Endless loop in SimpleObservation.getLastScope (original) (raw)

Describe the bug
Our client hits an endless loop in
at io.micrometer.observation.SimpleObservation$SimpleScope.getLastScope(SimpleObservation.java:327)
which is here

Currently this only happens in the production environment of our client and we cannot reproduce it anywhere else (yet).
A related stacktrace showing the context of the call (from the Hibernate saveAll() method) is attached.

Environment

• Micrometer version: 1.12.11
• Hibernate version: 6.4.10.Final
• Spring Boot version: 3.2.11
• Micrometer registry: prometheus
• OS: Linux
• Java version: 17

To Reproduce
The only "reproducer" we have is in the client's production environment.

Expected behavior
I can only suspect that because of a memory visibility issue in a concurrent environment the thread that executes the while loop does not ever see the end of the scope list. One would expect that the scope list does have a proper end and the while loop should stop there.

Additional context
The related stacktrace from a thread dump showing the context of the call which is the Hibernate saveAll() method.
As can be seen the DataSource is wrapped into a net.ttddyy proxy.
20250430-stacktrace-SimpleObservation-327-full.txt