title: (error) READONLY You can't write against a read only replica
body: <p>I installed Redis and phpredis, it was working fine. I tested the below code in PHP, after that, I'm not able to add/set anything. It shows only "(error) READONLY You can't write against a read-only replica."</p>
  
  <p>My added code:</p>
  
  <pre><code>$redis-&gt;slaveOf('10.0.1.7', 6379);
  $redis-&gt;lastSave();
  </code></pre>
  
  <p>I'm wondering what's wrong in this. assist me to get rid off this issue</p>