Messaging, Music and Moving Around
I recently wrote an article about new TypeScript bindings for the MQ and Node.js interface. Version 0.9.21 of the MQ Node.js interface includes an update to the TypeScript definitions that can assist further in writing correct programs by describing how MQI flags or bitfield parameters are set. Showing how this new capability works was a bit too long to simply add to the original article. So I’ve written this piece.
This post was last updated on January 28th, 2022 at 07:43 pm
MQ application programs for the Node.js environment can now use TypeScript definitions. This brings the opportunity to compile and check your JavaScript programs for correctness before running them. This post will talk more about what TypeScript is and how it can help your MQ Node.js development activity.
Substantial credit for the API definitions and translations of the example programs needs to be given to Andre, who submitted a Pull Request to our github repository.
Continue reading “MQ and Node.js: working with TypeScript”This post was last updated on January 26th, 2022 at 01:53 pm
It never fails to amaze me how often the same question gets asked by different people from different projects at around the same time. This time, I was asked by two people about resolving subscription authorisation failures. I could find lots of information about IBM MQ publish/subscribe, and general descriptions of what security checks are made. But there was not so much on how to use information from the queue manager that can help to deal with the inevitable failures.
Continue reading “Resolving subscription authorisation failures”This post was last updated on December 13th, 2021 at 01:23 pm
On Twitter, Michael asked: “any logic or hints on how to interpret the PCF parameter names returned as multiples from the com.ibm.mq.headers.pcf?” Which is a very good question but a proper answer is far too long to type there. There are several different ways that you can approach the problem, depending on what you are trying to do. So this post talks about decoding MQI constants.
Continue reading “Decoding MQI constants”This post was last updated on March 21st, 2022 at 09:47 am
IBM has just announced MQ 9.2.4. No matter how hard you search the announcement letters you will still not be able to find anything about the event formatter changes that I was able to slip into the release. That’s because changes to samples don’t normally deserve highlighting in formal marketing documents. But I hope this change still turns out to be useful.
Continue reading “Event formatter changes with MQ 9.2.4”This post was last updated on November 24th, 2021 at 01:12 pm
Something I dealt with recently in independent exchanges with several different people was about programming with IBM MQ, and dealing with MQI errors that might not be errors. This post is a short discussion about the not-quite-failed status of a warning. Is it an error? What is the difference between MQI errors and warnings?
Continue reading “Warning: is it an error”This post was last updated on November 15th, 2021 at 10:00 am
A recent thread on mqseries.net asked about controlling queue creation in MQ. In particular, how to set authorities so that one user can create queues like “ABC…” but not “DEF…”. There are answers given in that thread both on the ability to do it, and the reason why it’s not usually something that’s needed.
In summary, it’s not possible to control it with setmqaut commands. And since queue creation is usually done by administrators, there’s not really any need to restrict it further.
But the thread did remind me of some code I’d written a few years ago while considering the same question as part of a larger piece of work. And so I thought I’d dredge up that PoC and make it a bit more readable. It shows how you can, in fact, implement that level of control on platforms where you can install extensions to the MQ Authorisation interface.
Continue reading “Controlling queue creation”One of the common mistakes that people make when they first start programming with the MQI can be seen in this pseudo-code example:
MQMD md = {MQMD_DEFAULT}
MQGMO gmo = {MQGMO_DEFAULT}
int bufsize = 128
PMQCHAR buf = malloc(bufsize)
do {
MQGET(&md,&gmo,buf,bufsize))
} while (rc != MQRC_NO_MSG_AVAILABLE)
They complain that despite pre-loading the queue, only a single message is returned. Anyone reading this is likely to recognise immediately the problem: the MsgId of the first message is returned in the md variable. The next iteration of the loop tries to match that MsgID and doesn’t find any more messages.
There are aspects of the MQI that try to minimise your chances of getting this wrong, like the MatchOptions flag in the MQGMO structure. But that in turn requires you know a) to set it and b) override the default version of the structure.
Having worked with MQ for so many years, I am hopefully not going to make that kind of mistake. But I still got caught out recently by a very similar problem.
Continue reading “Variation on a theme: an MQI mistake”This post was last updated on September 20th, 2021 at 08:17 am
The mq-metric-samples collectors that send IBM MQ metrics and status data to a range of databases, ready to be viewed in Grafana, have just been enhanced to collect additional information. The Prometheus collector has also been extended so that it can continue providing limited status even when the queue manager is down.
The new metrics have all been suggested by users of the package either directly or via issues raised in the GitHub repository. Many previous articles on here show more about the collectors.
The InfluxDB collector is also refreshed for a new version of the database.
Continue reading “New features with the MQ Go metric collectors”This post was last updated on November 27th, 2021 at 02:59 pm
The Request for Enhancement (RFE) system that lets you submit new requirements and ideas for IBM MQ has been moved to a new interface. Just about all IBM products are moving to use Aha! to give a common front-end, and it is now MQ’s turn to migrate.
This post is a quick look at what this means.
Continue reading “New interface for MQ Requirements”This post was last updated on September 7th, 2021 at 02:33 pm
