SOA S90.09 問題集

質問 1：
You are an architect with a project team building services for Service Inventory A . You are
told that no SLAs for Service B and Service C are available. You cannot determine how
available these services will be, but it has been confirmed that both of these services
support atomic transactions and the issuance of positive and negative acknowledgements.
However, you also find out that the services in Service Inventory B use different data
models than the services in Service Inventory A.
Furthermore, recent testing results have shown that the performance of Service D is steady and reliable. However, Service D uses a
different transport protocol than the services in Service Inventory A.
The response time of Service A is not a primary concern, but Service Consumer A does need to be able to issue
request messages to Service A 24 hours a day without disruption. What steps can be taken
to fulfill these requirements?
A. The Event-Driven Messaging pattern is applied so that a subscriber-publisher
relationship is established between Service Consumer A and Service A . This gives Service
A the flexibility to provide its response to Service Consumer A whenever it is able to collect
the three data values without having to require that Service Consumer A remain stateful.
The Asynchronous Queuing pattern is applied so that a central messaging queue is
positioned between Service A and Service B and between Service A and Service C . The
Data Model Transformation and Protocol Bridging patterns are applied to enable
communication between Service A and Service B and between Service A and Service C .
The Service Autonomy principle is further applied to Service A in order to improve its
overall runtime behavioral predictability.
B. The Asynchronous Queuing pattern is applied so that a central messaging queue is
positioned between Service A and Service B and between Service A and Service C and
between Service A and Service D and so that a separate messaging queue is positioned
between Service A and Service Consumer A.
The Data Model Transformation pattern is
applied to enable communication between Service A and Service B and between Service A
and Service C . The Protocol Bridging pattern is applied to enable communication between
Service A and Service D .
C. The Reliable Messaging pattern is applied so that a system of acknowledgements is
established between Service Consumer A and Service A . This gives Service A the
flexibility to provide Service Consumer A with acknowledgements that indicate that the
processing steps that are occurring between Service A and Service B, Service C, and
Service D are progressing. The Asynchronous Queuing pattern is applied so that a central
messaging queue is positioned between Service A and Service B and between Service A
and Service C and between Service A and Service D . The Redundant Implementation
pattern is applied so that a copy of Service D is brought in-Upon reviewing these
requirements it becomes D with a standardized service contract that is in compliance with
the design standards used in Service Inventory A.
D. None of the above.
正解：B

質問 2：
Service Consumer A sends a message to Service A.
There are currently three duplicate implementations of Service A (Implementation 1, Implementation 2, Implementation 3).
The message sent by Service Consumer A is intercepted by Service Agent A (1), which
determines at runtime which implementation of Service A to forward the message to.
All three implementations of Service A reside on the same physical server.

You are told that after Service A was deployed, each of its three implementations was
claimed by a different IT department, which means each implementation of Service A has a
different owner. You are informed that a new service capability will soon need to be added
to Service A . This service capability will introduce new business logic specific to Service A
as well as logic required to access a shared database. What steps can be taken to ensure
that the service owners will each add the service capability in a consistent manner to their
respective implementations of Service A?
A. The Legacy Wrapper pattern can be applied to establish a new wrapper utility service
that will provide standardized data access service capabilities for the shared database.
This will avoid Service A from having to access the shared database directly and will further
support the application of the Service Loose Coupling principle between Service A and the
new utility service. By abstracting the data access logic into the wrapper service, there is
no need to add the new service capability to each implementation of Service A .
B. The Standardized Service Contract principle is applied to ensure that the new service
capability is consistently added to the service contract of each implementation and that it
extends the existing Service A service contract in a manner that is compliant with current
design standards. The Service Loose Coupling principle is applied to ensure that the new
service capability remains decoupled from the underlying logic and implementation so that
Service Consumer A does not become indirectly coupled to any new logic or to the shared
database.
C. The Contract Centralization pattern can be applied so that when the new service
capability is added, the Service A service contract will become the primary contact point for
Service A . This will avoid Service Consumer A or any other potential service consumer
from being designed to access the shared database directly. The Service Abstraction
principle can be applied to further hide the implementation details so that Service
Consumer A and other service consumers are unaware of the fact that the shared
database is being accessed.
D. None of the above.
正解：B

質問 3：
You are told that in this service composition architecture, all four services are exchanging
invoice-related data in an XML format. The services in Service Inventory A are
standardized to use a specific XML schema for invoice data. Design standards were not
applied to the service contracts used in Service Inventory B, which means that each
service uses a different XML schema for the same kind of data. Database A and Database
B can only accept data in the Comma Separated Value (CSV) format and therefore cannot
accept XML formatted data. What steps can be taken to enable the planned data exchange
between these four services?

A. The Data Model Transformation pattern can be applied so that data model
transformation logic is positioned between Service A and Service C . The Protocol Bridging
pattern can be applied so that protocol bridging logic is positioned between Service A and
Service B and between the Service C and Service D . The Data Format Transformation
pattern can be applied so that data format transformation logic is positioned between the
Service B logic and Database A and between the Service D logic and Database B.
B. The Data Model Transformation pattern can be applied so that data model
transformation logic is positioned between Service A and Service B, between Service A
and Service C, and between Service C and Service D . The Data Format Transformation
pattern can be applied so that data format transformation logic is positioned between the
Service B logic and Database A and between the Service D logic and Database B.
C. None of the above.
D. The Data Model Transformation pattern can be applied so that data model
transformation logic is positioned between Service A and Service C and between Service C
and Service D . The Data Format Transformation pattern can be applied so that data
format transformation logic is positioned between the Service B logic and Database A and
between the Service D logic and Database B.
正解：B

質問 4：
Service Consumer A sends a message to Service A (1), which then forwards the message
to Service B (2). Service B forwards the message to Service C (3), which finally forwards
the message to Service D (4).
Services A, B, and C each contain logic that reads the content of the message and, based
on this content, determines which service to forward the message to. As a result, what is
shown in the Figure is one of several possible runtime scenarios.

Currently, this service composition architecture is performing adequately, despite the
number of services that can be involved in the transmission of one message. However, you
are told that new logic is being added to Service A that will require it to compose one other
service in order to retrieve new data at runtime that Service A will need access to in order
to determine where to forward the message to. The involvement of the additional service
will make the service composition too large and slow. What steps can be taken to improve
the service composition architecture while still accommodating the new requirements and
avoiding an increase in the amount of service composition members?
A. None of the above.
B. The Rules Centralization pattern can be applied to establish a centralized service that
contains routing-related business rules. This new Rules service would replace Service B
and could be accessed by Service A and Service C in order for Service A and Service C to
determine where to forward a message to at runtime. The Service Composability principle
can be further applied to ensure that all remaining services are designed as effective
service composition participants.
C. The Intermediate Routing pattern can be applied together with the Service Agent pattern
by removing Service B or Service C from the service composition and replacing it with a
service agent capable of intercepting and forwarding the message at runtime based on pre-
defined routing logic. The Service Composability principle can be further applied to ensure
that all remaining services are designed as effective service composition participants.
D. The Asynchronous Queuing pattern can be applied together with the Rules
Centralization pattern to establish a Rules service that encapsulates a messaging queue.
This new Rules service would replace Service B and could be accessed by Service A and
Service C in order for Service A and Service C to determine where to forward a message to
at runtime. The Service Composability principle can be further applied to ensure that all
remaining services are designed as effective service composition participants.
正解：C