Abstract: A system synchronizes data across multiple data centers to geographically distributed clients may receive current versions of the objects (or portions of objects) from whatever data center is closest to the client. When one of the data centers receives an application object from a first client, it may save the application object in a data collection at that data center. It may also send the application object to other data centers so that the application object is replicated among each of the other data centers. Each of the data centers will relay the updates to the other data centers subscribing clients via various channels, while at least some of the data centers will make the updates available to clients who request the updates. Optionally, the data centers also may publish change notification messages to the channels.