title: Apache Flink & Kafka FETCH_SESSION_ID_NOT_FOUND info logs
body: <p>Our Flink application has a Kafka datasource. </p>
  
  <p>Application is run with 32 parallelism.</p>
  
  <p>When I look at the logs, I see a lot of statements about FETCH_SESSION_ID_NOT_FOUND.</p>
  
  <pre><code>2020-05-04 11:04:47,753 INFO  org.apache.kafka.clients.FetchSessionHandler                  - [Consumer clientId=consumer-81, groupId=sampleGroup]
  Node 26 was unable to process the fetch request with (sessionId=439766827, epoch=42): FETCH_SESSION_ID_NOT_FOUND.
  2020-05-04 11:04:48,230 INFO  org.apache.kafka.clients.FetchSessionHandler                  - [Consumer clientId=consumer-78, groupId=sampleGroup]
  Node 28 was unable to process the fetch request with (sessionId=281654250, epoch=42): FETCH_SESSION_ID_NOT_FOUND.
  </code></pre>
  
  <p>What do these log statements mean? </p>
  
  <p>What are the possible negative effects?</p>
  
  <blockquote>
    <p>Not: I have no experience with Apache Kafka</p>
  </blockquote>
  
  <p>Thanks..</p>