November 20, 2025

Everything from scratch (again)

And Again

In the course of thel ast years all of my private sites and projects rotted away due to personal circumstances (I was to lazy and did not care). So the only thing which seems to be operatable is the static homepage on 123k.pl and this also of course rotted away as nobody updated hugo for me.

So this fantastic elaborated blog-post marks the start of a new iteration. The long term goal (which I should have never written about here already now) is to have

May 12, 2019

Reactivated Obelometer

Welcome Back Obelometer

A few years ago I bought my first few raspberries and the first thing I invented was (of course) a thermometer application. Back then I even stored the data in MongoDB and calculated stuff with map-reduce - but as one rpi died and the host server also was re-installed I never looked back.

During my recent rebuild of the home-office I found some old rpis and even the thermometer and the wireless sticks. So I thought I should start one of them again.

February 24, 2019

Streaming Geo-Locations

Streaming Server Experiments

My first tests with streaming geo-locations from mongodb to a webclient started. The results are pretty promising and I even have two calls in production already.

Mosty - Spring-Boot Webflux

My first try will be a Spring-Boot application named Mosty (which is of course a small village nearby and home of the infamous sandpit). The result for now is basically a copy and paste from tutorials and stack-overflow - but it just works and the first stream of points is already consumed by my new static homepage.

February 9, 2019

New Year New Start

Back in Business

Hello there, I’m Back in Business (jak EPMD!) - only after three years of effective inactivity I decided to re-active this blog again. As I really did not prepare any content ¹ , I can only start with some small notes.

Disaster and Recovery

So in September 2018 I found out, that my server where the 123k project runs did not respond any more. I went to the fabulous Hetzner site and found out, that it just does not boot any more because of ZFS file system corruption. This was not recoverable - I saved a snapshot of the whole thing. So if some ZFS developer wants to know what happened to this special file system - you’re welcome. I myself did not investigate too much and just setup a new server (so I do not know if I was hacked or the underlying hypervisor had a hickup).

January 7, 2016

Many Clickable Points on a Leaflet Map With Leaflet.glify

Problem

As seen in the post before we collected some 12.000 points which we want to display on a leaflet map. Every attempt to put that many points on one map failed. Firefox completely stopped working, chrome did a little bit better and stayed responsive, but that was not a solution at all.

Solution

I pretty much tried everything L.geoJSON layer with points and polygons. Where polygons would have been a solution maybe, but you can not tell leaflet to just draw the corners of the polygons. So I needed something else. In the #leaflet on freenode i was pointed to the Leaflet.glify project.

January 7, 2016

Show routes to current geohash

The Plan

My geohashing alert2016-01-13 15:28-system at 123k.org shows the current geohash for my home graticule. The plan is to the nearest route which passes by.

Finding Something

As mentioned earlier I have all points i ever visited in a collection. This collection holds a geospatial index. Therefore I can issue mongo queries with the $nearSphere command. This command finds the first points from a given location.

So this just works. But what about other routes which may also be nice and just around the corner? We can select many points around the hash point and check which routes they’re on.

January 2, 2016

Build a Coverage Map With Mongodb

Introduction

When I started with my personal bike-track homepage at 123k.org a few years ago I decided to put all my tracks in a MongoDB. The model I use is very simple. I have a class Route which holds meta-data about the track and a class TrackPoint which represents a point and has a foreign key to the respective track (of course). After some years I have 612827 track-points. So 600k entries is not ‘big-data’ exactly, but it is too much to be displayed on a leaflet map at once. What I really wanted is a ‘Coverage View’, which just shows me where I’ve been with the bike.