org.springframework.jmx.export.UnableToRegisterMBeanException

With spring.jmx.enabled set to true (the default), any beans in the context that are MBeans will be automatically registered with the JMX server. This fails because Tomcat has already registered them. You have a few options:

1. Set spring.jmx.enabled=false
2. Exclude the bean from being exported as we do in our own JNDI DataSource configuration
3. Use application.properties and @Bean methods to configure your data sources directly rather than using JNDI

In the future, please ask this sort of question on Stack Overflow or Gitter. As mentioned in the guidelines for contributing, we prefer to use GitHub issues only for bugs and enhancements.

https://github.com/spring-projects/spring-boot/issues/9179