Recent content on cloud-infra.engineer
Welcome to the year 2027. The year where the net metering policy in the Netherlands stopped. This post is about owning a home battery system in 2027 onwards and the benefit it has financially, based on minute precise real-world usage- and solar data collected in 2024. In my previous blogpost about the Sessy Home Battery Experience, owning a home battery + dynamic contract resulted in €161.42 more…
Back in 2020 I wrote a post about Simulating a Tesla Powerwall. Much has changed since then. Electricity prices went up and down(!) Energy providers started offering contracts with dynamic hourly prices based on the hourly market value of electricity. The deadline for net metering has been postponed in the Netherlands and now has a final deadline, January 1st, 2027. And related to my setup at…
In a previous blog post I wrote about collecting server statistics with Collectd, passing them to InfluxDB and graphing them with Grafana. Using “Retention Policies” (RPs) and “Continuous Queries” (CQs) metrics could be downsampled to reduce storage usage. This blog post shows how to do the same with InfluxDB v2. InfluxDB v2 At the end of 2020 InfluxDB v2 was released. Moving to InfluxDB v2 with…
It’s a little over a year ago that I got solar panels installed on my roof. Not a Tesla Solar Roof, but the most efficient solar panels available last year. From SunPower. The SPR-X21-350-BLK. Together with a SolarEdge SE5K converter its producing 5300 Watt during peak hours. I’m interested if a Tesla Powerwall is worth it financially. Will it pay back the investment in a reasonable amount of…
In the Mendix Cloud we run thousands of Mendix apps on Cloud Foundry on AWS. Mendix Runtime Engines that currently run in 2, 4, 8 or 16 GB memory containers. Mendix developers have the possibility to start, stop, scale and upload new versions of their app themselves via our Developer Portal. This results in the fact that we must have diego-cell instances with at least 16 GB memory available at all…
Almost 10 years ago I started developing a web frontend for collectd, Collectd Graph Panel (CGP). A PHP frontend that displays graphs in PNG format using rrdtool and the RRD files created by collectd. A lot has happened since then. Because of the IoT hype time series databases like Graphite, InfluxDB and TimescaleDB became more popular. Also visualization tools gained more traction, of which…
A while ago I was researching the possibilities to measure the power consumption of some devices in my house via Wifi. I came across the Broadlink SP3S Smart Plug. It met my requirements: relatively cheap, power measurement and Wifi. It comes with an IOS and Android App. There a big chance the app is not directly connecting to the SP3S, but to “the Cloud” where the SP3S sends its data to.
At home my FTTH Internet connection is provided by XS4ALL. They provide a FRITZ!Box router to connect to the Internet. Instead of using the FRITZ!Box I’ve always used my own Debian GNU/Linux machine to route traffic to the internet. The XS4ALL uplink has 2 VLANs: VLAN4: TV (bridged, RFC1483) VLAN6: PPPoE IPv4 + IPv6 internet connection My XS4ALL uplink is connected to a managed switch. My Motorola…
In a marathon program from Christmas to New Year’s eve NPO Radio 2 broadcasts the so called “Top 2000“. A list of the 2000 most popular songs of all time. Because I’m not able to listen all 2000 songs in one go, I like to have them on a USB drive in MP3 format, so that I’m able to listen for example in my car. The shell script below downloads the full “Top 2000” of 2023 in MP3 format from the…
Debian Stretch was released last month, so it is time to upgrade my laptop. I’m an i3 window manager user. Previously my procedure was to backup /home, reinstall using the network installer (I don’t like apt-get dist-upgrade, I like to start clean) and tick the “Debian Desktop Environment … GNOME” checkbox and after the installer was done, install i3 and the rest of my tools. While I use some of…
v1 is here. CGP is finished 😆 Joking aside. It has been requested multiple times. So let’s get it over with. The last version was more then 3.5 years ago. This will be the last tagged version of CGP. Every commit in the master branch after this release can be considered as a new release. 😉 Use git and “git pull” to keep up-to-date or download the latest version here.
This post shows you how to use Telegram for Nagios notifications. First create a Telegram Bot by talking to the BotFather. The Telegram Bot will be the sender of the Nagios alerts. You’ll receive an API token that also includes the UserID of the Bot: Token: 200194008:AAEG6djWC9FENEZaVIo3y3vZm24P3GTMetw UserID: 200194008 Download the nagios_telegram.py script that will send the alerts via Telegram:…
In the “Mendix Cloud” we are hosting thousands of Mendix Apps. All these Apps are running on top of the Oracle Java Runtime Environment (JRE) in Debian Linux environments. We use java-package to package the Oracle JRE to be able to easily redistribute it to all our servers. After packaging and putting the Debian package in our local apt repository the Oracle JRE can be easily installed via…
In January 2007 I bought my first OS X device, a white 13.3-inch MacBook, running OS X 10.4 Tiger on a 2.0Ghz Intel Core 2 Duo processor, having 1GB of RAM. Along the way I upgraded it to 2GB RAM and gave it a fantastic boost by replacing the HDD by an Intel 320 Series SSD. I also upgraded OS X to 10.5 Leopard, 10.6 Snow Leopard and in the end to 10.
I recently upgraded my DNS server to Debian Jessie. In fact I reinstalled it from scratch and used puppet to install and configure all the required components. This DNS server, running bind9, is the authoritative nameserver for nethuis.nl. nethuis.nl uses DNSSEC. To apply DNSSEC I used dnssec-tools, which gives you tools like zonesigner, rollerd and donuts to sign, roll and check your DNSSEC…
In October 2012 I started using bcache as an SSD caching solution for my Debian Linux server. I’ve been very happy about it so far. Back then I used a manually compiled 3.2 Linux kernel based on the bcache-3.2 git branch provided by Kent (which has been removed). This patch needed to be applied to make bcache work with grsecurity. I also created a Debian package of the bcache-tools userspace tools…
Imagine… Imagine if you could setup a new Mendix hosting environment in seconds, everywhere. A lightweight, secure and isolated environment where you just have to talk to a RESTful API to deploy your MDA (Mendix Deployment Archive) and start your App. Since the 2nd quarter of this year a great piece of software became very popular to help to achieve this goal: Docker. Docker provides a high-level…
After 2,5 years and about 100 commits I’ve tagged version 0.4 of Collectd Graph Panel. This version includes a new interface with a sidebar for plugin selection. Javascript library jsrrdgraph has been integrated. Graphs will be rendered in the browser using javascript and HTML5 canvas by setting the “graph_type” configuration option to “canvas”. This saves a lot of CPU power on the server.…
A couple of manufacturers are selling solutions to speed up your big HDD using a relative small SSD. There are techniques like: Smart Response Technology (SRT) by Intel (hardware solution, Write-back) Dataplex by Nvelo (Windows, software, Write-back) ReadyCache by SanDisk (Windows, software, Writethrough) FancyCache by Romex Software (Windows, software) But there is also a lot of development on…
An interesting thing happened last week when I upgraded qemu-kvm from version 0.12.5 (Debian Squeeze) to 1.1.2 (Debian Wheezy). After a reboot (shutdown and start) of all my VM’s, they are using less CPU in total! I noticed this from the stats Collectd is collecting for me. I’m running about 5 Debian Linux VM’s on my low power home server (Intel G620, 8G DDR3, DH67CF). Most of the time the VM’s…
Since a while I’ve been monitoring the power consumption of devices in my home using a power meter from BespaarBazaar.nl (advised by Remi). This power meter is a good one because it is very precise. It starts measuring at 0.2 Watt. I needed an Ethernet switch to connect my TV, NMT and PS3 to my home network. While searching for a proper switch, I came across DLinkGreen.com. It looked promising.…
Bonnie++ is the perfect tool to benchmark disk I/O performance. When you want to run heavy disk I/O consuming applications on a server, you need to know what the disk I/O limits are to have an indication what you can run on it. Bonnie gives you information about read-, write-, rewrite Block I/O performance and the performance of file creation and deletion. Below is a sample piece of Bonnie++…
I have used RT (Request Tracker) for quite a while. Starting with RT 2.0.15 + MySQL. Later upgraded that version manually (with a couple of nasty PHP scripts) to RT 3.6.x + PostgreSQL. It worked and stayed consistent. I’ve never been very happy about RT. It now contains about 80K tickets and it is slow. I have been reading a lot of forum/mailinglist threads about migrating from OTRS to RT and RT…
It has been a while and many people were already using one of the development versions of CGP. Time to release a new version of CGP: v0.3. Special thanks for this version go to Manuel CISSÉ, Jakob Haufe, Edmondo Tommasina, Michael Stapelberg, Julien Rottenberg and Tom Gallacher for sending me patches to improve CGP. Also thanks to everyone that replied after the previous release. In this version…
Version 0.2 of Collectd Graph Panel (CGP) has been released. This version has some interesting new features and changes since version 0.1. A new interface is introduced, based on Daniel Von Fange’s styling. A little bit of web 2.0 ajax is used to expand and collapse plugin information on the host page. The width and heigth of a graph is configurable, also the bigger detailed one. UnixSock flush…
Just a couple of small changes to Stream Planner: add possibility to stop and delete a stream rewrite backend code to be more efficient fix test script to not use 100% cpu add notify script to send e-mailnotifications about starting streams Download: pommi.nethuis.nl/… Git: http://git.nethuis.nl/pub/stream-planner.git Demo: demo.nethuis.nl/stream-planner
Collectd Graph Panel (CGP) is a graphical web front-end for Collectd written in php. I’ve developed CGP because I wasn’t realy happy with the existing web front-ends. What I like to see in a front-end for Collectd is clear overview of all the hosts you are managing and an easy way to get detailed information about a plugin. This first release is a very basic version of what I have in mind.
Postgrey is a Postfix policy server implementing greylisting. This patch adds p0f support to Postgrey based on p0fq.pl from p0f, like the patch by Fedux. P0f is a fingerprint tool, to identify operating systems. The difference between Fedux’s patch and mine is that his patch requires p0f-analyzer. See the image below. My patch uses p0f’s socket created with the ‘-Q’ option. Because Postgrey…
Recently I bought a portable harddrive from Western Digital. The Western Digital Elements (WDE1U10000E) carries 1 Terabyte of space and can be connected via USB 2.0. 1TB, for just 99,00 Euro (2008-12-27). According to Wikipedia and the SI standard the drive must contain 1,000,000,000,000 bytes (1TB). fdisk shows us: Disk /dev/sda: 1000.2 GB, 1000204886016 bytes So that is correct. The disk is…
For downloading torrents I use TorrentFlux on a Debian Linux machine. All users on this system have a quota, so they don’t mess things up. TorrentFlux shows a storage bar on the main page with information about how much space is left on the device. Unfortunately it shows information about the complete partition, not about how much of your quota is left. This patch adds quota support and is…
It has just been released. There are some changes to v0.1: automatically create database if it doesn’t exist added comments per stream added backend alive signal added backend test script Download: pommi.nethuis.nl/… Demo: demo.nethuis.nl/stream-planner/
With this tool you’re able to schedule a application (like darkice) to run. Stream Planner is accessible via a webinterface written in php. The Stream Planner Backend (that is running the process) is written in perl. Both webinterface and backend are talking to a sqlite database with schedule information. Screenshot: Download: pommi.nethuis.nl…