title: what will be primary machine fail of postgresql replication
body: <p>I am new at postgresql replication and reading documentations. I looked some replication tutorials. There is one primary machine and multiple stand by machines.</p>
  
  <ul>
  <li>what will be if primary machine fails? Can I convert stand by machines to primary machine?</li>
  <li>if stand by machines fails, will system gives error? (for example database errors because of connection error.)</li>
  </ul>
  
  <p>I need some fail scenarios answer.</p>