title: Cassandra Compaction vs Repair vs Cleanup
body: <p>After posting a <a href="https://stackoverflow.com/questions/37661781/cassandra-compaction-tasks-number-keep-growing">question</a> and reading <a href="https://cassandra-zone.com/understanding-repairs/" rel="noreferrer">this</a> and <a href="http://www.datastax.com/dev/blog/common-mistakes-and-misconceptions" rel="noreferrer">that</a> articles, I still do not understand the relations between those three operations- </p>
  
  <ul>
  <li>Cassandra compaction tasks </li>
  <li>nodetool repair</li>
  <li>nodetool cleanup</li>
  </ul>
  
  <p>Is repair task can be processed while compaction task is running, or cleanup while compaction task is running? Is cleanup is a operation that need to be executed weekly as repair? Why repair operation need to be executed manually and it is not in Cassandra default behavior? </p>
  
  <p>What is the ground rules for healthy cluster maintenance?</p>