Make it… Build it… Break it… Fix it…
Butler adds various features to Qlik Sense Enterprise (the Windows server version), making it easier to develop, maintain and operate Qlik Sense environments and apps.
Butler is open source software.
Full docs, getting started guide available at butler.ptarmiganlabs.com.
The Corona pandemic made lots of people start working from home and the importance of instant messaging apps has increased quite dramatically since.
As a result more people are logged into Slack, Microsoft Teams and similar tools. This is good as it opens up for using these tools as a communication channel also from Qlik Sense apps to end users.
In this post we’ll take a look at how messages can be sent from Sense load scripts to Microsoft Teams. The same concept can be applied also to Slack and other IM tools that support webhooks from external tools to the IM tool – usually called “incoming webhooks”.
Continue reading “Post messages to Microsoft Teams from Qlik Sense”
Security is important – period.
Usability of web based systems is off course important, but so is security. In the previous (first) article in this series we looked at how the Traefik reverse proxy can be used set up end user friendly URLs for Qlik Sense Enterprise (QSE) environments, while at the same time adding a layer of security by hiding the internal structure of the QSE cluster.
Today we’ll look at how you can get free SSL/TLS certificates from Let’s Encrypt and how these are used to provide https for QSE.
Article 1: Superpowers to Qlik Sense Enterprise: The Traefik reverse proxy, part 1
All code, scripts etc used in this article is available in the Part 2 folder in this GitHub repository.
Let’s go!
Continue reading “Superpowers to Qlik Sense Enterprise, part 2: Free https certificates from Let’s Encrypt”
Edit: A GitHub repository has been created with the files mentioned in this article:
https://github.com/mountaindude/qlik-sense-and-traefik
Traefik is one of today’s most hyped reverse proxies. It’s available in both a commercial and a (very capable!) open source version. According to the company behind Traefik it’s been downloaded more than 2 billion times – that’s a lot…
In this blog post we’ll take a look at how Traefik can run natively on Windows server, providing services to a Qlik Sense Enterprise on Windows cluster.
We will see how this can make Qlik Sense easier to use for end users as well as easier to run and operate for sysadmins.
Specifically, we’ll use Traefik to set up TLS secured access (a.k.a. https) to Qlik Sense, while at the same time establishing a solid platform to which we can add more features in coming blog posts.
Starting with the basics makes sense though – let’s get to it!
Continue reading “Superpowers to Qlik Sense Enterprise: The Traefik reverse proxy, part 1”This is part 3 in a series about how healthchecks.io can be used to solve various kinds of monitoring scenarios for Qlik Sense Enterprise on Windows (QSEoW) environments.
Previous articles:
Part 1: Oh data where art thou?
Part 2: Black box monitoring of Windows servers
Tl;dr
Most of the Butler family of DevOps tools for Qlik Sense can now be monitored using healthchecks.io or similar tool.
If one of the supported Butler tools go down, an alarm is raised and one or more alerts are sent via email, Slack, Teams, PagerDuty or other supported channels.
This means that both infrastructure (servers etc), applications/services and data sources can be monitored using the same tool and on the same dashboards.
Lots of buzzwords in that title, but yes – things have now come together and the main members of the Butler family of tools for Qlik Sense now run as Docker containers on Arm64 and even Arm7.
In practice this means it is possible to run Butler SOS, Butler Cache Warming etc as Docker containers on for example a Raspberry Pi 4. If you are worried about that poor little Raspi failing you can add a bunch of them into a Kubernetes cluster, and then run the Butler tools there.
This actually works pretty well, here is a Raspberry Pi based Kubernetes (a.k.a “k8s”) cluster built using the excellent k3s distribution from Rancher, running the Butler tools:
And here is the Raspi cluster itself, with 4 of the 7 nodes installed:
Ok, ok – I hear you – is it really a good idea to run close to mission critical software on Raspberry Pi’s?
No of course not, but the cloud providers are starting to offer Arm based virtual machines (Amazon does this already with their EC2 A1 instances), with roughly twice the performance per dollar compared to Intel based VMs.
So running Butler on Arm VMs might be a way to save some money, if the cloud provider you use happens to offer Arm VMs.
Or just surrender to your inner geek and build your own Raspi k8s cluster… Lots of fun and a great way to learn about k8s!
Docker images available on Docker Hub, as always.
Time for another update of Butler SOS, this time to version 5.4.
Github release : https://github.com/ptarmiganlabs/butler-sos/releases Docker image : https://hub.docker.com/r/ptarmiganlabs/butler-sos Documentation : butler-sos.ptarmiganlabs.com
This release both adds some nice new features as well as enhancing existing ones and fixing some bugs. Let’s take a look at the highlights.
Curious what it looks like in practice?
Seeing is believing:
This is part 2 in a series about how healthchecks.io can be used together with Qlik Sense Enterprise on Windows (QSEoW).
Previous articles:
Oh data where art thou?
Usually, yes.
Still, things do happen and it certainly would be nice to get an push alert when a server hasn’t checked in according to schedule.
The most common monitoring – for Windows/Linux/…. servers, databases, Qlik Sense etc is based on the tool keeping an eye on some measurement and then alert when the measurement goes beyond some threshold.
This is fine, and this is a very important monitoring use case. But in cases where a server just hangs the last measurement received might be fine, and no alerts are sent.
Black box monitoring kind of reverses the roles:
The monitored system has to prove that it’s doing fine. Failing to do so within some predefined schedule will trigger an alarm, with an optional alert being sent.
The previous article showed how this concept can be used to ensure that some Qlik Sense app has reloaded as intended, before a specific time each day. A concrete, common use case would be that yesterday’s data should be processed and loaded into Sense before 7 am next day. Alert if not)
Now, let’s use the same tool and concept to monitor also the Windows servers that Qlik Sense Enterprise on Windows (QSEoW) runs on.
When implementing Qlik Sense solutions for enterprise clients they usually have various requirements regarding alerts for failed reloads, support SLAs etc.
Those are all interesting challenges to implement, but the most common request is probably:
“The system should alert me if data doesn’t arrive on time”
It’s a reasonable request. If some source system is delayed and doesn’t delivery data to Sense on time, they as a system or application owner should be notified.
The second thing almost all clients say is:
“Oh, I only want alerts when data is delayed. No messages when data is on time.”
Again, this is very reasonable.
Let’s say the extract app in Sense sends a notification email once data has been loaded from the source system. Great – we now know that data has arrived, and when it did.
Except that we will drown in such notifications from all our dozens (or hundreds..) of extract apps.
It’s kind of hard to implement this in a good way though, at least I have never found a really good, generic solution for this request.
Sure, you can have a Sense app who’s only job is to execute every 15 minutes and check whether data has arrived, and alert if data is delayed. That app will however put load on your Sense environment and use one of the reload slots. Even if the app reloads quickly it’s still pretty bad system design, IMHO.
I have a suggestion for a better option:
Set up a monitoring tool that views the Sense app (or rather its load script) as a black box with unknown function. The only thing the monitoring tool cares about is whether that black box has checked in within some configured interval.
I stumbled upon this while looking at ways to monitor servers in general, but quickly realised it could be used also with Sense.
By the way: while I have only used the described concept on Qlik Sense, it should work equally well with QlikView.
Don’t care for reading? This video outlines the concept, otherwise keep reading below.
During the past weeks I have developed what has turned into a fairly complex Qlik Sense solution, where reloading the main application takes on the order of 10 minutes.
I know – Qlik apps should be kept small, with intermediate data sets stored as QVDs. But sometimes that’s just not practical.
Qlik apps works the same as most apps – if you made a typo somewhere the reload (or compilation for regular computer applications) will fail. Sometimes after a few seconds, more often right towards the end, just before those 10 minutes have passed… Fix the typo and start another 10-minute reload. Sigh.
The other day I realised that I had been using an old trick without even thinking about it, to cut down the reload times from 10 minutes to a few seconds. Talking to some colleagues, it turned out they didn’t use this trick – so here it is: The best time saver ever for Qlik developers.
The idea is very simple: You want to run the entire load script to make sure it works, but without processing 100s of megabytes of data or more.
In Qlik scripting, this is achieved by using the First prefix, added before a Load statement. Two things needed:
It can look something like this:
Sense’s load script editor does not quite like using variables in this way, and complains about the syntax being incorrect. Don’t worry about that, the script loads fine.
To do a quick load (to ensure the script is solid from a syntax perspective), just enable one of the commented out lines at the top. This will limit the numer of lines loaded in the following load(s). The load time will be nice and short.
Once the script works, comment out that first variable again, setting it to an empty string. All data will be loaded from sources.
Easy trick – I know. But it has literally saved me days during past months!