Usually we monitor processes with Nagios or Naemon but sometimes you want to have really detailed graphs of resource usage of single processes in realtime resolution. Maybe to find and visualize memory leaks or to watch resource usage over time. Nagios based solutions are not worth the effort since you probably just want to nail down a specific single problem. So i used this opportunity to write a small desktop application with node-webkit.
For most employees at ConSol, today is the last day before their Christmas vacation. Eight of us took that opportunity and organized our first FedEx day:
During the full day event, we formed small teams and worked on innovative projects we are enthusiastic about.
At the end of the day, we had small presentations showing the results to the company.
In this blog post we’d like to share the projects we came up with:
There seem to be a lot of interest in building Raspberry Pi clusters for
One of the teams took the chance and built our own, with five Pis running an Infinispan distributed cache.
It turns out that having a real hardware cluster yields different results than testing Infinispan locally.
While clean shutdowns and startups are no problem, unplugging and plugging network cables is a much greater challange to the Infinispan infrastructure.
The Raspberry Pi hardware is sufficient to run embedded Infinispan instances, the JBoss based distributions don’t seem to fit well with the hardware.
The Raspberry Pi and a large screen is all that is needed for building an information kiosk.
One of the teams built a kiosk for our entrance hall, showing the current event schedule for our meeting rooms.
Access to the event database was implemented as a Spring application, on the front-end side
Ceylon 1.0.0 was released recently, and one of the teams took the chance to make some first experiences with the new programming language.
The strong type system enables a lot of tool support, but sometimes also results in errors that are hard to understand for the novice.
The ConSol academy is a company event where employees share their knowledge with their peers. One team used the FedEx day to build
a prototypical hardware for recording academy talks on video, to archive the talks for colleagues who cannot participate.
As most other project, the video recording hardware was also based on the Raspberry Pi.
The Pi was equipped with a small camera and a microphone, and streams the data over the network for recording.
The Raspberry Pi is currently the most popular thing
among our developers. It is easy to set up, and provides an open platform for a wide range of projects.
The FedEx day was a great opportunity to experiment with that, and it is also a good way to get together with colleagues who work in other projects.
check_oracle_health, check_mysql_health, check_mssql_health und check_db2_health bringen von Haus aus schon eine Menge Funktionalität mit. Allerdings wurden sie speziell für die Belange von Datenbankadministratoren entwickelt. Um auch den Betreibern von datenbankgestützten Applikationen die Möglichkeit zu geben, bestimmte Werte per SQL abzufragen, gibt es den Parameter "--mode sql". Damit lässt sich das numerische Ergebnis eines SQL-Aufrufs mit Schwellwerten vergleichen und in einen Nagios-Exitcode verwandeln. Üblicherweise sind die Anforderungen der Applikation an das Monitoring jedoch etwas komplexer. Am Beispiel von check_mysql_health und Wordpress wird gezeigt, wie man so etwas einfach umsetzen kann.
With LWP you can easily upload a file from within a perl script. To add some sugar this small example shows how to show a progressbar during the upload. This is especially useful for giving feedback while uploading large files. This technique is based on LWP’s DYNAMIC_FILE_UPLOAD hook for sending files chunk by chunk. BTW, this feature is a good thing anyway in order to avoid sucking large files completely into memory before doing an upload.
Ein Update von ESXi 3.5 auf 4.0 geht ganz einfach, auch wenn man keinen vCenter Update Manager hat. Für die meisten Nutzer der kostenlosen Variante von ESX dürfte das der Fall sein. Trotzdem gibt es auch für sie die Möglichkeit eines bequemen, automatisierten Updates.