JDBC transaction marked for rollback-only (exception provided for stack trace) at the start up of project in springboot 3

N.B This question might seem duplicate but I think this is not because in my case I am getting this error only in springboot 3 and during starting the project, not during actual transaction.

I am migrating from springboot 2.7.5 to 3.0.6 . Without making change to code except build.gradle I am getting a new exception during project startup only when debug mode is enabled

023-06-15 12:30:23,839 DEBUG [main] o.h.r.t.b.j.i.JdbcResourceLocalTransactionCoordinatorImpl:324 - JDBC transaction marked for rollback-only (exception provided for stack trace)
java.lang.Exception: exception just for purpose of providing stack trace
        at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.markRollbackOnly(JdbcResourceLocalTransactionCoordinatorImpl.java:324)
        at org.hibernate.internal.AbstractSharedSessionContract.buildNamedQuery(AbstractSharedSessionContract.java:1003)
        at org.hibernate.internal.AbstractSharedSessionContract.createNamedQuery(AbstractSharedSessionContract.java:866)
        at org.hibernate.internal.AbstractSharedSessionContract.createNamedQuery(AbstractSharedSessionContract.java:126)
        at jdk.internal.reflect.GeneratedMethodAccessor29.invoke(Unknown Source)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:568)
        at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:360)
        at jdk.proxy2/jdk.proxy2.$Proxy147.createNamedQuery(Unknown Source)
        at org.springframework.data.jpa.repository.query.NamedQuery.hasNamedQuery(NamedQuery.java:115)
        at org.springframework.data.jpa.repository.query.NamedQuery.lookupFrom(NamedQuery.java:144)
        at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$DeclaredQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:180)
        at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateIfNotFoundQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:252)
        at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$AbstractQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:95)
        at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.lookupQuery(QueryExecutorMethodInterceptor.java:111)
        at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.mapMethodsToQuery(QueryExecutorMethodInterceptor.java:99)
        at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.lambda$new$0(QueryExecutorMethodInterceptor.java:88)
        at java.base/java.util.Optional.map(Optional.java:260)
        at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.<init>(QueryExecutorMethodInterceptor.java:88)
        at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:357)
        at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.lambda$afterPropertiesSet$5(RepositoryFactoryBeanSupport.java:279)
        at org.springframework.data.util.Lazy.getNullable(Lazy.java:245)
        at org.springframework.data.util.Lazy.get(Lazy.java:114)
        at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:285)
        at org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet(JpaRepositoryFactoryBean.java:132)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1816)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1766)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:598)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:520)
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:326)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:324)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:967)
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:917)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:584)
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146)
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:732)
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:310)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1304)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1293)
        at com.Application.main(Nid1StreamsApplication.java:10)

My service class is annotated with @Transactional . Hibernate provides this message JDBC transaction marked for rollback-only when exception occurs. My question is

1. Why transactions is marked for rollback-only when there is no exception during project startup?
2. exception just for purpose of providing stack trace, does this mean I should ignore this exception?

Edit: I am getting this exception for each repo method. Before each exception I am getting logs like this

2023-06-19 11:04:53,967 DEBUG [main] o.s.b.f.s.DefaultListableBeanFactory:225 - Creating shared instance of singleton bean 'countryRepo'
2023-06-19 11:04:53,968 DEBUG [main] o.s.o.j.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler:302 - Creating new EntityManager for shared EntityManager invocation
2023-06-19 11:04:53,970 DEBUG [main] o.s.d.r.c.s.RepositoryFactorySupport:272 - Initializing repository instance for com.demo.repo.CountryRepo…
2023-06-19 11:04:53,971 DEBUG [main] o.s.o.j.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler:302 - Creating new EntityManager for shared EntityManager invocation
2023-06-19 11:04:53,975 DEBUG [main] o.s.d.j.r.q.NamedQuery:141 - Looking up named query CountryRepo.findByName

TL;DR Yes ignore this stacktrace as it is for information purpose only!

This is because Spring Data JPA, at startup, will check if the query method is either a named query or needs to be parsed to generate a query. If not a named query it will generate and validate the query.

Apparently the newer Hibernate version included in Spring Boot 3.x now throws an error at debug level for this. Where older versions didn't.

In short there is no such thing as "I only upgraded from Spring Boot 2.7 to Spring Boot 3.0" as it will upgrade a lot more dependencies and libraries. For which you should read the changelogs as well (depending on the library/framework you might need to change other things as well!).