title: Configure minimal Log4j2 in parallel to existing SLF4J&Logback
body: <p>We have more than 200 Spring Boot microservices, using Logback as their default logging framework through SLF4j as API. It is not possible to switch this large amount of services to use Log4j2 easily. Therefore and for a very special use-case I would like to use the asynchronous features in Log4j2 only. </p>
  
  <p>Unfortunately the automatic configuration of Log4j2 always configures the <code>SLF4LoggingContextFactory</code> which uses the Logback implementation in the background.
  My attempts to configure Log4j2 independently of the Logback framework seems not to work.</p>
  
  <p>My questions are:</p>
  
  <ol>
  <li>How can I stop Log4j2 to do the default configuration? (static initializer in the class <code>LogManager</code>)</li>
  <li>How can I just configure one logger in an asynchronous way to send log events via HTTP to a REST API?</li>
  </ol>
  
  <p>I know that programmatic configuration is not recommended by the Log4j2 team, but I could live with any changes in the future. And maybe an API can be added that allows such changes without setting VM parameters or messing around with internal classes.</p>