Service A is a task service that is required to carry out a series of updates to a set of databases in order to complete a task. To perform the database updates Service A must interact with three other services, each of which provides standardized data access capabilities.

Service A sends its first update request message to Service B (1), which then responds with a message containing a success or failure code (2). Service A then sends its second update request message to Service C (3), which also responds with a message containing a success or failure code (4). Finally, Service A sends a request message to Service D (5), which responds with its own message containing a success or failure code (6).

You've been given a requirement that all database updates must either be completed successfully or not at all. This means that if any of the three response messages received by Service A contain a failure code, all of the updates carried out until that point must be reversed. Note that if Service A does not receive a response message back from Services B, C, or D, it must assume that a failure has occurred. How can this service composition architecture be changed to fulfill these requirements?

A. The Reliable Messaging pattern can be applied to guarantee the delivery of positive or negative acknowledgements. This way, Service A will always be informed of whether a failure condition has occurred with any of the database updates performed by Services B, C, and D. Furthermore, the Service Loose Coupling principle can be applied to ensure that the request and response messages exchanged by the services do not contain any implementation details that would indirectly couple Service A to any of the databases.

B. The Atomic Service Transaction pattern can be applied individually to Services B, C, and D so that each of these services performs its own database update within the scope of an atomic transaction. If anyone update fails, that change can be rolled back on that database. Furthermore, the Service Loose Coupling principle can be applied to ensure that Service A is kept out of the scope of the atomic transaction so that it is not negatively coupled to the proprietary database technologies that are required to enable the atomic transaction functionality.

C. The Compensating Service Transaction can be applied to Service A so that when any one response message containing a failure code is received by Service A, it can invoke exception handling logic that will log the failed database updates. The Service Loose Coupling principle can be further applied to ensure that Services B, C, or D are not indirectly coupled to the exception handling logic, especially if Service A requires additional access to Services B, C, or D in order to collect more information for logging purposes.

D. None of the above.

Service A is a task service that is required to carry out a series of updates to a set of databases in order to complete a task. To perform the database updates Service A must interact with three other services, each of which provides standardized data access capabilities.

Service A sends its first update request message to Service B (1), which then responds with a message containing a success or failure code (2). Service A then sends its second update request message to Service C (3), which also responds with a message containing a success or failure code (4). Finally, Service A sends a request message to Service D (5), which responds with its own message containing a success or failure code (6).

You've been asked to change this service composition architecture in order to fulfill a set of new requirements: First, if the database update performed by Service B fails, then it must be logged by Service

A. Secondly, if the database update performed by Service C fails, then a notification e-mail must be sent out to a human administrator. Third, if the database update performed by either Service C or Service D fails, then both of these updates must be reversed so that the respective databases are restored back to their original states. What steps can be taken to fulfill these requirements?

A. Service A is updated to perform a logging routine when Service A receives a response message from Service B containing a failure code. Service A is further updated to send an e-mail notification to a human administrator if Service A receives a response message from Service C containing a failure code. The Atomic Service Transaction pattern is applied so that Services A, C, and D are encompassed in the scope of a transaction that will guarantee that if the database updates performed by either Service C or Service D fails, then both updates will be rolled back.

B. The Compensating Service Transaction pattern is applied to Service B so that it invokes exception handling logic that logs failed database updates before responding with a failure code back to Service

A . Similarly, the Compensating Service Transaction pattern is applied to Service C so that it issues an e-mail notification to a human administrator when a database update fails. The Atomic Service Transaction pattern is applied so that Services A, C, and D are encompassed in the scope of a transaction that will guarantee that if the database updates performed by either Service C or Service D fails, then both updates will be rolled back. The Service Autonomy principle is further applied to Service A to ensure that it remains consistently available to carry out this sequence of actions.

C. The Atomic Service Transaction pattern is applied so that Services A, C, and D are encompassed in the scope of a transaction that will guarantee that if the database updates performed by either Service C or Service D fails, then both updates will be rolled back. The Compensating Service Transaction pattern is then applied to all services so that the scope of the compensating transaction includes the scope of the atomic transaction. The compensating exception logic that is added to Service D automatically invokes Service B to log the failure condition and Service C to issue the e-mail notification to the human administrator. This way, it is guaranteed that the compensating logic is always executed together with the atomic transaction logic.

D. None of the above.

Service A is an entity service that provides a set of generic and reusable service capabilities. In order to carry out the functionality of any one of its service capabilities, Service A is required to compose Service B

(1) and Service C (2) and Service A is required to access Database A (3), Database B (4), and Database C (5). These three databases are shared by other applications within the IT enterprise.

All of service capabilities provided by Service A are synchronous, which means that for each request a service consumer makes. Service A is required to issue a response message after all of the processing has completed.

Depending on the nature of the service consumer request, Service A may be required to hold data it receives in memory until its underlying processing completes. This includes data it may receive from either Service A or Service B or from any of the three shared databases.

Service A is one of many entity services that reside in a highly normalized service inventory. Because Service A provides agnostic logic, it is heavily reused and is currently part of many service compositions.

You are told that Service A has recently become unstable and unreliable and several of the service consumers that access it have had to raise runtime exceptions due to these problems. What steps can be taken to solve these problems without compromising the normalization of the service inventory?

A. The Service Autonomy principle can be applied to increase the physical isolation of Service A and to reduce dependencies Service A has on external resources. In support of this, the Service Data Replication pattern can be applied in order to establish a dedicated database that contains replicated data from shared Databases A, B, and C . Furthermore, the Redundant Implementation pattern can be applied so that the logic Service A requires from Services B and C can be redundantly placed inside of Service A . This way, Service A avoids having to separately compose Services B and C

B. The Service Statelessness principle can be applied with the help of the State Repository pattern in order to establish a state database that Service A can use to defer state data it may be required to hold for extended periods. The Service Autonomy principle can also be applied in order to increase the physical isolation of Service A and to reduce dependencies Service A has on external resources. In support of this, the Service Data Replication pattern can be applied in order to establish a dedicated database that contains replicated data from shared Databases A, B, and C.

C. The Service Loose Coupling and Standardized Service Contract principles can be applied by introducing a separate utility service that provides centralized data access to the Databases A, B, and C, and exposes a standardized service contract that can be used by Service A . This will prevent Service A from direct dependencies on the shared databases in case any of them are replaced in the future. By following this approach, the Legacy Wrapper pattern is effectively applied via the introduction of the new utility service.

D. None of the above.

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. 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 .

B. 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.

C. 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.

D. None of the above.

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. 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.

B. 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.

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 predefined routing logic. The Service Composability principle can be further applied to ensure that all remaining services are designed as effective service composition participants.

D. None of the above.

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. 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 .

C. 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.

D. None of the above.

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. 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.

B. 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.

C. 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.

D. None of the above.

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 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.

B. 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.

C. 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.

D. None of the above.

When Service A receives a message from Service Consumer A(1),the message is processed by Component A. This component first invokes Component B (2), which uses values from the message to query Database A in order to retrieve additional data. Component B then returns the additional data to Component A.

Component A then invokes Component C (3), which interacts with the API of a legacy system to retrieve a new data value. Component C then returns the data value back to Component A.

Next, Component A sends some of the data it has accumulated to Component D (4), which writes the data to a text file that is placed in a specific folder. Component D then waits until this file is imported into a different system via a regularly scheduled batch import. Upon completion of the import, Component D returns a success or failure code back to Component A.

Component A finally sends a response to Service Consumer A (5) containing all of the data collected so far and Service Consumer A writes all of the data to Database B (6).

Components A, B, C. and D belong to the Service A service architecture. Database A, the legacy system, and the file folders are shared resources within the IT enterprise.

Service A is a task service that completes an entire business task on its own without having to compose other services. However, you have received many complaints about the reliability of Service A . Specifically, it has three problems. First, when Component B accesses Database A, it may not receive a response for several minutes when the database is being accessed by other applications in the IT enterprise. Secondly, the legacy system accessed by Component C frequently crashes and therefore becomes unavailable for extended periods of time. Third, for Component D to respond to Component A, it must first wait for the batch import of the files to occur. This can take several minutes during which Service Consumer A remains stateful and consumes excessive memory. What steps can be taken to address these three problems?

A. The Legacy Wrapper pattern can be applied so that Component B is separated to wrap the shared database, thereby allowing Component A to interact with this new service instead of directly interacting with the database. The Legacy Wrapper pattern can be applied again so that Component C is separated into a separate service that acts as a wrapper of the legacy system API. Component D can then be separated into a separate service and the Event-Driven Messaging pattern can be applied to establish a publisher- subscriber relationship between this new service and Component A and between Service A and Service Consumer A. The interaction between Service Consumer A and Component A is then redesigned so that Component A issues a message back to Service Consumer A when the event related to the batch import is triggered.

B. The Service Data Replication pattern can be applied so that Component B can access a replicated database instead of having to access the shared Database A directly. The Legacy Wrapper pattern can be applied so that Component C is separated into a separate service that acts as a wrapper of the legacy system API. Next, the Reliable Messaging pattern can be applied so that acknowledgements are issued from the new wrapper service to Component A, thereby enabling notifying Component A during times when the legacy system is unavailable. Finally, Component D is separated into a separate service and the Event-Driven Messaging pattern is applied to establish a publisher-subscriber relationship between this new service and Component A. The interaction between Service Consumer A and Component A is then redesigned so that Component A first interacts with Component B and the new wrapper service. Service A then issues a final message back to Service Consumer A.

C. The Service Data Replication pattern can be applied so that Component B can access a replicated database instead of having to access the shared Database A directly. The Legacy Wrapper pattern can be applied so that Component C is separated into a separate service that acts as a wrapper of the legacy system API. Next, the Asynchronous Queuing pattern can be applied so that a messaging queue is positioned between Component A and the new wrapper service, thereby enabling communication during times when the legacy system is unavailable. Finally, Component D is separated into a new service and the Event-Driven Messaging pattern is applied to establish a publisher-subscriber relationship between this service and Component A and between Service A and Service Consumer A. The interaction logic is redesigned as follows: Component A interacts with Component B, the new wrapper service, and then issues a request to the new event-driven service. Upon receiving a response triggered by the event related to the batch import, Service A responds to Service Consumer A.

D. None of the above.

Service Consumer A sends a message with a business document to Service A (1), which writes the business document to Database A (2). Service A then forwards the business document to Service B (3), which writes the business document to Database B (4).

Service B then responds to Service A with a message containing a failure or success code (5) after which Service A responds to Service Consumer A with a message containing a failure or success code (6). Upon receiving the message, Service Consumer A updates a log table in Database B (7). The log entry is comprised of the entire business document. Database A is dedicated to the Service A service architecture and Database B is a shared database.

You are told that the database updates performed by Service A and Service B must be either both successful or they cannot happen at all. The database update performed by Service Consumer A must happen after it is given the outcome of the database updates performed by Service A and Service B . Given that Service Consumer A must also update Database B as part of this service composition architecture, how is it possible to fulfill these requirements?

A. The State Repository pattern can be applied so that Service A writes the business document data to a separate state database until it receives a response message from Service B . If the response message contains a success code, Service A writes the business document to Database A. If the response contains a failure code, Service A discards the data that was written to the state database.

B. The Service Data Replication pattern can be applied to Service Consumer A and Service B so that separate dedicated databases can be established allowing Service Consumer A to make updates independently of Service B . Service A is simply redesigned to not write the business document to Database A until after it receives a message containing a success code from Service B.

C. The Atomic Service Transaction pattern can be applied to encompass Service A, Service B and Service Consumer A. This will guarantee that all of the actions performed by the service composition participants will either be successful or will be rolled back if anyone is not successful.

D. None of the above.