Files
spring-cloud-sleuth/spring-cloud-sleuth-samples
Marcin Grzejszczak 88d17f79f3 Introduce sampling logic when incoming request has only trace and span ids
without this change when there were tracing headers without sampled decision, we always exported the span.
with this change if:

Trace Id and Span Id are set but there is no Sampled flag - delegate sampling decision to Sampler
Trace Id and Span Id and Sampled flag are set - pass the value from Sampled Flag

fixes gh-1115
2018-10-25 23:26:12 +02:00
..
2017-11-20 23:06:13 +01:00

== Spring Cloud Sleuth Samples

=== Running the samples

There are a few samples with slightly different features. You can run all of them from an IDE via the main method, or on the command line with `mvn spring-boot:run`. They all log trace and span data on the console by default. Here's a list:

* `spring-cloud-sleuth-sample`: vanilla (no zipkin) web app that calls back to itself on various endpoints ("/", "/call", "/async")

* `spring-cloud-sleuth-sample-zipkin`: same as vanilla sample but with zipkin (set `sample.zipkin.enabled=true` if you have a collector running)

* `spring-cloud-sleuth-sample-messaging`: a Spring Integration application with two HTTP endpoints ("/" and "/xform")

* `spring-cloud-sleuth-sample-ribbon`: two endpoints ("/" and "/call") that make calls to the "zipkin" sample via Ribbon. Also has `@EnableZUulProxy" so if the other samples are running they are proxied at "/messaging", "/zipkin", "/vanilla" (see "/routes" for a list).

The Ribbon sample makes an interesting demo or playground for learning about zipkin. In the screenshot below you can see a trace with 3 spans - it starts in the "testSleuthRibbon" app and crosses to "testSleuthMessaging" for the next 2 spans.

=== Running samples with Zipkin

1. Optionally run the https://github.com/openzipkin/zipkin[Zipkin] Server, e.g. via docker compose (there's a `docker-compose.yml` in https://github.com/spring-cloud/spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-zipkin[Spring Cloud Sleuth], or in https://github.com/openzipkin/docker-zipkin[Docker Zipkin]
7. Run the zipkin sample application (set `sample.zipkin.enabled=false` if you have no Zipkin running). If you are using a VM to run docker you might need to tunnel port 9411 to localhost, or change the `spring.zipkin.baseUrl`.
8. Hit `http://localhost:3380`, `http://localhost:3380/call`, `http://localhost:3380/async` for some interesting sample traces (the app callas back to itself).
9. Go to `http://localhost:9411` for Zipkin's UI (if you are using boot2docker the host will be different)

NOTE: You can see the zipkin spans without the UI (in logs) if you run the sample with `sample.zipkin.enabled=false`.

image::{github-raw}/docs/src/main/asciidoc/images/zipkin-trace-screenshot.png[Sample Zipkin Screenshot]

> The fact that the first trace in says "testSleuthMessaging" seems to be a bug in the UI (it has some annotations from that service, but it originates in the "testSleuthRibbon" service).