Cloud-Computing on Chen Kai Blog

Cloud Computing (8): 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 evolved into something more practical: Which clouds, in what combination, and how do you manage them 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 Computing (7): 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 Computing (6): 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 Computing (5): Cloud Network Architecture and SDN

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

A cloud platform is essentially a network with attached computers. The compute layer scales by adding servers; the storage layer scales by adding disks; the network layer integrates these into 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 in a security group, or an under-provisioned load balancer — and the whole platform goes dark.

Cloud Computing (4): 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 Computing (3): 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.

Cloud Computing (2): 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 (1): 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.