 1
    sameSpan: true
    id128Bit: false
rules:
  - paths:
    - pathPrefix: /pipeline
      backend: pipeline-example