Максим Барабанов

var myMap = new ymaps.Map('map', {
  center: [55.76, 37.64], 
  zoom: 10,
  controls: ['zoomControl']
}, {
   searchControlProvider: 'yandex#search'
});

function init () {
  if(myMap)
    myMap.geoObjects.removeAll();
  objectManager = new ymaps.ObjectManager({
    clusterize: true,
    gridSize: 32
  });
  objectManager.objects.options.set('preset', 'islands#darkGreenCircleDotIcon');
  objectManager.clusters.options.set('preset', 'islands#invertedDarkGreenClusterIcons');
  myMap.geoObjects.add(objectManager);

  $.ajax({
    url: "1.json"
  }).done(function(data) {
    objectManager.add(data);
  });
}