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It’s been a while since lab one, this time I am going to cover how I finished the lab two Raft implementation. If you are interested in lab one, check this out https://medium.com/codex/journey-to-mit-6-824-lab-1-mapreduce-ebe58800ef9e.

Raft Overview

First, let’s have an overview of Raft. Raft is a consensus algorithm for managing a replicated log. The core idea of Raft from my understanding is:


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Running an Azure/AWS/GCP managed k8s cluster can be costly if you are simply playing with it for dev/test purpose. However, if you happen to have a Raspberry Pi, you can run a k8s cluster on it.

If you google “running k8s on raspberry pi”, there are many available Kubernetes distributions, in this post, I will briefly try some popular distributions, namely MicroK8s/k3s/kind/k3d/k0s and provide my two cents that which one is best fit for your Raspberry Pi.

In this post, I am using a single Raspberry Pi Model 4B 4G Ram model with 32GB storage card running Raspberry Pi OS…


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The motivation

Early this year I was randomly browsing our company’s discussion group, and the MIT online course MIT 6.824 Distributed System happened to come across to me. After I did a quick look at the course syllabus, I was immediately intrigued by it and decided to follow this course as much as I can.

https://pdos.csail.mit.edu/6.824/schedule.html

I was having a tough time with my daily work dealing with a complex and highly distributed system at that time, and I hoped I could get some inspiration from this course as well as systematic understanding of distributed system rather than several fragmented online articles…


Write your blog posts like contributing to a GitHub repo.

There are plenty ways to build your personal blog, but with Gatsby and GitHub, you can build a blog where you can easily set up but you still have the full control of your website layout at no cost.

Using Gatsby to build your blog site

Gatsby is a React-based open source framework for creating websites and apps. Let’s use it to build our blog site in a few minutes.

Gatsby supports many starters to let you build your websites faster and easier. Your website can achieve this out of box:


Recently my work requires me to implement the encryption of the credentials entered by the customer from the browser and the decryption at server side, in a secure and compliance manner.

The first thought came to my mind was the RSA public key/private key encryption algorism, which is straightforward.

Code is also straightforward:

https://gist.github.com/QingpingMeng/f51902e2629fc061c6b9fc9bb0f3f57b

This worked fine until I learned asymmetric encryption can only encrypt small amount of data which is up to the length of key size modulus minus a small number depending on padding mode.

After some research, it’s usually recommended to use symmetric encryption like AES to…

Qingping Meng

Someone who is obsessed to build things

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