- What is QueueManager in IBM WebSphere MQ? …
- What is Channel in IBM WebSphere MQ? …
- What is dead letter queue in IBM MQ Series ? …
- What is the CCDT file on WebSphere MQ or WMQ? …
- What is SSLPEER in IBM Websphere MQ?
☆ A middle ware from IBM. ☆ It has runtime managers such as Queue Managers and Queues. ☆ Queue is an object which holds messages of various formats – XML/text/byte. ☆ Queue manger maintains and manages objects like Queues, channels. ☆ Various listener applications listen to these queues for grabbing the messages, followed by processing these messages. ☆ Java Messaging Service is one of the standards provided by JEE specification for asynchronous messaging. ☆ The queues can be defined in JEE container and send messages on these queues. ☆ Message Driven Bean can be configured for listening the JMS queues. ☆ When a message is on the JMS queue, the corresponding MDBs onMessage() method is invoked and the message processing can be done.
☆ WebSphere MQ will significantly improves the flow of information across an enterprise. ☆ The message is placed and adjusted for dynamic business requirements. ☆ MQ series reduce maintenance, integration costs and acts as a bridge to various technologies. ☆ MQ Series reduces costs and all the disruptions are processed from data loss. ☆ Allows ongoing maintenance efforts through universal service delivery. ☆ Security breaches are eliminated and insures the compliance through message and. ☆ transaction integrity.
The following are the types of queues: 1) Model Queue: A queue definition is called a model queue. It is used when a dynamic queue is created 2) Alias Queue: Another name for a local queue or a remote queue. Its usage is for security and maintenance 3) Remote Queue: Remote queue is a queue definition pertaining to another Q Manager 4) Initiation Queue: It is a local queue. Queue manager writes a trigger message at the time of meeting certain conditions on another local queue 5) Dynamic Queue : A dynamic queue is created on the fly on demand by the application. The dynamic queues may be retained or automatically deleted when the application program ends. It is used to store any intermediate result 6) Cluster Queue: A local queue. It is known throughout a cluster of queue managers 7) Reply-to-queue: A request message must have the queue name, into which the program that is responding must put the reply message
The following are some of the reserved queue names of IBM Websphere MQ Series: ☆ SYSTEM.ADMIN.CHANNEL.EVENT Queue for events of channel ☆ SYSTEM.CHANNEL.INITQ A distributed queuing queue on z/OS without CICS ☆ SYSTEM.CHANNEL.SEQNO A distributed queuing queue on z/OS using CICS ☆ SYSTEM.CHANNEL.SYNCQ A distributed queuing queue on z/OS without CICS ☆ SYSTEM.ADMIN.COMMAND.QUEUE Queue for PCF command messages to be sent for ☆ non- z/OS ☆ SYSTEM.ADMIN.CONFIG.EVENT Queue for events of configuration ☆ SYSTEM.ADMIN.PERFM.EVENT Queue for events of performance ☆ SYSTEM.ADMIN.QMGR.EVENT Queue for events of queue manager ☆ SYSTEM.CHANNEL.COMMAND A distributed queuing queue on z/OS using CICS ☆ SYSTEM.CICS.INITIATION.QUEUE Queue for utilization of triggering for non- z/OS ☆ SYSTEM.CLUSTER.COMMAND.QUEUE Queue for communication repository changes among queue managers (applicable for AIX, HP-UX, Linux, OS/2 Warp, OS/400, Solaris, Windows, and z/OS only) ☆ SYSTEM.CLUSTER.REPOSITORY.QUEUE Queue for holding information about repository (applicable for AIX, HP-UX, Linux, OS/2 Warp, OS/400, Solaris, Windows, and z/OS only)
Sending messages from one queue manager to another queue manager is known as inter communication/ ☆ The receiving queue manager may by on the same machine or another. ☆ It could be executing on the platform where the local queue manager exists ☆ It could be executing on another platform supported by Web Sphere MQ ☆ The participating entities are: 1) Message channels, message channel agents 2) Transmission queues, channel initiators and listeners 3) Programs those are co-existing
MQ messages types are: ☆ Data-gram – It is an unsolicited message ☆ Request – A message for which a response is expected ☆ Reply – A message event such as a confirmation on arrival or delivery. It can be an error ☆ MQ messages can be persistent or non-persistent
☆ Persistent messages are usually logged. ☆ The performance of the application is reduced by logged messages. ☆ Persistent messages are utilized only for essential data. ☆ When the queue manager is stopped / failed or the data in the message is discarded, then use a non persistent message. ☆ As the logged data is persisted for long time and need to keep track about the events that are happening in the systems, this data need to be persisted. ☆ Use buffering mechanism to improve the speed of retrieving data from the logged messages.
☆ The exchanging of messages among sending and receiving programs is time independent ☆ The sending and receiving application programs are decoupled ☆ Senders process can continue with out the need of waiting for the receivers acknowledgement message ☆ The receivers application need not be running while the message is sent ☆ The receiver can retrieve the messages after it has been started
☆ When a queue is not delivered to their correct destinations, then it is called as Dead Letter queue. ☆ When the destination queue is full, the dead-letter queue occurs. It is identified by SYSTEM.DEAD.LETTER.QUEUE. ☆ A dead-letter queue is defined for distributed queuing, on each queue manager.
☆ Initiation queues are used for triggering ☆ A trigger message is put by a queue manager on an initiation queue when a trigger is occurred ☆ Logical combinations are part of a trigger event which is detected by the queue manager
top 150+ Mq interview questions and answers for freshers and experienced
IBM WebSphere Message Queue Interview Questions and Answers
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.
What are the benefits that corporations can have through IBM Websphere MQ
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.
4. What is the Queue? Ans: 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.
1. ALTER 2. START 3. STOP 4. DELETE 5. CLEAR 6. DEFINESUSPEND 7. REFRESH 8. RESUME.
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.
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.
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.
Suppose you need to install the IBM Websphere MQ in Aix, what would be the requirements related to the software you need to fulfill?
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.
FAQ
What is MQSeries used for?
What are different types of queues in MQ?
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For a full description of these attributes, see Attributes for queues.
- Local queues. …
- Remote queues. …
- Alias queues. …
- Dynamic and Model queues. …
- Defining queues. …
- Queues used by IBM MQ.
How many messages can MQ handle?
What protocol is used by IBM MQ?
