SOA S90.09 actual dump : SOA Design & Architecture Lab

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.

Because Service A and Service B are not always available at the same times, messages
are getting lost and several invocation attempts by Service Consumer A fail. What steps
can be taken to solve this problem?

• A. None of the above.
• 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 Asynchronous Queuing pattern can be applied so that a messaging queue is
  established between Service A and Service B . This way, messages are never lost due to
  the unavailability of Service A or Service B . The Service Agent pattern can be further
  applied to establish a service agent that makes a log entry and issues a notification when
  re-transmission attempts by the messaging queue exceeds a pre-determined quantity.
• D. The Asynchronous Queuing pattern can be applied so that a messaging queue is
  established between Service Consumer A and Service A.
  This way, messages are never lost due to the unavailability of Service A or Service B.
  The Service Agent pattern can be
  further applied to establish a service agent that makes a log entry each time a runtime exception occurs.

Service A has become increasingly difficult to maintain. Its core service logic has become
bloated and convoluted because it has been updated numerous times during which
additional functionality was added to interact with the database and the legacy system and
to support interaction with Service Consumers A and B (via the two service contracts) as
well as interaction directly with Service Consumer C.

What steps can be taken to solve these problems and to prevent them from happening
again in the future?

• A. The Service Faade pattern can be applied to position a Facade component between the
  core service logic and the two service contracts. The Contract Centralization pattern can be
  applied to limit access to Service A to one of its two published service contracts. The
  Service Loose Coupling principle can be applied so that Service Consumer C does not
  negatively couple itself directly to the core service logic of Service A .
• B. The Official Endpoint pattern can be applied to limit access to Service A to one of its two
  published service contracts. The Service Loose Coupling principle can be applied so that
  Service Consumer C does not negatively couple itself directly to the core service logic of
  Service A . B.
  The Service Facade pattern can be applied to position a Facade component
  between the core service logic and the implementation resources (the database and the
  legacy system) and to position a faade component between the core service logic and the
  two service contracts. The Contract Centralization pattern can be applied to limit access to
  Service A to one of its two published service contracts. The Service Abstraction principle
  can be applied to hide the implementation details of Service A from service consumers.
• C. The Service Facade pattern can be applied to position a Facade component between
  the core service logic and the implementation resources (the database and the legacy
  system) and to also position a Facade component between the two service contracts and
  Service Consumers A and
• D. None of the above.

Service A.
Service B.
and Service C are each designed to access the same shared legacy
system. The service contracts for Service A, Service B, and Service C are standardized
and decoupled from the underlying service logic. Service A and Service B are agnostic
services that are frequently reused by different service compositions. Service C is a non-
agnostic task service that requires access to the legacy system in order to retrieve
business rules required for the service to make runtime decisions that determine its service
composition logic. The legacy system uses a proprietary file format that Services A, B, and
C need to convert to and from.

You are told that additional services need to be created, all of which need access to the
legacy system. You are also told that the legacy system may be replaced in the near future.
What steps can be taken to ensure that the replacement of the legacy system has a
minimal impact on Services A, B, and C and any future services that are designed to rely
upon it?

• A. The Legacy Wrapper pattern can be applied together with the Data Format
  Transformation pattern and the Standardized Service Contract principle in order to
  establish an intermediate layer of standardized transformation logic that is positioned
  between the legacy system and Services A, B, and C.
  This way, if the legacy system is replaced, the services will not be affected because of the abstraction established by the
  standardized transformation layer.
• B. The Legacy Wrapper pattern can be applied together with the Official Endpoint pattern
  so that the Service A service contract is positioned as the sole access point for the legacy
  system. The Data Format Transformation pattern is applied to enable the conversion
  between the proprietary legacy system file format and the XML format used in the Service
  A service contract. Finally, the Contract Centralization pattern is applied so that Service A
  is forced to only access the legacy system via its published standardized service contract.
• C. None of the above.
• D. The Legacy Wrapper pattern can be applied together with the Standardized Service
  Contract principle to position a standardized service contract between the legacy system
  and any services that require access to it. This effectively establishes a new utility service
  dedicated to the encapsulation of the legacy system. When the legacy system is replaced,
  the utility service can keep its standardized service contract. To build the utility service, the
  Data Format Transformation pattern is applied to convert between the proprietary legacy
  system file format and the XML format used in the standardized service contract.

Service A is an entity service with a functional context dedicated to invoice-related
processing. Service B is a utility service that provides generic data access to a database.
In this service composition architecture, Service Consumer A sends a SOAP message
containing an invoice XML document to Service A(1). Service A then sends the invoice
XML document to Service B (2), which then writes the invoice document to a database.
The data model used by Service Consumer A to represent the invoice document is based
on XML Schema A.
The service contract of Service A is designed to accept invoice documents based on XML Schema B.
The service contract for Service B is designed to accept invoice documents based on XML Schema A.
The database to which Service B needs to write the invoice record only accepts entire business documents in Comma
Separated Value (CSV) format.

Due to the incompatibility of XML schemas used by the services, the sending of the invoice
document from Service Consumer A through to Service B cannot be accomplished using
the services as they currently exist. Assuming that the Contract Centralization and Logic
Centralization patterns are being applied, what steps can be taken to enable the sending of
the invoice document from Service Consumer A to the database without adding logic that
will increase the runtime performance of the service composition?

• A. The service composition can be redesigned so that Service Consumer A sends the
  invoice document directly to Service B.
  Because Service Consumer A and Service B use
  XML Schema A, the need for transformation logic is avoided. This naturally applies the
  Service Loose Coupling principle because Service Consumer A is not required to send the
  invoice document in a format that is compliant with the database used by Service B.
• B. None of the above.
• C. The Standardized Service Contract principle can be applied to the service contract of
  Service A so that it is redesigned to use XML Schema A.
  This would make it capable ofreceiving the invoice document from Service Consumer A and sending the invoice
  document to Service B without the need to further apply the Data Model Transformation pattern.
• D. The Data Model Transformation pattern can be applied so that the invoice document
  sent by Service Consumer A is transformed into an invoice document that is compliant with
  the XML Schema B used by Service A . The Data Model Transformation pattern can be
  applied again to ensure that the invoice document sent by Service A is compliant with XML
  Schema A used by Service B.