Basic example showing distributed tracing with a Ratpack app

This is a single Ratpack example service with 2 endpoints that show usage of simple request/response timing, http client call timing, local spans and context propagation with Ratpack ParallelBatch.

The 3 endpoints are:

• /generate

  Generates a single UUID with request/response tracing

• /remote/generate

  Generates a single UUID by performing an HTTP client request to /generate.

• /remote/generatemany

  Generates many UUIDs by calling /generate with an HTTP client request. Before making a remote HTTP client call a local span is created. All client calls are executed concurrently using a ParallelBatch.

Here's an example of what /remote/generatemany looks like

TODO add screenshot

#Implementation Overview Web request are served by Ratpack, which traces request by using Brave Ratpack plugin.

These traces are sent out of process over http to Zipkin.

#Running the example This example has a single service which calls itself for the /remote/* endpoints.

Once the service is started, open one of the 3 URLs, http://localhost:5050/generate; http://localhost:5050/remote/generate; http://localhost:5050/remote/generatemany

Next, you can view traces via http://localhost:9411/zipkin/?serviceName=example

• This is a locally run Zipkin service which keeps traces in memory

##Starting the Services Run the Ratpack example:

$ ./mvnw compile exec:java

Next, run Zipkin, which stores and queries traces reported by the above service.

$ curl -sSL https://zipkin.io/quickstart.sh | bash -s
$ java -jar zipkin.jar