Cloud Computing on Chen Kai Blog

Multi-Cloud and Hybrid Architecture

Wed, 14 Jun 2023 09:00:00 +0000

The first article in this series asked “what is the cloud, and why does it matter?” Eight articles later, the question has matured into something more practical: which clouds, in what combination, and how do you operate the result without losing your mind? Multi-cloud and hybrid architectures are how serious organizations answer that question. They distribute workloads across providers and on-premises infrastructure for resilience, cost optimization, and strategic flexibility – but they introduce a new class of problems that single-cloud architectures never face.

Cloud Operations and DevOps Practices

Fri, 26 May 2023 09:00:00 +0000

In 2017 GitLab lost six hours of database state. An engineer, exhausted, ran rm -rf on the wrong server during an incident. The backup procedures had silently been broken for months; nobody noticed because no one was restoring from backups. The lesson is not “be careful with rm”. The lesson is that operations is a system - tools, runbooks, monitoring, automation, and the rituals around them. When the system is healthy, no single tired engineer can take down production. When the system is rotten, every late-night fix is one keystroke from disaster.

Cloud Security and Privacy Protection

Sun, 07 May 2023 09:00:00 +0000

In 2019 Capital One lost a hundred million customer records. The exploit chain was small: a misconfigured WAF allowed server-side request forgery against the EC2 metadata endpoint, that endpoint handed back IAM credentials, and the IAM role those credentials belonged to had wildcard s3:* on every bucket in the account. One misconfiguration, one over-broad role, one rule the security team had not written. The bill, before legal: more than 80 million dollars.

Cloud Network Architecture and SDN

Tue, 18 Apr 2023 09:00:00 +0000

A cloud platform is, in the end, a network with computers attached. The compute layer scales by adding boxes; the storage layer scales by adding disks; the network layer is what makes those boxes and disks behave as a single coherent system. Get the network right and the rest of the stack feels effortless. Get it wrong – a missing route, a 5-tuple mismatch on a security group, an under-provisioned load balancer – and the whole platform goes dark.

Cloud Storage Systems and Distributed Architecture

Thu, 30 Mar 2023 09:00:00 +0000

When Netflix stores petabytes of video, when Instagram serves billions of photos, when a quant fund replays a year of market data in minutes – behind every one of these workloads is a distributed storage system. Storage looks deceptively simple from a developer’s window (PUT key, GET key), but the moment you cross the boundary of a single machine, you inherit a stack of problems that has driven decades of research: how to survive disk failures, how to scale linearly, how to provide a consistency model that does not surprise the application, and how to do all of this while paying cents per gigabyte rather than dollars.

Cloud-Native and Container Technologies

Sat, 11 Mar 2023 09:00:00 +0000

The shift from monolithic applications to cloud-native architectures is one of the most consequential changes in software engineering this decade. The headline – containers and Kubernetes – is well known. The interesting story is why this stack won, what each layer actually does, and where the seams are that determine whether your platform feels effortless or feels like a maze.

This article walks the cloud-native stack from first principles. We start with the architectural shift that motivates everything else, then dig into what a container really is at the Linux kernel level, climb up to Kubernetes orchestration, examine when a service mesh earns its complexity, and finish with packaging and delivery via Helm and GitOps. Examples are deliberately concrete: copy-pastable Dockerfiles, real manifests, and the trade-offs that matter when you run this in production.

Virtualization Technology Deep Dive

Mon, 20 Feb 2023 09:00:00 +0000

Without virtualization, there is no cloud. Every EC2 instance, every Lambda invocation, every Kubernetes pod ultimately stands on the same trick: lying convincingly to an operating system about the hardware underneath it. This article walks the full stack – from the CPU instructions that make the trick cheap, through the four hypervisors that dominate the market, to the production-grade tuning knobs that decide whether your VMs run at 70 % or 99 % of bare metal.

Cloud Computing Fundamentals and Architecture

Wed, 01 Feb 2023 09:00:00 +0000

Every team building software in 2025 inherits the same buy-or-rent question their predecessors faced – only the answer has flipped. Twenty years ago you put hardware in a closet; today you describe the hardware in YAML and a global provider conjures it up in seconds, bills it by the second, and tears it down when you stop paying. Cloud computing is not just “someone else’s computer”. It is a programmable, metered, multi-tenant abstraction over compute, storage and networking that has fundamentally changed how businesses are built and how engineers spend their day.