Efficiently re-starting and recovering synchronization operations between a client and server

Systems, methods and computer program products for efficiently re-starting and/or recovering interrupted synchronizations between a client and a server are described herein. A server transmits sync data to a client during a synchronization operation. The sync is interrupted for some reason prior to the client receiving all of the sync data. The client sends to the server a request to re-start the synchronization operation. The request includes information that identifies a point in the sync data that was received by the client prior to interruption of the sync. Such information may include (a) information identifying the last data received by the client prior to interruption of the sync; and/or (b) information identifying the next data needed by the client upon re-start of the sync. Thereafter, the server re-starts the sync by transmitting to the client the sync data starting from said point in said sync data identified by said request.