Monitoring Blog
Release announcements, technical guides and monitoring insights from the ConSol team.
Reguläre Schwellwerte
Thursday, June 02, 2016 in Insights
In der neuesten Version von GLPlugin habe ich die Möglichkeit vorgesehen, Thresholds auch als reguläre Ausdrücke anzugeben. Wie schaut das nun genau aus? $ check_wut_health --hostname dcenv2.de.xxxx --community public --mode sensor-status OK - return air temperature Unit 1.1 is 21.40C, humidity Unit 1.1 is 49.40%, return air temperature Unit 2.1 is 22.40C, humidity Unit 2.1 is 46.80% | 'temp_Unit 1.1'=21.40;25;28;; 'hum_Unit 1.1'=49.40%;40:60;35:65;0;100 'temp_Unit 2.1'=22.40;25;28;; 'hum_Unit 2.1'=46.80%;40:60;35:65;0;100 Wir sehen hier die hartcodierten Default-Schwellwerte 25 und 28 für die Temperatur bzw. 40:60 und 35:65 für die Luftfeuchtigkeit. Bisher gab es zwei Möglichkeiten, diese zu ändern, z.b. in 20 und 30 für die Temperaturen zu ändern. {% labs_sticker top:50 left:200 …
Literate Shell Scripting with Markdown and Packer
Monday, April 04, 2016 in Insights
Markdown is great for writing documentation or tutorials. However, executing the steps from a tutorial usually means to copy and paste the commands into a shell. There is no guarantee that the documentation is complete, and there is no protection against copy-and-paste errors. This post shows how to use Packer for automatically executing code snippets from Markdown files on a variety of platforms. Machine images are created directly from the code snippets in the documentation. That way, documentation is guaranteed to be up-to-date and complete, and it can be integrated in an automated delivery pipeline. We call this approach literate Shell scripting, as a reference to Donald Knuth’s way of documenting computer programs. Example Project To exemplify this post, we created a tutorial on how …
SSL - No more excuses
Monday, March 28, 2016 in Insights
There are many reasons to enable encryption on your webserver and since Let’s Encrypt openend its public beta, there are no more excuses to not use ssl. Besides the official scripts, programs and webpage, there is also already a Perl module Crypt::LE available which uses the Lets Encrypt API and makes requesting and renewing certificates super easy and most important… scriptable. Example Scenario We are assuming the following scenario with an apache configured for the domain example.com serving content from the folder /var/www. Preparation We first need to install the Crypt::LE perl module from cpan. Because we do not want to install modules from cpan into the system folders, we use cpanm together with local::lib. Luckily there is a debian package for both of them. (This has to be done as …
Testing web-applications with a Citrus twist
Tuesday, March 15, 2016 in Insights
In a previous article we went through how to build a chat room web application that used REST and STOMP for communicating between the client and server. In this article I use the very same application and show how to write automated integration tests using the open source Citrus integration test framework. If you haven’t read the first article don’t worry. A quick summary of all the important bits will be shown shortly below. But before I get to that lets talk a little bit about automated integration testing and citrus. One of the biggest challenges when testing any application is being able to simulate all endpoints. If you take an online web shop for example it typically interacts with numerous backend services (product catalogue, credit check, shipping, billing, etc.) during the course …
Caching with JCache
Saturday, March 12, 2016 in Insights
Introduction A couple of years have passed since we last looked into in-memory Java caches here at ConSol. In that time a bunch of things have happened: Probably the most significant thing that happened was that the oldest Java Service Request JSR 107, also known as JCache, finally reached ‘Release’ status. This JSR was a long time in the making taking a whole 13 years since the initial proposal back in 2001. Grid Gains In-memory Data Fabric became an open source project and is now available under the Apache Foundation Project and known as Apache Ignite. The existing In-memory caches providers, like Hazelcast, have received a whole host of new features including things like support for distributed transactions, a new Map-Reduce API, interceptors for executing business logic, when the cache …
Nagios Scheduling Insights
Wednesday, March 02, 2016 in Insights
The host- and servicecheck scheduling of Nagios has always been some kind of black box. Checks pile up when using timeperiods which often leads to performance issues while the Nagios host idles again just a minute later. Latest Thruk release (2.06) ships a new addon which visualizes and alleviates this issue. Visualization The first step in fixing a problem is visualizing the problem. Therefor the ‘Core Scheduling Plugin’ from the latest Thruk release draws a chart with all scheduled active host and service checks. The red line draws the current time, so everything right from that line are scheduled checks while everything left from that line should be actually running checks. Running checks have a darker colored bar in this chart, so if there are checks behind the current date which are …
OMD 2.10 Labs Edition Released
Friday, November 13, 2015 in Insights
OMD Labs Edition 2.10 in has been released today. The OMD Labs Edition is based on the standard OMD but adds some more useful addons like Grafana and Influxdb or additional cores like Icinga 2 and Naemon. Todays release is a great milestone because it introduces grafana based graphing out of the box in the usual easy OMD way. Whats new Grafana / Influxdb based graphing As new alternative to the well-known PNP4Nagios graphs a new way of graphing has been implemented in this release. It’s easy to enable grafana graphing with the omd config menu. It’s even possible to use both in parallel to make a smooth migration. A few highlights of this solution are: interactive graphs annotations of downtimes and notifications user designed dashboards Coshsh Another new component in OMD Labs is the …
Devoxx Talks about HTTP2 and Citrus Framework
Friday, November 13, 2015 in Insights
Fabian and Christoph have been invited to speak at Devoxx Conference 2016 in Antwerp, Belgium. Watch their talks to learn more about HTTP2 and Citrus Framework. Dr. Fabian Stäber: unRESTful Web Services with HTTP/2 HTTP/2, the new version of the HTTP protocol, provides a lot of new features for server-to-server communication: bidirectional communication using push requests multiplexing within a single TCP connection long running connections stateful connections HTTP/2 does not define a JavaScript API, so JavaScript clients running in a Web browser can make only limited use of the new capabilities. However, for server-to-server communication, HTTP/2 provides a lot of ways to go beyond existing REST APIs. This talk shows HTTP/2’s potential for new server-to-server APIs. …
Upload Travis Artifacts to Dropbox
Wednesday, November 04, 2015 in Insights
Travis CI is a free platform for continues integration tests which fits perfectly in our opensource products workflow with Github. Unfortunately it only supports uploading artifacts to amazon aws. Usually not a major problem, because most tests result in simple text output. Latest Thruk Tests however are based on Sakuli and Docker and produce screenshots on errors because we do full enduser gui tests of the dashboard and other javascript based parts. So we need a way to store these screenshots on Dropbox. Preparation Dropbox Uploader First thing you need is a dropbox account with an API application. Just follow the Dropbox Commandline guide. Then run the Dropbox uploader once to make sure it’s working. You will have to authorized your newly created application on the first run by hitting …
Aktivieren der Grafana-Graphen in der OMD Labs Edition
Wednesday, October 21, 2015 in Insights
In der OMD Labs Edition gibt es seit kurzem die Möglichkeit, die Performance-Daten in einer InfluxDB zu speichern. Die Daten werden dabei von der Komponente Nagflux in die InfluxDB geschrieben, Histou übernimmt das Erzeugen der Graphen auf Basis von Templates und Grafana übernimmt die eigentliche Anzeige. Einen ausführlichen Vortrag vom Autor von Nagflux und Histou, Philip Griesbacher, wird es auf der diesjährigen OSMC geben. Das Aktivieren des kompletten Gespanns ist ab der Version omd-2.01.20151021-labs-edition aus unserem Testing-Repository in einer OMD site sehr einfach möglich. Erfahrene OMD-Benutzer verwenden die folgenden Kommandos, für OMD-Einsteiger gibt es die ausführlichere bebilderte Anleitung weiter unten. omd config set PNP4NAGIOS off omd config set GRAFANA on omd config set …