Ibm Websphere Message Broker Interview Questions & Answers

Question 1. What Are The Features Of Message Broker?

Answer :

Routing, Transformation and Integration.

Question 2. What Is The Role Of Configuration Manager?

Answer :

Connect to the broker and to deploy the message flows onto the broker.

Question 3. How To Create Broker From Command Prompt?

Answer :

Using mqsicreatebroker command.

Question 4. What Are The Default Properties Of Mq Input Node?

Answer :

Message Domain, Message Set, Message Type, Message Format, Topic.

Question 5. Which Nodes Are Used To Change The Message In The Flow?

Answer :

Compute Node, Filter Node an  ResetContentDescriptor node.

Question 6. Name 6 Built-in Nodes In Mb Toolkit?

Answer :

1. MQInput node
2.  MQOutput node
3. Compute node  
4. Database node
5. AggregateControl node
6. Filter node.

Question 7. How To Call The Method Or Function In The Esql Coding?

Answer :

Using the “CALL” keyword.

Question 8. What Is The Broker Domain?

Answer :

Group of brokers that coordinate a single configuration manager constitute a Broker Domain.

Question 9. Name The Message Formats Which Mb Support?

Answer :

XML, TDS, CWF, EDI, SWIFT.

Question 10. What Is An Execution Group?

Answer :

An execution group is a named grouping of message flows that have been assigned to a broker.

Question 11. Difference Between Root And Outputroot?

Answer :

Root is used in the Database content changing and in Filter node. OutputRoot is used in the ESQL code for a Compute node that creates a new output message based on the input message.

Question 12. What Is User Name Server And Where It Is Defined?

Answer :

The User Name Server is an optional runtime component that provides authentication of users and groups performing publish/subscribe operations.

Question 13. How Can We See The Error Log Files In Broker?

Answer :

The Windows Event Viewer is where WebSphere Message Broker writes records to the local system.

Question 14. What Are The Perspectives There In Mb Toolkit? In Which Perspective We Deploy The Flow?

Answer :

1. Administration Perspective
2. Application Development Perspective
3. Debugging Perspective
4.  Java Perspective .

We deploy flows in Administration Perspective .

Question 15. What Are The Different Ways To Give Input Without Using Mqinput Node?

Answer :

SCADAInput, HTTPInput, FileInput, Real-timeInput, JMSInput, Custom Input nodes.

Question 16. What Is Parser? Difference Between Parser And Format?

Answer :

A Parser is defined as a program that interprets the bit stream of an incoming message and creates an internal representation of it in a tree structure.    

Ex: MRM parser

A Format is a physical representation of a message.    

Ex: XML wire format

Question 17. Define Correlation Names?

Answer :

A correlation name is a field reference that identifies a well-defined starting point in the logical message tree and is used in field references to describe a standard part of the tree format.

Question 18. How Will We Use A Cobol Copybook In Mb?

Answer :

You can populate your message set with message definitions by importing COBOL copybook files, using either the New Message Definition File wizard or the mqsicreatemsgdefs command line utility.

Question 19. What Is Schema Of Broker?

Answer :

A broker schema is a symbol space that defines the scope of uniqueness of the names of resources defined within it. The resources are message flows, ESQL files, and mapping files.

Question 20. How Can You Interact With Database Using Compute Node?

Answer :

Specify in Data Source the name by which the appropriate database is known on the system on which this message flow is to execute.

Question 21. What Exactly Do You Understand By Message Broker??

Answer :

 A Message Broker is an intermediary program that helps communicating multiple system to each other by transforming, routing the messages in the way they need.

Question 22. Why Do We Require Message Broker When We Have Mq?

Answer :

 Both message broker and mq works as middleware programs, that is to help communicating different systems, but mq has a slight drawback that it cannot transform the messages. It can just send the message to other system.

Question 23. What Is The Difference Between Message Broker And Mq?

Answer :

WebSphere MQ facilitates communication between applications by sending and receiving message data via messaging queues. WebSphere MQ provides a secure and reliable layer of transport for moving data unchanged in the form of messages between applications but it is not aware of the content of the messages.

WebSphere Message Broker is built to extend WebSphere MQ, and it is capable of understanding the content of each message that it moves through the Broker.

Message Broker can do the following:

•  Matches and routes communications between services
• Converts between different transport protocols
• Transforms message formats between requestor and service
• Identifies and distributes business events from disparate sources.

Question 24. What Are The Advantages Of Using Websphere Message Broker?

Answer :

Websphere message broker provides services, based on message brokers to allow you to:

1. Route a message to several destinations, using rules that act on the contents of one or more of the fields in the message or message header.
2. Transform a message, so that applications using different formats can exchange messages in their own formats.
3. Store a message, or part of a message, in a database.
4. Retrieve a message, or part of a message, from a database.
5. Modify the contents of a message; for example, by adding data extracted from a database.

Question 25. What All Are The Main Components Used In Message Broker?

Answer :

The main components used in Message Broker Name Server are

1. User Name Server
2. Configuration Manager
3. Broker

Question 26. What Do You Understand By Broker Domain?

Answer :

Group of brokers under a single configuration manager constitute a Broker Domain.

Question 27. What Is The Significance Of Nodes In Message Flows?

Answer :

 A message flow node receives a message, performs a set of actions against the message, passes the original message or the changed message, to the next node in the message flow.

Question 28. If Configuration Manager Is Down, What Are The Effects On The Running Brokers?

Answer :

The running broker will also be down at the moment when configuration manager is down.

Question 29. How Can We Create Broker?

Answer :

 Two ways to create broker:

1. By using Websphere Message Broker Explorer.
2. By using command prompt.

Question 30. What Is The Command Used To Create Broker?

Answer :

 mqsicreatebroker is the command used to create broker.

Question 31. What Is User Name Server?

Answer :

The User Name Server is an optional runtime component that provides authentication of users and groups and give an administrative control over who can publish and who can subscribe operations.

Question 32. What Is The Role Of Username Server?

Answer :

The User Name Server interfaces with operating system facilities to provide information about valid users and groups in a broker domain.

Question 33. Can A Single Queue Manager Have Two Brokers?

Answer :

  Not a single queue manager cannot have two brokers.

Question 34. With Which Command One Can Deploy The Bar Files?

Answer :

Using the mqsideploy command one can deploy the bar files.

Question 35. What Is The Difference Between A Root And Outputroot?

Answer :

• Root is used in the Database content changing and in Filter node.
• Output Root is used in the ESQL code for a Compute node that creates a new output message based on the input message.

Question 36. What Is The Use Of Configmanager?

Answer :

To Connect to the remote broker or local broker and to deploy the message flows onto the Broker.

Question 37. Which Perspective You Used To Deploy The Flow?

Answer :

 Administrator perspective is used to deploy the flow.

Question 38. What Do You Understand By Eai? Name Some Eai Tools?

Answer :

Enterprise Application Integration refers to the integration of one or more applications and processes together.

Tools: WBI Message Broker, Tibco, WebMethods and IC

Question 39. What Do You Mean By An Execution Group?

Answer :

An execution group is a named grouping of message flows that have been assigned to a broker. The broker enforces a degree of isolation between message flows in distinct execution groups by ensuring that they execute in separate address spaces, or as unique processes.

Question 40. What Is The Significance Of Schema In Message Broker?

Answer :

A broker schema is a symbol space that defines the scope of uniqueness of the names of resources defined within it. The resources are message flows, ESQL files, and mapping files.

Question 41. What Are The Perspectives You Have Mainly Used While Development In Message Broker?

Answer :

The perspectives mainly used while the development in message broker:

1. Administration Perspective
2. Application Development Perspective
3. Debugging Perspective
4. Java Perspective (MB 6)

Question 42. What Is The Significance Of Message Flows In Message Broker?

Answer :

A message Flow describes the sequence of steps followed in the broker that processes an input message when an input message is received.

Question 43. What Is Parser?

Answer :

A Parser is a program that takes the incoming message, interprets its bit stream and creates an internal representation of it in a tree like structure, which can be then understand by message broker assembly.

Question 44. What Is A Format?

Answer :

 Physical Representation of a message is a Format.

Question 45. What You Do To Make Your Services Actually Run?

Answer :

 Packaging services in a BAR file and deploy the BAR file on the broker.

Question 46. What Is A Bar?

Answer :

 Broker Archive or BAR is a package of message flows, message sets, java utility classes, xslts etc. that are grouped together to be deployed on the broker.

Question 47. Which Command Is Used To Create A Bar?

Answer :

mqsipackagebar command.

Question 48. What Does Mqsiapplybaroverride Command Do?

Answer :

The mqsiapplybaroverride command is used to replace configurable values in the broker archive (BAR) with new values that you specify in a properties file.

Question 49. Which Nodes In Wmb Supports Aggregation?

Answer :

1. AggregateControl
2. AggregateRequest
3. AggregateReply

Question 50. Is It Possible To Create Multiple Instances Of A Message Flow?

Answer :

Yes. We can create multiple instance of a message flow by deploying the message flows to different execution group.

Question 51. What Is A Logical Message Tree?

Answer :

Logical message tree is the internal representation of a message.

Question 52. What Are The Types Of Trees?

Answer :

Four sub tree of a logical tree created by input node of a message flow:

1. Message tree
2. Environment tree
3. Local Environment tree
4. Exception List tree.

Question 53. What Is The Purpose Of A Filter Node?

Answer :

 The purpose of a filter node is to route a message based on the content dynamically

Question 54. What Are The Types Of Traces?

Answer :

• User trace
• Service trace.

Question 55. What Are The Types Of Queues, One Can Create In Mq?

Answer :

1. Local queue
2. Remote queue
3. Transmission queue
4. Alias queue
5. Dead letter queue

Question 56. What Are The Types Of Clients In Mq?

Answer :

There are two types of clients in MQ:

1. Fat Clients: Does have a local queue manager.
2. Slim clients: Does not have a local queue manager, whereas the queue manager reside on the server.

Question 57. With Which All Nodes One Can Change Message In A Message Flow?

Answer :

Compute Node, Message Mapping Node, Filter Node, ResetContentDescriptor Node ca change message in a message flow.

Question 58. What Will Happen If We Don’t Specify Queue Name In A Mqoutput Or Mqinput Node?

Answer :

Message will be backed out and an exception will be thrown with the message no queue name is defined.

Question 59. What Happen If A Message Is Sent To A Queue And The Queue Is Filled?

Answer :

Then the message goes to the relevant dead letter queue.

Question 60. What Is The Difference Between Environment And Local Environment Tree?

Answer :

The environment tree differs from the local environment tree in that a single instance of it is maintained throughout the message flow. If you include a Compute node, a Mapping node, or a JavaCompute node in your message flow, you do not have to specify whether you want the environment tree to be included in the output message. The environment tree is included automatically, and the entire contents of the input environment tree are retained in the output environment tree. Any changes that you make are available to subsequent nodes in the message flow, and to previous nodes.

Question 61. In What All Cases Message Goes Into Deadletter Queue?

Answer :

1. When the Destination queue is full
2. When the Destination queue doesn’t exist
3. When the incoming message too large
4. When the Sender is not authorized to use the destination queue.

Question 62. Wmb Provide Supports For What Types Of Messages?

Answer :

 WMB provide support for following type of messages:

1. MRM
2. XML
3. XMLNS
4. XMLNSC
5. JMSMap
6. JMSStream
7. MIME
8. BLOB
9. IDOC
10. TOP

Question 63. What Do You Mean By Correlation Names?

Answer :

A correlation name is a field reference referencing a well-defined starting point in the logical message tree and to describe a standard part of the tree format.

Question 64. What Do You Mean By Resetcontentdescriptor Node?

Answer :

ResetContentDescriptor node request to parse the message with different parser, leaving the message content unchanged.

Question 65. What Is The Difference Between An Mqget Node And Mqinput Node?

Answer :

The MQGet node reads a message from a specified queue, and establishes the processing environment for the message. Whereas, The MQInput node receives a message from a WebSphere MQ message queue that is defined on the queue manager of the broker.

You can use an MQGet node anywhere in a message flow, unlike an MQInput node, which you can use only as the first node in a message flow.

Question 66. What Is The Difference Between Soap Request Node And Soap Async Request Node?

Answer :

The SOAP Async Request node sends a Web service request, but the node does not wait for the associated Web service response to be received. This asynchronous functionality enables multiple outbound requests to be made almost in parallel because the outbound request is not blocked waiting for the response.

Whereas, The SOAPRequest node is a synchronous request and response node, which blocks processing after sending the request until the response is received.

Question 67. What Is The Difference Between Mapping Node And Compute Node Transformation?

Answer :

In Compute node you can transform the message by coding ESQL in the ESQL resource file attached. Whereas, In mapping node you can use graphical maps to transform input message by associating an input message model such as a DFDL or XML schema, or an MRM Message Set and an output message model.

In compute node you can change the entire message even the header assemblies. But, In mapping node you can change the message assembly, message body, and properties.

Question 68. What Is The Difference Between Input And Mqinput Node?

Answer :

Use the Input node as an In terminal for an embedded message flow (a subflow).The MQInput node receives a message from a WebSphere MQ message queue that is defined on the queue manager of the broker. It is the first node of your message flow.

Question 69. What Is The Purpose Or Use Of Compute Node?

Answer :

 The Compute node is used to:

• Build a new message using a set of assignment statements
• Copy messages between parsers
• Convert messages from one code set to another
• Transform messages from one format to another

Question 70. How The Interaction With Database Does Take Place Using Compute Node?

Answer :

In Data Source specify the name by which the appropriate database is known on the system on which this message flow is to execute.

Question 71. Difference Between Try Catch Node And Throw Node?

Answer :

 Include a Throw node to force an error path through the message flow if the content of the message contains unexpected data.

If a downstream node (which can be a Throw node) throws an exception, the TryCatch node catches it and routes the original message to its Catch terminal. Connect the Catch terminal to further nodes to provide error processing for the message after an exception.

Question 72. How Will Input Messages With Different – Different Delimiters Between The Fields Are Handled In Wmb?

Answer :

 Using MRM domain we can input messages with different – different delimeters between the fields in WMB.

Question 73. What Do You Mean By Depth Of A Queue?

Answer :

 Queue depth, is the number of pending input/output messages in a queue.

Question 74. How Can We Know The Current Depth Of A Queue?

Answer :

Using MQSC property CURDEPTH we can know the current depth of a queue.

Question 75. Message Broker Supports What All Formats?

Answer :

 Message Broker supports XML, TDS, CSV, CWF, EDIFACT, SWIFT, COBOL formats

Question 76. What Nodes Uses Esql?

Answer :

ESQL can be used with the Compute, Database, and Filter nodes.

Question 77. What Is Esql?

Answer :

Extended Structured Query Language (ESQL) is a programming language based on Structured Query Language (SQL), which is commonly used with relational databases such as DB2. ESQL extends the constructs of the SQL language to provide support for you to work with both message and database content.

Question 78. What Functionality Esql Provides?

Answer :

• Through ESQL you can
• Change the message content.
• Modify an existing message
• Create a new message
• Add dynamic terminals
• Route a message
• Propagate a new request

Question 79. What Are The Types Of Variables In Esql?

Answer :

ESQL variables can be described as external variables, normal variables, or shared variables.

Question 80. What Are External Variables, Normal Variables, Or Shared Variables?

Answer :

External variables:

• Also known as user defined properties.
• Exist for entire life time of a message flow and are visible to all messages passed through the flow.
• Defined at module or schema level.
• You have to assign an initial value at the time of declaring an external variable and then can modify the initial value at deployment time by using the BAR editor.

Normal Variables:

• Have lifetime of just one message pass through a node.
• Visible to that message only in which it was defined.
• To define, omit both EXTERNAL and SHARED keyword.

Shared variable:

• Used to implement in-memory cache in the message flow.
• Have a long life time and are visible to multiple messages pass through the flow.
• Exist for the lifetime of Execution group, lifetime of flow or node, lifetime of node’s ESQL that declares the variable.
• Initialized when the first message pass through the node or flow after broker startup.

Question 81. What Are Patterns?

Answer :

 A pattern captures a tested solution to a commonly recurring problem, addressing the objectives that you want to achieve.

Question 82. What Are The Benefits Of Using Patterns?

Answer :

Patterns provide the following benefits:

• Give you guidance for the implementation of solutions.
• Increase development efficiency, because resources are generated from a set of predefined templates.
• Result in higher quality solutions, through reuse of assets and common implementation of programming approaches, such as error handling and logging.

Question 83. How Do You Ensure That Messages Do Not Lose?

Answer :

For application and internal messages traveling across WebSphere MQ, two techniques protect against message loss:

Message persistence – If a message is persistent, WebSphere MQ ensures that it is not lost when a failure occurs, by copying it to disk.

Sync point control – An application can request that a message is processed in a synchronized unit-of-work .

Question 84. How To Use Functions In Your Esql Code?

Answer :

Use CALL keyword to call functions or methods.

Question 85. What Are The Ways In Which You Can Access Databases From A Message Flow?

Answer :

 You can access a database from a message flow in two ways:

You can design a message flow that responds to events generated by the database.

After a flow has already started, you can access the database to read or update information in it. Information from the database can be used to enhance or influence the operation of the message flow.

Question 86. What All Nodes Can Access Databases?

Answer :

We can access a database from a message flow by using the following nodes:

Compute

Database

DatabaseInput

DatabaseRetrieve

DatabaseRoute

Filter

JavaCompute

Mapping

Question 87. What Is Publish/subscribe?

Answer :

Publish/subscribe is a style of messaging application in which the providers of information (publishers) are decoupled from the consumers of that information (subscribers).

Question 88. What Are The Techniques Used In Transforming And Enriching Messages In Wmb?

Answer :

 We can transform and enrich messages by using one or more of the following techniques:

Mappings

ESQL

Java

XSL style sheets

PHP

.NET

Question 89. What Are The Basic Error Handling Techniques Available In Message Flow?

Answer :

 There are two general approaches to handle errors in a message flow:

• Failure checking
• Catching Exceptions

Question 90. What Are Message Models?

Answer :

Most message formats are not self-defining, and a parser must have access to a predefined model that describes the message, if it is to parse the message correctly. A message model is used by WebSphere Message Broker to model a message format.

Question 91. What Are The Advantages Of Modeling Messages?

Answer :

Even if your messages are self-defining, and do not require modeling, message modeling has the following advantages:

1. Runtime validation of messages. Without a message model, a parser cannot check whether input and output messages have the correct structure and data values.
2. Enhanced parsing of XML messages. Although XML is self-defining, all data values are treated as strings if a message model is not used. If a message model is used, the parser is provided with the data type of data values, and can cast the data accordingly.
3. Improved productivity when writing ESQL. When you are creating ESQL programs for WebSphere Message Broker message flows, the ESQL editor can use message models to provide code completion assistance.
4. Drag-and-drop operations on message maps. When you are creating message maps for WebSphere Message Broker message flows, the Message Mapping editor uses the message model to populate its source and target views. Without message models, you cannot use the Message Mapping editor.
5. Reuse of message models, in whole or in part, by creating additional messages that are based on existing messages.
6. Generation of documentation.
7. Provision of version control and access control for message models by storing them in a central repository.

Question 92. What Are The Ways To Create Message Models?

Answer :

You can create a message model by using the following methods:

• Importing an application message format that is described by an XML Schema, XML DTD, C structure, COBOL structure, SCA import or export, or WSDL definition.
• By creating an empty message model file, then creating your message by using the editors provided in the WebSphere Message Broker Toolkit.
• By using the Adapter Connection wizard to import EIS metadata.
• By creating a populated model file from example message data.

Question 93. What Is The Difference Between Mqsicreatemsgdefs Or Mqsicreatemsgdefsfromwsdl Command-line Utilities?

Answer :

 The mqsicreatemsgdefs command has a bulk import capability, but mqsicreatemsgdefsfromwsdl imports only one WSDL definition at a time.

Question 94. What Are Message Sets?

Answer :

 A message set is a folder in a message set project that contains a logical grouping of your messages and the objects that comprise them (elements, types, groups).

Question 95. What Is A Message Definition File?

Answer :

A message definition file contains the messages, elements, types, and groups which make up a message model within a message set. Every message set requires at least one message definition file to describe its messages. Message definition files use the XML Schema language to describe the logical format of one or more messages.

Question 96. What Is A Multipart Message?

Answer :

A multipart message contains one or more other messages within its structure. The contained message is sometimes referred to as an embedded message. A multipart message must contain a group, or a complex type, with its Composition property set to Message.

Question 97. What Is Triggering In Mq?

Answer :

  A message is put to a queue defined as Triggering.

Question 98. What Does A Propagate Keyword Do?

Answer :

 The PROPAGATE statement is used to generate multiple output messages in the Compute node. The output messages may have same or different message content. You can also send output messages to any alternate output terminals of the Compute node.

Question 99. Why Do We Use Sequence Node?

Answer :

The Sequence node enables you to receive groups of messages from an input source, and preserve the order in which the messages in each group arrived.

Question 100. Which Command Is Used To Modify Broker Parameters?

Answer :

 mqsichangebroker command is used to modify broker parameters.

Question 101. What Do You Mean By Resetcontentdescriptor Node?

Answer :

ResetContentDescriptor node request to parse the message with different parser, leaving the message content unchanged.