title: Is MySQL Replication out of sync? Waiting for the slave SQL thread to free enough relay log space
body: <p>MySQL slave server was showing <code>Waiting for the slave SQL thread to free enough relay log space</code> status for about a week because the relay logs were full.</p>
  
  <p>It happened because the SQL Thread was stuck on an error. Once I cleared the error, it started processing relay logs again and freeing space.</p>
  
  <p>Does this mean that the Slave will be out of sync with master, even after reading through all all the relay logs?</p>
  
  <p>My reasoning is that since the slave couldn't download any relay logs for a week, that data would be lost.</p>
  
  <p>Please clarify to me what's going on, so I can determine whether or not to resync servers. Re-syncing slave with master is not my favorite option since the database is huge.</p>