Arcitura Education SOA Design & Architecture Lab S90.09 Exam Questions

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Total 40 questions

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Question 1

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 the 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 pattern is being applied and that the Logic Centralization is not 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 requirements of the service composition?

AService Consumer A can be redesigned to use XML Schema B so that the SOAP message it sends is compliant with the service contract of Service A . The Data Model Transformation pattern can then be applied to transform the SOAP message sent by Service A so that it conforms to the XML Schema A used by Service B . The Standardized Service Contract principle must then be applied to Service B and Service Consumer A so that the invoice XML document is optimized to avoid unnecessary validation.

BThe 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 .

CService Consumer A can be redesigned to write the invoice document directly to the database. This reduces performance requirements by avoiding the involvement of Service A and Service B . It further supports the application of the Service Abstraction principle by ensuring that Service Consumer A hides the details of the data access logic required to write to the database.

DNone of the above.

Answer : B

Question 2

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.)

A project team recently proclaimed that it has successfully applied the Contract Centralization pattern to the service inventory in which the Invoice service, InvProc service, and ProcInv service reside. Upon reviewing the previously described architecture you have doubts that this is true. After voicing your doubts to a manager, you are asked to provide specific evidence as to why the Contract Centralization is not currently fully applied. Which of the following statements provides this evidence?

AThe Contract Centralization pattern is not fully applied to the Invoice, InvProc, and ProcInv services because they are being accessed by different service consumers and because they have redundant logic that introduces denormalization into the service inventory.

BThe Contract Centralization pattern is not fully applied because Service Consumer D is accessing the shared accounting database directly.

CThe Contract Centralization pattern is not fully applied because none of the invoice-related services are carrying out data access logic via a centralized and standardized invoice service. This is primarily because the Standardized Service Contract principle was not consistently applied during the delivery processes of the individual services.

DNone of the above.

Answer : B

Question 3

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?

AThe 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

BThe 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.

CThe 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 .

DNone of the above.

Answer : B

Question 4

Services A, B, and C are non-agnostic task services. Service A and Service B use the same shared state database to defer their state data at runtime. An assessment of these three services reveals that each contains some agnostic logic, but because it is bundled together with the non-agnostic logic, the agnostic logic cannot be made available for reuse. The assessment also determines that because Service A and Service B and the shared state database are each located in physically separate environments, the remote communication required for Service A and Service B to interact with the shared state database is causing an unreasonable decrease in runtime performance.

How can the application of the Orchestration pattern improve this architecture?

AThe application of the Orchestration pattern will result in an environment whereby the State Repository and Service Data Replication patterns are naturally applied, allowing the shared state database to be replicated for Services A and B so that each task service can have its own dedicated state database. The Process Centralization pattern can also be applied to Services A and B, so that their logic is physically centralized, turning them into orchestrated task services.

BThe application of the Orchestration pattern will result in an environment whereby the Process Abstraction and Process Centralization patterns are naturally applied to Services A, B, and C, resulting in a clean separation of non-agnostic task services from newly designed agnostic services with reuse potential. Also, the State Repository pattern can be applied by the availability of a central state database that can be shared by Services A and B . This database can be made available as a local part of the environment so that Services A and B can avoid remote communication.

CThe application of the Orchestration pattern will result in an environment whereby the Compensating Service Transaction is naturally applied, resulting in the opportunity to create sophisticated exception logic that can be used to compensate for the performance problems caused by Services A and B having to remotely access the state database. The Process Abstraction and Service Broker patterns are also naturally applied, enabling the separation of nonagnostic logic and agnostic logic while providing common transformation functions required to overcome any disparity in the service contracts that will need to be created for the new agnostic services.

DNone of the above.

Answer : B

Question 5

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.

You are told that the current service composition architecture is having performance problems because of two specific reasons. First, too many services need to be explicitly invoked in order for the message to arrive at its destination. Secondly, because each of the intermediary services is required to read the entire message contents in order to determine where to forward the message to, it is taking too long for the overall task to complete. What steps can be taken to solve these problems without sacrificing any of the functionality that currently exists?

AThe Intermediate Routing pattern can be applied together with the Service Agent pattern in order to establish a set of service agents capable of intercepting and forwarding the message based on pre-defined routing logic. To avoid the need for service agents to read the entire message contents, the Messaging Metadata pattern can be applied so that content relevant to the routing logic is placed in the header of a message. This way, only the message header content needs to be read by the service agents.

BThe Intermediate Routing pattern can be applied together with the Service Agent pattern in order to establish a set of service agents capable of intercepting and forwarding the message based on pre-defined routing logic. To avoid the need for service agents to read the entire message contents, the Rules Centralization pattern can be applied so that content relevant to the routing logic is isolated into a separate Rules service. This way, service agents are only required to access the Rules service in order to determine where to forward messages to. The Standardized Service Contract principle will need to be applied to ensure that the new Rules service and the new service agents provide service contracts that are compliant to existing design standards.

CThe Intermediate Routing pattern can be applied together with the Service Agent pattern in order to establish a set of service agents capable of intercepting and forwarding the message based on pre-defined routing logic. The Service Discoverability principle can be applied to improve the communications quality of message contents, which will reduce the time required by service agents to read the message contents at runtime.

DNone of the above.

Answer : A

Question 6

Service A is a task service that sends Service B a message (2) requesting that Service B return data back to Service A in a response message (3). Depending on the response received. Service A may be required to send a message to Service C (4) for which it requires no response. Before it contacts Service B, Service A must first retrieve a list of code values from its own database (1) and then place this data into its own memory. If it turns out that it must send a message to Service C, then Service A must combine the data it receives from Service B with the data from the code value list in order to create the message it sends to Service C . If Service A is not required to invoke Service C, it can complete its task by discarding the code values. Service A and Service C reside in Service Inventory A . Service B resides in Service Inventory B . You are told that the services in Service Inventory A were designed with service contracts based on different design standards than the services in Service Inventory B . As a result, Service A and Service B use different data models to represent the data they need to exchange. Therefore, Service A and Service B cannot currently communicate. Furthermore, Service C is an agnostic service that is heavily accessed by many concurrent service consumers. Service C frequently reaches its usage thresholds during which it is not available and messages sent to it are not received. How can this service composition architecture be changed to avoid these problems?

AThe Data Model Transformation pattern can be applied by establishing an intermediate processing layer between Service A and Service B that can transform a message from one data model to another at runtime. The Intermediate Routing and Service Agent patterns can be applied so that when Service B sends a response message, a service agent can intercept the message and, based on its contents, either forward the message to Service A or route the message to Service C . The Service Autonomy principle can be further applied to Service C together with the Redundant Implementation pattern to help establish a more reliable and scalable service architecture.

BThe Data Model Transformation pattern can be applied by establishing an intermediate processing layer between Service A and Service B that can transform a message from one data model to another at runtime. The Asynchronous Queuing pattern can be applied to establish an intermediate queue between Service A and Service C so that when Service A needs to send a message to Service C, the queue will store the message and retransmit it to Service C until it is successfully delivered. The Service Autonomy principle can be further applied to Service C together with the Redundant Implementation pattern to help establish a more reliable and scalable service architecture.

CThe Data Model Transformation pattern can be applied by establishing an intermediate processing layer between Service A and Service B that can transform a message from one data model to another at runtime. The Intermediate Routing and Service Agent patterns can be applied so that when Service B sends a response message, a service agent can intercept the message and, based on its contents, either forward the message to Service A or route the message to Service C . The Service Statelessness principle can be applied with the help of the State Repository pattern so that Service A can write the code value data to a state database while it is waiting for Service B to respond.

DNone of the above.

Answer : B

Question 7

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?

AThe 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.

BThe 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 .

CThe 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.

DNone of the above.

Answer : D