title: Keeping distributed databases synchronized in a unstable network
body: <p>I'm facing the following challenge:</p>
  <p>I have a bunch of databases in different geographical locations where the network may fail a lot (I'm using cellular network). I need to keep all the databases synchronized but there is no need to be in real time. I'm using Java but I have the freedom to choose any free database.</p>
  <p>How can I achieve this?</p>