I was asked recently how I did enable my home automation to send push notifications to members of the household.
The service I am using on which all of our notification needs are served by is PushOver.
Pushover gives you a simple API and a device management and allows you to trigger notifications with icons and text to be sent to either all or specific devices. It allows to specify a message priority so that more or most important push notifications even are being pushed to the front when your phone is set on do-not-disturb.
The device management and API, as said, is pretty simple and straight forward.
As for the actual integration I am using the NodeRed integration of Pushover. You can find it here: node-red-contrib-pushover.
With the newest client for iOS it even got integration for Apple Watch. So you not only are limited to text and images. You can also send our a state that updates automatically on your watch face.
As Pushover seems consistent in service and bringing updates I don’t miss anything – yet I do not have extensively tested it on Android.
I had redone the header of this blog a while ago but since I was trying around some things on the template I wanted something more dynamic but without any additional dependencies.
So I searched and found:
Tim Holman did a very nice implementation of this “worm generator” with only using the HTML5 canvas tag and some math. I made some very slight changes and integrated it into the header graphic. It will react to your mouse movement and resets if you click anywhere. Give it a go!
I had to solve a problem. The problem was that I did not wanted to have the exact same session and screen shared across different work places/locations simultaneously. From looking at the same screen from a different floor to have the option to just walk over to the lab-desk solder some circuits together and have the very same documents opened already and set on the screens over there.
One option was to use a tablet or notebook and carry it around. But this would not solve the need to have the screen content displayed on several screens simultaneously.
Also I did not want to rely on the computing power of a notebook / tablet alone. Of course those would get more powerful over time. But each step would mean I would have to purchase a new one.
Then in a move of desperation I remembered the “old days” when ThinClients used to be the new-kid in town. And then I tried something:
It turns out: Nothing really. Docker is well prepared to host desktop environments. With a bit of tweaking and TigerVNC Xvnc I was able to pre-configure the most current Ubuntu to start my preferred Mate desktop environment in a container and expose it through VNC.
So I took one of those RaspberryPis, booted up the Raspbian Desktop lite and connected to the dockers VNC port. It all worked just like that.
The screenshot above holds an additional information for you. I wanted sound! Video works smooth up to a certain size of the moving video – after all those RaspberryPis only come with sub Gbit/s wired networking. But to get sound working I had to add some additional steps.
First on the RaspberryPI that you want to output the sound to the speakers you need to install and set-up pulseaudio + paprefs. When you configure it to accept audio over the network you can then configure the client to do so.
In the docker container a simple command would then redirect all audio to the network:
pax11publish -e -S thinclient
Just replace “thinclient” with the ip or hostname of your RaspberryPI. After a restart Chrome started to play audio across the network through the speakers of the ThinClient.
Now all my screens got those RaspberryPIs attached to them and with Docker I can even run as many desktop environments in parallel as I wish. And because VNC does not care about how many connections there are made to one session it means that I can have all workplaces across the house connected to the same screen seeing the same content at the same time.
And yes: The UI and overall feel is silky smooth. And since VNC adapts to some extend to the available bandwidth by changing the quality of the image even across the internet the VNC sessions are very much useable. Given that there’s only 1 port for video and 1 port for audio it’s even possible to tunnel those sessions across to anywhere you might need them.
Working in the IT industry requires us to spend copious amounts of time focused on our screens mostly sitting at our desks. But this does not have to be that way.
For me sitting down for long times creates a lot of unwanted effects and essentially leads to me not being able to focus anymore properly.
In 2015 my wife and I attacked that “health problem” as a team. And in the 12 months until 2016 we both lost 120 kg / 260lbs added up together in body weight and completely changed the way we deal with food and sport.
With that I also changed the way I work. Sitting down was from now on the exception.
Coincident with this lifestyle change my then-employer Rakuten rolled out it’s then new workplace concept and everyone got great electric stand-up desks that allowed you to change the height up and down effortlessly.
When I started with SIEMENS of course their workplace concept included standing desks as well!
For those times I am working from home one of the desks is equipped with a standing desk with an additional twist.
So this desk let’s you work while standing. But it also allows you to walk while you work. You can set the speed from 0 to 6.4 km/h.
Given a good headset I personally can attend conference calls without anyone noticing I am walking with about 4 km/h paces.
When I am spending a whole day working from this desk it is not uncommon to accumulate 25-40 km of total distance without really noticing it while doing so. Of course: later the day you’ll feel 40km in one way or the other
It took a bit of getting used to as your feet are doing something entirely different from what the rest of the body is doing. But at least for me it started to feel natural very quickly.
I’ve put two curved 24″ monitors onto it and aside from the docking ports for a company notebook I am using thinclients to get my usual work machines screens teleported there. There’s a bit of a media set-up as well as sometimes I am using one of the screens for watching videos.
For those now interested in the purchase of such a great walking desk: I can only recommend doing so! But be aware of some thoughts:
There are not a lot of vendors of such appliances. And those vendors are not selling a lot of them. This means: be ready for a € 1000+ purchase and be ready to shell out some good money on extended warranties.
My first desk + treadmill was replaced 3 times before. It was LifeSpans first generation of treadmill desks and it just kept exploding. I actually had glowing sparks of fire spitting out of the first generation treadmill.
I’ve returned it for no money loss and waited for the second generation. This current, second generation of LifeSpan treadmill desks is really doing it for me for longer than the first generation ever had without breaking. Looking at the use of the device I would see it as a purchase over 5 years. After 5 years of actual and consistent use I wouldn’t be overly annoyed if the mechanical parts of the appliance would stop working. I am not expecting such a device to live much longer anyhow.
Energy consumption wise it’s quite impressive how much energy this thing consumes. I wasn’t quite expecting those levels. So here’s for you to know:
So just around 500 Watts when in use. The 65W base load is the monitors and computers on top.
I can only recommend to try something like this out. Unfortunately it’s quite hard to find a place to try it out. At least I was not able to try before buy.
But then again I could answer your questions if you had any.
Since a couple of months we are trying harder to learn a foreign language.
And as we excepted it is very hard to get a proper grasp on speaking the language. Especially since it is a very different language to our mother tongue.
And while comfortably interacting with digital assistants around the house every day in english and german the thought came up: why don’t these digital assistants help with foreign language listening and speaking training?
I mean Google Assistant answers questions in the language you have asked them. Siri and Alexa need to know upfront in which language you are going to ask questions. But at least Alexa can translate between languages…
But with all seriousness: Why do we not already have the obvious killer feature delivered? Everyone could already have a personal language training partner…
When you take a picture with an iPhone these days it does generate haptic feedback – a “kachung” you can feel. And a shutter sound.
Thankfully the shutter sound can be disabled in many countries. I know it can’t be disabled on iPhones sold in Japan. Which kept me from buying mine in Tokyo. Even when you switch the regions to Europe / Germany it’ll still produce the shutter sound.
Anyway: With my iPhone, which was purchased in Germany, I can disable the shutter sound. But it won’t disable the haptic “kachung”.
It’s interesting that Apple added this vibration to the activity of taking a picture. Other camera manufactures go out of their way to decouple as much vibration as possible even to the extend that they will open the shutter and mirror in their DSLRs before actually making the picture – just so that the vibration of the mirror movement and shutter isn’t inducing vibrations to the act of taking the picture.
With mirror less cameras that vibration is gone. But now introduced back again?
Since AVM has started to offer wireless mesh network capabilities in their products through software updates I started to roll it out in our house.
Wireless mesh networks often consist of mesh clients, mesh routers and gateways. Mobility of nodes is less frequent. If nodes constantly or frequently move, the mesh spends more time updating routes than delivering data. In a wireless mesh network, topology tends to be more static, so that routes computation can converge and delivery of data to their destinations can occur. Hence, this is a low-mobility centralized form of wireless ad hoc network. Also, because it sometimes relies on static nodes to act as gateways, it is not a truly all-wireless ad hoc network.
With the rather complex physical network structure and above-average number of wireless and wired clients the task wasn’t an easy one.
To give an impression of what is there right now:
So there’s a bit of almost everything. There’s wired connections (1Gbit to most places) and there is wireless connections. There are 5 access points overall of which 4 are just mesh repeaters coordinated by the Fritz!Box mesh-master.
There’s also powerline used for some of the more distant rooms of the mansion. All in all there are 4 powerline connections all of them are above 100 Mbit/s and one even is used for video streaming.
All is managed by a central Fritz!Box and all is well.
Like without issues. Even interesting spanning-tree implementations like from SONOS are being properly routed and have always worked without issues.
The only other-than-default configuration I had made to the Fritz!Box is that all well-known devices have set their v4 IPs to static so they are not frequently switching around the place.
How do I know it works? After enabling the Mesh things started working that have not worked before. Before the Mesh set-up I had several accesspoints independently from each other on the same SSID. Which would lead to hard connection drops if you walked between them. Roaming did not work.
With mesh enabled I’ve not seen this behavior anymore. All is stable even when I move actively between all floors and rooms.
We are using Apples smartwatch to measure some health stats during our workouts. And Apple Watch is doing a great job at that.
With all that polish one would expect better from what Apple has to offer in the software department…
Apple Watch has monthly challenges that get automatically generated from previous measurements. But seeing that an already much above average activities number would have to be doubled to complete the challenge is absurd. To a degree where challenges are arguably health risks…
Dicordianism is a paradigm based upon the book Principia Discordia, written by Greg Hill with Kerry Wendell Thornley in 1963, the two working under the pseudonyms Malaclypse the Younger and Omar Khayyam Ravenhurst.
According to its primary historian, Adam Gorightly, Discordianism was founded as a parody religion. Many outside observers still regard Discordianism as a parody religion, although some of its adherents may utilize it as a legitimate religion or as a metaphor for a governing philosophy.
The Principia Discordia, if read literally, encourages the worship of Eris, known in Latin as Discordia, the goddess of disorder, or archetypes and ideals associated with her. Depending on the version of Discordianism, Eris might be considered the goddess exclusively of disorder or the goddess of disorder and chaos.
Both views are supported by the Principia Discordia. The Principia Discordia holds three core principles: the Aneristic (order), the Eristic (disorder), and the notion that both are mere illusions.
Due to these principles, a Discordian believes there is no distinction between disorder and chaos, since the only difference between the two is that one refers to ‘order’.
This is likely a major reason for the inconsistency in the wording. An argument presented by the text is that it is only by rejecting these principles that you can truly perceive reality as it is, chaos.
We use the term “smart home” lightly these days. It has become a term of marketing and phantastic stories.
Considering how readily available lots of different sensors, actors and personal-assistants are these days one would think that most people would start to expect more from the marketing “smart-home”.
I believe that the smart is to be found in the small and simple. There are a lot of small things that actually make something feel smart without it actually being smart about anything.
Being smart is something not achieved yet – not even by a far stretch of the sense of the word. So let’s put that to the sides of the discussion for now and move a simple thing in the middle of this article.
Have you ever had an argument about who should or should have cleared out the dishwasher after it’s finished?
So we outsourced the discussion and decision to a 3rd party. We made our house understand when the dishwasher starts and ends it’s task. And made it flip a coin.
There was already a power consumption monitoring in place for the dishwasher. Adding a hysteresis over that monitoring would yield a simple “starts running” / “stops running” state of the dishwasher.
Pictured above is said power consumption.
When the values enter the red area in the graph the dishwasher is considered to be running.
When it leaves that area the dishwasher is considered finished/not running
Now adding a bit of random coin-tossing by the computer and each time when the dishwasher is detected to have started work a message is sent out depending on the result of the coin-toss.
That message is published and automatically displayed on all active displays in the house (TVs/…) and sent as push notifications to all members that need to be informed of this conclusive and important decision.
Everyone gets a push notification who is going to clear out the dishwasher based upon a coin-toss by a computer every time the dishwasher starts.
The base of all of this is a Node-RED flow that that uses the power consumption MQTT messages as an input and outputs back to MQTT as well as pushes out the push notifications to phones, screens and watches.
Additionally it creates a calendar entry with the start-finish time of the dishwasher run as well as the total energy consumption for this run.
The flow works like this: on the right the message enters the flow from MQTT. The message itself contains just the value of the power consumed at this very moment. In this case consumed the dishwasher.
The power consumption is updated regularly, every couple of seconds this way. So every couple of seconds this flow runs and gets an updated value of
Next a hysteresis is applied. In simple terms this means: when the value goes above a certain threshold the dishwasher is considered to be running. When it goes below a certain threshold then it is considered finished.
When the dishwasher changed it’s state to “running” the flow will generate a random number between 0 and 1. This give a 50:50 chance for either Steffi or Daniel be the chosen one to clear out the dishwasher for this run. This message is sent out as push notification to all phones, watches and TVs.
When the dishwasher finishes it’s run the total energy consumption is taken and sent out as the “I am done message”. Also this information is added to the calendar. Voilá.
A calendar? Why a calendar you may ask. Oh well there are several reasons. Think of calendars as another way to interact with the house. All sorts of things happen on a timeline. A calendar is only a visual aid to interact with timelines.
May it be a home appliance running and motion being sensed for your home alarm system. All of that can be displayed in a calendar and thus automatically sync to all your devices capable to display this calendar.
And if you start adding entries to a calendar that the house uses to know what to do next… how about putting light on-off times into an actual calendar right on your phone instead of a complicated browser user interface like many of those marketing smart-homes want us to use?
As of early 2019 I’ve started to bring back my content output stream to this website/weblog.
So far I am feeling quite confident publishing content here and even with changing legislation I am doing my best to provide an as good as possible experience to each visitor.
As of End-of-February 2018 this blog is being provided securly encrypted with SSL certificates from Let’s Encrypt.
So security is one thing. Data privacy and safety another.
Apart from the commenting and searching there’s no functionality provided to enter/store data.
When you enter a comment the assumption is that this is your call for consent. Your comment will be stored. With the information you’ve entered and can see on-screen as well as the IP address you’ve used. Akismet then is used to provide Anti-comment-SPAM functionality – so part of this data is transferred over to Akismet for processing. After moderation the comment is visible for everyone under the article you’ve created it.
cookies and browser local storage
No cookies are used or required by the website.
There are no logfiles. No access and no error logs. There is no tracking or analysis. There is no advertisting or monitoring. All I can see is an nginx and php process delivering websites. Your IP address is know to the server for as long as it takes to do his job of delivering the asset you asked for. Nothing gets stored on server side for your read requests.
No content is loaded from other domains or websites. Everything is hosted on my server. No data is exchanged with externals to bring you this website.
Apple has started to force developers that want to develop and publish on the MacOS and iOS platform to enable two-factor authentication.
Two-factor authentication (also known as 2FA) is a type, or subset, of multi-factor authentication. It is a method of confirming users’ claimed identities by using a combination of two different factors: 1) something they know, 2) something they have, or 3) something they are.
When I just got around enabling it for one of the apple accounts I’ve got there seems to be a much much higher security barrier in place already…
That’s probably some sort of zero-factor no-authentication. I guess. Anyway: Kudos to Apple for finally forcing people to minimum standards. Properly integrating the second factor will make this so much simpler for users. Apples ecosystem solution already is quite well integrated.
Have you switched all your daily used services to two-factor authentication yet?
Ever since we had changed our daily diet we started to weigh everything we eat or cook. Like everything.
Quickly we found that those kitchen scale you can cheaply buy are either not offering the convenience we are looking for or regularly running out of power and need battery replacements.
As we already have all sorts of home automation in place anyway the idea was born to integrate en ESP8266 into two of those cheap scales and – while ripping out most of their electronics – base the new scale functionality on the load cells already in the cheap scale.
So one afternoon in January 2018 I sat down and put all the parts together:
After the hardware portion I sat down and programmed the firmware of the ESP8266. The simple idea: It should connect to wifi and to the house MQTT broker.
It would then send it’s measures into a /raw topic as well as receive commands (tare, calibration) over a /cmd topic.
Now the next step was to get the display of the measured weights sorted. The idea for this: write a web application that would connect to the MQTT brokers websocket and receive the stream of measurements. It would then add some additional logic like a “tare” button in the web interface as well as a list of recent measurements that can be stored for later use.
An additional automation would be that if the tare button is pressed and the weight is bigger than 10g the weight would automatically be added to the measurements list in the web app – no matter which of the tare buttons where used. The tare button in the web app or the physical button on the actual scale. Very practical!
Here’s a short demo of the logic, the scale and the web app in a video:
We are looking at our screens more and more time of the day and most of that time we are reading or writing text. Text needs to look pretty for our eyes not to get sore – apart from the obvious “being able to tell what letter that is” there is a big portion of personal taste and preference when it comes to the choice of the font.
If you ever traveled on a train or plane with good active noise cancellation headphones you might agree how much more pleasant the trip was with much less noise reaching your ears.
When I tried active noise cancellation for the first time I had that weird sensation as if the pressure around suddenly changed. Like being in a very fast elevator or going for a quick dive. It felt weird but luckily it went away and the aww of joy replaced it. Quietness. Bliss.
Now there seem to be people for whom that feeling won’t go away. They get headaches and cannot stand the feeling when using active noise cancellation.
I’ve never had any explanation to this phenomena – until now. I ran across an article on SoundStage describing that in fact the feeling is not caused by actual changes of pressure but…
According to the engineer, eardrum suck, while it feels like a quick change in pressure, is psychosomatic. “There’s no actual pressure change. It’s caused by a disruption in the balance of sound you’re used to hearing,” he explained.
Aha! The brain gets confused by signals reaching your ears that naturally would not exists. Those signals make no sense so the brain tries to make sense of it. And voilá something is sucking your ear drum!
In 2017 Texas Instruments had released a line of cheap industry grade LED projectors meant to be used in production lines and alike:
DLP® LightCrafter Display 2000 is an easy-to-use, plug-and-play evaluation platform for a wide array of ultra-mobile and ultra-portable display applications in consumer, wearables, industrial, medical, and Internet of Things (IoT) markets. The evaluation module (EVM) features the DLP2000 chipset comprised of the DLP2000.2 nHD DMD, DLPC2607 display controller and DLPA1000 PMIC/LED driver. This EVM comes equipped with a production ready optical engine and processor interface supporting 8/16/24-bit RGB parallel video interface in a small-form factor.
After I had learned about the existence of those small projectors I had to get a couple and try for myself. There would be so many immediate and potential applications in our house.
After having them delivered I did the first trial with just a breadboard and the Raspberry Pi 3.
The projector module has a native resolution of 640×360 – so not exactly high-pixel-density. And of course if the image is projected bigger the screen-door effect is quite noticeable. Also it’s not the brightest of images depending on the size. For the usual use-cases the brightness is definitely sufficient.
too low brightness for large projection size – no daylight projection
low resolution is an issue for text and web content – it is not so much of an issue for moving pictures as you might think. Video playback is well usable.
flimsy optics that you need to set focus manually – works but there is no automatic focus or alike.
very low powered – 2.5A/5V USB power supply is sufficient for Pi Zero + Projector on full brightness (30 lumen)
low brightness is not always bad – one of our specific use cases requires an as dim as possible image with fine grain control of thr brightness which this projector has.
extremely small footprint / size allows to integrate this device into places you would not have thought of.
almost fully silent operation – the only moving part that makes a sound is the color wheel inside the DLP module. You have to put your ear right onto it to hear anything.
passive cooling sufficient – even at full brightness an added heat sink is enough to dissipate the heat generated by the LED.
So what are these use cases that require such a projector you ask?
Night status display:
For the last 20+ years I am used to sleep with a “night playlist” running. So far a LED TV was used at the lowest brightness possible. Still it was pretty bright. The projector module allows to dim the brightness down to almost “moon brightness” and also allows to adjust the color balance towards the reds. This means: the perfect night projection is possible! And the power consumption is extremely low. A well watchable lowest brightness red-shifted image also means much lower temperatures on the projector module – it’s crazy how low powered, low temperature.
Season Window Projection:
Because the projector is small, low-powered and bright enough for back-lit projection we tried and succeeded with a Halloween window projection scene the last season.
It really looks funky from the outside – funky enough to have several people stop in front of the house and point fingers. All that while power consumption was really
House overall status projections:
When projecting information is that cheap and power efficient it really shines when used to display overall status information like house-alarm status, general switch maps, locations of family members and so on. I’ve left those to your imagination as these kind of status displays are more or less giving away a lot of personal information that isn’t well suited for the internet.
Many cars these days come with head up displays. These kind of displays are used to make information like the current speed appear “floating” over the street ahead right in your field of vision.
This has the clear advantage that the driver can stay focused on the street rather than looking away from the street and to the speedometer.
As practical as it seems these displays are not easy to build and seemingly not easy to design. Every time I came across one it’s built-in functionalities where limited in a way that I only can assume not a lot of thought had gone into what exactly would the driver like to see and how that would be displayed. There was always so much left to desire.
Apparently the technology behind these HUDs is at a point where it’s quite affordable to start playing with some ideas to retrofit a car with a more personal and likeable version.
So I started to take a look at what is available – smart phones have bright displays and I had never tried to see what happens when you try to utilize them to project information into the windshield. So I tried.
As you can see – bright enough, readable but hazy and not perfectly sharp. The reason is quite simple:
“In the special windshield normally used, the transparent plastic safety material sandwiched in between the two pieces of glass must have a slight and very precise wedge, so that the vehicle operator does not see a HUD double image.”
There are some retrofit adhesive film solutions available that claim to help with that. I have not tried any yet. To be honest: to my eye the difference is noticeable but not a deal-breaker.
So I’ve tried apps available. They work. But they do a lot of things different from how I would have expected or done them. They are bearable, but I think it could be done better.
tldr: I started prototyping away and made a list of things that need to be done about the existing HUD applications.
Here’s my list of what I want to achieve:
display orientation according to driving direction – I had expected all HUD applications to do this. They know the driving direction. They know how the device is oriented in space. They can tell which direction the windshield is. They know how to correctly turn the screen. They do not do that. None of them.
fonts and numbers – I cannot stand the numbers jumping around when they change up and down
speed steps interpolation – GPS only delivers a speed update every second or so. In this time speed might jump up and down by more than +1. The display has 60 fps and gyros to play with and interpolate… I want smooth number transitions.
have an “eco-meter” – using gyros the HUD would be able to display harsh accelleration and breaking. Maybe display a color-coded bar and whatever is measured is reflected in the bar going left or right…
speed-limit display – apparently this is a huge issue looking at the data availability. There seems to be open-street-map data and options to contribute. Maybe that can be added.
have a non-hud mode – non mirrored to use for example to set speed limits and contribute to OpenStreetMap this way!
automatically switch between HUD and non-HUD mode – because the device knows it’s orientation in space – if you pick it up from the dashboard and look into it, why not automatically switch?
speed zones color coding – change the color of the speed display depending on configurable speed regions. 0-80 is green, 80-130 is yellow, 130-250 is red.
turn display off when car stopped – if there’s nothing displayed or needs to be displayed, for example because the car stopped the display can be turned off completely on it’s own.
Navigation is of limited value as the only way I could think of adding value would be a serious AR solution that uses the whole windshield. Now I’ve got these small low-power projectors around… that get’s me thinking…
What would you want to have in such a HUD in your car?
As you might know I am living in Germany. Germany is the one country where you have some roads that are legally not having any speed limit whatsoever. If the circumstances allow to safely drive 250 km/h you are allowed to do so. It’s up to the drivers judgement.
Now as much as this is a great thing of personal freedom it also has some negative side effects on the climate.
Your car is burning a lot more fuel when driving those kind of speeds. And a lot meaning that it resembles more an exponential curve than a linear line. Rule of thumb: 2x the speed is more than 4x the consumption.
Ever once in a while people start discussing about a general speed limit for Germany – as every other country has it. Some talk about 160 km/h, some about 120 km/h.
The motivations are diverse: climate, resource use, safety, …
In any case additional limits would need to be enforced. More speed traps…
What if things would be handled differently?
How about this:
Politics would introduce a “best speed lottery”. On every street without a speed limit there would randomly be speed controls and speed traps. Those who follow the best practices of driving … Let’s say 120 km/h… Would be rewarded when randomly photographed. The reward would be a tax discount on car tax and/or gas tax and one ticket put into the countries lottery pool. Once a quarter a new electric car or similar would be given to a random winner.
What would you think would make people drive slower in their own motivation?
I am at the stage of “trying to comprehend” the japanese spoken language.
I’ll be a happy camper if I would understand most of what is being said and could follow daylight normal conversations pointed towards me japanese. Like, you know, when trying to make a purchase or having to ask for that one bit of information.
For this, apart from excessive exposure to the spoken language, I am using some tools to help with reading to a small degree.
For those completely out of the loop:
Japanese has no genetic relationship with Chinese, but it makes extensive use of Chinese characters, or kanji (漢字), in its writing system, and a large portion of its vocabulary is borrowed from Chinese. Along with kanji, the Japanese writing system primarily uses two syllabic scripts, hiragana (ひらがな or 平仮名) and katakana (カタカナ or 片仮名). Latin script is used in a limited fashion, such as for imported acronyms, and the numeral system uses mostly Arabic numerals alongside traditional Chinese numerals.
Not having time for a full-day-of-focus I postponed the upgrade to this saturday. With the agreement of the family as they are suffering through the maintenance period as well.
The upgrade would need cautious preparation in order to be doable in one sitting. And this was also meant to be some sort of disaster-recovery-drill. I would restore the house central docker and service infrastructure from scratch along this.
And this would need to happen:
all services, zfs pools, docker containers, configurations needed to be double checked for full backup – as this would be used to restore all (ZFS snapshots are just the bomb for these things!)
the main central docker server would have to go down
get a fresh Ubuntu 18.04 LTS set-up and booting from ZFS on a NVMe SSD (bios update(s)!, secure boot disabling, ahci enabling, m.2 instead of sata express switching…you get the idea)
get the network set-up in order: upgrading from Ubuntu 16.04 to 18.04 means ifupdown networking was replaced by netplan. Hurray! Not.
get docker-ce and docker-compose ready and set-up and all these funky networkings aligned – figure out in this that there are major issues with IPv6 in docker currently.
pull in the small number of still needed mechanical hard disks and import the ZFS pools
start the docker builds from the backup (one script \o/)
start the docker containers in their required order (one script \o/)
Apart from some hardware/bios related issues and the rather unexpected netplan introduction everything went fairly good. It just takes ages to see data copied.
Bandwidth was the only real issue with this disaster recovery. All building blocks seemed to fall into place and no unplanned measure had to be taken. The house systems went partially down at around 12:30 and were back up 10 hours later 22:00. Of course non-automated things like internet kept working and all switches were only manual push-buttons. So everything could be done still but with a lot less convenience.
All in all there are more than 40 vital docker container based services that get started one after the other and interconnect to deliver a full house home automation. With the added SSD performance this whole ship is much much more responsive to activities. And hopefully less prone to mechanical defects.
Backup and Disaster-Preparations showed to be practical and working well. There was no beat missed (except sensor measure values during the 10 hours downtime) and no data lost.
What could be done better: It could be much more straight forward when there were less dependencies on external repositories / docker-hub. Almost all issues that came up with containers where from the fact that the maintainers had just a day before introduced something that kept them from spinning up naturally. Bad luck. But that can be helped! There’s now a multi-page disaster-recovery-procedure document that will be used and updated in the future.
Oh and what speeds am I seeing? The promissed 3 Gbyte/s read and write speeds are real. It’s quite impressive to see 4-digit megabyte/s values in iotop frequently.
I almost forgot! During this exercise I had been in the server room less than 30 minutes. But I was on a warm and nice work-desk set-up I am using in the house as much as I can – and I will tell you about it in another article. But the major feature of this work-desk set-up is that it is (a) a standing desk and (b) has a treadmill under it. Yes. Treadmill.
You will get pictures of the set-up in that mentioned article, but since I had spent more than 10 hours walking on saturday doing the disaster recovery I want to give you a glimpse of what such a set-up means:
This large amount of spinning disks means that there are also failing drives that stop spinning once every while. Backblaze saw the need to take note about what hard-drive series fails more of less often and started to generate a yearly report on the reliability of these hard drives.
Yesterday they published their report for 2018 – if you got storage requirements or if you are in the market to purchase storage space for your operation – it probably is very helpful to take a look at the report.