Archives for 2025 | HU Xiaoxu

How to Expose the Kubernetes Service via NodePort

In the previous article, we discussed the ClusterIP service type. In this one, we'll briefly cover the NodePort service type, which allows us to expose a service as an entry point to the public network.Kubernetes Manifests ExamplapiVersion: apps/vkind: Deploymenmetadataname: my-apspecreplicas: selectormatchLabelsapp: my-aptemplatemetadatalabelsapp: my-apspeccontainers- name: my-ap Read More

How the Kubernetes ClusterIP Service Works

A ClusterIP Service is the default Kubernetes service type. It provides a virtual IP address (VIP) inside the cluster to allow pods to communicate with each other. It is internal-only, meaning it is not accessible from outside the cluster.Example ManifestapiVersion: apps/vkind: Deploymenmetadataname: my-apspecreplicas: selectormatchLabelsapp: my-aptemplatemetadatalabelsapp: my-apspec... Read More

From Polling to QUIC: How Modern Web Communication Works

Today, I’m revisiting client-server communication mechanisms. The main methods are outlined in the table below for easier understanding.MechanismBased onDirectionProsConsTypical Use CasesPollingHTTP/1.xClient → Server• Very simple to implement• Works everywhere• High latency (depends on interval)• High overhead (many HTTP headers & TCP handshakes)• Wastes resourcesPeriodic updates, legacy apps... Read More

[Learning Notes] Course: How Transformer LLMs Work

Course Link: How Transformer LLMs Wor2025-08-1chapter: understanding language models: language as a Bag-of-Wordnon-transformer, encoder-only, decoder-only, encoder-decodedecoder-only: such GPtokenization -> tokens -> vocabulary -> vector embeddingchapter: understanding language models: (word) embeddingword2vec, the way to express the natural meaning is an array of floatsuch as cats [.91, -... Read More

New Features from C++20 Release

I recently did a quick study of the new features introduced in C++20, and I’d like to summarize what I’ve learned here.Core Languages Enhancementconstinit & consteval & enhanced constexpThe above three keywords enable code to be evaluated or initialized at compile time.The main goal of these keywords, from my perspective, are shown as followingconstiniensure deterministic initialization of glob... Read More

Duolingo to Replace Contractors with AI

Today, I came across an internal email from Duolingo's all-hands, announcing that Duolingo is going to make a significant platform shift - AI-first. Luis, the CEO, believes that AI is happening and changing much of how they work today, they can't wait until the AI is 100% perfect, and would rather move with urgency and take occasional small hits on quality. Also some constructive constraints are r... Read More

Year: 2025