S90.09 Exam Training Practice Tests (SOA Design & Architecture Lab)]

Question 1

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.
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 . B. None of the above. 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. 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.

Correct Answer: B

Question 2

Service A is a utility service that provides generic data access logic to a database that
contains data that is periodically replicated from a shared database (1). Because the
Standardized Service Contract principle was applied to the design of Service A, its service
contract has been fully standardized.
The service architecture of Service A is being accessed by three service consumers.
Service Consumer A accesses a component that is part of the Service A implementation by
invoking it directly (2). Service Consumer B invokes Service A by accessing its service
contract (3). Service Consumer C directly accesses the replicated database that is part of
the Service A implementation (4).
You've been told that the shared database will soon be replaced with a new database
product that will have new data models and new replication technology. How can the
Service A architecture be changed to avoid negative impacts that may result from the
replacement of the database and to establish a service architecture in which negative
forms of coupling can be avoided in the future?

A. The Contract Centralization pattern can be applied to force Service Consumer C to
access the Service A architecture via its published service contract. This will prevent
Service Consumer A from being negatively impacted when the database is replaced in the
future. B. The Contract Centralization pattern can be applied to force all service consumers to
access the Service A architecture via its published service contract. This will prevent
negative forms of coupling that could lead to problems when the database is replaced. The
Service Abstraction principle can then be applied to hide underlying service implementation
details so that future service consumers cannot be designed to access any part of the
underlying service implementation. C. None of the above. D. The Standardized Service Contract principle can be applied to force Service Consumer
B to comply to the standardized service contract of Service A.
As a result, the coupling between Service Consumer B and Service A is reduced. The Logic Centralization pattern
can then be applied to position the logic provided by Service A as a primary access point
for the database. As a result, the component within the Service A architecture abstracts the
proprietary details of the database, thereby shielding Service Consumer A (and any future
service consumers) from changes made to the database.

Correct Answer: B

Question 3

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 despite the fact that duplicate implementations of Service A exist,
performance is still poor at times. Also, you are informed that a new service capability will
soon need to be added to Service A that will introduce functionality that will require access
to a shared database that is used by many other clients and applications in the IT
enterprise. This is expected to add further performance demands on Service A . How can
this service architecture be changed to improve performance in preparation for the addition
of the new service capability?

A. None of the above. B. The Service Loose Coupling principle is applied together with the Standardized Service
Contract principle to ensure that Service Consumer A is not indirectly coupled to the shared
database after the new service capability is added to the service contract. The Legacy
Wrapper pattern can be applied to establish a new utility service that will provide
standardized data access service capabilities for the shared database. C. The Standardized Service Contract principle is applied to ensure that the new service
capability extends the existing service contract in a manner that is compliant with current
design standards. The Redundant Implementation pattern is applied to establish separate
implementations of Service A that include duplicate databases with copies of the data that
Service A requires from the shared database. D. The Service Autonomy principle is applied to further isolate the individual
implementations of Service A by separating them onto different physical servers. When the
new service capability is added, the Service Data Replication pattern is applied to give
each implementation of Service A its own copy of the data it requires from the shared
database.

Correct Answer: D

Question 4

The Client and Vendor services are agnostic services that are both currently part of
multiple service compositions. As a result, these services are sometimes subjected to
concurrent access by multiple service consumers.
The Client service is an entity service that primarily provides data access logic to a client
database but also provides some calculation logic associated with determining a client's
credit rating. The Vendor service is also an entity service that provides some data access
logic but can also generate various dynamic reports.
After reviewing historical statistics about the runtime activity of the two services, it was
discovered that the majority of concurrent runtime access is related to the processing of
business rules. With the Client service, it is the calculation logic that is frequently required
and with the Vendor service it is the dynamic reporting logic that needs to be accessed
separately from the actual report generation.

Currently, due to the increasing amount of concurrent access by service consumers, the
runtime performance of both the Client and Vendor services has worsened and has
therefore reduced their effectiveness as service composition members. What steps can be
taken to solve this problem without introducing new services?

A. None of the above. B. The Redundant Implementation pattern can be applied to the Client and Vendor
services, thereby establishing duplicate implementations that can be accessed when a
service reaches its runtime usage threshold. The Intermediate Routing pattern can be
further applied to provide load balancing logic that can, at runtime, determine which of the
redundant service implementations is the least busy for a given service consumer request. C. The Rules Centralization pattern can be applied by extracting the business rule logic
from the Client and Vendor services and placing it into a new Rules service. This will
naturally improve the runtime performance of the Client and Vendor services because they
will no longer be subjected to the high concurrent access of service consumers that require
access to the business rules logic. D. The Rules Centralization pattern can be applied together with the Redundant
Implementation pattern to establish a scalable Rules service that is redundantly
implemented and therefore capable of supporting high concurrent access from many
service consumers. The Service Abstraction principle can be further applied to hide the
implementation details of the Rules service.

Correct Answer: B

SOA Design & Architecture Lab - S90.09 Exam Practice Test