J.J. Beam questions

• is synchronized needed in getValue() ? & volatile needed?
• Is it possible in Kafka to read messages in reverse manner?
• How and why and what for do tombstone records appear in Kafka?
• What happens when kubernetes liveness-probe return false?
• @SpringBootTest Vs @WebMvcTest & @DataJpaTest &service unit tests, what is the best?
• What if a Kafka's consumer handles a message too long? Will Kafka reappoint this partition to another consumer and the message will doubly handled?
• How can I combine @DataJpaTest @SpringBootTest in one MVC application for testing every layer?
• Java 8 Map merge VS compute, essential difference?
• Why is the finalize() method deprecated in Java 9?
• Java IntStream iterate vs generate when to use what?

J.J. Beam answers