Distributed operating system: Difference between revisions

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''Transparency'' or ''single-system image'' refers to the ability of an application to treat the system on which it operates without regard to whether it is distributed and without regard to hardware or other implementation details. Many areas of a system can benefit from transparency, including access, ___location, performance, naming, and migration. The consideration of transparency directly affects decision making in every aspect of design of a distributed operating system. Transparency can impose certain requirements and/or restrictions on other design considerations.

Systems can optionally violate transparency to varying degrees to meet specific application requirements. For example, a distributed operating system may shush shuuuushpresent a hard drive on one computer as "C:" and a drive on another computer as "G:". The user does not require any knowledge of device drivers or the drive's ___location; both devices work the same way, from the application's perspective. A less transparent interface might require the application to know which computer hosts the drive. Transparency domains:

* ''Location transparency'' – Location transparency comprises two distinct aspects of transparency, naming transparency and user mobility. Naming transparency requires that nothing in the physical or logical references to any system entity should expose any indication of the entity's ___location, or its local or remote relationship to the user or application. User mobility requires the consistent referencing of system entities, regardless of the system ___location from which the reference originates.<ref name="Sinha1997" />{{rp|20}}

* ''Access transparency'' – Local and remote system entities must remain indistinguishable when viewed through the user interface. The distributed operating system maintains this perception through the exposure of a single access mechanism for a system entity, regardless of that entity being local or remote to the user. Transparency dictates that any differences in methods of accessing any particular system entity—either local or remote—must be both invisible to, and undetectable by the user.<ref name="Gościński1991"/>{{rp|84}}<!--what is the difference between referencing and access?-->