S90.09無料問題集「SOA Design & Architecture Lab」

質問 1

Service A is an entity service that provides a Get capability that returns a data value that is
frequently changed.
Service Consumer A invokes Service A in order to request this data value (1). For Service
A to carry out this request, it must invoke Service B (2), a utility service that interacts (3.4)
with the database in which the data value is stored. Regardless of whether the data value
changed, Service B returns the latest value to Service A (5), and Service A returns the
latest value to Service Consumer A (6).
The data value is changed when the legacy client program updates the database (7) When
this change happens is not predictable. Note also that Service A and Service B are not
always available at the same time.
Any time the data value changes. Service Consumer A needs to receive it as soon as
possible. Therefore, Service Consumer A initiates the message exchange shown in the
Figure several times a day. When it receives the same data value as before, the response
from Service A is ignored. When Service A provides an updated data value, Service
Consumer A can process it to carry out its task.

The current service composition architecture is using up too many resources due to the
repeated invocation of Service A by Service Consumer A and the resulting message
exchanges that occur with each invocation. What steps can be taken to solve this problem?

（A）The Event-Driven Messaging pattern can be applied by establishing a subscriber-
publisher relationship between Service Consumer A and Service A . This way, every time
the data value is updated, an event is triggered and Service A, acting as the publisher, can
notify Service Consumer A, which acts as the subscriber. The Asynchronous Queuing
pattern can be applied between Service Consumer A and Service A so that the event
notification message sent out by Service A will be received by Service Consumer A, even
when Service Consumer A is unavailable.

（B）The Asynchronous Queuing pattern can be applied so that messaging queues are
established between Service A and Service B and between Service Consumer A and
Service A . This way, messages are never lost due to the unavailability of Service A or
Service B.

（C）The Event-Driven Messaging pattern can be applied by establishing a subscriber-
publisher relationship between Service A and Service B . This way, every time the data
value is updated, an event is triggered and Service B, acting as the publisher, can notify
Service A, which acts as the subscriber. The Asynchronous Queuing pattern can be
applied between Service A and Service B so that the event notification message sent out
by Service B will be received by Service A, even when Service A is unavailable.

（D）None of the above.

正解：D 解答を投票する

質問 2

（A）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 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 .

（B）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 Redundant Implementation pattern is applied so that a copy of Service D is brought in-
house for fail-over purposes. The Legacy Wrapper pattern is further applied to wrap
Service D with a standardized service contract that is in compliance with the design
standards used in Service Inventory A.
This wrapper utility service first attempts to access the external service, but if that service is unavailable it will access the redundant internal
service instead.

（C）None of the above.

（D）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 Redundant Implementation pattern is applied so that a copy of Service D is brought in-
house and made part of Service Inventory A.

（E）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 so
that a separate messaging queue is positioned between Service A and Service Consumer

正解：E 解答を投票する

質問 3

Our service inventory contains the following three services that provide invoice-related data
access capabilities: Invoice, InvProc, and Proclnv. These services were created at different
times by different project teams and were not required to comply to any design standards.
Therefore each of these services has a different data model for representing invoice data.
Currently each of these three services has one service consumer: Service Consumer A
accesses the Invoice service(1). Service Consumer B (2) accesses the InvProc service,
and Service Consumer C (3) accesses the Proclnv service. Each service consumer
invokes a data access capability of an invoice-related service, requiring that service to
interact with the shared accounting database that is used by all invoice-related services (4,
5, 6).
Additionally, Service Consumer D was designed to access invoice data from the shared
accounting database directly (7), (Within the context of this architecture. Service Consumer
D is labeled as a service consumer because it is accessing a resource that is related to the
illustrated service architectures.)

Assuming that the Invoice service, InvProc service, and ProcInv service are part of the
same service inventory, what steps would be required to fully apply the Official Endpoint
pattern?

（A）One of the invoice-related services needs to be chosen as the official service providing
invoice data access capabilities. Service Consumers A, B, and C then need to be
redesigned to only access the chosen invoice-related service. Because Service Consumer
D does not rely on an invoice-related service, it is not affected by the Official Endpoint
pattern and can continue to access the accounting database directly. The Service
Abstraction principle can be further applied to hide the existence of the shared accounting
database and other implementation details from current and future service consumers.

（B）Because Service Consumers A, B, and C are already carrying out their data access via
published contracts, they are not affected by the Official Endpoint pattern. Service
Consumer D needs to be redesigned to not access the shared accounting database
directly, but to perform its data access by interacting with the official invoice-related service.
The Service Abstraction principle can be further applied to hide the existence of the shared
accounting database and other implementation details from current and future service
consumers.

（C）None of the above.

（D）One of the invoice-related services needs to be chosen as the official service providing
invoice data access capabilities. Service Consumers A, B, and C then need to be
redesigned to only access the chosen invoice-related service. Service Consumer D also
needs to be redesigned to not access the shared accounting database directly, but to also
perform its data access by interacting with the official invoice-related service. The Service
Abstraction principle can be further applied to hide the existence of the shared accounting
database and other implementation details from current and future service consumers.

正解：D 解答を投票する

質問 4

Service Consumer A sends a message to Service A.
Before the message arrives with Service A, it is intercepted by Service Agent A (1). which checks the message for
compliance to Policy A that is required by Service A.
If the message fails compliance, Service Agent A will not allow it to proceed and will instead write the message contents to a
log. If the message does comply to the policy, it continues to be transmitted toward Service
A, but before it arrives it is intercepted by Service Agent B (2), which validates the security
credentials in the message header. If the security credential validation fails, the message is
rejected and a runtime exception is raised. If the security credentials are validated, the
message is sent to Service A.
Upon receiving the message, Service A retrieves a data value from a database and
populates the message header with this data value (3) prior to forwarding the message to
Service B.
Before the message arrives at Service B.
it is intercepted by Service Agent C (4) which checks the message for compliance with two policies: Policy B and Policy C.
Policy
B is identical to Policy A that was checked by Service Agent A.
To check for compliance to Policy C.
Service Agent C uses the data value added by Service A.
If the message complies with both of the policies, it is forwarded to Service B (5), which stores the message contents in its own database.

You are told that Policy B and Policy C have changed. Also, in order to carry out the
compliance check of Policy C, Service Agent C will now require a new data value from the
Service B database. How can this service composition architecture be changed to fulfill
these new requirements?

（A）The Policy Centralization pattern can be applied so that only one service agent is used
to enforce Policy A and Policy B.
The policy enforcement logic for Policy C is removed from
Service Agent C and instead embedded within the logic of Service B . This way, Service B
can itself retrieve the value required to check compliance with Policy C.
If the message received is not in compliance, Service B will reject it.

（B）The Policy Centralization pattern can be applied so that only one service agent is used
to enforce Policy A and Policy B.
Service A is redesigned to first query Service B for the value required by Service Agent C to check the compliance of the updated Policy C.
If the compliance check is successful, the message is sent to Service B .

（C）The Policy Centralization pattern can be applied so that only one service agent is used
to enforce Policy A and Policy B.
Service Consumer A is redesigned to first query Service
B for the value required by Service Agent C.
This way, Service Consumer A can include this value in the message header prior to sending the message to Service A .

（D）None of the above.

正解：D 解答を投票する

S90.09 無料問題集「SOA Design & Architecture Lab」

弊社を連絡する

関連リンク

トップ試験