Distributed operating system

[1] Each individual node holds a specific software subset of the global aggregate operating system.

Second is a higher-level collection of system management components that coordinate the node's individual and collaborative activities.

To a user, a distributed OS works in a manner similar to a single-node, monolithic operating system.

The components match the functions of a single-entity system, adding the transparency required in a distributed environment.

[3] The distributed nature of the OS requires additional services to support a node's responsibilities to the global system.

In addition, the system management components accept the "defensive" responsibilities of reliability, availability, and persistence.

A consistent approach, balanced perspective, and a deep understanding of the overall system can assist in identifying diminishing returns.

As such, the logical price of realizing a distributed operation system must be calculated in terms of overcoming vast amounts of complexity in many areas, and on many levels.

This calculation includes the depth, breadth, and range of design investment and architectural planning required in achieving even the most modest implementation.

For instance, a deep understanding of a distributed operating system's overall architectural and design detail is required at an exceptionally early point.

A number of distributed operating systems were introduced during this period; however, very few of these implementations achieved even modest commercial success.

Fundamental and pioneering implementations of primitive distributed operating system component concepts date to the early 1950s.

[11][12][13] Some of these individual steps were not focused directly on distributed computing, and at the time, many may not have realized their important impact.

These pioneering efforts laid important groundwork, and inspired continued research in areas related to distributed computing.

The accelerating proliferation of multi-processor and multi-core processor systems research led to a resurgence of the distributed OS concept.

For example, the SEAC or other computers similar to it could be harnessed to the DYSEAC and by use of coordinated programs could be made to work together in mutual cooperation on a common task… Consequently[,] the computer can be used to coordinate the diverse activities of all the external devices into an effective ensemble operation.The specification discussed the architecture of multi-computer systems, preferring peer-to-peer rather than master-slave.

Each member of such an interconnected group of separate computers is free at any time to initiate and dispatch special control orders to any of its partners in the system.

As a consequence, the supervisory control over the common task may initially be loosely distributed throughout the system and then temporarily concentrated in one computer, or even passed rapidly from one machine to the other as the need arises.

This was similar to a modified hash table data structure that allowed multiple values (parameters) for each key (name).

These entity subsets in turn combine at higher levels, ultimately culminating at a central master element.

Finally, the distributed operating system requires no pattern; direct and indirect connections are possible between any two elements.

Control involves allocating tasks and data to system elements balancing efficiency, responsiveness, and complexity.

Centralized and decentralized systems offer more control, potentially easing administration by limiting options.

Distributed systems are more difficult to explicitly control, but scale better horizontally and offer fewer points of system-wide failure.

The consideration of transparency directly affects decision making in every aspect of design of a distributed operating system.

Systems can optionally violate transparency to varying degrees to meet specific application requirements.

In this sense, Interprocess communication is the greatest underlying concept in the low-level design considerations of a distributed operating system.

While these resources and operations can be either local or remote with respect to each other, the distributed OS maintains state and synchronization over all processes in the system.

Distributed OS can provide the necessary resources and services to achieve high levels of reliability, or the ability to prevent and/or recover from errors.

[citation needed] Managing the task granularity of parallelism in a sensible relation to the messages required for support is extremely effective.