CoreOnline43 min
IBM MQ messaging
How applications on and off the mainframe hand work to each other reliably with IBM MQ: queue managers, queues, channels, the MQI calls COBOL programs use, and what to check when messages stop flowing.
What you will be able to do
- Explain why banks put a message queue between systems instead of calling each other directly
- Name the main MQ objects (queue manager, local, remote, alias, transmission and dead-letter queues, channels) and what each is for
- Read a COBOL program that uses MQOPEN, MQPUT, MQGET and MQCLOSE, and interpret completion and reason codes
- Troubleshoot the classic production problems: growing queue depth, stopped channels, poison messages and the dead-letter queue
Lessons
- Why messaging existsIBM MQ lets one program put a message on a queue and carry on, while another program picks it up when it is ready.
- Queue managers, queues and channelsEverything in MQ belongs to a queue manager. Queues hold messages; channels move them between queue managers.
- Programming with the MQI in COBOLPrograms talk to MQ through a small set of calls known as the MQI. A COBOL program connects, opens a queue, puts or gets messages, closes and disconnects, checking a completion…
- Running and troubleshooting MQWhen messages stop flowing, the same few checks find most problems: is the queue growing, is anyone reading it, is the channel running, and has anything landed on the dead-letter…
Track your progress and earn a certificate.
Free account, 24 quiz questions for this subject.