title: FluentValidation, Validators lifecycle and using Validators to check against Db
body: <p>I'm using <strong>FluentValidation</strong> in my <strong>MVC4</strong> project. Every thing <strong>works perfectly</strong> and it's connected to my <strong>IoC</strong> (<strong>StructureMap</strong>).</p>
  
  <p><em>I have 2 questions:</em></p>
  
  <ol>
  <li><p>How should I manage <strong>lifecycle of my validators</strong>? Is it ok to make them <strong>singleton</strong>? or it makes no difference and I can <strong>manage lifecycle according to my needs</strong>? What is the best practice here?</p></li>
  <li><p><strong>FluentValidation</strong> is very good. I have been using it for <strong>simple validations</strong> (like: property is not empty, etc.). I'm thinking about doing some <strong>Db validations</strong> using it(like: <strong>property value is unique</strong>.) I can pass my <strong>repository</strong> to it using <strong>StructureMap</strong> and check values against Db. <strong>Is this a good idea</strong>? or should I implement this logic in my <strong>service layer</strong> and not in my IValidator?</p></li>
  </ol>
  
  <p>If you used it in similar scenarios, what was your experience?</p>