Code Trips & Tips

Gossip-based Failure Detectors – 0.8.0 released

September 8, 2017

We have just released version 0.8.0 of our distlib C++ library that implements a number of popular distributed systems algorithms. This concludes a first iteration of the “SWIM Gossip Protocol” for failure detection: the implementation is now fully thread-safe and can scale up to many servers with minimal process overhead. The gossip_example.cpp toy server shows how a client … More Gossip-based Failure Detectors – 0.8.0 released

Uncompromising Python Formatting

December 24, 2018

I wanted to give a shout out to Black, “the uncompromising Python code formatter.” It really is liberating not to have to worry about code formatting, not having to have unproductive, sterile discussions over PRs about code minutiae and yet being reassured that all your code is nicely formatted; most importantly, the quality of the … More Uncompromising Python Formatting

HOW-TO Install Minikube on MacOS

September 29, 2018

Minikube is an extremely useful tool to run a development Kubernetes single-node cluster locally, on a development machine. I use it regularly on my Linux box and, as I want to do development on my MacBook Pro too, I thought I’d use it there to. In order to do so, I have created a simple … More HOW-TO Install Minikube on MacOS

QNAP NAS Hybrid Backup Sync restart

August 2, 2018

I have now had a TS-212 QNAP NAS for many years and I am really (really!) happy with it: it works exceedingly well for what I originally bought it for (a networked backup drive, essentially) but it has also so many more facilities that I really have come to depend on it for a number … More QNAP NAS Hybrid Backup Sync restart

HOW-TO Move your code out of GitHub

June 9, 2018

As everyone knows by now, Microsoft has bought Github for several $BN’s. Depending on your point of view, this can be either a catastrophe or a disaster: nothing good can possibly come out of it, apart from, possibly, having prevented Github (the corporation) going into a steady, sad decline, as they seemed unable to figure … More HOW-TO Move your code out of GitHub

Beware of C++11 `auto`

December 10, 2017

Here’s a puzzler for you: given the code below, what does the for loop print? using HandlersMap = std::map<std::string, std::function<std::string(const std::string&)>>; using MetaMap = std::map<std::string, HandlersMap>; void insert(MetaMap& meta, const std::string& key, const std::string& sub) { auto handlers = meta[key]; handlers[sub] = [=](const std::string& msg) { return “The response for ” + sub + ” … More Beware of C++11 `auto`

Detection of Fast-Moving Objects (FOM) using OpenCV

October 29, 2017

A “fast-moving object” (FOM) in the world of image detection is defined as one whose motion is faster than can be captured by a single image, and will result in a blurred “streak”. This poses some challenges when trying to detect its speed and trajectory, as well as estimating future trajectory and impact. Typical examples … More Detection of Fast-Moving Objects (FOM) using OpenCV

File Encryption Utility now offers file sharing

October 16, 2017

With the 0.5.0 version just released, crytto now allows file sharing (e.g., via email) by sharing public keys: encrypt_send -o /tmp/my-secret.enc \ -p /home/marco/.ssh/my-key.pub \ ./my-secret.doc This generates an encrypted file (in the location specified with the -o option) and an equally encrypted “passphrase” which can then be sent (ideally via a separate sharing mechanism; although, as … More File Encryption Utility now offers file sharing

Adventures in developing distributed systems in Java and Python