Deadlock may occure when Openfeign works with deferred JPA repository

[michaldo]

Spring Cloud version "Hoxton.SR9"

Under some condition deadlock happens with Openfeign + deferred JPA repository. I can reproduce the case only in tests.

I created a simple project to reproduce the problem: https://github.com/michaldo/feign-jpa-deffered-deadlock

I think the same case is reported on https://stackoverflow.com/questions/65078382/spring-boot-context-load-test-hangs

I guess the reason is that FeignClientFactoryBean does not extend AbstractFactoryBean

[OlgaMaciaszek]

@michaldo Thanks for reporting this.

Further analysis:
From here new child context is being created, which triggers ContextRefreshedEvent. DataSourceInitializedPublisher listens on this event and tries to get dataSourceInitialization future. This is causing a deadlock.
dataSourceIniitialization is being initialized within the postProcessEntityManagerFactory method.

[OlgaMaciaszek]

The problem seems to be in Spring Boot. Have created spring-projects/spring-boot#24966. Also, upgrading to Boot 2.3.7 should help as the deferred mode was set to non-default (spring-projects/spring-boot#24249).
Closing in favour of the Spring Boot issues.

[michaldo]

Initially Spring Boot guys told it is OpenFeing issue :)