Platform:

• Spring Boot (Webflux server & WebClient) -> 2.5.5

IDE:

• IntelliJ -> 2021.2

Build system:

• Maven -> 3.6.3-jdk-11

Platform installed with:

• Maven Central

The version of the SDK:
5.2.4

I have the following issue:

Many (tens or even ~hundred) unrelated http breadcrumbs recorded with events. These breadcrumbs are:

• Incoming server http requests (to actuator endpoints, for example)
• Outgoing http client requests to external services, but they are old and/or unrelated to original incoming server request

Steps to reproduce:

• Use spring-boot webflux server application
• Use sentry-spring-boot-starter
• Use actual sentry server (probably won't work with NoOpHub)
• Start app locally
• Put some load on application
  • I used 50 threads in jmeter accessing actuator health, info and prometheus endpoints without delays
  • prometheus worked better
• Make some meaningful requests which should cause some kind of error which should be sent to sentry
• Observe events on sentry server or via debugging SentryClient (less effective)

Actual result:
Screenshot from actual server-running instance

Expected result:
Only a couple of related http breadcrumbs are present

Personal thoughts
Both SentryWebFilter & SentrySpanClientWebRequestFilter use HubAdapter, which uses static Sentry.getCurrentHub() method, which returns ThreadLocal instance of Hub.

It seems like this mechanism may not work correctly with reactive application, which serves requests on a small number of threads, and they are switched frequently.

As far as I know, there is a way of storing arbitrary request-related data in webflux:

• org.springframework.web.server.ServerWebExchange.getAttributes()
• org.springframework.web.reactive.function.client.ClientRequest.attributes()