In something a bit different, I’ve decided to look back in time. That’s because, while digging through some old files recently, I realised that IBM MQ on Linux is
21 years old today.
SupportPac MA57, as far as I can find, made MQ the first IBM product to have any kind of public support for Linux and was released on 1 Feb 1996. There might have been some research projects or tools before then, and there were certainly other products considering options, (my email archives suggest that several corporate lawyers rapidly got involved, as IBM got to grips with GPL and other open source licenses) but I don’t remember anything else officially released at the time. Read about SupportPac MA57
IBM MQ has always been able to generate event messages when something “interesting” has occurred in the queue manager. These events could be showing that a queue is full, or that there has been an authorisation failure; someone needing an audit trail might want to capture the command and configuration events. These events are written as MQ messages to well-known queues, using PCF structures which can be decoded to give the full description of the event.
Go is a language created at Google and made available as an open-source project. Although originally designed for building reliable large-scale distributed applications, its general-purpose nature and the collection of interface packages provided in the core language and from other projects has helped it become popular for a much broader set of applications.
In this article, I’ll show how Go programs can make use of IBM MQ, permitting Go applications access to the services provided by MQ-enabled applications, with an API that is more natural for Go programmers than some of the elements in MQ’s C API.
Permissions for accessing MQ functions have traditionally relied on using operating system definitions for users and groups. That could mean you having a requirement to define those users and groups on each system individually, which is challenging enough in a static topology, but becomes even worse in a dynamic environment such as a cloud where systems may be being defined and deleted regularly. And so some central definition of the identities becomes essential. Continue reading “IBM MQ – Using Active Directory for authorisation in Unix queue managers”
An earlier blog entry showed how to integrate MQ with the Prometheus database, capturing statistics that can then be shown in a Grafana dashboard. In this article, I’ll show how that initial work has been extended to work with more databases and collection tools.
The latest updates allow MQ to write directly to InfluxDB and OpenTSDB databases, and also to provide data to collectd.
In a previous blog entry I wrote about using the Go language with MQ. One of the reasons for creating that Go package was to enable the creation of a program that sends MQ statistics to Prometheus and hence to be easily visualised in Grafana. This blog shows how it all fits together.
Introduction
MQ V9 metrics
MQ V9 (and the MQ appliance) makes many statistics available through a pub/sub interface. One huge benefit of the pub/sub model is that this data can be collected without interfering with any other monitoring programs. An early prototype of the MQ exporter for Prometheus used the RESET QSTATS command just to prove the concept, but that is not a good command to use in general when you have any other tools that may also use it. Publish/subscribe gives easy isolation for monitors.
Prometheus is an open-source monitoring and alerting solution, whose particular strength is the collection of time series data, with the ability to easily query that data. For example, the number of MQPUTs to a queue may be of interest, and this kind of database makes it easy to see how many operations occurred in an interval, or calculate averages. Prometheus works by pulling information from exporters such as this MQ program at configured intervals over an HTTP connection. It provides libraries in several languages to enable products to export data to it, but the most commonly used is probably the Go library – hence the need for an MQ Go package.
What is Grafana
Grafana provides a way to create dashboards and visualise data held in time series databases. It has Prometheus as a built-in data source, making this pair of products a natural fit together.
Getting started with the monitor
Building the monitor
The github repository contains the monitoring program, the ibmmq package that links to the core MQ application interface and other prerequisite components.
should pull down the client code and its dependencies. The README file in the root of that package shows how to compile the code, either locally or within a Docker container.
Configuring MQ
It is convenient to run the monitor program as a queue manager service, automatically started and stopped along with the queue manager.
The source code directory contains an MQSC script to define such a service. In fact, the service definition points at a simple script (also provided) which sets up any necessary environment and builds the command line parameters for the real monitor program. As the last line of the script calls “exec”, the process id of the script is inherited by the monitor program, and the queue manager can then check on the status, and can drive a suitable STOP SERVICE operation during queue manager shutdown.
Edit the MQSC script and the shell script to point at appropriate directories where the programs exist, and where you want to put stdout/stderr. Ensure that the mqm id running the queue manager has permission to access the programs and output files.
The monitor listens for calls from Prometheus on a TCP port. The default port, reserved for this use in the Prometheus list, is 9157. If you want to use a different number, then use the -ibmmq.httpListenPort command parameter.
The monitor always collects all of the available queue manager-wide metrics. It can also be configured to collect statistics for specific sets of queues. The sets of queues can be given either directly on the command line with the -ibmmq.monitoredQueues flag, or put into a separate file which is also named on the command line, with the -ibmmq.monitoredQueuesFile flag. An example is included in the startup shell script. For example,
starts the monitor to collect the statistics for all queues whose names begin APPA and APPB.
Note on queue patterns
For now, the queue patterns are expanded only at startup of the monitor program. If you want to change the patterns, or new queues are defined that match an existing pattern, the monitor must be restarted with a STOP SERVICE and START SERVICE pair of commands.
Configuring Prometheus
The Prometheus server has to know how to contact the MQ monitor. The simplest way is just to add a reference to the monitor in the server’s configuration file. For example, add this block to /etc/prometheus/prometheus.yml with any changes needed for your hostnames and ports.
# Adding a reference to an MQ monitor. All we have to do is
# name the host and port on which the monitor is listening.
# Port 9157 is the reserved default port for the MQ monitor.
- job_name: 'ibmmq'
scrape_interval: 15s
static_configs:
- targets: ['hostname.example.com:9157']
The Prometheus documentation has information on more complex configuration options, including the ability to pull information on which hosts should be monitored from a variety of discovery tools.
Once the Prometheus server has picked up the MQ configuration, the metrics can be seen under the jobname of ibmmq. The values are labelled with the queue and queue manager names, to assist with selection. This picture shows some of the available information in the selection drop-down:
Selecting metrics
You can select an item from this panel and see its recent values with the queue and queue manager labels. For example,
However, it is more flexible to work with the graphing and dashboard views from Grafana.
Configuring Grafana
Once the Prometheus system is working, grafana can use it as a datasource – again, only a hostname and portnumber is required when adding this type of datasource. And from there, all of the MQ metrics can be accessed and added to dashboards. As an example, this dashboard is looking at several items including the same queues as above, and CPU and logging information:
This picture shows how the top panel was configured, to select several metrics and show the object name in the legend:
Deployment in Docker containers
All of these components can be configured to run inside Docker containers to simplify deployment. To get started, almost everything in the existing Prometheus and Grafana containers can be left to default, except for the need to add the MQ configuration to prometheus.yml. For example, I have this simple Dockerfile
FROM prom/prometheus
ADD prometheus.yml /etc/prometheus/prometheus.yml
where I’ve added the ibmmq block shown above to the default yml file.
And then this script gets both the Prometheus and Grafana components running, using local directories under /var/docker to hold their persistent data:
The MQ exporter program and its configuration can also of course be baked into a Docker image. The MQ docker image on Github has information on the configuration of MQ. The service definition, the shell script and the actual monitoring program can all be copied into a new image.
Conclusion
This article has shown how the statistics generated by MQ can easily be used in some of the monitoring packages that are commonly used with various cloud and container-based systems. The MQ data can be integrated with other metrics to give a complete view of your environment.
I would welcome feedback on this tool. Please leave any feedback here, or in the GitHub issue tracker, whether bugs, enhancements, or thoughts on the value of the monitoring.
This article is going to talk about some new code shipped with the V8.0.0.4 FixPack to make it easier to see what a queue manager is doing, simplify investigation of possible problems, and to assist with writing your own MQ applications. Formatting MQ Events is now available as part of the MQ product.
To start with, we need to talk a little about MQ’s event generation.
One of the pleasures (and I suppose there have to be some) of frequent travel is when we discover somewhere good to eat, that wasn’t expected. You can always look up the good restaurants near the hotel, or the nearest brewpub for a tasty IPA. But sometimes you can be surprised by what’s on your immediate doorstep. More about interesting places
