title: Cassandra uneven partitions and hotspots
body: <p>I have one doubt regarding partition distribution in Cassandra.</p>
  
  <p>My problem is that my partitions are not even-sized, and some of the partitions are more accessed than others, so I'm afraid I'll have a hot spot in some partitions sooner or later.</p>
  
  <p>For example: </p>
  
  <ol>
  <li>I've two partitions: A and B. </li>
  <li>Size of A is 10, size of B is 5. </li>
  <li>read the full A partition twice the times I read B. </li>
  <li>have three (1, 2, and 3) nodes, with replication factor 2.</li>
  </ol>
  
  <p>Results:</p>
  
  <ul>
  <li>Node 1 (A) Node 2 (B, A) Node 3 (B)</li>
  <li>Node 1 size is 10, read 1.0</li>
  <li>Node 2 size is 15, read 1.5</li>
  <li>Node 3 size is 5, read 0.5</li>
  </ul>
  
  <p>My nodes 1 and 2 are overloaded.</p>
  
  <p>I started researching about my problem, and I found the Virtual Nodes concept, but I'm not too sure about what it actually means.</p>
  
  <p>Will a single partition key be assigned to different virtual nodes (1 partition key -> n token ranges)?</p>
  
  <p>One partition key can only be stored in a virtual node?</p>
  
  <p>I have to partition my keys adding some partition info (like a random % 10 or something) or there's a way to make Cassandra do it automatically?</p>