zipkin.md

title
Zipkin

Summary

• Name
• Attributes
• How To Enable
• Test Plugin
  • run the Zipkin instance
• Disable Plugin

Name

Zipkin is a OpenTracing plugin.

It's also works with Apache SkyWalking, which is support Zipkin v1/v2 format.

Attributes

Name	Type	Requirement	Default	Valid	Description
endpoint	string	required			the http endpoint of Ziplin, for example: http://127.0.0.1:9411/api/v2/spans.
sample_ratio	number	required		[0.00001, 1]	the ratio of sample
service_name	string	optional	"APISIX"		service name for zipkin reporter
server_addr	string	optional			IPv4 address for zipkin reporter, default is nginx built-in variables $server_addr, here you can specify your external ip address.
span_version	integer	optional	2	[1, 2]	the version of span type

Currently each traced request will create spans below:

request
├── proxy: from the beginning of the request to the beginning of header filter
└── response: from the beginning of header filter to the beginning of log

Previously we created spans below:

request
├── rewrite
├── access
└── proxy
    └── body_filter

Note: the name of span doesn't represent the corresponding Nginx's phase.

If you need to be compatible with old style, we can set span_version to 1.

How To Enable

Here's an example, enable the zipkin plugin on the specified route:

curl http://127.0.0.1:9080/apisix/admin/routes/1  -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
    "methods": ["GET"],
    "uri": "/index.html",
    "plugins": {
        "zipkin": {
            "endpoint": "http://127.0.0.1:9411/api/v2/spans",
            "sample_ratio": 1,
            "service_name": "APISIX-IN-SG",
            "server_addr": "192.168.3.50"
        }
    },
    "upstream": {
        "type": "roundrobin",
        "nodes": {
            "127.0.0.1:1980": 1
        }
    }
}'

You also can complete the above operation through the web interface, first add a route, then add zipkin plugin:

Test Plugin

run the Zipkin instance

e.g. using docker:

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

Here is a test example:

$ curl http://127.0.0.1:9080/index.html
HTTP/1.1 200 OK
...

Then you can use a browser to access the webUI of Zipkin:

http://127.0.0.1:9411/zipkin

Disable Plugin

When you want to disable the zipkin plugin, it is very simple, you can delete the corresponding json configuration in the plugin configuration, no need to restart the service, it will take effect immediately:

$ curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
    "methods": ["GET"],
    "uri": "/index.html",
    "plugins": {
    },
    "upstream": {
        "type": "roundrobin",
        "nodes": {
            "127.0.0.1:1980": 1
        }
    }
}'

The zipkin plugin has been disabled now. It works for other plugins.

example code for upstream ( golang with Gin )

func GetTracer(serviceName string, port int, enpoitUrl string, rate float64) *zipkin.Tracer {
    // create a reporter to be used by the tracer
    reporter := httpreporter.NewReporter(enpoitUrl)
    // set-up the local endpoint for our service host is ip:host

    thisip, _ := GetLocalIP()

    host := fmt.Sprintf("%s:%d", thisip, port)
    endpoint, _ := zipkin.NewEndpoint(serviceName, host)
    // set-up our sampling strategy
    sampler, _ := zipkin.NewCountingSampler(rate)
    // initialize the tracer
    tracer, _ := zipkin.NewTracer(
        reporter,
        zipkin.WithLocalEndpoint(endpoint),
        zipkin.WithSampler(sampler),
    )
    return tracer
}

func main(){
    r := gin.Default()

    tracer := GetTracer(...)

    // use middleware to extract parentID from http header that injected by APISIX
    r.Use(func(c *gin.Context) {
        span := this.Tracer.Extract(b3.ExtractHTTP(c.Request))
        childSpan := this.Tracer.StartSpan(spanName, zipkin.Parent(span))
        defer childSpan.Finish()
        c.Next()
    })

}