What is MQ?
MQ stands for Message queuing. MQ allows application programs to use the message queuing to participate in message-driven processing.
what are the advantages of MQ?
- Integration
- Asynchrony
- Assured delivery
- Scalability
What is the format of the command "dspmqver"?
Version.release.modification.fixpack.
6.0.2.7
What is a user exit in terms of MQ?
Using these user exits, we can insert our code into the queue manager function.
What are the logging configuration files?
mqs.ini - config file for mq level settings
qm.ini - config file for queue manager level settings
What is the algorithm used in MQ for ensuring integrity?
Log write integrity is the algorithm used to ensure integrity. This can be changed in QM config file
Version.release.modification.fixpack.
6.0.2.7
What is a user exit in terms of MQ?
Using these user exits, we can insert our code into the queue manager function.
What are the logging configuration files?
mqs.ini - config file for mq level settings
qm.ini - config file for queue manager level settings
What is the algorithm used in MQ for ensuring integrity?
Log write integrity is the algorithm used to ensure integrity. This can be changed in QM config file
When a queue manager starts, what are the default components that start with the Queue manager?
The Queue Manager task:
- LOGGER-IO
- ERROR-LOG
- CHECKPOINT
- ASYNCQ
- EXPIRER
- STATISTICS
What is the communication protocol used by MQ Explorer to connect to the remote QMs?
TCP/IP Protocol
What is a Channel?
Channel can be depicted as a pipe/connection for communication between queue managers to exchange messages.
What are various types of channels in MQ v6?
- Sender(SDR)
- Receiver(RCVR)
- Cluster Receiver(CLUSRCVR)
- Cluster Sender(CLUSSDR)
- Server(SVR)
- Requester(RQSTR)
- Client Connection(CLNTCONN)
- Server connection(SVRCONN)
What is the purpose of Channel Initiator in MQ?
monitor the system-defined initiation queue SYSTEM.CHANNEL.INITQ
Channel Listener - listens for any incoming network requests and starts the appropriate receiver channel.
monitor the system-defined initiation queue SYSTEM.CHANNEL.INITQ
Channel Listener - listens for any incoming network requests and starts the appropriate receiver channel.
What are the types of Queues available in MQ V6?
- Local
- Alias
- Remote
- Model - dynamic queues that are created on the fly by the applications
- Cluster queue
What are the types of logging in MQ?
- Circular -lc
- Linear - ll
Inorder to instruct Websphere MQ to advance/write to a new linear log, "RESET QMGR TYPE(ADVANCELOG)"
In order to recover a queue from a media failure, what type of logging combined with messaging should be?
ans. Linear logging with persistent messaging
Name the log control file in MQ v6?
Log control file is amqhlctl.lfh
Default location of logs
- UNIX: /var/mqm/log/
- Windows: C:\Program Files\IBM\WebSphere MQ\log\
Log Defaults in UNIX:
- LogPrimaryFiles=3
- LogSecondaryFiles=2
- LogFilePages=1024
- LogType=CIRCULAR
- LogBufferPages=0
- LogDefaultPath=/var/mqm/log
What is a dead-letter queue handler? How do you invoke it?
runmqdlq - command to start the DLQ handler(monitor & handle messages in DLQ)
dead letter queue handler can be used to both select a message and perform various actions on that message. The runmqdlq command takes its input from stdin. When the command is processed, the results and a summary are put into a report that is sent to stdout. By taking stdin from the keyboard, you can enter runmqdlq rules interactively.
What is a MCA?
A Message Channel Agent(MCA) - sits at each end of the channel controlling the sending and receiving messages. MCA takes the messages from the transmission queue and puts them on the communication link(channel) between the queue managers.
What is an Initiation queue?
Queues that are used in triggering. A message is put by the queue manager on the initiation queue when the trigger event occurs
What is a Command Server in Websphere MQ z/OS?
Command Server is a component of Websphere MQ that works with command processor component.
Reads messages from system-command input queue, verifies them, passes the valid ones as commands to the command processor
command processor processes the message and replies back to the reply-to queue that is specified.
System command input queue -> SYSTEM.COMMAND.INPUT
SYSTEM.ADMIN.COMMAND.QUEUE
reply-to queue -> SYSTEM.COMMAND.REPLY.MODEL
Security/Authorization
Authorization for using MQI calls, commands and access to objects is provided by the Object Authority Manager (OAM). The “setmqaut” command is used to grant or revoke authorizations as required.
A security refresh is required after setmqaut commands are issued. This can be done by recycle of QMGR to refresh the security cache or
by runmqsc command “refresh security(*) all”
“dspmqaut” and “dmpmqaut” can be used to view authorities.
A security refresh is required after setmqaut commands are issued. This can be done by recycle of QMGR to refresh the security cache or
by runmqsc command “refresh security(*) all”
“dspmqaut” and “dmpmqaut” can be used to view authorities.
