Property:Availability

From OIAr Archive 2013
Jump to navigation Jump to search
Informational
Page maturity
This page has maturity level 3 (usable)

This is a Quality Attribute document

Document icon Availability Version: 0.1 OIAr logo
Document type: Quality Attribute Owner:

J.A.H. Schoonderbeek



A facility's/products Availability, denoted as a single string, determines to what degree a facility/product is functioning correctly, and is able to provide sufficient capacity to handle requested use in a timely fashion (within pre-defined service windows). In general, the more robust a facility of product is built, the higher the degree of availability that can be guaranteed. The most common practices in enhancing robustness are the use of redundant components to construct a facility, and/or using a redundant set of facilities to construct a product.

Defined values for Availability:

ordinal value meaning
0 NS no availability specified
10 Best-Effort the operation of a facility/solution is not safe-guarded against incidents and disasters
20 Medium the operation of a facility/solution is unaffected by incidents
30 High the operation of a facility/solution is unaffected by incidents and disasters

The table below provides an overview of these classes and the provisions that should be made to get a facility or Product in a certain class:

Provision Best-Effort Medium High
Single facility/solution, on a single location X X
Redundant or highly resilient facility/solution,
on a single location
X
Redundant facility/solution, on two or more locations X
Fail-over none manual, active-passive automatic, active-active
... more about "Availability"
Availability +
J.A.H. Schoonderbeek +
unspecified +
Allows value"Allows value" is a predefined property that can define a list of permissible values to restrict value assignments for a property and is provided by Semantic MediaWiki.
NS +, Best-Effort +, Medium +  and High +
Has type"Has type" is a predefined property that describes the datatype of a property and is provided by Semantic MediaWiki.