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Niu Liu

A slightly rustic name 🤠 A tech veteran navigating the internet wave Hardcore tech: fixing all bugs and tough challenges

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Latest from Niu Liu

25 recent articles

Niu Liu

Jul 5, 2026 · Databases

DSP’s Shift from Single‑Node to Distributed: A Deep Look at Its gRPC Cluster Architecture

The article dissects DSP’s transition from a single‑node database to a distributed system, detailing the gRPC‑based cluster communication skeleton built in dsp‑raft and dsp‑register, the three node roles, GrpcServer/GrpcClient abstractions, proto services, the registration workflow, and the missing heartbeat, node‑discovery and Raft consensus components that must be added for a full‑featured distributed storage engine.

Raftcluster communicationdistributed database

0 likes · 12 min read

DSP’s Shift from Single‑Node to Distributed: A Deep Look at Its gRPC Cluster Architecture

Niu Liu

Jul 5, 2026 · Databases

How to Build a MySQL Protocol Server from Scratch for the DSP Database

This article walks through the complete implementation of a MySQL‑compatible front‑end protocol in the DSP (Sloth) database, covering why MySQL compatibility matters, Netty pipeline design, packet framing, three‑step handshake, two‑level command routing, result‑set encoding, length‑encoded integers, variable substitution, and current limitations.

DSP DatabaseLengthEncodedIntegerMySQL Protocol

0 likes · 10 min read

How to Build a MySQL Protocol Server from Scratch for the DSP Database

Niu Liu

Jul 4, 2026 · Backend Development

Designing an E‑commerce Pricing Engine with Aviator Rule Engine

The article explains how a unified ActivityBO model and three Aviator rule‑chains (check, compute, show) were used to build a flexible pricing‑engine middle‑platform that handles 40+ promotion types, solves allocation precision, supports self‑service configuration, and dramatically reduces deployment time for e‑commerce businesses.

AviatorPricing Enginebackend architecture

0 likes · 13 min read

Designing an E‑commerce Pricing Engine with Aviator Rule Engine

Niu Liu

Jul 1, 2026 · Backend Development

E‑commerce Pricing Engine Architecture: Promotion Calculation Using Aviator Rule Engine

This article details the design of an e‑commerce pricing engine that processes shopping‑cart items and multiple promotional activities through a three‑stage workflow, copy‑on‑trial execution, configurable Aviator rule chains, and a two‑phase discount sharing algorithm, with code examples and engineering considerations.

AviatorBackenddesign patterns

0 likes · 11 min read

E‑commerce Pricing Engine Architecture: Promotion Calculation Using Aviator Rule Engine

Niu Liu

Jun 29, 2026 · Big Data

Designing a Management Backend for Real‑Time Data Warehousing with Flink + Paimon (Part 1)

The article explains why small‑to‑medium teams need a unified web‑based management console for Flink + Paimon real‑time data warehouses, outlines the operational pain points of current script‑driven workflows, and details the proposed solution’s core modules, tech stack, and role‑based access design.

Backend ManagementFlinkPaimon

0 likes · 8 min read

Designing a Management Backend for Real‑Time Data Warehousing with Flink + Paimon (Part 1)

Niu Liu

Jun 29, 2026 · Big Data

Designing a Real‑Time Data Warehouse Backend with Flink and Paimon for SMBs

The article walks through the architecture and core workflow of a lightweight real‑time data warehouse built on Flink and Paimon, covering service‑layer refactoring, CDC task lifecycle, dual Flink submission modes, metadata synchronization, and layered security measures for small‑to‑medium enterprises.

CDCFlinkPaimon

0 likes · 11 min read

Designing a Real‑Time Data Warehouse Backend with Flink and Paimon for SMBs

Niu Liu

Jun 25, 2026 · Backend Development

Don’t Mix Them Up: When to Use RPC, MQ, or Offline Scripts

The article breaks down three fundamental mechanisms—synchronous RPC, asynchronous MQ, and offline scripts—by comparing their lifecycles, IO models, bottlenecks, and consistency guarantees, and provides a concrete decision framework for choosing the right tool for different business scenarios.

Batch ProcessingRPCconsistency

0 likes · 12 min read

Don’t Mix Them Up: When to Use RPC, MQ, or Offline Scripts

Niu Liu

Jun 24, 2026 · Databases

Splitting an Order Database into Hot and Cold Stores: Our Practical Approach

The article details how an e‑commerce platform re‑architected its order database by separating recent data into a hot store and historical data into a cold store, describing the motivations, design principles, write and read routing, downstream impacts, consistency safeguards, risks, and observed performance improvements.

BinlogDatabase ShardingOrder Management

0 likes · 8 min read

Splitting an Order Database into Hot and Cold Stores: Our Practical Approach

Niu Liu

Jun 22, 2026 · Artificial Intelligence

Hands‑On Underground Personnel Control in Coal Mines with YOLOv8 and ReID

The article details a full‑stack solution for real‑time underground personnel monitoring in coal mines, covering why identity recognition is needed, the YOLOv8‑based detection pipeline, OSNet‑based ReID, edge‑box hardware choices, deployment costs, and practical pitfalls learned over two years of field work.

Coal Mine SafetyComputer VisionReID

0 likes · 12 min read

Hands‑On Underground Personnel Control in Coal Mines with YOLOv8 and ReID

Niu Liu

Jun 21, 2026 · Operations

10 AM System Auto‑Paid ¥600K: A Full Post‑mortem of a Commission Settlement Incident

At 10 am a monitoring alarm revealed that the day's commission settlement jumped to ¥600 K—seven times the usual amount—prompting an immediate shutdown of withdrawals, a rapid root‑cause investigation that uncovered a missing else‑if condition, and a nine‑hour data rollback followed by the launch of a real‑time business monitoring platform.

Operationsbusiness monitoring platformcommission settlement

0 likes · 9 min read

10 AM System Auto‑Paid ¥600K: A Full Post‑mortem of a Commission Settlement Incident