SAS 认证-真题集2-a.pdf - SAS Warehouse Architect...

Info icon This preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 6
Image of page 7

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 8
Image of page 9

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 10
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: SAS Warehouse Architect Concepts Certification Study Guide 4 SAS Exam # ADO-204 Study Guide SAS Server Enterprise Developer Exam Questions 1. Which of the following statements are true regarding MDBs (Message Driven Beans) on version 6.0 of SAS App Server? a. MDBs support concurrent processing for both Topics and Queues. b. MDBs support concurrent processing for only Topics. c. MDBs support concurrent processing for only Queues. d. MDBs support concurrent processing neither Topics nor Queues. 2. The two primary cluster services provided by SAS Server are? a. Http Session State Clustering b. File Service Clustering c. Time Service Clustering d. Object Clustering e. Event Clustering 3. Which of the following are recommended practices to be performed in the eijassivate() method of a stateful session Bean? a. Close any open resources, like database connections b. All non-transient, non-serializable fields(except some special types) should be set to null. c. All transient fields should be set to null d. Make all database connection reference fields transient e. All primitive type fields should be set to null Study Guide From 490 SAS Warehouse Architect Concepts Certification Study Guide 4 SAS Exam # ADO-204 Study Guide d. Make the Servlet client to be remote instead of internal to SAS server. 7. The Multicast TTL setting for a cluster in the SAS Admin console sets which of the following values? a. Maximum time taken for multicast messages to reach their final destination b. The number of routers a multicast message can pass through before the packet can be discarded c. The multicast address to be used by the messages sent from the cluster cl. Minimum time taken for broadcasting a multicast message from the cluster 8. Which of the following algorithms is used by the SAS Server as the default load balancing strategy for clustered object stubs when no algorithm is specified ? a. Round-robin b. Weight-based c. Random cl. None of the above 9. Which of the following statements are true regarding the identity of two EJBs? a. Two stateful session Beans are identical if their data attributes are identical. b. Two stateful session Beans are identical if their session contexts are equal. c. Two stateless session Beans are identical if they are of the same type. Study Guide From 492 SAS Warehouse Architect Concepts Certification Study Guide 4 SAS Exam # ADO-204 Study Guide b. The total amount of time that SAS Server spends receiving HTTP POST data. c. The time spent by SAS server to post data to other servers in the cluster. CI. The number of bytes of data received in a POST from a single request. 13. A client wants to preserve the reference to the EJBHome object of an enterprise Bean instance and use it later. Which of the following can be serialized for this purpose ? a. Home b. Handle c. HomeHandle d. EJBHomeHandle e. HomeObject 14. Match the EJB functions given below with the functionality equivalent in SQL A.) eijtore() 1.)INSERT B.) eijoad() 2.) UPDATE C.) ejbCreate() 3')SELECT a. A->1, B->2, C->3 b. A—>2, B->1, C->3 c. A->3, B->2, C->1 d. A—>1, B->3, C->2 e. A->2, B—>3, C->1 Study Guide From 494 SAS Warehouse Architect Concepts Certification Study Guide 4 SAS Exam # ADO-204 Study Guide c. Multiple JMS Servers may exist on one SAS 6.0 server. d. A JMS Server can be deployed on only one server. 18. Which of the following is NOT true about the security implementation in the SAS Server? a. Servlets, JSPs, EJBs, RMI objects, and SAS applications use the SAS Authentication and Authorization Service to authenticate SAS Server. b. The default security realm in SAS Server is the File realm. c. The default authentication scheme for SAS Server is two-way authentication. d. An Administration Server may contain configuration information for one SAS Server or a cluster of SAS servers. 19. For EJB applications with Bean-managed transaction demarcations, which of the following is used by the client to get a reference to the UserTransaction object for the SAS Server domain? a. JTA b. JNDI c. JMS d. JTS e. JMX 20. Which of the following are true about the transaction support in the SAS server? a. SAS Server allows transactions to be terminated only by the client that created the transaction. b. SAS Server does not support multithreaded transactional clients. Study Guide From 496 SAS Warehouse Architect Concepts Certification Study Guide 4 SAS Exam # ADO-204 Study Guide 24. Which is the only method defined in the SASX.ejb.Handle interface? a. getEJBHome b. getEJBObject c. getPrimaryKey d. getHomeHandle 25. In CORBA, which of the following files generated by the "idltoSAS" compiler must be compiled before running the server application? a. Only The Holder Classes b. Only The Helper and Holder Classes c. The implementation class(es) written by the user to provide body to the methods defined in the interface class d. All idltoSAS generated files (stubs, skeletons, helper, holder and interface classes) 26. Considering the code below, which of the lines of code (given in the choices) should be placed at line 4 to make this JSP prints "My score is : 100"? Please ignore the line numbers for the purpose of validity of the JSP code. 1: 2: 3- My Progress Report wwewe Study Guide From 498 SAS Warehouse Architect Concepts Certification Study Guide 5 SAS Exam # AGO-204 Study Guide more than one, the container will spawn as many threads as specified. SAS Server maintains a free pool of EJBs for every stateless session Bean and message driven Bean class. The max-Beans-in-free—pool element defines the size of this pool. By default, max-Beans-in-free-pool has no limit; the maximum number of Beans in the free pool is limited only by the available memory. For complete information about Deployment Descriptor properties on WLS, refer to http:[[edocs.SAS.comiwlsldocsGOZejbzreference.html 2. Choices A and D are correct. A SAS Server cluster is a group of servers that work together to provide a more scalable and reliable application platform than a single server. A clustered service is an API or interface that is available on multiple servers in the cluster. HTTP session state clustering and object clustering are the two primary cluster services that SAS Server provides. SAS Server also provides cluster support for JMS destinations and JDBC connections. SAS Server provides clustering support for servlets and JSPs by replicating the HTTP session state of clients that access clustered servlets and JSPs. To benefit from H'I'I'P session state clustering, you must ensure that the session state is persistent, either by configure in-memory replication, file system persistence, or JDBC persistence. If an object is clustered, instances of the object are deployed on all SAS Servers in the cluster. The client has a choice about which instance of the object to call. This is Object Clustering. The APIs and internal services that cannot be clustered in SAS Server version6.0 are File services, Time services, SAS Events, Workspaces and ZAC. 3. Choices A, B and D are correct. When a Bean is about to be passivated, its eijassivate() method is invoked, alerting the Bean instance that it is about to enter the Passivated state. At this time, the Bean instance should close any open resources and set all non transient, non serializable fields to null. This will prevent problems from occurring when the Bean is serialized. Transient fields will simply be ignored.SeriaIizab|e fields will be saved.Open resources such as sockets or JDBC connections must be closed whenever the Bean is passivated. In stateful session Beans, open resources will not be maintained for the life of the Bean instance. When a stateful session Bean is passivated, any open resource can cause problems with the activation mechanism. A Bean's conversational state may consist of only primitive values, objects that are serializable, and the following special types-SessionContext, EJBHome, EJBObject, UserTransaction and Context (only when it references the JNDI ENC) . The types in this list (and their subtypes) are handled specially by the passivation mechanism. They don't need to be serializable; they will be maintained through passivation and restored automatically to the Bean instance when it is activated Study Guide From 500 SAS Warehouse Architect Concepts Certification Study Guide 5 SAS Exam # ADO-204 Study Guide This restriction does not apply to a stateless session Bean because the container routes each request to a different instance of the session Bean class. 7. Choice B is correct. The Multicast TTL(1TL-Time to Live) setting specifies the number of routers a multicast message can pass through before the packet can be discarded. To configure the multicast TI'L for a cluster, you should change the Multicast 'l'l'L value in the SAS Server administration console. This sets the number of network hops a multicast message makes before the packet can be discarded. If you choose to distribute a cluster over a WAN (or across multiple subnets), you must plan and configure your network topology to ensure that muiticast messages are reliably transmitted to all servers in the cluster. One of the requirements to be met by the network is that the multicast Time To Live (Tl'L) value must be high enough to ensure that routers do not discard muiticast packets before they reach their final destination. 8. Choice A is correct. The basic idea behind load balancing is that by distributing the load proportionally among all the servers in the cluster, the servers can each run at full capacity. SAS Server clusters support several algorithms for load balancing clustered objects. The particular algorithm you choose is maintained within the replica-aware stub obtained for the clustered object. Configurable algorithms for load balancing clustered objects are: Round-robin, Weight-based and Random. SAS Server uses the round-robin algorithm as the default load balancing strategy for clustered object stubs when no algorithm is specified. Round- robin is the only load balancing strategy used by SAS proxy plug-ins for H'lTP session state clustering. The round-robin algorithm cycles through a list of SAS Server instances in order. For clustered objects, the server list consists of SAS Server instances that host the clustered object. For proxy plug-ins, the list consists of all SAS Servers that host the clustered servlet or JSP. 9. B and C are correct. Since the stateful session Beans maintain the conversational state of the clients, they are identical when their session contexts are equal. Two stateful session Beans may have identical data attributes, but if the session contexts are different they are not identical. Thus choice A is incorrect and B is correct. Since stateless Beans do not retain the conversational state, they are considered identical if they are of the same type. Thus choice C is correct. If two entity objects have the same home interface and primary key, they are considered identical. The EJB specification does not mention object equality based on the = = operator. Also, if you compare two object references using the SAS API, Object.equals(0bject obj), the result is unspecified. The only way to compare object equality is through the isIdentical (EJBObject) API. Thus choice E and F are incorrect. Study Guide From 502 SAS Warehouse Architect Concepts Certification Study Guide 5 SAS Exam # ADO-204 Study Guide from a single request. If this limit is triggered, a MaxPostSizeExceeded exception is thrown and a message is sent to the server log. 13. Choice C is correct. Once a client has obtained the EJBHome object for an EJB instance, it can create a reference to the home object by calling getHomeHandle(). getHomeHandle() returns a HomeHandle object, which can be used to obtain the home interface to the same EJB instance at a later time. A client can pass the HomeHandle object as arguments to another client, and the receiving client can use the handle to obtain a reference to the same EJBHome object. Clients can also serialize the HomeHandle and store it in a file for later use. The HomeHandle interface has only one method getEJBHome(), which returns the EJBHome reference. 14. Choice E is correct. When the create() method on a home interface is invoked, the container delegates the create() method call to the Bean instance's matching ejbCreate() method. The ejbCreate() methods are used to initialize the instance state before record is inserted into the database. The ejbCreate() method is analogous to INSERT. The eijtore() method is invoked just before the container the container is about to write the Bean container-managed fields to the database. It is analogous to the UPDATE . The eijoad() is invoked just after the container has refreshed the Bean container-managed files with its state from the database. It is analogous to the SELECT. Thus choice E is correct and others are not. 15. Choice C is correct. By default, simultaneous access to a stateful session EJB results in a RemoteException. However, you can set the allow- concurrent-calls option in the SAS EJB deployment descriptor to specify that a stateful session Bean instance will allow concurrent method calls. This access restriction on stateful session EJBs applies whether the EJB client is remote or internal to SAS Server. By default, allows-concurrent-calls is false. However, when this value is set to true, the EJB container blocks the concurrent method call and allows it to proceed when the previous call has completed. The concurrency-strategy element determines eijoad() and eijtore() behavior for entity EJB instances. 16. Choice C is correct because it is NOT true. A and B are true about deploying EJBs in the SAS server. The SAS/config/examples/applications directory acts as an automatic deployment directory for EJB 2.0 .jar files and EJB .jar deployment directories. When you start SAS Server, it automatically deploys any valid EJB 2.0 .jar files or .jar directories that reside in the applications directory. SAS Server also checks the contents of applications every ten seconds to determine whether an EJB deployment has changed. If a deployment has changed, it is automatically redeployed using the dynamic deployment feature. Study Guide From 504 SAS Warehouse Architect Concepts Certification Study Guide 5 SAS Exam # ADO-204 Study Guide Server may contain configuration information for one SAS Server or a cluster of SAS servers. 19. Choice B is correct. SAS Server supports the SASx.transaction package and the SASx.transaction.xa package, which implement the SAS Transaction API (JTA) for SAS applications. SASx.transaction.UserTransaction provides an interface to the transaction manager that allows the application developer to manage the scope of a transaction explicitly. The client application uses JNDI to obtain an object reference to the UserTransaction object for the SAS Server domain. The code used by the client is given. UserTransaction ut=(UserTransaction)jndicontext.lookup("SASx.transaction.UserTransaction”) If a Bean needs a reference to the UserTransaction object, it obtains it from the EJBContext as given. UserTransaction ut=ejbContext.getUserTransaction() 20. Choices A and C are correct. SAS Server provides a Transaction Service that supports transactions in EJB and RMI applications. SAS Server allows transactions to be terminated only by the client that created the transaction. SAS Server implements the flat transaction model. Nested transactions are not supported. SAS Server supports multithreaded transactional clients. Clients can make transaction requests concurrently in multiple threads. In SAS Server, a client or a server object cannot invoke methods on an object that is infected with (or participating in) another transaction. The method invocation issued by the client or the server will return an exception. Also in SAS Server, clients using third—party implementations of the SAS Transaction API (for SAS applications) are not supported. 21. Choices A and C are correct. To publish to a SAS Server, we can use the ZAC publish wizard. For this, the server must be running, and you will need to know a user and password that has permission to publish. You can also use the ZAC Publish Wizard to create a set of native programs - an installer and a bootstrap - for various operating systems that become part of a published SAS application. The installer program is a native executable that installs your published SAS program on the local machine. It doesn't require a SAS environment itself, so it can run out-of-the—box in the native OS. The bootstrap is also a native program; the user runs the bootstrap to invoke the published application. Study Guide From 506 SAS Warehouse Architect Concepts Certification Study Guide 5 SAS Exam # ADO-204 Study Guide 25. Choice C and D are correct. The Helper class (a final class) provides auxiliary functionality, notably the narrow() method required to cast CORBA object references to their proper types. The Holder class provides operations for out and inout arguments, which CORBA has but which do not map easily to SAS's semantics. The server application cannot be compiled successfully until the implementation class(es) has/have been written and compiled. All the other generated files however must be compiled to form '.class' files from the '.SAS' files. Thus all the implementation classes written by the user and all the "idltoSAS" generated files must be complied to run the CORBA Server. 26. A is the correct choice. The above JSP will work on declaring and initializing the variable score. The syntax for declaring and initializing a variable in JSP is as follows: Thus A is the correct choice. The tag is used to declare directives like include directive. Thus choice C is incorrect. The code is used to insert scriptlets (lines of code in SAS) like the one at line 5. The code written inside the scriptlet becomes part of the service() method of the generated servlet. Thus 'score' becomes the local variable of the service method. And for this JSP to compile properly, the variable 'score' should have been initialized. If "" is replaced by "" , the choice B would also be correct. In the present scenario, the choice B will give compilation error saying "Variable score may not have been initialized". Choice D is incorrect as it's not a valid tag. 27. Choices B and C are correct. A message-driven Bean is a special kind of EJB that acts as a message consumer in the SAS JMS messaging system. As with standard JMS message consumers, message-driven Beans receive messages from a JMS Queue or Topic, and perform business logic based on the message contents. EJB deployers create listeners to a Queue or Topic at deployment time, and SAS Server automatically creates and removes message-driven Bean instances as needed to process incoming messages. Because message-driven Beans are implemented as EJBs, they benefit from several key services that are not available to standard JMS consumers. Most importantly, message-driven Bean instances are wholly managed by the SAS Server EJB container. Using a single message-driven Bean class, SAS Server creates multiple EJB instances as necessary to process large volumes of messages concurrently. This stands in contrast to a standard JMS messaging system, where the developer must create a MessageListener class that utilizes a server—wide session pool. Thus choice A is incorrect. SAS Server provides standard EJB services to MDBs, such as security services and automatic transaction management. Thus choice B is correct. Being implemented as EJBs, MDBS benefit from the write-once, deploy- anywhere quality of EJBs. Whereas a JMS MessageListener is tied to specific session pools, Queues, or Topics, message-driven Beans can be developed independently of available server resources. Thus Choice C is also correct. Study...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern