MQ Interview Questions and Answers

MQ Interview Questions and Answers will be very helpful for the beginners who are willing to learn from scratch to an advanced level.

1. What exactly do you understand with the term MQ and what it is responsible for?
Ans: MQ abbreviates Message Queuing. When it comes to message-driven processes, IBM enables users to simply keep up the pace with the WebSphere with which all application programs can simply be managed. There is no strict upper limit on the platforms when it comes to communicating and the good thing is vast support is available from IBM to enable the users to manage everything simply.

2. Can I still access IBM Connections 3.0 metrics in IBM Connections 4.0?
Yes, any Connections user who is assigned the metrics-reader role can access metrics. To access metrics in IBM Connections 3.0.1, the user must have the correct URL. If the user can access global metrics, selecting View all Metrics->More Metrics provides a link to the IBM Connections 3.0.1 application. (E laerning)

3. SSL certificate selection?
Ans: I am having a queue manager to whom 10 different applications connect. I want to make them connect over SSL svrconn channels and for them to represent different unique certificates. So all 10 application key repositories will have the same queue manager certificate but my queue manager key repository will have 10 different certificates, one from each application.

4. What is the Queue?
A queue is a data structure used to store messages. A queue manager owns each queue. The queue manager is responsible for maintaining the queues it owns, and for storing all the messages it receives onto the appropriate queues.

5. How does MQ support the Integration?
The above arethe ways to support integration

  • MQ is operating system independent.
  •  MQ is protocol independent.
  • it supports TCP/IP, LU6.2, SNA, NetBIOS, UDP.
  •  Sender and receiver can be from any platform.

6. What are “dimensions”?
 In Cognos Business Intelligence, a dimension is a broad grouping of descriptive data about a major aspect of a business, such as products, dates, or locations. Each dimension includes different levels of members in one or more hierarchies and an optional set of calculated members or special categories. Refer to the Power cube dimensions topic to learn the dimensions used in Metrics.

7. In IBM Websphere MQ, what is an MQ client and how it is different from an MQ server?
Ans: Many times there is a need to issue MQI calls to a queue manager. IT is not always necessary that it runs on the same system. MQ client is responsible for issuing the same for an application. The output can be modified up to some extent. On the other side, the MQ server is a manager for the queue which is responsible for offering the queuing service to the clients. All the objects which are classified in the MQ appear only on the server and not on the client’s machine.

8. Tell us about the storage needs when it comes to the IBM Websphere MQ installation?
The installation of the IBM Websphere MQ needs to have some basic storage requirements which are as under. It needs 50 MB for data storage on the server. The server installation needs around 40 MB. While the data storage for the client and the installation of the file at client end have 5 MB and 15 MB needs. 

9. What is the IBM MQ Series?
Ans: 1. A middleware from IBM
2. It has runtime managers such as Queue Managers and Queues
3. A queue is an object which holds messages of various formats – XML/text/byte
4. Queue manager maintains and manages objects like Queues, channels
5. Various listener applications listen to these queues for grabbing the messages, followed by processing these messages
6. Java Messaging Service is one of the standards provided by JEE specification for asynchronous messaging
7. The queues can be defined in JEE container and send messages on these queues
8. Message Driven Bean can be configured for listening to the JMS queues
9. When a message is on the JMS queue, the corresponding MDB’s onMessage() method is invoked and the message processing can be done

10. What is Local administration and Remote administration?
Ans: Local Administration: Means carrying out administration tasks on any queue managers you have defined on your local system.
Remote Administration: This allows you to issue commands from your local system that are processed on another system. For example, you can issue a remote command to change a queue definition on a remote queue manager. You do not have to log on to that system, although you do need to have the appropriate channels defined. The queue manager and command server on the target system must be running.

11. Name the different objects that are used in the WebSphere MQ?
Ans: These are Channels, Processes, Queue Manager, Name Lists and Processes. All these objects can have a similar nature or a different one depending on the operation they are engaged in.

12. Suppose you need to install the IBM Websphere MQ in Aix, what would be the requirements related to the software you need to fulfill?
Ans: The one and the only prime requirement is the machine should be of 32-bit OS. Although it works on 64-bit OS, it needs some customized settings. The Aix should be installed on it and there will be no corrupt files related to programming.

13. Name some script commands and tell one basic condition for their use?
Ans: These are:


14. What’s the message code for Stopping a Queue Manager?
Ans: AMQ4044 Queue manager stopping.

15. How does an application send and receives messages from the Queues?
 Application programs send and receive messages using MQI calls.

MQOPEN: It is used to open the Require Queue.

MQPUT: It is used to PUT the message into the Required Queue.

MQGET: It is used to get the message from the required Queue.

MQCONNX: This command used to connect to the queue manager

MQPUT1: It performs the putting, browsing and getting the application at a time on a single queue.

MQCLOSE: It closes the connection with the Queue.

M-DISC: This is used to disconnect the application with the Queue manager.

16. Explain about the Message Client and Message server?

1. Message Client:
A Web Sphere MQ Client is an application’s component that is running on a system for sending MQI calls to a queue manager which is running on another system.
The response is sent back to the client, which passes back to the application.

2. Message Server:
1. A Web Sphere MQ Server is an application’s component that provides queuing services to several clients.
2. All the MQ objects of an application, like the queues, exist only in the queue manager machine.
3. Web Sphere MQ server can also support the Web Sphere MQ Applications that are running locally.

17. What is IBM Cognos Business Intelligence (BI)?
Ans: IBM Cognos Business Intelligence is an application that provides reports, analysis, dashboards, and scoreboards to help support the way people think and work when they are trying to understand business performance. You can freely explore information, analyze key facts, and quickly collaborate to align decisions with key stakeholders. For more information about Cognos Business Intelligence, refer to the IBM Cognos Business Intelligence 10.1.1 information center.

18. hat do the People, Participation, and Content themes mean?
Ans: The People theme tracks the users who visit IBM Connections. The Participation theme tracks actions in IBM Connections, such as downloading files or updating profiles. The Content theme tracks information shared in IBM Connections, such as files and comments.

19. What are the Telemetry capabilities you are familiar with?
Ans: Telemetry allows the remote sensors to be connected with a node. When it comes to optimizing the sensor networks, its telemetry that provides optimization technique. In satellite networks, it can help to save a lot of costs simply.

20. Is the procedure of installation the IBM WebSphere MQ on Aix similar to that for Windows?
Ans: Yes, all the requirements are the same except for a few basic ones. For older versions of Windows such as 2000 and XP, it needs some customized settings in the application. It is free from the network protocols and thus users have no reason to worry about this.

21. What is the MQ Client?
Ans: A Web Sphere MQ client is a component that allows an application running on a system to issue MQI calls to a queue manager running on another system. The output from the call is sent back to the client, which passes it back to the application.

22. How to MQ update DB on another computer?
Ans: From Machine A, a client program sends a request to the MQ server in Machine B. Now, that computer updates the DB situated in another Machine C.

23. What is the significance of the MQ Series?
Ans: Significance of Websphere MQ Series:

1. WebSphere MQ will significantly improve the flow of information across an enterprise
2. The message is placed and adjusted for dynamic business requirements
3. MQ series reduce maintenance, integration costs and acts as a bridge to various technologies
4. MQ Series reduces costs and all the disruptions are processed from data loss
5. Allows ongoing maintenance efforts through universal service delivery
6. Security breaches are eliminated and ensure compliance through message and transaction integrity.

24. What are the channel and mention different types of channels in MQ?
 Channels are objects that provide a communication path from one queue manager to another. Channels are used in distributed queuing to move messages from one queue manager to another. They shield applications from the underlying communications protocols. The queue managers might exist on the same, or different, platforms.

Different types of Channels:

1. Sender-Receiver Channels

2. Requester-Server Channels

3. Client Connection channels

4. Server Connection Channels.

5. Cluster Sender.

6. Cluster Receiver Channels.

25. What is the Keep-Alive Interval?
Ans: The Keep-Alive Interval parameter is used to specify a time-out value for a channel. The Keep-Alive Interval parameter is a value passed to the communications stack specifying the Keep-Alive timing for the channel. It allows you to specify a different keep-alive value for each channel. The value indicates a time, in seconds, and must be in the range 0 to 99999.

26. What is the difference between the Full & Partial repository in WebSphere MQ?
A full repository will contain all the information on cluster images and other objects. The partial repository will contain all the information of the particular qmgr and other instances for communication.

27. What is the difference between community metrics and global metrics?
IBM Connections provides metrics on two levels: global and community. Global metrics report on overall usage; for example, the total number of people who logged into IBM Connections last week. Community metrics report on a particular community.

28. Is there is any chance for the Message lost?
Ans: If the target queue manager does.t contain the dead letter queue defined and if the messages are running on a fast channel and of nonpersistent, Then there is a chance of the message loss.

29. What information we have in the auto define channel?
It contains a channel name, port no. And ip addresses that are mentioned in the receiver channel.

30. In what formats are reports available?
Metrics reports can be presented as tables or charts, which can be refined by selecting options such as the time, a particular application, or how to group users in the results.

31. What are commands used on the Command server?

1.strmqcsv: to start the command server
2. dspmqcsv: to display the command server
3. endmqcsv: To end the command server.

32. Difference between MQSC commands and Control commands?

MQSC Commands: These commands are used to handle the admin related functions for the components that are present in the MQ Series. In general MQSC commands are used for creating and maintaining Message channels, Queue Managers, Clusters, etc…

Control Commands: These commands are used to manage the processes and services that are helpful in the functioning of the MQ Series. In general, these commands are used for Channel listener, Channel Initiator, Trigger monitor, etc.

33. What is Asynchrony?
Ans: With message queuing, the exchange of messages between the sending and receiving programs are independent of time. This means that the sending and receiving application programs are decoupled; the sender can continue processing without having to wait for the receiver to acknowledge receipt of the message. The target application does not even have to be running when the message is sent. It can retrieve the message after it is has been started.

34. What is the dead letter queue in IBM MQ Series?
Ans: Dead letter Queue in WebSphere MQ is a queue that is used by QueueManager to archive messages for a nonexistent queue. For example, QueueManagerQMGR receives a message for queue ABC and if it didn’t exist on that QueueMangaer then the message will be routed to the dead letter queue.

35. What is the Difference between Predefined & Dynamic Queues?
Ans: Queues can be characterized by the way they are created:
1. Predefined queues are created by an administrator using the appropriate MQSC or PCF commands. Predefined queues are permanent; they exist independently of the applications that use them and survive Web Sphere MQ restarts.

2. Dynamic queues are created when an application issues an MQOPEN request specifying the name of a model queue. The queue created is based on a template queue definition, which is called a model queue.

36. Which WebSphere MQ version have you worked on? What is the latest IBM WebSphere MQ version?
Ans: This MQ interview question is more to know that which version of MQ have you worked upon, do you familiar with any issue with that particular version or many major changes to previous or next version, etc. Based upon your answer, you may expect some follow-up Q.s. By the way, the current version of WMQ is WebSphere MQ 7.5 but it always good to check IBM’s MQ website for the latest version.

37. What is a different Channel status?
Ans: Channel Status:
1. Inactive
2. Running
4. Stopped.

38. What is SSLPEER in IBM Websphere MQ?
Ans: Another interesting and frequently asked WebSphere MQ Interview Q. You can easily answer this MQ Q. if you connected MQ via SSL. SSLPEER is a String usually DN (Distinguished Name) of MQ Client which connects to QueueManager securely using QueueManager. This is a mechanism WMQ uses to identify the client. In the case of Java or JMS client, SSLPEER is DN of client certificate stored in its keyStore and sent to the server during SSL handshake.

39. What do you mean by message descriptor?
Ans: A massage doesn’t just contain information that needs to be transferred but it contains other information too. For example, type of message and what exactly its priority is. The same is described in the message descriptor which is defined by WebSphere MQ. It contains all other relevant information about the message and among all of the same, its priority that largely matters.

40. What is LONG Retry count?
Ans: Specify the maximum number of times that the channel is to try allocating a session to its partner. If the initial allocation attempt fails, the short retry count number is decremented and the channel retries the remaining number of times.

41. What out-of-box reports are available in IBM Connections 4.0 Metrics?
 The Metrics application in IBM Connections 4.0 provides more than 110 reports for global metrics and community metrics. You can view each report using different filters, including time ranges and user attributes such as geography, department, and role. For more information, refer to the: IBM Connections 4.0 Metrics Reports Introduction article.

42. Is there a quarterly report in Metrics?
No. Metrics do not provide reports by quarter. It provides a Last quarter report that includes data for the last three months.

Organizations and corporations can simply send bulk messages over complex networks. There are no strict protocols that need to be followed. Even if they are, the same can be managed very easily. Enterprises can make sure of quick information delivery to the destinations and can always have the things done in the best possible manner.

43. Name the default port number for the MQ Queue Manager. Is it possible to change this?
Ans: The default number is 1414 and the same cannot be changed.

44. What are the advantages of the MQ?

1. Integration.
2. Asynchrony
3. Assured Delivery
4. Scalability.

45. What is the Max Length of the message does MQ support?
Ans: The default maximum message length is 4 MB, although you can increase this to a maximum length of 100 MB.

46. How can we write the MQSC commands that have too many parameters?.
Ans: For commands that have too many parameters to fit on one line, use continuation characters to indicate that a command is continued on the following line:
1. A minus sign (- ) indicates that the command is to be continued from the start of _ the following line.
2. A plus sign (+) indicates that the command is to be continued from the first nonblank character on the following line.

47. Can this affect any performance in the settings elsewhere?
Ans: The space used to hold the value for MaxMsgLen is a constant; it’s the same no matter what number is used for MaxMsgLen.
The only way that, for example, setting the MaxMsgLn for all queues, channels, and images to the maximum possible will have any performance impact is if your logs are not sized to handle that size of message AND someone SENDS a big message.
Set it to the largest value you can handle, and then you don’t have to worry about changing it every time an application needs a bigger value. Setting the MaxMsgLn doesn’t affect anything else. Sending a large message does.
Max Message length is only a safety feature to not receive an unexpectedly large message.

48. What is the CCDT file on WebSphere MQ or WMQ?
Ans: CCDT file or Client Channel Definition table is a binary file that contains connection details required by MQ clients e.g. Java application using JMS to connect to MQ Server. To connect to MQ Server, MQ clients need MQ Server hostname, MQ Server port name, and server channel name. All these details are encapsulated in the CCDT file named AMQCLCHL.TAB. To create MQ Connection, MQ clients need the location of this file, which is provided as configuration. most of MQ errors comes either with incorrect CCDT files.

Ans: The batch heartbeat interval allows a sending channel to verify that the receiving channel is still active just before committing a batch of messages so that if the receiving channel is not active, the batch can be backed out rather than becoming in-doubt, as would otherwise be the case. By backing out the batch, the messages remain available for processing so they could, for example, be redirected to another channel.

50. What is the Algorithm followed in retrieving the Messages from the Queue?
 1.First-in-first-out (FIFO).

2. Message priority, as defined in the message descriptor. Messages that have the same priority are retrieved on a FIFO basis.

3. A program request for a specific message.

51. What are the Different Logging Methods available?
Ans: There are two different types available:

1. Circular: The circular logging is used for restart recovery. It is the default logging method. Circular is used in Development and Testing Queues. Circular logging keeps all restart Data in a ring of log files. Logging fills the first file in the ring, then moves on to the and so on, until all the files are full. It then goes back to the first file in the ring and starts This continues as long as the product is in use, and has the advantage that you never run out of log files.

2. Linear: Linear logging gives you both restart recovery and media recovery. It is used in Production. Linear logging keeps the log data in a continuous Sequence of files. Space is not reused, so you can always retrieve any record logged from the time that the queue manager was created. As disk space is finite, you might have to think about some form of archiving. It is an administrative task to manage your disk space for the log, reusing Or extending the existing space as necessary.

52. What are the MQI channels and their types?
Ans: MQI channels are the channels that carry messages from MQ Client application to the MQ server and vice versa.They are Bi-directional Channels
1. Server-connection
2. Client-connection.

53. Is there a list of all Metrics reports in the Metrics UI?
 You can get a list of all metrics reports from the View all Metrics link in the navigation panel of the Metrics UI.

54. What is packet loss in Messaging and how the receiver knows which packet is not received by it?
Ans: Packets are the sub-parts of a message that needs to be sent from a sender to a receiver. Sometimes a situation arrives when a packet doesn’t reach its destination. Because all the packets have a well-defined address on them, the receiver can understand and acknowledge which message has been lost.

55. What do you understand by the term congestion control?
Ans: Well, the fact is sometimes there are so many messages on a network. The channel has its limit of processing the data and when the same exceeds, the situation is considered as congestion. It is similar to a traffic jam on a road. The clearance needs time and so do the messages get a bit delayed for delivery.

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