Distributed computing and grid computing systems are open and mappable. This means that the specifications of the deployed hardware and software can be quantified and categorized, allowing users to anticipate the capabilities of the system. High openness makes it easy to improve and extend the computing system as needed. Openness can be achieved by publishing a detailed standardized component interface. It also makes it easier to find compatible components for scalability and redundancy purposes.
Closely related to openness is transparency, a property that allows both distributed and networked computing systems to be viewed as a coherent unit rather than a collection of components running simultaneously. High transparency allows programmers and users to access, operate, modify, and manage these systems without problems.
The types of transparency are as follows:
- Location transparency: Location transparency allows stakeholders to track or hide the physical location of an object in the system. Adherence to a standardized and global naming convention makes location transparency easy to achieve. One such naming convention can be the assignment of “logical names” to objects. This allows technicians to easily understand the location and role of an object, regardless of their location in the organization. Location transparency also allows end users to access any copy of a resource without worrying about where it is stored;
- Migration transparency: Distributed and grid systems use migration transparency to ensure high mobility of resources and processes. Software components can be moved into the system without affecting existing operations and communications;
- Replication transparency: replication is an important feature of distributed and grid systems. Resources are copied, and the copy is placed closer to the location where it is regularly accessed to increase availability and performance. Another advantage of replication is that it allows computing systems to deploy a copy of a resource to take over in the event of a failure of another. The transparency of replication allows users to track the existence of copies of a resource and mask their existence from external users. One way to achieve this is to give all copies the same name. Combining replication transparency with location transparency allows the system to refer to copies stored in different locations even if they have the same name;
- Concurrency transparency: Sharing resources on a network is an important goal of distributed computers and computers that use a network. Although in most cases sharing is cooperative, for example for communication processes, it can also be competitive, for example in cases where two users have access to the same file in the same database. In the case of competitive sharing, concurrent transparency helps mask the fact that other users are accessing the same resource at the same time;
- Error transparency: Error transparency in distributed and networked systems hides from programs or users that an object in the system failed to execute properly. Meanwhile, the error is automatically corrected.