Spring WebClient tracing issue

Hi! I am trying to set-up tracing for a stateless GraphQL api-gateway (simple HttpServlet), which accepts requests at POST /graphql. The gateway makes use of WebClient in order to call another service for retrieving data.

The problem I am facing is that both the /graphql, as well as the endpoints the api-gateway is calling are showing up in the resource list displayed in Datadog.

I have extracted the information on the traces below:

DDSpan [ t_id=6496705132716908527, s_id=3252327453084076151, p_id=0] trace=api-gateway/servlet.request/POST /graphql metrics={} tags={component=java-web-servlet, http.method=POST, http.url=http://localhost:9090/graphql, runtime-id=6407f4f3-21b7-4314-8b4e-6c50e1125e82, span.kind=server, span.origin.type=org.apache.catalina.core.ApplicationFilterChain, thread.id=63, thread.name=http-nio-9090-exec-10}, duration_ns=0

DDSpan [ t_id=7417067946456931379, s_id=5348444464491720869, p_id=0] trace=api-gateway/netty.client.request/GET /books/?/author metrics={} tags={component=netty-client, http.method=GET, http.status_code=200, http.url=http://localhost:8060/books/12345/author, peer.hostname=localhost, peer.port=8060, runtime-id=6407f4f3-21b7-4314-8b4e-6c50e1125e82, span.kind=client, thread.id=28, thread.name=reactor-http-nio-4}, duration_ns=50383986

It seems that the async WebClient request is not properly linked to the initial request.

The issue I am experiencing seems very similar to the one described here: https://github.com/htmldoug/datadog-netty4-failing/pull/1.

[johanvandeweerd]

I created PR #831 to add support for WebClient. It’s still rough around the edges but it’s a start. Hope this is enough to speed things up.

[tylerbenson]

This is included in https://github.com/DataDog/dd-trace-java/releases/tag/v0.31.0