IPv6 and Monitoring

We are all happy when we are able to get IPv6 connectivity for our new servers. In case the network is provided by someone else and some kernel settings you can get in some tricky situations.

With IPv6 there are so many addresses your Laptop and Mobile can have a unique public IPv6 address forever - pretty cool huh? The downside is, it would be pretty easy to trace every connection you ever do back to your device - this really not what you want! When you provide a service this behavior is not so useful. Otherwise there are several ways to autoconfigure your IPv6 configuration, beside DHCPv6 the interesting one is stateless address configuration.

Pimp my Mail Notifications

Notifications are important if you do monitoring. I never liked mail notifications from monitoring systems where all the information is hidden in non-sense text. Otherwise notifications never look the same, so I’m always forced to read all that useless crap again and again. This is an approach to improve the usability of monitoring notifications using more a table pattern which helps me to recognize useful information much quicker.

Probably a lot of E-Mail guys will hate me for the reason I’m using HTML in mails. The notifications work so much better for me so I don’t care. I’ve used just inline CSS and there is no JavaScript involved. All the things are in the mail and there are no external resources loaded. Here is how I work with OpenNMS mail notifications.

Material Workshop OpenNMS im Büro 2.0

Am 30.03.2015 haben wir im Büro 2.0 in Berlin einen Workshop mit OpenNMS durchgeführt. Die Zielgruppe waren NeueinsteigerInnen und alle die Interesse an Monitoring mit freier Software haben. Es wurden Installationszenarien, das Provisioning und beispielhaft diverse Monitore für Anwendungen und Dienste eingerichtet.

Die Slides sind unter einer freien CC-BY 3.0 lizenziert und stehen auf GitHub zur Verfügung.

Kickstart Workshop OpenNMS im Büro 2.0

Für diejenigen, die kurzentschlossen sind – hier eine letzte Erinnerung für einen kostenfreien Kickstart workshop zu OpenNMS. Die Registrierung und Anfahrt findet ihr unter:

• Büro 2.0 Veranstaltung
• Registrierung bei Meetup
• Anfahrt

Conferences OUCE 2015 and 31c3

I spent some time with preparing the OUCE 2015 and we use the free an open-source software frab as conference management system. I do most of my server automation with Chef and my playground is running with Vagrant. For this reason I decided to spend some time an built a Vagrant / Chef environment and contributed it back to the frab project. This guys do a really good job and IMHO it is the best free conference management system you can get. If you want to play with it feel free and give it a try and contribute.

Open-source Experience

I spend a lot of time in the OpenNMS project and I love to work in free software and the workflows around it. We moved with our project from SourceForge to GitHub a few years ago and I think it was the right decision. There are now some established workflows in this ecosystem and they tear down borders between different open-source projects and here is an example of it.

I develop with IntelliJ IDEA and spend currently some time working in documentation of OpenNMS. We have migrated from Docbook XML format to AsciiDoc and started with the help of a few brave community volunteers a new documentation environment. I’ve found a plugin for IDEA which renders AsciiDoc and gave it a try to have a better workflow working on documentation and navigating through source code in just one program.

Investigate file descriptor issues

If you run a centralized monitoring system in large environment you can run in some issues regarding file descriptor limits. Linux gives you very detailed information in the kernel control and information center in /proc. The soft and hard limits have effect for file and network sockets, which can end up in a too many files open exception in OpenNMS.

The default values for soft and hard limits can be checked with

OpenNMS and Documentation

To help the OpenNMS project I spent a year together with Alexander Finger and Klaus Thielking-Riechert writing an OpenNMS book. We started with a development version of for 1.8 and tried to find a mixture between consistent slow changing and new concepts in 1.8. It was kind a complicated thing and from my point of view not perfectly done. Nevertheless I’ve thought about something like: “It’s about time writing a second edition covering the topics in coming 1.14?” The problem I’ve with books, it doesn’t allow contribution and hasn’t a really long life cycle. So I’ve decided instead of spending a year again writing a book, I want something which is more helpful to the project itself.

DevOps Guy

I started in 1998 in IT-Services and I did all the funny stuff – was involved building new networks for companies, migrated software from commercial vendors from version A to B to C to D and I have wasted too much lifetime on broken RAID 5s, backups and restores.

If you want to learn how to operate a computer network – this is a good place. You will always be called for the complicated problems nobody can solve with a simple Google search. You get also a good feeling, which solution is maintainable over a longer period of time. Fortunately people developing software experienced enough pain and started thinking about how to make code maintainable. Good developers realized years ago, people spend more time maintaining software than writing it. In my point of view an underestimated acceptance criteria in an “Agile” process ;) Since I spend more and more time in the OpenNMS project, I get much better an idea what the meaning about testing, documenting, Continuous Integration and Test Driven programming is. What people realize is a nameless magical connectivity between the guys who develop Things™ and the ones who bring them to production and the poor souls which have to keep it productive. In the late 90s there wasn’t a name for it. To make a good job Ops-Guys and the Dev-Guys have to work together – which wasn’t/isn’t a default behavior by nature.

OpenNMS Dev-Jam 2014

We are right in the middle of our 5th season of the year – DevJam. It is always a lot of fun spending one week with people from all over the world on the campus of the University of Minnesota. I’ve put on my personal agenda for this week, spending time with the folks working on the way how we want to document our project. I try also to gather the project ideas and where they contribute the code to the project. Currently i try to get some updates from the progress through the opennms.eu page. We have the following topics on the list: