title: How to join multiple Kafka topics?
body: <p>So I have...</p>
  
  <ul>
  <li>1st topic that has general application logs (log4j). Stores things like HTTP API requests/responses and warnings, exceptions etc... There can be multiple logs associated to one logical business request. (These logs happen within seconds of each other)</li>
  <li>2nd topic contains commands from the above business request which other services take action on. (The commands also happen within seconds of each other, but maybe couple minutes from the original request)</li>
  <li>3rd topic contains events generated from actions of those other services. (Most events complete within seconds, but some can take up to 3-5 days to be received) </li>
  </ul>
  
  <p>So a single logical business request can have multiple logs, commands and events associated to it by a uuid which the microservices pass to each other.</p>
  
  <p>So what are some of the technologies/patterns that can be used to read the 3 topics and join them all together as a single json document and then dump them to lets say Elasticsearch?</p>
  
  <p>Streaming?</p>