title: Spring boot application and concurrency issues
body: <p>I am developing an application that will run under spring boot context with tomcat. This project connects on startup to Kafka, pulls messages and process them. The tomcat is used for some management APIs.</p>
  
  <p>When Spring is loading, it connects with Kafka by several threads.
  Each thread is autowired with a spring bean that handles a message. This bean of-course autowired with more beans etc..</p>
  
  <p>Do I need to consider concurrency issues? Synchronize stuff? use concurrent types such as ConcurrentHashMap instead of normal HashMap for example?</p>