transparently migrate data from local file storage to key-value-stores like RIAK KV

About 2 years ago I sat down and wrote a filesystem. Well not from scratch but using the great FUSE (Filesystem in Userspace) framework. I’ve released it as open-source later on Github:

This script acts as glue between a local file storage mount point and RIAK. It is targeted at specific use cases when local mount-points need to be migrated to RIAK without changing the applications accessing those mount point. Think of it as a transparent RIAK filesystem layer with multiple options to control it’s behavior regarding local files.

riakfuse

I had a very specific purpose in mind when I wrote this: There was a local filesystem that got filled up and because of technical restrictions we were not able to resize it or even completely copy it without interrupting the service using the data stored there.

Since we were already using the RIAK Key-Value Database for certain binary loads the idea came up to also utilize this key-value concept for a filesystem.

The idea now is: You have a local filesystem that holds a lot of folders and files already and you want to gradually want to move it to new grounds.

This migration needed to happen with minimal service interruptions assuming that there is constant reading and writing happening.

In this riak-fuse project I’ve written an overlay filesystem that steps between the application and the underlying “old”-filesystem. It looks and behaves identical to the application reading and writing.

But, depending on the mode you have chosen while mounting, every file read will at first be read from the “old”-filesystem and after successfull read stored into the key-value store.

On the next read it will be read from the key-value store directly.

The same applies for writing. Riak-fuse will write either to both, local storage and key-value store or just to the key-value store.

So in a nutshell: Data is slowly but surely on each access transferred over to the key-value store and load + storage space is slowly moving over from the local storage to the key-value store.

To facilitate this there are a lot of options for this script:

This all comes with ready-to-use docker and docker-compose files for you to try out.

Also it might interest you as an extremely simplified example of how to write an actual file system module for FUSE in Python.

Disclaimer: This effectively is my first python script as well as fuse module. Don’t be too hard on your judgement.

Things you do with Microsoft Excel

Many of us are happy when they can accomplish the most simple tasks with Excel without pulling their own hair out.

And then there are these people who do something entirely different with Excel:

Finding engineering work quite unchallenging lately I decided to start this blog in which to share cool ways of solving engineering problems or just interesting modeling of natural phenomena in MS Excel 2003. I use mainly cell formulas with minimum of VBA in order to take advantage of the ease of “programming” and the native speed of the Excel spreadsheet.

http://www.excelunusual.com/

Time estimation in software development

I’ve found myself in these spots several times in my life. Either I had to deliver on an estimate or I had to acknowledge an estimation and deal with the outcomes.

If you are involved in anything digital / software this is a recommended piece to read:

Anyone who built software for a while knows that estimating how long something is going to take is hard. It’s hard to come up with an unbiased estimate of how long something will take, when fundamentally the work in itself is about solving something. One pet theory I’ve had for a really long time, is that some of this is really just a statistical artifact.

Why software projects take longer than you think

“Around Tokyo” project

If you are interested in even some older video recordings, pictures and impressions about some areas of Tokyo this is a good time-sink for you.

Lyle Saxon has several old-fashioned looking websites (wonderful) with lots and lots of browsing content as well as a YouTube channel with recordings from earlier times:

Tokyo resident since 1984. Video material from 1990-93, as well as newer material from 2008 onwards.

The “Around Tokyo” project was and is to document life in Tokyo and the surrounding areas, as well as some material from other areas of Japan.

YouTube Channel

QR codes – how do they work?

I came across a very nice explanatory piece for QR codes. If you always wanted to know the basic principles this is a good chance to get a grasp.

QR code (abbreviated from Quick Response Code) is the trademark for a type of matrix barcode (or two-dimensional barcode) first designed in 1994 for the automotive industry in Japan. A barcode is a machine-readable optical label that contains information about the item to which it is attached. In practice, QR codes often contain data for a locator, identifier, or tracker that points to a website or application. A QR code uses four standardized encoding modes (numeric, alphanumeric, byte/binary, and kanji) to store data efficiently; extensions may also be used.[1]

Wikipedia

I am using QR codes in several of my projects – one example: Miataru uses QR codes to encode the device ID and help with the device handshake. You scan the QR code of your friend with your Miataru client app and immediately will be able to see his location in Miataru. Without the need to enter long rows of numbers.

convert Markdown scribbles to vector drawings

Every task you take
Every meeting you make
Every keyboard you break
Every note you take
I’ll be storing it for you

my text editor

Well that was fun! And indeed: a big portion of my professional daily business is taking place in a text editor taking notes and scribbling ideas and thoughts.

I’ve tried many things but the only way that resonated with me was taking notes in Markdown in a text editor that supports markdown. Currently that editor is Atom.io. Mainly because it is not in the way and quite portable. Runs on Linux, Windows, MacOS.

extra cheesy 80s neon theme

This way – I just took a count – I noted down 364.416 words in the last 1.5 years on my current job (equals to about 46 hours of average speed reading…).

Along side those simple text notes and bullet lists I am doing very simple tables as well as ASCII scribbles in Markdown as well. With the right tools it’s extremely easy and much faster than booting up the Powerpoint or worse.

When you have all in Markdown you then can freely stylesheet away and convert to handy PDF files as well. All even with embedded images if you so desire.

But even if you sit on that treasure trove of Markdown there comes the time when you wish you could convert your scribbles to graphics. Even if it is for the sole reason to not have to draw it again for that fancy Powerpoint slide deck.

You’ve got multiple options to accomplish this:

svgbob is at first a command line tool that got a recent level-up with a proper web-frontend:

When given Markdown it creates graphics. In the picture above the input is on the left and the svgbob output on the right (as SVG).

Markdeep is the alternative. Which of both work for your case depends on that specific case. Knowing and using both properly is the best way.

Japanese Highway Junctions

Highways allows us to travel long distances and interchanges, or junctions, connect those highways so that traffic can pass or change direction without interruption. And in Japan, where heavy mountainous terrain and dense cities create unique constraints, interchanges are, simply put, magnificent feats of structural engineering that we sometimes can’t appreciate through the typical vantage point of a car window.

Spoon & Tamago

Of course, go ahead and browse the highway system on Google Maps.

from now on console emulation will look much better

A modder going by the handle DerKoun has released an “HD Mode 7” patch for the accuracy-focused SNES emulator bsnes. In their own words, the patch “performs Mode 7 transformations… at up to 4 times the horizontal and vertical resolution” of the original hardware.

The results, as you can see in the above gallery and the below YouTube video, are practically miraculous. Pieces of Mode 7 maps that used to be boxy smears of color far in the distance are now sharp, straight lines with distinct borders and distinguishable features. It’s like looking at a brand-new game.

ArsTechnica

Michelin Guide Restaurants in Tokyo

You are likely aware of the existence of the “Michelin Guide“.

Michelin Guides are a series of guide books published by the French tyre company Michelin for more than a century. The term normally refers to the annually published Michelin Red Guide, the oldest European hotel and restaurant reference guide, which awards up to three Michelin stars for excellence to a select few establishments.

Wikipedia

You might also be aware that Tokyo is the city with the highest density of Michelin star rated restaurants. Nice, eh?

A purchase of this guide is recommended in any case but these days people also need something they can intuitively use and which integrates into already existing workflows.

These people, like myself, need a map and maybe more details in a machine readable, filterable spreadsheet.

And as time goes on it might be quite useful to have all the sources that lead to these great tables and maps. Sources that allow you to crawl and grab these information.

A script that crawls Tokyo-based michelin guide establishments and saves it into a JSON file. I personally did this project so I can plan my tokyo trip based on the cheapest and most-renowned restaurants,

Michelin Guide Crawler on GitHub