Trace Requests with Zipkin

Traces are one of the three pillars of observability, along with metrics and logs. A trace tracks the journey of a request as it traverses through various parts of a system. It is an effective mechanism that helps developers and administrators monitor system performance, identify bottlenecks, and improve user experience.

This guide will walk you through how to trace requests to APISIX using the zipkin plugin and send traces to Zipkin.

Prerequisite(s)

• Install Docker.
• Install cURL to send requests to the services for validation.
• Follow the Getting Started tutorial to start a new APISIX instance in Docker.

Start Zipkin Instance

Start a Zipkin instance in Docker:

docker run -d --name zipkin -p 9411:9411 openzipkin/zipkin

Configure APISIX

Save the IP address of your host to an environment variable for APISIX configuration:

HOST_IP=192.168.42.145   # replace with your host IP

You can either enable the zipkin plugin globally, which traces requests to all routes; or on a specific route:

Global

Configure zipkin to be a global plugin:

curl "http://127.0.0.1:9180/apisix/admin/global_rules/zipkin" -X PUT -d '
{
  "plugins": {
    "zipkin": {
      "endpoint": "http://'"$HOST_IP"':9411/api/v2/spans",
      "sample_ratio": 1
    }
  }
}'

❶ Set to the /spans Zipkin endpoint.

❷ Configure the sample ratio to 1 to trace every request.

Create a sample route where requests through the route will be traced:

curl "http://127.0.0.1:9180/apisix/admin/routes" -X PUT -d '
{
  "id": "zipkin-tracing-route",
  "uri": "/anything",
  "upstream": {
    "type": "roundrobin",
    "nodes": {
      "httpbin.org": 1
    }
  }
}'

Route

Create a route with zipkin:

curl "http://127.0.0.1:9180/apisix/admin/routes" -X PUT -d '
{
  "id": "zipkin-tracing-route",
  "uri": "/anything",
  "plugins": {
    "zipkin": {
      "endpoint": "http://'"$HOST_IP"':9411/api/v2/spans",
      "sample_ratio": 1
    }
  },
  "upstream": {
    "type": "roundrobin",
    "nodes": {
      "httpbin.org": 1
    }
  }
}'

❶ Set to the /spans Zipkin endpoint.

❷ Configure the sample ratio to 1 to trace every request.

Trace Requests

Send a request to the route:

curl "http://127.0.0.1:9080/anything"

You should receive an HTTP/1.1 200 OK response similar to the following, with trace information in the headers:

{
  "args": {}, 
  "data": "", 
  "files": {}, 
  "form": {}, 
  "headers": {
    "Accept": "*/*", 
    "Host": "127.0.0.1", 
    "User-Agent": "curl/7.64.1", 
    "X-Amzn-Trace-Id": "Root=1-65b1dd40-339dc8832b4b78d36703cbc0", 
    "X-B3-Parentspanid": "6ca01ad46bdb0198", 
    "X-B3-Sampled": "1", 
    "X-B3-Spanid": "f02ab1a9b2d5c3e4", 
    "X-B3-Traceid": "ef5b16781c7ad00ea2e3efa6f784031a", 
    "X-Forwarded-Host": "127.0.0.1"
  }, 
  ...
}

Navigate to the Zipkin web UI at http://127.0.0.1:9411/zipkin and click Run Query, you should see a trace corresponding to the request:

Click Show to see more tracing details:

By default, the plugin uses span version 2, where every traced request has proxy and response spans. More specifically:

• proxy represents the time from the beginning of the request to the beginning of header_filter
• response represents the time from the beginning of header_filter to the beginning of log

To understand the differences between different span versions, see the plugin doc.

Next Steps

You have now integrated Zipkin with APISIX for tracing. In addition to sending traces to Zipkin, the zipkin plugin can also send traces to Jaeger and other compatible collectors. See the zipkin plugin doc for more details.