brave-webmvc-example
Example Spring Web MVC service implementation that shows the use of the client and server side interceptors from the
brave-spring-web-servlet-interceptor and brave-spring-resttemplate-interceptors modules and the usage of brave in general.
What is it about?
On one hand there is the service resource which can be found in following class:
brave.webmvc.ExampleController
Next to that there is an integration test: brave.webmvc.ITWebMvcExample that sets up
an embedded Jetty server at port 8081 which deploys our service resource at context path http://localhost:8081.
The resource (WebExampleController) makes available 2 URI's
The test code (ITWebMvcExample) sets up our endpoint, does a http GET request to http://localhost:8081/a The code that is triggered through this URI will make a new call to the other URI: http://localhost:8081/b
For both requests our client and server side interceptors that use the Brave api are executed. This results in 2 spans being reported. The test uses log integration which associates span IDs in log output:
16:34:39,858 [79270535a7e54a1f/79270535a7e54a1f] INFO [qtp112302969-17] webmvc.ExampleController - in /a
16:34:40,347 [79270535a7e54a1f/a710aa8929a7f038] INFO [qtp112302969-18] webmvc.ExampleController - in /b
Here's what the log says:
- The first span is the root of the trace (notice the trace ID and span ID are the same).
- The second span is a child of that (notice the same trace ID, but a different span ID).
Running the example
Run Zipkin, which stores and queries traces reported by the above services.
wget -O zipkin.jar 'https://search.maven.org/remote_content?g=io.zipkin.java&a=zipkin-server&v=LATEST&c=exec'
java -jar zipkin.jarNext, from one of the implementation directories, run mvn verify, which will run the test scenario (ITWebMvcExample)
Finally, browse zipkin for the traces the test created: http://localhost:9411/
Deploying to Tomcat
From one of the implementation directories, run mvn package, which creates a war file.
Next, make it the root war in tomcat. Ex. cp target/*war $CATALINA_HOME/webapps/ROOT.war
Ensure zipkin is running and hit the tomcat URL to the path /a. Ex. http://localhost:8080/a