This article explains why traditional macro performance metrics are insufficient, introduces ten essential micro‑metrics covering memory, thread, and network aspects, and shows how to capture them using GC logs, thread dumps, and tools like netstat or open‑source APM solutions.
This article explains the differences between user space and kernel space in Linux, describes process and interrupt contexts, outlines how the kernel manages memory and execution modes, and clarifies related concepts such as kernel/user mode, context switches, and the system’s virtual address layout.
This article explains the concept of cosine distance, compares it with Euclidean distance, discusses when cosine similarity is preferable, and shows why cosine distance does not satisfy all metric axioms, providing examples and interview‑style analysis.
This article walks through the development of a Vue‑based single‑page application for the JD Car Maintenance project, covering why Vuex was chosen, its core concepts, store implementation, state persistence, cross‑origin handling, Axios/JSONP requests, code refactoring, lazy loading, and component extraction to improve maintainability and performance.
This article explains how to extend a red‑black tree with a subtree‑size counter to support O(log n) rank and selection operations, detailing the required count updates during insertion, deletion, and tree rotations, and provides complete pseudocode for left/right rotations, rank queries, and element‑by‑rank retrieval.
The article outlines seven common big‑data initiatives—data integration, specialized analytics, Hadoop‑as‑a‑service, stream processing, complex event handling, ETL pipelines, and SAS replacement—explaining their goals, typical technologies such as HDFS, Hive, Spark, Storm, Kafka, and practical considerations for enterprises adopting Hadoop ecosystems.
The article describes the requirements, architecture, data‑sync strategy, monitoring, and operational workflow of a search open platform that enables fast, zero‑code creation of searchable interfaces, supporting real‑time indexing, customizable ranking, and extensible backend services.
This article shares the author's experience and lessons learned from a two‑day intensive discussion on microservice migration, outlining a concrete implementation plan, current architectural challenges, key debates, and the final target architecture blueprint for a third‑party payment company.
This tutorial walks through using Python's urllib and regular expressions to crawl a Baidu Tieba page, extract all .jpg image URLs, and download each image locally with a sequential naming scheme.
The article recounts the evolution of Google's Test Certified (TC) program from its 2006 inception, explains its three (later five) certification levels, outlines the informal certification process, and discusses the program’s impact, challenges, and cultural significance within Google’s engineering teams.
This article introduces Google’s ARCore platform, compares it with Apple’s ARKit, explains its relationship to Tango, details its core capabilities such as motion tracking, environmental understanding and light estimation, showcases several demo experiences, and outlines the key ARCore API components for developers.
Alibaba's R&D efficiency team explains how intelligent operations—spanning resource planning, change management, monitoring, stability, and one‑click site building—are being transformed from manual tooling to automated, AI‑driven DevOps practices to boost efficiency, cut costs, and ensure high availability at massive scale.
This article surveys the most essential Python packages for data science in 2017, covering core scientific computing, data manipulation, visualization, machine learning, deep learning, natural language processing, and web scraping, and explains why each library remains indispensable for modern analysts.
This article explains the concept of load balancing, compares HTTP redirection, DNS load balancing, reverse proxy, and various LVS methods (NAT, Direct Routing, IP Tunnel), discusses their advantages, limitations, configuration steps, and practical considerations for building scalable server architectures.
This article explains Java HashMap internals by walking through a concrete Country‑key example, illustrating how keys are hashed, stored in an internal Entry array, and how the put and get methods handle collisions using linked lists, complemented by full source code snippets.
The article chronicles Google’s Test Certified initiative from its 2006 inception, detailing its three original levels, certification process, expansion efforts, cultural impact, and both positive and negative aspects, illustrating how a grassroots testing program reshaped engineering practices and code quality across the company.
At PyCon China 2023, Dada‑JD Daojia’s algorithm team presented their AI‑driven practices for dynamic pricing, route planning, and order assignment, detailing how multi‑dimensional supply‑demand balancing, genetic‑algorithm‑based TSP solutions, and multi‑objective optimization improve real‑time logistics efficiency.
This article shares practical Go microservice building experiences, covering gRPC-based communication, TLS security, request tracing, and comprehensive monitoring with Prometheus, including metric selection, alerting, and log management using Logrus and Graylog, to help reduce coupling and improve system observability.
This guide explains the factors that affect MySQL INSERT performance and presents a collection of practical techniques—including multi‑row INSERT, bulk_insert_buffer_size tuning, INSERT DELAYED, LOAD DATA INFILE, table creation with disabled keys, LOCK TABLES, and the proper use of IGNORE and ON DUPLICATE KEY UPDATE—to dramatically speed up large‑scale data loading.
This article explains why native WebGL line drawing is insufficient for map engines and presents a shader‑based approach that splits lines into triangles, handles custom line widths, line joins, dash patterns, and anti‑aliasing to achieve consistent, high‑quality map rendering.
