t 4 t 1 t 2 and t 3 u03b8 the relative difference between the time systems of the synchronization source and the management node u03b41 a period of time consumed for propagation of the request message over the network u03b42 a period of time consumed for propagation of the response message over the network assumed u03b41 u03b42 and then the following equations hold after deriving the relative difference u03b8 the management node adds the difference u03b8 to its own time to derive the time system temporarily synchronized to the synchronization source during temporal synchronization in the foregoing method the periods of time consumed for propagation over the network u03b41 u03b42 may also be derived for other purposes for example an administrator may determine from the time delay whether there is congestion over the network or an node may set its own timer of transmission timeout according to the time delay etc fig4 b illustrates a schematic diagram of temporal synchronization of a storage node in the method for version control in the distributed system according to the second embodiment of the invention after the management node is temporarily synchronized to the synchronization source the management node may be taken as a time synchronization source in a corresponding domain and temporarily synchronize respective storage nodes in the domain as illustrated in fig4 b temporary synchronization of a management node to a selected synchronization source in the present embodiment includes 1 each of the storage nodes in the domain initiates to the management node a synchronization request message carrying.