title: Sync time between servers
body: <p>I have a web server, that process events from several sources / machines.
  For each event I give a timestamp, and store it in the DB. This way, even if not all of the clocks in the source machines has the exact time - it doesn't matter. the order of the events will be preserved, because the server is responsible to the timestamp.</p>
  
  <p>Now, I want to add one more server that can handle these events, and store them in the same DB.
  What is the best way to synch the clock between the servers? the servers are deployed on costumer site, and although i can instruct him that the clocks must be synch- i want to ensure that.</p>
  
  <p>Is there any way to solve it without communicating between the servers?
  Is there any way to use the DB machine clock, in SQL statement? (I should support mysql, sqlserver and oracle. My O/R mapping is hibernate).</p>