Observe tracing using Zipkin

The sample shop service will be used in this guide. Follow the steps given below to observe BI tracing in Zipkin.

Step 1 - Set up Zipkin

You can configure BI to support distributed tracing with Zipkin. This section focuses on configuring Zipkin with Docker as a quick installation.

Tip

There are many possible ways to deploy Zipkin. For more information, see Zipkin Quickstart.

Install Zipkin via Docker and start the Docker container by executing the command below.

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

Step 2 - Import Ballerina Zipkin extension

Create the sample shop service. To include the Zipkin extension into the executable, the ballerinax/zipkin module needs to be imported into your BI project by navigating to file explorer and adding the following to main.bal file.

import ballerinax/zipkin as _;

Zipkin extension has a Zipkin Span Exporter which will push tracing data as batches to the Zipkin server endpoint (default - http://localhost:9411) in Zipkin format.

Step 3 - Enable observability for the project

Observability can be enabled in a BI project by adding the following section to the Ballerina.toml file by navigating to the file explorer view.

[build-options]
observabilityIncluded=true

Step 4 - Configure runtime configurations for observability

Tracing can be enabled in your BI project using configurations similar to the following in your Config.toml file.

[ballerina.observe]
tracingEnabled=true
tracingProvider="zipkin"

[ballerinax.zipkin]
agentHostname="localhost"
agentPort=9411
samplerType="const"
samplerParam=1.0
reporterFlushInterval=1000
reporterBufferSize=10000

The table below provides the descriptions of each configuration option and possible values that can be assigned.

Configuration key	Description	Default value	Possible values
ballerinax.zipkin. agentHostname	Hostname of the Zipkin agent	localhost	IP or hostname of the Zipkin agent. If it is running on the same node as Ballerina, it can be localhost.
ballerinax.zipkin. agentPort	Port of the Zipkin agent	4317	The port on which the Zipkin agent is listening.
ballerinax.zipkin. samplerType	Type of the sampling methods used in the Zipkin tracer.	const	const, probabilistic, or ratelimiting.
ballerinax.zipkin. samplerParam	It is a floating value. Based on the sampler type, the effect of the sampler param varies	1.0	For const 0 (no sampling) or 1 (sample all spans), for probabilistic 0.0 to 1.0, for ratelimiting any positive integer (rate per second).
ballerinax.zipkin. reporterFlushInterval	The Zipkin client will be sending the spans to the agent at this interval.	2000	Any positive integer value.
ballerinax.zipkin. reporterBufferSize	Queue size of the Zipkin client.	2000	Any positive integer value.

Step 5 - Run the BI service

When BI observability is enabled, the BI runtime collects tracing data and traces will be published to Zipkin.

Run the the BI service.

Compiling source

Running executable

ballerina: started publishing traces to Zipkin on http://localhost:9411

Step 6 - Send requests

Send requests to http://localhost:8090/shop/products.

Example cURL commands:

$ curl -X GET http://localhost:8090/shop/products

$ curl -X POST http://localhost:8090/shop/product \
-H "Content-Type: application/json" \
-d '{
    "id": 4, 
    "name": "Laptop Charger", 
    "price": 50.00
}'

$ curl -X POST http://localhost:8090/shop/order \
-H "Content-Type: application/json" \
-d '{
    "productId": 1, 
    "quantity": 1
}'

$ curl -X GET http://localhost:8090/shop/order/0

Step 7 - View distributed tracing on the Zipkin server

Go to http://localhost:9411 and load the web UI of Zipkin to make sure it is functioning properly. You can select the service for which you need tracing information find traces.

The image below is the sample tracing information you can see in Zipkin.