Configuring HP DCE Cells

Integrating DCE Services with MC/ServiceGuard

exported to the name space, the name space entry will also identify every IP address on the node as providing the service associated with that entry.

While it is possible to edit the contents of the binding vector before using it to register endpoints or add entries in the name space, few, if any, DCE server programs actually edit the binding vector. In addition, the DCE runtime does not re-determine the list of available IP addresses during the course of server execution, and, again, DCE servers do not, as a general rule, go through their initialization sequence a second time. As a result, for all the DCE core servers and most known application DCE servers, the IP addresses used by the server are set once during initialization, including all the IP addresses available on the node. The addresses do not change once set.

In an MC/ServiceGuard environment, these characteristics might be problematic. Suppose a node had several packages running on it, each based on a DCE service and each with its own IP address. The DCE servers in each package would not only register endpoints using their own IP address, but will also include the IP address of all the other packages configured on the node at the time the server started up. Since all the DCE core services cache IP addresses and store them in their internal databases, the result is a potentially large number of invalid entries, adversely affecting performance, causing the generation of a large number of misleading log messages, and potentially causing the failure of the DCE infrastructure. These considerations and their affects do not preclude the use of MC/ServiceGuard with DCE by any means; they do, however, require that system administrators be particularly careful when planning, configuring, and operating a DCE-MC/ServiceGuard installation.

Through an environment variable, the DCE runtime provides the means to restrict the IP addresses identified by the rpc_server_use_* routines. Used correctly, this variable can alleviate the adverse effects of the characteristics noted above.

Planning for a DCE-MC/ServiceGuard Installation

Planning for a package that includes one or more DCE servers is primarily a process of identifying the disk and network resources necessary for the operation of the server. The planning process should follow the steps outlined in Managing MC/ServiceGuard. Especially

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HP UX DCE Software manual Planning for a DCE-MC/ServiceGuard Installation
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UX DCE Software specifications

HP UX DCE Software, or Hewlett-Packard UNIX Distributed Computing Environment, represents a significant tool in the realm of distributed system architecture. Designed primarily for enterprise environments, HP UX DCE enhances the reliability, scalability, and manageability of applications over diverse networked systems.

One of the main features of HP UX DCE is its ability to integrate various computing platforms, enabling seamless communication and resource sharing across distributed nodes. This facilitates the creation of complex applications that can operate on a multitude of systems, thus enhancing operational flexibility. DCE employs standardized interfaces, which means applications written for one platform can run on any other platform that supports DCE, promoting cross-platform compatibility.

In terms of technologies, HP UX DCE utilizes Remote Procedure Calls (RPC) as a core feature. This mechanism allows different applications to communicate and invoke procedures on remote systems as if they were local calls. Additionally, DCE includes a robust security model that incorporates Kerberos for authentication, ensuring that communication between nodes remains secure and protected against unauthorized access.

Another significant characteristic of HP UX DCE is its distributed file system, which allows for transparent file access across different machines. The DCE File System (DFS) provides a unified namespace and manages data replication and consistency across distributed storage resources. This reduces the complexity of data management and enhances data availability.

HP UX DCE also supports a variety of programming languages, making it accessible for developers accustomed to different coding environments. This versatility encourages widespread adoption and innovation, as developers can leverage existing skills to create distributed applications.

Furthermore, HP UX DCE is built for high availability, ensuring that critical applications remain responsive even in the face of hardware or network failures. Its inherent component redundancy and fault-tolerant architecture are designed to minimize downtime, which is essential for mission-critical applications in enterprise scenarios.

In conclusion, HP UX DCE Software provides a comprehensive framework for developing, deploying, and managing distributed applications. Its core features such as RPC support, a secure authentication mechanism, a robust file system, and cross-platform compatibility make it a vital resource for organizations aiming to leverage distributed computing effectively. As enterprises evolve, HP UX DCE stands out as an influential solution in the dynamic landscape of distributed environments.
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