DEFINIÇÕES
- ACID
- Acrônimo de atomicity, consistency, isolation, durability. Conceito antigo e um dos mais
importantes de SBDRs, cuja falta, os torna "não confiáveis". Fonte: The ACID Model.
- ATOMICIDADE
- Conceito de banco de dados que indica que as alterações devem ser feitas por completo ou não devem ser feitas, ou
seja, seguir a regra do "tudo ou nada". Assim cada transação é dita ser atômica, se alguma parte da operação (transação) falhar, a operação toda falha e o estado anterior do banco é recuperado. Fonte: The ACID Model.
- BASE
- Significa basically available, soft state, eventually consistent, ou seja, Fonte: BASE An ACID Alternative.
- CONSISTÊNCIA
- Conceito de banco de dados que indica que somente dados válidos devem ser gravados, se, por alguma razão, uma transação gerar um dados que quebre as regras de consistência, ela deve ser cancelada
e o último estado consistente do banco deve ser recuperado. Fonte:
The ACID Model.
- DURABILIDADE
- Conceito de banco de dados que indica que dados "comitados" são dados perpetuados no sistema e podem ser recuperados por qualquer
usuário, ou seja, são dados que duram. Fonte: The ACID Model.
- ISOLAMENTO
- Conceito de banco de dados que indica que multiplas transações ocorrendo ao mesmo tempo não têm impacto entre si, ou seja, uma transação não interfere na outra. Fonte: The ACID Model.
- Resource:
A physical or virtual entity of limited availability. Physical
resources are computer, storage and communication resources,
etc. Virtual resources are usually services, which
provide direct or indirect access to physical resources.
- Service: An entity which
provides a capability on a resource, or which allows actions to be
performed on resources. Services can in turn be Low Level Services -
which act primarily on physical resources, or High Level Services which
act primarily on virtual resources (i.e. on other services). Services
expose their capabilities via Service Interfaces.
- System: A set of services
and
resources, which form an integrated whole. The concept of a system is
inherently hierarchical, i.e. there are systems of systems. Higher
Level Systems are systems which make use of other systems (i.e. Lower
Level Systems), through aggregation.
- Semantics (of Systems):
The
set of capabilities, or features, available within a system. The
semantics of a system can be greater (more powerful) than the semantics
of its individual (lower level) systems combined.
- System Interface: A set of
interfaces that allow an application (and other higher level systems)
to access the capabilities of a system. APIs provide programmatic
access to these interfaces. Application Environments provide user level
abstractions to APIs. System interfaces often expose only parts of the
entire semantics of the system.
- Virtualization: An
additional
layer between systems and applications which translates concurrent
access to real systems into seemingly exclusive access to the virtual
system, and vice versa. The virtualization interface often hides
details and differences of the real system components.
- Application: An entity
making
use of a system, e.g. by using an API, or an application environment
(see below). Often, Application is used synonymously to Higher Level
System. A Abstract Application is a description of an Application,
which can be instantiated. It does not consume resources. A Concrete
Application is an instantiated Abstract Application, and is consuming
resources.
- Portals and Science Gateways:
High level application environments that are oriented towards
facilitating end usage; these access interfaces allows the description,
instantiation, deployment and management of applications -- both
abstract and concrete -- on a system. Application environments may
provide additional, often application specific, semantics which is
originally not available in the underlying system.
- Usage Mode: A commonly
occurring resource access and deployment pattern for an application or
for a class of applications. For example, Usage Modes may be parameter
sweeps, logical coupling of components (such as in workflows) etc.
- Affinity: An inherent
property
of a system that describes a relationship between two or more (real or
virtual) resources. The relationship is indicative of the types of
Usage Modes that the system supports. Affinities can be indicative of
support for data-oriented, compute intensive, or communication
intensive computing, etc.
- General Purpose Grid: A
system
whose interfaces expose the maximal semantics available within the
system, and are open to any Usage Mode.
- Narrow Grid: A system
whose
interfaces expose the maximal semantics available within the system,
for a specific set of Usage Modes.
- Cloud: A system whose
interfaces expose the minimal semantics available within the system,
while still being usable for a specific set of Usage Modes.
- BASE: