WMB & IIB Interview Q & As

7/25/2019 WMB & IIB Interview Q & As

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WMB & IIB Interview Q & As


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Q:What exactly do you understand by message broker?

A:A Message Broker is an intermediary programthat helps communicating multiple

system to each other by transforming, routing the messages in the way theyneed.

Q:Why do we require message broker when we have MQ?

A:

Both message broker and mq works as middleware programs, that is to helpcommunicating different systems, but mq has a slight drawback that it cannottransform the messages. It can just send the message to other system.

Q:What is the difference between Message Broker and MQ?A:WebSphere MQ facilitates communication between applications by sending and

receiving message data via messaging queues. WebSphere MQ provides a secureand reliable layer of transport for moving data unchanged in the form of messagesbetween 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.

Q:What are the advantages of using Websphere message broker?A:Websphere message broker provides services, based on message brokers to allow

you to:

Route a message to several destinations, using rules that act on thecontents of one or more of the fields in the message or message header.

Transform a message, so that applications using different formats canexchange messages in their own formats.

Store a message, or part of a message, in a database.

Retrieve a message, or part of a message, from a database.

Modify the contents of a message; for example, by adding data extractedfrom a database.

Q:What all are the main components used in Message Broker?

A:

The main components used in Message Broker Name Server are

User Name Server

Configuration Manager

Broker

Q:What do you understand by Broker Domain?


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A:Group of brokers under a single configuration manager constitute a Broker

Domain.

Q:What is the significance of nodes in message flows?

A: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 nodein the message flow.

Q:If configuration manager is down, what are the effects on the running

brokers?

A:The running broker will also be down at the moment when configuration manageris down.

Q:How can we create broker?

A:Two ways to create broker:

By using Websphere Message Broker Explorer.

By using command prompt.

Q:What is the command use to create broker?

A:mqsicreatebroker is the command used to create broker.

Q:

What is User name Server?

A: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.

Q:What is the Role of Username server?

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

Q:Can a single queue manager have two brokers?

A:No a single queue mnager cannot have two brokers.

Q:With Which command one can deploy the bar files?

A:Using the mqsideploy command one can deploy the bar files.


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Q:What is the difference between a Root and OuputRoot?

A: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

Q:What is the Use of Configmanager?

A:To Connect to the remote broker or local broker and to deploy the message flowsonto the Broker.

Q:Which perspective you used to deploy the flow?A:Administrator perspective is used to deploy the flow.

Q:What do you understand by EAI? Name some EAI tools?

A:Enterprise Application Integration refers to the integration of one or more

applications and processes together.

Tools: WBI Message Broker, Tibco, WebMethods and ICS

Q:What are the Features of Message Broker?

A:WMB has many features, The main features are :

Routing

Transformation and Integration

Q:What do you mean by an Execution Group?

A: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 messageflows in distinct execution groups by ensuring that they execute in separate

address spaces, or as unique processes.


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Q:What is the significance of SCHEMA in message broker?A: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.

Q:What are the perspectives you have mainly used while development in

message broker?

A:The perspectives mainly used while the development in message broker are

Administration Perspective

Application Development Perspective

Debugging Perspective Java Perspective (MB 6)

Q:

What is the significance of message flows in message broker?A:A message Flow describes the sequence of steps followed in the broker that

processes an input message when an input message is received.

Q:What is PARSER?A: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 bethen understand by message broker assembly.

Q:What is a Format?

A:Physical Representation of a message is a Format.

Q:

What you do to make your services actually run?A:Packaging services in a BAR file and deploy the BAR file on the broker.

Q:What is a BAR?

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

Q:Which command is used to create a BAR?

A:mqsipackagebar command.

Q:What does mqsiapplybaroverride command do?

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

Q:Which nodes in WMB supports aggregation?

A: AggregateControl


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AggregateRequest AggregateReply

Q:Is it possible to create multiple instances of a message flow?

A:

Yes. We can create multiple instance of a message flow by deploying the message

flows to different execution group.

Q:What is a logical message tree?

A:Logical message tree is the internal representation of a message.

Q:What are the types of Trees?

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

Message tree

Environment tree

Local Environment tree

Exception List tree.

Q:What is the purpose of a filter node?

A:The purpose of a filter node is to route a message based on the contentdynamically

Q:What are the types of TRACES?

A: User trace

Service trace.

Q:What are the Types of Queues, one can create in MQ?

A: Local queue

Remote queue

Transmission queue

Alias queue

Dead letter queue

Q:What are the types of clients in MQ?

A:There are two types of clients in MQ

Fat Clients: Does have a local queue manager. Slim clients: Does not have a local queue manager, whereas the queue manager

reside on the server.


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A:WMB provide support for following type of messages:

MRM

XML

XMLNS

XMLNSC

JMSMap

JMSStream

MIME

BLOB IDOC

Q:What do you mean by Correlation names?

A: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.

Q:What do you mean by ResetContentDescriptor node?

A:ResetContentDescriptor node request to parse the message with different parser,

leaving the message content unchanged.

Q:What is the difference between an MQGet node nd MQInput node?

A:The MQGet node reads a message from a specified queue, and establishes the

processing environment for the message. Whereas, The MQInput node receives amessage 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.

Q:What is the difference between SOAPRequest node and

SOAPAsyncRequest node?A:The SOAPAsyncRequest 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 parallelbecause 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.

Q:

What is the difference between Mapping node and Compute nodetransformation?

A: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 totransform 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


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properties.

Q:What is the difference between Input and MQInput node?

A: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 messagequeue that is defined on the queue manager of the broker. It is the first node of

your message flow.

Q:What is the purpose or use of compute node?

A: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

Q:How the interaction with Database does take place using Compute node?

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

Q:Difference between try catch node and throw node?A: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 themessage after an exception.

Q:How will input messages with different - different delimiters between the

fields are handled in WMB?

A:Using MRM domain we can input messages with different - different delimetersbetween the fields in WMB.

Q:What do you mean by depth of a Queue?

A:

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

Q:How can we know the current depth of a queue?A:Using MQSC property CURDEPTH we can know the current depth of a queue.


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Q:Message Broker supports what all formats?

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

Q:What all nodes uses ESQL?A:ESQL can be used with the Compute, Database, and Filter nodes.

Q:What is ESQL?A: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 toprovide support for you to work with both message and database content.

Q:What functionality ESQL provides?

A:

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

Q:

What are the types of variables in ESQL?

A:ESQL variables can be described as external variables, normal variables, or shared

variables.

Q:What are external variables, normal variables, or shared variables?

A: External variables:

Also known as user defined properties.

Exist for entire life time of a message flow and are visible to all messagespassed through the flow.

Defined at module or schema level.

You have to assign an initial value at the time of declaring an externalvariable and then can modify the initial value at deployment time by usingthe BAR editor.

Normal Variables:

Have lifetime of just one message pass through a node.

Visible to that message only in which it was defined.


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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

nodes ESQL that declares the variable.

Initialized when the first message pass through the node or flow afterbroker startup.

Q:What are patterns?

A:A pattern captures a tested solution to a commonly recurring problem, addressing

the objectives that you want to achieve.

Q:What are the benefits of using patterns?

A:Patterns provide the following benefits:

Give you guidance for the implementation of solutions

Increase development efficiency, because resources are generated from aset of predefined templates

Result in higher quality solutions, through reuse of assets and common

implementation of programming approaches, such as error handling andlogging

Q:How do you ensure that messages do not lose?

A: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 processedin a synchronized unit-of-work .

Q:How to use functions in your esql code?


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A:Use CALL keyword to call functions or methods.

Q:What are the ways in which you can access databases from a message

flow?

A: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 orupdate information in it. Information from the database can be used toenhance or influence the operation of the message flow.

Q:What all nodes can access databases?

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

Compute

Database

DatabaseInput

DatabaseRetrieve

DatabaseRoute

Filter

JavaCompute

Mapping

Q:What is Publish/Subscribe?A:Publish/subscribe is a style of messaging application in which the providers of

information (publishers) are decoupled from the consumers of that information(subscribers).

Q:What are the techniques used in transforming and enriching messages inWMB?

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

techniques:

Mappings

ESQL

Java

XSL style sheets

PHP

.NET

Q:What are the basic error handling techniques available in message flow?

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

Failure checking


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Catching Exceptions

Q:What are message models?

A: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 messagecorrectly. A message model is used by WebSphere Message Broker to model a

message format.

Q:What are the advantages of modeling messages?

A:Even if your messages are self-defining, and do not require modeling, message

modeling has the following advantages:

Runtime validation of messages. Without a message model, a parser

cannot check whether input and output messages have the correctstructure and data values.

Enhanced parsing of XML messages. Although XML is self-defining, all datavalues are treated as strings if a message model is not used. If a messagemodel is used, the parser is provided with the data type of data values, andcan cast the data accordingly.

Improved productivity when writing ESQL. When you are creating ESQL

programs for WebSphere Message Broker message flows, the ESQL editorcan use message models to provide code completion assistance.

Drag-and-drop operations on message maps. When you are creating

message maps for WebSphere Message Broker message flows, theMessage Mapping editor uses the message model to populate its sourceand target views. Without message models, you cannot use the Message

Mapping editor.

Reuse of message models, in whole or in part, by creating additionalmessages that are based on existing messages.

Generation of documentation.

Provision of version control and access control for message models bystoring them in a central repository.

Q:What are the ways to create message models?

A: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, orWSDL definition.

By creating an empty message model file, then creating your message byusing 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..


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Q:What is the difference between mqsicreatemsgdefs ormqsicreatemsgdefsfromwsdl command-line utilities?

A:The mqsicreatemsgdefs command has a bulk import capability, butmqsicreatemsgdefsfromwsdl imports only one WSDL definition at a time.

Q:What are message sets?A: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).

Q:What is a message definition file?

A: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. Messagedefinition files use the XML Schema language to describe the logical format of one

or more messages.

Q:What is a multipart message?

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

property set to Message.

Q:What is Triggering in MQ?A:A message is put to a queue defined as Triggering.

Q:What does a PROPAGATE keyword do?

A:The PROPAGATE statement is used to generate multiple output messages in the

Compute node. The output messages may have same or different messagecontent. You can also send output messages to any alternate output terminals of

the Compute node.

Q:Why do we use Sequence node?

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

Q:Which command is used to modify broker parameters?

A:mqsichangebroker command is used to modify broker parameters.

Q:What is the purpose of using mqsichangeproperties command?


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A:mqsichangeproperties command can be used to change properties associated with

a broker such as:

that affect the whole broker; for example, an HTTP listener or Service

Federation Management

that affect one or more execution groups; for example, the broker registry

that affect a configurable service; for example, a JMS provider.


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///////////////////////////////////////////////////////////////////////////////////////////////////

1.What are the features of Message Broker?

Ans:Routing, Transformation and Integration.

2.What is the role of configuration manager?

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

3.How to create Broker from Command prompt?

Ans: Using mqsicreatebroker command.

4.What are the default properties of MQ Input node?

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

5.Which nodes are used to change the message in the flow?

Ans:Compute Node, Filter Node and ResetContentDescriptor node.

6.Name 6 built-in nodes in MB Toolkit?

Ans: (i) MQInput node (ii) MQOutput node (iii) Compute node (iv) Database node (v) AggregateControl node

(vi)Filter node.

7.How to call the method or function in the eSQL coding?

Ans:Using the "CALL" keyword.

8.What is the Broker Domain?

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

9.Name the message formats which MB support?

Ans:XML, TDS, CWF, EDI, SWIFT.

10.What is an Execution Group?

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

11.Difference between Root and OutputRoot?

Ans: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.


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12.What is User name Server and where it is defined?

Ans:The User Name Server is an optional runtime component that provides authentication of users and

groups performing publish/subscribe operations.

13.How can we see the error log files in broker?

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

14.What are the perspectives there in MB Toolkit? In which perspective we deploy the flow?

Ans:(i) Administration Perspective (ii) Application Development Perspective (iii)Debugging Perspective (iv)

Java Perspective . We deploy flows in Administration Perspective .

15.What are the different ways to give input without using MQInput node?

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

16.What is PARSER? Difference between PARSER and FORMAT?

Ans: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

17.Define Correlation names?

Ans: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.

18.How will we use a Cobol copybook in MB?

Ans: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.

19.1)What is SCHEMA of broker?

Ans: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.

20.How can you interact with Database using Compute node?

Ans:Specify in Data Source the name by which the appropriate database is known on the system on which

this message flow is to execute.


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Q: What do you mean by Reset Content Descriptor node?

A: Reset Content Descriptor node request to parse the message withdifferent parser, leaving the message content unchanged.

Q: What is the difference between an MQ Get node and MQInput node?

A: The MQ Get node reads a message from a specified queue, andestablishes the processing environment for the message. Whereas, The MQInput node receives a message from a WebSphere MQ message queue thatis defined on the queue manager of the broker.

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

Q: What is the difference between SOAP Request node and SOAP

Async Request node?

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

waiting for the response.

Whereas, The SOAP Request node is a synchronous request and responsenode, which blocks processing after sending the request until theresponse is received.

Q: What is the difference between mapping node and Computenode transformation?

A:In Compute node you can transform the message by coding ESQL in theESQL resource file attached. Whereas, In mapping node you can usegraphical maps to transform input message by associating an inputmessage model such as a DFDL or XML schema, or an MRM Message Setand an output message model.

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

Q: What is the difference between Input and MQ Input node?A:Use the Input node as an in terminal for an embedded message flow (asub flow).The MQ Input node receives a message from a WebSphere MQmessage queue that is defined on the queue manager of the broker. It is thefirst node of your message flow.


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Q: What is the purpose or use of compute node?

A:The Compute node is used to:

Build a new message using a set of assignment statements

Copy messages between parser

Convert messages from one code set to another Transform messages from one format to another

Q: How the interaction with Database does take place usingCompute node?

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

Q: Difference between try catch node and throw node?A:Include a Throw node to force an error path through the message flow ifthe content of the message contains unexpected data.

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

Q: How will input messages with different - different delimitersbetween the fields arehandled in WMB?

A: Using MRM domain we can input messages with different - differentdelimiters between the fields in WMB.

Q: What do you mean by depth of a Queue?

A: Queue depth, is the number of pending input/output messages in aqueue.

Q: How can we know the current depth of a queue?

A:Using MQSC property CURDEPTH we can know the current depth of aqueue.

Q: Message Broker supports what all formats?A: Message Broker supports XML, TDS, CSV, CWF, EDIFACT, SWIFT,COBOL formats

Q: What all nodes use ESQL?A:ESQL can be used with the Compute, Database, and Filter nodes.


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Q: What is ESQL?A: Extended Structured Query Language (ESQL) is a programminglanguage based on Structured Query Language (SQL), which is commonlyused with relational databases such as DB2. ESQL extends the constructsof the SQL language to provide support for you to work with both

message and database content.

Q: What functionality ESQL provides?

A: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

Q: What are the types of variables in ESQL?

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

Q: What are external variables, normal variables or sharedvariables?

A:External variables:

Also known as user defined properties.

Exist for entire life time of a message flow and are visible to allmessages passed through the flow.

You have to assign an initial value at the time of declaring anexternal variable and then can modify the initial value at deploymenttime by using the BAR editor.

Normal Variables:

Have lifetime of just one message pass through a node.

Visible to the message only in which it was defined. To define, omit both EXTERNAL and SHARED keyword.

Shared variable:

Used for implementing in-memory cache in the message flow.


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Have a long life time and are visible to multiple messages passthrough the flow.

Exist for the lifetime of Execution group, lifetime of flow or node,lifetime of nodes ESQL that declares the variable.

Initialized when the first message pass through the node or flow

after broker start-up.

Q: What are patterns?

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

Q: What are the benefits of using patterns?

A: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 andcommon implementation of programming approaches, such as errorhandling and logging

Q: How do you ensure that messages do not lose?

A:

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

Message persistence - If a message is persistent, WebSphere MQensures that it is not lost when a failure occurs, by copying it todisk.

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

Q: How to use functions in your e SQL code?

A:Use CALL keyword to call functions or methods.

Q: What are the ways in which you can access databases from amessage flow?

A:


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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.


23/23

1. What is the purpose of WSDL?

2.Use of compute node?

3.How to handle of Exceptions in your flows?

4.What are the nodes used in your flow?

5.Sample syntax of compute node?

Documents

WMB & IIB Interview Q & As