Abstract: A distrbuted services program installed on each of a plurality of data processing systems in a network allows the processors to access data files distrbuted across the various nodes of the network.To reduce the network traffic overhead when files at other nodes are accessed, and to preserve the file system semantics, i.e. the file integrity, the accessing of the various files are managed by file synchronization modes. A file is given a first synchronization mode if a file is open at only one node for either read or write access. A file is given a second synchronization mode if a file is opened for read only access at any node. A file is given a third synchronization mode if the file is open for read access in more than one node, and at least one node has the file open for write access.If a file is in either the first or second synchronization mode, the client node, which is the node accessing the file, uses a client cache within its operating system store the file.