title: Redis Sentinel DEL command issue
body: <p>Because of the security concerns I had to rename DEL command on all of the 3 Redis Sentinel nodes. Master is able to expire its keys and remove them off the memory. However Slaves are not able to remove the keys. Eventually memory gets maxed up and node becomes unstable.  </p>
  
  <p>I checked the redis.log file:</p>
  
  <h1>== CRITICAL == This replica is sending an error to its master: 'unknown command <code>DEL</code>, with args beginning with: <code>test-11146</code>, ' after processing the command ''</h1>
  
  <p>When I comment out renaming the DEL command on redis.conf file, things get back to working again. 
  I think this issue has been around for a while as I came across a few Google Searches with similar context. </p>
  
  <pre><code>rename-command PEXPIRE WF4RSp2s3a
  rename-command DEL m6T1V5Fn1a
  rename-command CONFIG 3Zg871qH1a
  </code></pre>
  
  <p>I would appreciate if someone can point me in the right direction.</p>