Asynchronous cache failover example

DRY.js

function cacheOrDB (id, callback) {
  asynchronousCache.get("id:"+id, function(err, myThing) {
    if (myThing == null) {
      asynchronousDB.query("SELECT * from something WHERE id = "+id, function(err, myThing) {
        callback(err, myThing);
      });
    } else {
      callback(err, myThing);
    }
  });
}

cacheOrDB("3244", function(err, myThing){
  // Do something with myThing
});