Ease of ProgrammingTable of Contents
OSF's Distributed Computing Environment (DCE) is a comprehensive set of services that support the development, use and maintenance of distributed applications. DCE allows diverse systems to work together cooperatively and masks the technical complexities of the network. Because DCE is independent of the operating system and network, it is compatible with many diverse environments currently in place by users.
The primary goal for DCE 1.2 is to continue the trend of enterprise-wide deployment of DCE. Release 1.2 will be delivered in two phases 1.2.1 and 1.2.2. DCE 1.2.1 is scheduled for release in Q1 1996. It will offer increased robustness, performance improvements, and significant enhancements to DCE 1.1. These changes concentrate on the important areas of integration with other computing environments, ease of programming, and enhancements to the DCE Distributed File System (DFS) and DCE administration.
System vendors have either announced or are currently shipping DCE on all major computer platforms, including Unix, MVS, Windows, Windows NT, VMS, and OS/2. DCE 1.2.1 will help developers in building DCE applications, and users in administering and working with applications, resulting in accelerated deployment of DCE-based information technology environments.
Ease of ProgrammingInterface Definition Language (IDL) Support for C++
enables C++ developers to write client and server programs that utilize DCE RPC in a highly transparent manner using natural C++ constructs.The IDL language has been extended to support C++ features such as inheritance and object references.
A client using these features can create remote objects or look up ex isting remote objects by invoking the static member functions of the interface. Once an object reference is obtained, any of its member functions can be invoked. Local and remote objects can both be used in the application with no client code differences.
The IDL C++ support provides language enhancements and re lated runtime functions for applications to manage distributed ob jects. Application developers can use the C++ support as is, or as the underlying framework for an object model at a higher level of abstraction. The C++ support does not force adoption of any one object model or class hierarchy, providing the developer with much flexibility.
Integration with Other Computing
EnvironmentsONC Co-existence
enhances the secure NFS protocol gateway of DCE Release 1.1 with support for the DFS host-specific (@HOST) and architecture-specific (@SYS) file naming features. With DCE 1.2.1, NFS inherits the DFS benefits of machine-independent file names, making scripts and configuration files more portable.Netware Co-existence provides file sharing services and administrative aids that allow Netware 3.X users and DCE users to have a single identity and access to the DCE file system, DFS. Netware users now are integrated into the DCE environment with transparent access to enterprise-wide data.
In DCE 1.2.1, Netware clients can define any directory tree in DFS as a Netware volume and use standard Netware or DOS/Windows commands and APIs to manipulate its files and directories. File access security is maintained through a gateway similar to the NFS gate way delivered as part of DCE 1.1. By adding data to the NetWare user object, DCE 1.2.1 can map a Netware user into an authenticated DCE principal. The gateway maps identities, filenames, and permis sions across the two domains.
Improved Distributed File System
(DFS)Optimized Token Manager
decreases the memory requirements and improves the performance and reliability of DFS. The new token manager is about half the size of that in Release 1.1 and improves perfor mance of token-related operations by as much as a factor of six.DFS Server Preferences enables administrators to identify server preferences on a per-fileset basis. Default preferences are based on IP subnet numbers. DFS clients now can make intelligent choices about which servers to use for different filesets enhancing the performance and scalability of DFS in a wide area network (WAN).
Vnode/VM Management enables DFS to perform significantly better as the system is subjected to higher levels of stress. In particular, fine-grain locking will operate more efficiently at high concurrent administrative and user loads, and will operate more efficiently on multiprocessor machines. In addition, an improved interface between Local File System (LFS) and the native virtual memory subsystem simplifies I/O access patterns and code paths.
Replication Enhancements improve the DFS replication implementation to achieve greater reliability and better performance. DCE 1.2.1 converts the replication server from a serial server to a concurrent server. Users will get the benefit of a system which has higher availability and better scalability. Administrators will be able to reorganize how data are lo cated and replicated.
Bulk Status RPC supports more efficient directory browsing by fetching the status of up to 32 files in one RPC, as opposed to fetching the status one file per RPC. With the bulk status RPC the throughput of lookup in open directories im proves by about 50% for directories that have fewer than 1000 entries.
Enhanced Backup Utility supports unattended backup of large DFS file systems using stackers and jukeboxes. Backup in DCE 1.2.1 provides for external callout routines that perform physical tape operations, without operator interaction, for appropriate stor age devices.
DCE Administration EnhancementsDCECP (Distributed Computing Environment Control Program) En hancements
build on the Release 1.1 dcecp by completing adminis trative functions and adding useful extensions. Included are new com mands; new actions on existing commands; and new options on existing actions.Reference PlatformsThe OSF-supported reference platform for DCE Release 1.2.1 is the IBM RS/6000 running AIX 3.2.5. Besides AIX 3.2.5, Release 1.2.1 de velopment was performed on Hewlett Packard HP-UX, Digital UNIX, Sun Solaris, and Hitachi HI-UX (PC compatible with Netware 3.12) platforms.
For More InformationFor more information on OSF membership, DCE or other OSF technologies, contact OSF Direct Channels at (617) 621-7300 or email direct@osf.org. For detailed DCE information, consult the documen tation. You may also obtain DCE and other information from OSF's worldwide web site: http://www.osf.org
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