In
distributed computing
A distributed system is a system whose components are located on different networked computers, which communicate and coordinate their actions by passing messages to one another from any system. Distributed computing is a field of computer sci ...
, failure semantics is used to describe and classify
error
An error (from the Latin ''error'', meaning "wandering") is an action which is inaccurate or incorrect. In some usages, an error is synonymous with a mistake. The etymology derives from the Latin term 'errare', meaning 'to stray'.
In statistic ...
s that distributed systems can experience.
[, pp 14–16.]
Types of errors
A list of types of errors that can occur:
* An omission error is when one or more responses fails.
* A
crash error is when nothing happens. A crash is a special case of omission when all responses fail.
* A
Timing error is when one or more responses arrive outside the time interval specified. Timing errors can be ''early'' or ''late''. An omission error is a timing error when a response has infinite timing error.
* An arbitrary error is any error, (i.e. a wrong value or a timing error).
* When a client uses a
server
Server may refer to:
Computing
*Server (computing), a computer program or a device that provides functionality for other programs or devices, called clients
Role
* Waiting staff, those who work at a restaurant or a bar attending customers and su ...
it can cope with different type errors from the server.
** If it can manage a crash at the server it is said to assume the server to have crash failure semantics.
** If it can manage a service omission it is said to assume the server to have omission failure semantics.
*** Failure semantics are the type of errors that are expected to appear.
* Should another type of error appear it will lead to a service failure because it cannot be managed.
References
{{reflist
Failure
Distributed computing problems