title: apache ignite on-heap and off-heap memory
body: <p>I am using ignite 2.9. Native persistence is disabled.</p>
  <p>Enabled on heap caching using</p>
  <p>CacheConfiguration.setOnheapCacheEnabled(true)</p>
  <p>But I can still see off-heap metrics in logs.</p>
  <ol>
  <li>shouldn't it use only heap memory after making on-heap true?</li>
  <li>What type of data gets stored off-heap?</li>
  <li>How eviction works incase of eviction policy defined for default data region is random2Lru and LRU for on heap?</li>
  </ol>