This article presents a comprehensive, four‑stage roadmap for backend developers, covering foundational Go knowledge, engineering best practices, advanced system architecture, and expert‑level soft skills, offering practical guidance for career growth and technical mastery.
This article explains the internal workings of HashMap traversal in Java, showing why using keySet() results in two passes—first converting to an iterator and then fetching values—and details the underlying iterator, KeyIterator, and HashIterator implementations with code examples.
When Tubi upgraded from Node.js 14 to 20, server‑side requests began returning 404 errors, leading to a deep investigation that uncovered how the Request library and Sentry SDK altered HTTP module arguments, causing the built‑in URL detection to misclassify plain objects as URLs.
The article chronicles Bilibili’s voice‑chat room transformation from a simple one‑to‑one live‑streaming setup to a scalable multi‑host RTC system, detailing the new session‑channel model, server‑driven mic‑seat management, extensive monitoring, state‑synchronization techniques, revenue‑engine integration, domain‑driven design, and continuous‑delivery practices.
An urgent overnight incident revealed a MySQL server’s CPU soaring to 400% due to poorly written queries, prompting a detailed analysis of execution plans, identification of costly operations like filesort and temporary tables, and concrete recommendations for query and team improvements.
This article explains why asynchronous processing is needed in evolving systems, outlines the goals of guaranteeing execution without blocking the main flow, and walks through a complete SDK design that uses Spring transaction events, Kafka, XXL‑Job, MySQL, and a Vue UI, including configuration, code snippets, and deployment details.
This comprehensive guide explains Java's collection framework, covering the core interfaces Collection, List, Set, and Map, their abstract and concrete implementations, iterator mechanisms, and key differences that are essential for both interview preparation and real‑world backend development.
This tutorial guides you step‑by‑step through creating a basic PHP MVC framework, covering MVC concepts, Composer setup, project structure, core components like routing and controllers, view rendering, model creation, and testing the application with the built‑in PHP server.
This article explains how duplicate form submissions occur, outlines common prevention techniques such as token validation and timestamp checks, and demonstrates a practical SpringMVC interceptor implementation with token storage and scheduled cleanup to ensure request uniqueness and reduce server load.
This article details the complete redesign of QQ Browser's content ingestion system, explaining why the original micro‑service architecture caused low efficiency and performance, and how a zero‑base redesign using a monolithic service, plugin framework, fault‑tolerant pipelines, and thread separation dramatically improved throughput, latency, and developer productivity.
This article explains the Chain of Responsibility design pattern and demonstrates how to apply it in a Java backend to evaluate login risk factors such as password errors, unusual login times, IP whitelist violations, and abnormal login locations, providing full code examples and execution flow.
This article introduces LiteFlow, a lightweight and fast component‑based rule engine that decouples complex business logic, explains its design principles, demonstrates usage in both non‑Spring and SpringBoot environments with Maven dependencies and XML configurations, and delves into its core components and execution flow through detailed source code analysis.
This article explains the concept of request merging for high‑concurrency web services, outlines its advantages and drawbacks, and provides a complete Java implementation using ScheduledExecutorService, a memory queue, and a generic BatchCollapser utility with usage examples.
This article examines the causes of Java OutOfMemoryError in a distributed backend service, analyzes MyBatis-related memory leaks, demonstrates a reproducible scenario with large SQL concatenations and multithreading, and offers practical mitigation strategies to prevent heap and metaspace overflow.
This article explains what a service gateway is, why it is needed in microservice architectures, its core functions such as routing, authentication, monitoring and rate limiting, and provides practical technology choices like Java, Spring Boot, Zuul, Consul, JWT, Prometheus, Grafana, ELK and JMeter.
This article explains how to replace repetitive try‑catch blocks in Spring applications with a clean, assertion‑based approach combined with @ControllerAdvice and enum‑driven error codes, providing a unified way to handle service‑layer, controller‑layer, and unknown exceptions while keeping responses consistent and internationalized.
This article explains RocketMQ's core components, the differences between push and pull consumption modes, and how the framework implements a pseudo‑push mechanism using long polling, including detailed code analysis of the consumer and broker side processes.
This article explains the challenges of data permission control in multi‑system environments, outlines a unified RBAC‑based model with extensible dimensions, and provides a step‑by‑step integration guide and SDK implementation for Java backends, including code snippets and practical considerations.
This article details Qunar's systematic approach to reducing service complexity and code volume by half, covering background challenges, two‑phase planning, criteria for merging or deleting services, tooling such as Serviceability Agent for method‑level analysis, automated and semi‑automated deletion workflows, verification steps, and the measurable performance gains achieved.
This article reviews the most widely adopted Java language enhancements introduced after Java 8, covering features such as local variable type inference, switch expressions, text blocks, records, pattern matching for instanceof, sealed classes, and improved NullPointerException messages, helping developers decide which upgrades to adopt.
This article details the design and implementation of the Pylon APM monitoring platform for NetEase Cloud Music, covering background challenges, the choice of Pinpoint, extensions to trace models, tail‑based exception sampling, Prometheus integration, automated JStack collection, and the resulting APM product features.
Although many developers avoid using thread pools in business code, this article explains how thread pools already exist in web containers and RPC frameworks, why inserting custom pools can backfire, and when proper tuning or message queues are the better solution for improving throughput.
The Shenzhen recap of Pupu's 12th server‑side tech salon presents three technical talks covering order transaction system design, community comment‑moderation architecture, and customer‑service platform engineering, highlighting practical challenges, solution strategies, and key architectural decisions.
This guide introduces the PEST PHP testing framework, explains its key features and expressive syntax, and demonstrates how to write tests using the “it” and “test” functions with practical code examples for common arithmetic operations.
This guide demonstrates how to use Python's ItChat library to programmatically send text, image, and video messages to multiple WeChat contacts, including code examples, setup instructions, and troubleshooting tips for Windows environments.
This article presents a comprehensive, step‑by‑step roadmap for backend engineers, covering everything from basic Go language concepts, data structures, and OS fundamentals to advanced microservice design, high‑performance networking, scalability, reliability, security, DevOps practices, team and product management, and real‑world project execution.
The article explains why forcibly stopping a Java thread is unsafe, outlines common scenarios that require thread exit, compares graceful and forced termination, and presents practical techniques such as flag checks and Thread.interrupt() to achieve safe and predictable thread shutdown.
This article introduces several essential PHP array functions—including array_push, array_pop, array_shift, array_unshift, and array_reverse—explaining their usage, parameters, and effects with clear code examples to help developers manipulate arrays efficiently.
This article compiles a variety of Python web‑scraping utilities—including file download assistants, video downloaders, proxy IP pool builders, captcha bypass scripts, and game data extractors—providing descriptions, installation commands, usage examples, download links, and reference links for each tool.
A scheduled task system that frequently accesses MySQL and cache crashes at night due to a SIGSEGV in the HotSpot JVM caused by JIT compilation of hotspot code, and the article explains the JVM internals, JIT behavior, and provides configuration and driver downgrade solutions to prevent the failure.
This article explains Netty 4's global multithreaded, locally single‑threaded (event‑loop) design, detailing boss and worker EventLoopGroups, the internal structure of NioEventLoop, channel binding, task queues, pipeline handling, and best practices for avoiding blocking operations, with a RocketMQ example.
The article details the motivation, design, architecture, key features, deployment workflow, and future roadmap of Ctrip's PGClowcode low‑code platform, which enables rapid visual development of backend pages through a front‑end React UI and a Spring WebFlux backend, addressing common challenges in large‑scale internal tool development.
This article explains how to improve PHP application response speed and throughput through code, configuration, and server optimizations, covering caching strategies, precompilation, efficient data structures, loop reduction, high‑performance servers, and profiling tools such as XHProf and Blackfire.
This guide explains how to compile the PHP Curl extension with experimental HTTP/3 support, detect whether Curl supports HTTP/3, and use PHP code to issue HTTP/3 requests, including required libraries, build steps, and practical code examples.
This article describes the background, goals, architecture, and implementation details of a low‑code data platform that enables fast creation, configuration, and execution of data‑related tools for testing, development, and operations, highlighting its component library, rule engine, security, version control, and measurable efficiency gains.
This article examines the pitfalls of using SpringBoot's @ControllerAdvice and @ExceptionHandler for global exception handling, illustrates common issues across controller, service, and data layers, and proposes more precise logging and debugging strategies to improve error traceability and maintainability.
This article details how Vivo identified heavy CPU usage in Dubbo's routing and load‑balancing modules, applied asynchronous processing, cache‑based routing, disabled unused routers, and introduced grouping strategies, resulting in over 100% TPS gains and significant CPU reductions for large service clusters.
An extensive backend development roadmap, distilled from a decade of experience at a leading tech firm, guides engineers through foundational Go concepts, system design, microservices, performance optimization, DevOps, security, and leadership skills, offering a structured path from junior to expert level.
The article introduces mica-mqtt, a Java AIO‑based open‑source MQTT component offering simple, low‑latency, high‑performance IoT messaging, outlines its extensive feature set, typical use cases, recent updates, and provides detailed configuration examples for custom business thread pools and Spring Boot integration.
This article explains how tldb implements distributed locks, details the lock, tryLock, and unlock APIs, and provides step‑by‑step Go and Java code examples—including blocking, non‑blocking, and spin‑lock patterns—plus test results to illustrate correct usage.
This article explains the principle of pagination and provides three reusable PHP functions—get_total_pages, get_offset, and generate_pagination—along with example code to calculate total pages, determine record offsets, and render a navigation bar for efficient web page data paging.
This article explains how to use JaCoCo probes to analyze online Java code execution, identify and remove zombie code, and improve development efficiency through detailed steps including Maven dependencies, a REST dump endpoint, javaagent configuration, script automation, and coverage analysis results.
This article explains how Nginx's ip_hash directive implements session affinity by routing all requests from the same client IP to a single backend server, provides configuration examples, discusses practical pitfalls, and shares real‑world test results.
This guide shows how to clone the SmallChat repository, compile the C source with gcc, launch the server binary, and connect via telnet to test the default 7771 port, including code snippets and command‑line examples.
The article presents Baidu’s Aladdin vertical search product and introduces the tanGo framework, which abstracts search pipelines into resources, cards, and scenes, enabling configuration‑driven, graph‑based resource scheduling for single results, demand clusters, and groups, while measuring scale, efficiency, and user satisfaction.
This article explains PHP callback functions, covering their definition, types such as regular, anonymous, and static methods, typical use cases like event handling, asynchronous and functional programming, and provides clear code examples with important precautions and advantages.
This article explains PHP closure functions, covering their definition, typical use cases such as event handling, asynchronous and functional programming, detailed syntax examples, usage patterns, precautions, advantages, and a practical example of handling asynchronous results.
This article explains why software architecture matters, defines the essence of Clean Architecture, compares it with Hexagonal and DDD layered models, and walks through a practical, step‑by‑step process—from business analysis and domain modeling to layer implementation and code examples—showing how to reduce complexity and maintenance cost.
The article describes the design background, overall architecture, management backend, and header/footer client implementations (Nginx and Java) of JD's unified header/footer management system, explaining how it enables rapid, centralized updates of site-wide header and footer content across hundreds of services.
This article explains how to develop a recharge feature for WeChat Mini Programs using PHP, covering the setup of payment parameters, generating prepay orders, invoking wx.requestPayment, and handling payment callbacks with example code.
This article demonstrates how to invoke external services from a Spring Boot application by using raw HttpClient, the RestTemplate utility, and Feign client, providing complete code examples, configuration steps, and tips for handling headers and tokens.
The phpBB forum software released version 3.3.11 on October 22, raising the minimum PHP requirement to 7.2 for better PHP 8 compatibility, adding search index progress bars, improving deprecated function handling, and strengthening security with CAPTCHA attempt limits.
This tutorial explains how to build a PHP‑based ChatGPT chatbot, covering environment setup, API key acquisition, library installation, core code implementation, a simple web interface, and steps to run and extend the application.
To overcome storage, compute, and I/O bottlenecks in Bilibili’s risk‑control engine, the team combined pre‑fetching with Redis caching, batch retrieval, asynchronous writes via Railgun, aggressive log compression, and a multi‑level cache plus Bloom filter, cutting latency to sub‑100 ms, reducing Redis QPS by over 90 % and storage by ~38 %, while supporting million‑level query throughput.
The article explains the architecture of an online advertising system, detailing the roles of ad placement and playback, the design of coarse ranking modules, budget pacing mechanisms, and pricing algorithms that aim to maximize ROI while controlling costs.
This article explains the importance of timezones in PHP date and time processing, demonstrates how to use date_default_timezone_get() and date_default_timezone_set() with code examples, and outlines practical scenarios for retrieving and managing the default timezone.
This article explains Java's Error and Exception hierarchy, differentiates compile-time and runtime exceptions, demonstrates standard try‑catch handling, shows how to throw custom exceptions, and introduces custom assertion interfaces that combine readable assertions with tailored exception types for cleaner backend code.
This article explains PHP 8’s new Attributes feature, describing what attributes are, how to attach custom attributes such as @Table and @Route to classes and methods, and demonstrates retrieving attribute values via reflection, providing clear code examples for backend developers.
This article explains the thundering herd effect, walks through Nginx's master‑worker architecture and its use of epoll, and compares three practical solutions—accept_mutex, EPOLLEXCLUSIVE, and SO_REUSEPORT—to eliminate wasted wake‑ups in high‑concurrency servers.
This article explains how to extract a particular key from each JSON object in a list, optionally filter out unwanted entries, and download images from URLs using Python's requests and os modules, providing complete example code for both tasks.
This article explains why excessive try‑catch blocks hurt readability, introduces Spring's @ControllerAdvice and custom Assert utilities combined with enums to create a clean, centralized exception handling framework, and demonstrates the approach with full code examples and practical test scenarios.
Rate limiting controls request flow to protect system stability, covering its definition, motivations, common algorithms such as token bucket, leaky bucket, fixed and sliding windows, their pros and cons, single‑machine vs distributed implementations, and practical component choices for backend services.
This article introduces PHP 8’s new Stringable interface, explains its purpose, shows how to implement it with example code, and demonstrates its seamless integration with common string functions such as str_replace, strlen, and substr for more concise string handling.
This article explains the thundering herd phenomenon in multi‑process servers, walks through Nginx’s master‑worker architecture and its use of epoll, and compares three practical mitigation techniques—accept_mutex, EPOLLEXCLUSIVE, and SO_REUSEPORT—complete with code excerpts and configuration examples.
This tutorial provides an in‑depth guide to Spring Boot covering core concepts such as project setup, configuration files, logging frameworks, MVC architecture, CRUD examples, error handling, embedded servlet containers, Docker integration, JDBC/MyBatis/JPA data access, startup process, and how to create custom starter modules.
This article introduces a simplified Seckill (flash‑sale) system built with SpringBoot, detailing its overall architecture, key backend techniques such as distributed sessions, Redis caching, RabbitMQ asynchronous ordering, security measures, oversell prevention, rate limiting, and provides essential code snippets and deployment screenshots.
This guide explains the distinction between exceptions and errors in PHP, shows how to install the Tinywan exception‑handler package, configure it for Webman, use built‑in and custom exception classes, customize JSON responses, and extend the handler for advanced scenarios such as DingTalk notifications.
This article explores multiple strategies for enabling fuzzy search on encrypted phone numbers, including in‑memory caching, database decryption functions, segment‑wise storage, and dedicated fuzzy‑search fields, comparing their trade‑offs in performance, memory usage, and data consistency.
This article explains what a 502 Bad Gateway error means, why it is usually generated by a reverse‑proxy like nginx, and provides step‑by‑step methods to identify common causes such as backend timeouts, process crashes, and misconfigured upstream servers.
This article explains the fundamentals and types of MySQL indexes, provides guidelines for selecting appropriate indexes based on query frequency, uniqueness and complexity, and presents PHP code examples for adding and using indexes, along with optimization strategies such as proper schema design, data types, and index maintenance.
This guide explains the concepts of ZooKeeper cluster roles and provides step‑by‑step instructions, including configuration file edits and command‑line operations, to set up a pseudo‑cluster on a single machine for testing and learning purposes.
The article examines various delayed‑task solutions for order timeout handling in Java, including database polling with Quartz, JDK DelayQueue, Netty's HashedWheelTimer, Redis sorted‑set and key‑space notifications, and RabbitMQ delayed queues, analyzing their implementation steps, advantages, and drawbacks.
This article demonstrates how to implement a statistical query on a student_score table using three ORM frameworks—Fluent Mybatis, native Mybatis, and Mybatis‑Plus—showing code examples, configuration steps, and a side‑by‑side comparison of their ease of use and generated code.
This article explains how to use Redis BitMap to build a memory‑efficient sign‑in feature and continuous‑sign‑in statistics in a Spring Boot microservice, covering basic BitMap commands, key design, core Java code, testing steps, and a bitmap‑based solution for cache‑penetration protection.
The article recounts a developer's painful experience with un‑preheated Redis cache that caused severe latency spikes, then outlines practical cache warm‑up techniques such as gray‑release traffic, database scanning, and ETL‑driven data pipelines to prevent performance degradation and cache snowball effects.
This article explains Java annotations, their purposes such as providing compiler metadata, generating code, runtime processing, and documentation, introduces built‑in and meta‑annotations, and demonstrates how to create and use custom annotations both via reflection and with Spring AOP for logging, including full code examples.
This article explains why upgrading from JDK 8 to JDK 11 is worthwhile, details performance gains, new language and API features, garbage‑collector improvements, modularization concepts, step‑by‑step migration procedures, common pitfalls, and practical verification methods.
This article reviews the most important PHP 8.3 enhancements—including typed class constants, dynamic class constant access, a native json_validate() function, improved unserialize() error handling, read‑only property cloning support, and typed constants—showing code examples and practical usage tips.
This article explains what logs are, why they are crucial for debugging, monitoring and auditing, when to record them, the fundamental principles and level conventions, and provides concrete best‑practice recommendations and code examples to help Java developers implement robust, secure, and efficient logging.
The article explains why high‑frequency disk reads can become a performance bottleneck, introduces common caching patterns such as Cache‑Aside, Read‑Through, Write‑Through and Write‑Behind, discusses consistency problems, cache penetration and avalanche, and presents practical solutions like null‑caching, Bloom filters, distributed locks, staggered TTLs, Redis‑Cluster and Hystrix.
This article provides a comprehensive overview of Spring Framework utility classes—including Assert, ObjectUtils, StringUtils, CollectionUtils, FileCopyUtils, ResourceUtils, StreamUtils, ReflectionUtils, and AopUtils—explaining their purpose, key methods, and usage examples with code snippets for backend developers.
This article examines the evolution of Trip.com’s ticket product structure, detailing its transition from low to high‑level schema, the technical challenges faced across user, merchant, platform and R&D perspectives, and the systematic solutions—including structure integration, sales‑attribute standardization, and description‑attribute layering—that improved efficiency, data quality, and internationalization.
This article explains what ZooKeeper is, describes its data model and four znode types, introduces the watch mechanism, and provides step‑by‑step commands for installing ZooKeeper, creating nodes, and verifying the service on a Java‑enabled machine.
This article explains how Volcano Engine identified the tangled authorization, data‑fetching, and performance problems of its advertising AB‑testing platform and refactored it by splitting services, redesigning the data model with MySQL and ClickHouse, applying DAG scheduling, time‑wheel algorithms, Domain‑Driven Design, and rigorous unit testing to achieve a more stable, extensible backend solution.
This tutorial demonstrates how to use Redis' GEO data structure together with Docker, RedisInsight, and a NestJS backend to store location data, perform distance calculations and radius searches, and finally display nearby points on a web map using AMap and Axios.
This article explains the fundamental asynchronous messaging patterns, compares RabbitMQ and Apache Kafka in terms of architecture, queue and pub/sub models, and provides guidance on selecting the appropriate technology for different backend scenarios.
This article enumerates and explains sixteen Spring and SpringBoot extension interfaces, illustrates their positions in the bean lifecycle with a call‑order diagram, and provides concrete usage scenarios and code samples so developers can harness these hooks to write more elegant and maintainable applications.
This article compares Java-WebSocket and Netty-WebSocket implementations by examining their thread models, running single‑connection and high‑connection benchmarks (including a Go WebSocket server), and summarizing the performance and resource‑usage differences observed.
This article presents a complete Netty TCP long‑connection demo built with Spring Boot 2.2.0 and Redis, explains the project architecture, module layout, business flow using a local BlockingQueue instead of RocketMQ, and provides detailed source code for the queue holder, processing logic, client implementation, handler, and test controllers.
This article outlines the goals, evolutionary stages, functional and non‑functional requirements, and detailed component design of a unified enterprise notification system that supports multiple channels, high performance, scalability, and seamless integration for modern distributed applications.
This article details how to dramatically improve the performance of a million‑level QPS Java service by reusing a singleton HttpClient, enabling keep‑alive connection pooling, and handling responses efficiently, cutting average request time from 250 ms to about 80 ms.
This article explains why rate limiting is essential for high‑traffic Java services, compares common strategies such as Hystrix, Sentinel, token‑bucket algorithms, and Redis‑based counters, and provides concrete Spring‑Boot code examples for implementing both local and distributed throttling.
This article demonstrates how to implement a captcha‑based login mechanism in a Spring Boot application with a front‑end/back‑end separation, detailing the traditional session‑based approach, the new Redis‑backed token solution, and providing complete code examples for configuration, service, controller, and data objects.
This article presents a self‑developed automated testing platform for backend services that achieves full test‑case coverage with low maintenance cost by unifying HTTP and RPC access, introducing a parameter‑pool, integrating JSON Schema and JSONPath validation, and leveraging traffic‑driven test‑case generation and scheduling.
This article explains the various scheduled tasks in RocketMQ, covering architecture overview, producer and consumer periodic operations, broker maintenance jobs, and NameServer housekeeping, while providing concrete Java code examples to illustrate how each task contributes to message handling, monitoring, and system reliability.
This article explains the concept, advantages, and drawbacks of request merging, and provides a complete Java implementation using ScheduledExecutorService, a memory queue, and generic batch handling interfaces, along with usage examples and sample code.
This article explains the initialization order of Java classes, the pitfalls of using @Autowired for dependency injection, compares it with @Resource, and demonstrates setter, constructor, and Lombok-based injection methods with code examples to help avoid null‑pointer exceptions and improve coupling.
This article explains why MySQL LIKE queries struggle with large datasets, introduces Elasticsearch and Sphinx as powerful PHP search engine alternatives, and provides step‑by‑step PHP code examples for setting up indices, adding documents, and performing full‑text searches.
This article explains how Nginx's ip_hash directive implements session affinity by routing all requests from the same client IP to a single backend server, demonstrates configuration examples, analyzes behavior when servers go down, and discusses the method's limitations such as load imbalance and dynamic IP issues.
This article introduces several widely used PHP web frameworks—ThinkPHP, Laravel, Yii, CodeIgniter, Webman, and Hyperf—detailing their design philosophies, key features, performance characteristics, and typical use cases for modern backend development.
