This article traces the evolution of HTTP from its 1991 origins through HTTP/2 and HTTP/3, explains how QUIC leverages UDP to reduce latency, and details QUIC's connection establishment, migration, head‑of‑line blocking mitigation, congestion control, and flow‑control mechanisms.
This article explains how a legacy task system was redesigned by standardizing incoming messages, introducing a rule engine (QLExpress) for configurable completion conditions, and building a lightweight admin UI, reducing task‑integration time from a week to a few minutes.
This article explains why Spring Cloud Gateway can return duplicate Access-Control-Allow-Origin and Vary headers, analyzes the request processing flow, and provides two solutions—using the built‑in DedupeResponseHeader filter with retention strategies or implementing a custom CorsResponseHeaderFilter—to eliminate the CORS error caused by multiple header values.
This article explains the PHP str_replace() function, covering its syntax, parameter details, return value, and provides three practical code examples—including single, multiple, and case‑insensitive replacements—to help developers master string manipulation in backend development.
This article explains the PHP array_merge() function, shows its syntax, and provides three practical examples—including merging two indexed arrays, merging several arrays, and merging associative arrays—while illustrating the resulting output and key‑overriding behavior.
This article explains the limitations of traditional Cookie+Session authentication, explores distributed session sharing techniques such as replication, sticky sessions, and centralized storage, and demonstrates why using ThreadLocal can simplify user state management in a web application like the Echo project.
This article walks through five practical Spring Boot 3.2.5 enhancements—including collection‑parameter validation, wildcard @PropertySource loading, improved method injection, custom thread‑pool scheduling, and robust Number‑type request handling—showing code examples, console output, and migration tips from older versions.
This technical article describes how a senior architect designed, configured, and migrated loan and repayment application tables to a sharded MySQL setup using ShardingSphere, Spring Boot, and MyBatis‑Plus, covering schema design, historical data sync, dual‑write switches, code integration, and common pitfalls.
This article explains how to build a dynamic IP blacklist that blocks malicious crawlers or users by using Nginx with a Lua access script and Redis for storage, covering requirements, environment setup, design choices, configuration steps, Lua code, and advanced extensions.
In this detailed live interview transcript, a senior engineer questions a recent graduate on topics ranging from Redis data structures and system design to Java concurrency, evaluates the candidate's answers, and provides career advice and hiring recommendations.
This article demonstrates how to automatically embed userId and orderId into Java log statements by defining log placeholders, storing these values in ThreadLocal and MDC, and using a custom @UserLog annotation together with Spring AOP to inject the context without manual code changes.
This article explains the distinction between Java system properties and operating‑system environment variables, shows how to read and set them in Java, and demonstrates advanced techniques using reflection to modify environment variables at runtime for the current process.
This article explains the concept of technical debt, its various classifications, the distinct impacts on front‑end and back‑end development, the multi‑dimensional cost consequences, and practical governance methods—including identification, prioritisation, repayment planning and preventive measures—to help teams manage and reduce debt effectively.
This article demonstrates how to leverage Spring's TransactionSynchronizationManager to detect active transactions and register synchronization callbacks that asynchronously publish payment ledger messages to Kafka after transaction commit, while providing a starter-style library for easy integration.
This article explains how to securely hash passwords in PHP using the password_hash function, demonstrates code examples for hashing and verifying passwords, discusses automatic salting, and highlights best practices for protecting user credentials.
This guide outlines the comprehensive technology stack a full‑stack developer needs, covering front‑end frameworks, back‑end languages and frameworks, databases, mobile development, cloud platforms, UI/UX tools, and DevOps practices for building modern applications.
The article presents MyPerf4J, a Java‑agent based, low‑overhead performance monitoring library that provides real‑time metrics such as method latency, QPS, memory usage, GC statistics, and class loading, along with quick‑start instructions, configuration details, and open‑source links for Java backend services.
This article explains how Java developers can leverage Apache Commons Pool's GenericObjectPool to implement custom process pooling, covering the required factory interface, configuration options, and practical code examples for creating, borrowing, and returning pooled process objects to improve performance.
The article explains the distinction between Service Provider Interfaces (SPI) and Application Programming Interfaces (API), discusses three possible package placements for interfaces, outlines rules and advantages of each, and provides guidance on choosing between SPI and API based on extensibility, interaction, and stability.
This article explains how to enable cross‑server WebSocket communication in a distributed Spring application by using a message queue such as Redis or Kafka, detailing two architectural approaches, concrete code examples, configuration files, and a sample client page.
This article explains why Spring Cloud prefers HTTP over RPC for remote calls, covering the embedded Tomcat architecture, JSON data exchange, the fundamentals of RPC over TCP, and compares their advantages, disadvantages, and suitability for microservice development.
This article explains the PHP file_exists() function, its syntax, parameters, return values, provides example code for checking both files and directories, and lists important usage notes and best practices for reliable file handling.
This article explains how to connect to a MySQL database with mysqli_connect, execute queries using mysqli_query, and fetch each row as an associative array with mysqli_fetch_assoc, providing a complete PHP code example and best‑practice tips.
This article explains how to use PHP's filemtime function to obtain a file's last modification timestamp, demonstrates formatting the timestamp with date, and provides code examples for handling both single and multiple files.
Spring offers multiple HTTP clients—RestTemplate, WebClient, and the newer RestClient—each with distinct features, performance characteristics, and suitability for different scenarios, and this guide compares their core capabilities, advantages, drawbacks, and best-use cases to help developers select the optimal client for their projects.
This article explains why the default Spring Boot show_sql setting only prints SQL to the console, demonstrates its limitations, and provides a reliable approach using Hibernate logging and a datasource‑proxy to capture full SQL statements, parameters, and batch execution details in log files.
To prevent audit pipelines from choking during traffic surges, the article proposes augmenting the classic Chain of Responsibility with a sliding‑window anomaly detector, a statistically‑driven dynamic detector, a rule‑based backflow mechanism, and AI‑powered traffic forecasting, enabling adaptive routing and proactive scaling.
This article explains how to improve the speed and stability of bulk email delivery in modern web applications by using PHP asynchronous coroutines with Swoole, providing a detailed code example that leverages PHPMailer, channels, and coroutine management.
This article details the evolution of Ctrip's vacation product log system—from a simple single‑table DB in 2019, through a platformized ES + HBase architecture with custom RowKey design, to a V3.0 version that adds business and supplier empowerment, scalable storage, advanced search, and flexible data presentation for billions of daily change records.
This tutorial walks through creating a remote procedure call (RPC) system with RabbitMQ in Java, covering client and server design, callback queues, correlation IDs, code examples, deployment steps, scalability benefits, and common pitfalls to avoid.
This article explains the PHP array_merge() function, covering its purpose, syntax, parameters, return values, a complete code example with output, and practical tips for merging arrays in backend development.
This article explains PHP's is_bool() function, its syntax, parameters, return values, and provides a detailed code example demonstrating how to check whether variables are of boolean type, along with analysis of the output and practical usage tips.
This tutorial explains how to use the Ratchet library to create a PHP WebSocket server, covering environment setup, Composer installation, server-side code, a simple HTML/JavaScript client, and steps to run and test real‑time data transmission.
This article outlines essential backend best practices for integrating WeChat Pay v2, covering correct handling of order amounts, trade type fields, second signatures, merchant binding, currency units, duplicate consumption prevention, payment result verification, non‑transactional operation logging, and the unified order API.
This tutorial explains how to implement IP‑and‑URL rate limiting in a Spring Boot application by creating a custom HandlerInterceptor that tracks request counts in Redis, uses a distributed lock to enforce limits, and registers the interceptor to protect services from malicious or excessive traffic.
This article explains how to generate a unique TraceId, propagate it via HTTP headers and SLF4J MDC, integrate the mechanism with Logback, Feign clients, thread pools, and SkyWalking, and details the underlying MDC and Logback placeholder implementations for reliable log tracing in Java backend applications.
This article explains PHP's array_flip() function, detailing its purpose of swapping array keys and values, its syntax, parameter and return information, and provides three practical code examples illustrating its behavior with associative and indexed arrays.
This article explains PHP's versatile date() function, detailing its syntax, required format parameter, optional timestamp argument, and demonstrates numerous usage examples—including retrieving current date, time, individual components, and formatting specific timestamps—highlighting its importance for backend web development.
This guide walks through installing LuaJIT, ngx_devel_kit, lua-nginx-module, compiling Nginx with Lua support, troubleshooting common errors, and adding a Lua-based Web Application Firewall (WAF) on an OpenResty platform.
This article explains the Spring Boot startup mechanism, covering the @SpringBootApplication entry annotation, its constituent annotations, the role of SpringApplication.run, and the step‑by‑step initialization flow that powers Java backend applications.
This article explains how JWT provides stateless user authentication while Session adds an extra security layer and state management, detailing their respective roles, the reasons for using Session alongside JWT, and offering Java code examples that illustrate their combined implementation.
This article explains how to let users upload a JAR containing a custom implementation of a predefined Java interface, then hot‑deploy the JAR by loading it with a URLClassLoader and dynamically registering or deregistering Spring beans using reflection or annotation modes.
This comprehensive guide walks backend architects through six core optimization methods—caching, batch processing, asynchronous handling, data compression, parallelization, and eliminating unnecessary requests—detailing their problem domains, implementation strategies, real‑world scenarios, benefits, and trade‑offs.
The article compares Spring Cloud’s HTTP‑based, Tomcat‑served JSON services with TCP‑based RPC, highlighting HTTP’s cross‑platform flexibility and ease of use versus RPC’s faster, binary‑serialized calls that mimic local methods, and advises choosing HTTP for microservice, loosely‑coupled architectures despite RPC’s speed advantage.
This article explains the PHP file_exists() function, its syntax, parameters, return values, provides example code for checking both files and directories, and lists important usage notes and best practices for reliable filesystem operations.
This article reviews the three most popular PHP frameworks of 2024—Laravel, ThinkPHP, and webman—detailing their key features, performance characteristics, and suitable use‑cases to help developers choose the best fit for their projects.
This article explains PHP's date() function, its syntax, required and optional parameters, and provides multiple code examples demonstrating how to retrieve and format current dates, times, and timestamps for various use cases in backend development.
This article explains the PHP str_replace() function, its syntax, parameters, and demonstrates various usage examples including simple string replacement, array-based replacements, URL and HTML tag modifications, and mentions related functions like preg_replace().
This guide explains why and how to replace the deprecated ereg_replace() with the modern preg_replace() in PHP, covering performance benefits, syntax differences, migration steps, advanced usage, and practical code examples to help developers update their code safely and efficiently.
This article explains four typical cache problems—penetration, avalanche, breakdown, and distributed cache efficiency—describing their causes and offering practical mitigation strategies such as top‑level filtering, Bloom filters, staggered expirations, null caching, and locking mechanisms.
This guide introduces AMPHP’s event‑driven async MySQL library for PHP, explains its non‑blocking API, connection‑pool architecture, supported features, and provides step‑by‑step installation and code examples for basic queries, iterators, and transactional operations.
This article systematically catalogs every Spring and Spring Boot extension interface—from ApplicationContextInitializer to DisposableBean—illustrates their invocation order with a diagram, explains practical use‑cases, and provides concrete code samples for each hook, enabling developers to tap into the bean lifecycle for custom initialization, monitoring, and cleanup.
This article presents a comprehensive backend engineering methodology for building "three‑high" systems that simultaneously achieve high performance, high concurrency, and high availability, covering performance tuning, horizontal and vertical scaling, hot‑key mitigation, fault‑tolerance mechanisms, isolation strategies, and practical DDD‑driven design.
This article explains PHP's is_executable() function, its definition, parameters, return values, provides a full code example, discusses usage notes, and outlines common scenarios such as securing uploaded files, checking executable status, and verifying file permissions.
This article explains how the PHP tmpfile() function creates a unique temporary file that is automatically deleted at script termination, demonstrates its syntax and usage with example code, and highlights important considerations such as resource handling and manual deletion with unlink().
This article explores the evolution of software complexity and presents a comprehensive backend development methodology for building high‑performance, high‑concurrency, and highly available systems, covering performance optimization, read/write strategies, scaling techniques, fault isolation, and deployment practices with real‑world examples.
This article shares a backend‑centric methodology and practical experiences for constructing systems that simultaneously achieve high performance, high concurrency, and high availability, covering performance optimization, read/write strategies, scaling techniques, fault‑tolerance mechanisms, and deployment considerations.
This article introduces a reusable asynchronous processing SDK for Java backend systems, explaining its purpose, advantages, underlying principles, component choices, design patterns, database schema, configuration options, usage instructions, and best‑practice notes, while providing complete code snippets and deployment details.
This article explains how PHP's array_pop() function removes the last element from an array, demonstrates its usage with a complete code example, shows the resulting output, and discusses best practices such as handling multiple removals and preserving the original array.
This article explains how to replace repetitive try‑catch blocks in Java backend code with a unified exception handling mechanism based on Spring's @ControllerAdvice, custom Assert utilities, and error‑code enums, resulting in cleaner, more maintainable services and controllers.
Rate limiting safeguards system stability by capping request rates, employing algorithms such as fixed‑window, sliding‑window, leaky‑bucket, and token‑bucket, and can be applied at application, proxy, or hardware layers while using strategies like threshold setting, request classification, feedback, and ensuring fairness, flexibility, and transparency.
This course provides a detailed, step‑by‑step curriculum covering Spring Cloud microservice architecture, distributed systems fundamentals, performance optimization, source‑code deep dives, middleware, cloud services, data handling, performance tuning, design patterns, and essential development tools for building high‑performance, scalable backend solutions.
This article explains how Go modules define version information through the go directive, toolchain directive, go env GOTOOLCHAIN variable, and system GOTOOLCHAIN environment variable, detailing their syntax, effects, interactions, and priority rules for reliable project builds.
This article explains JMX (Java Management Extensions), outlines its typical monitoring and configuration scenarios, details its three‑layer architecture, and provides a practical guide with code examples on defining MBeans, implementing them, and using JConsole to modify bean properties at runtime.
This article explains why third‑party payment is needed, outlines Alipay’s workflow, guides through obtaining APPID and generating public/private keys, and provides a complete Python implementation—including key handling, request signing, and API usage—to integrate Alipay payments into backend applications.
This article compares three inventory deduction approaches—single‑field MySQL updates, sharded MySQL records, and Redis INCRBY with Lua scripting—analyzes their concurrency drawbacks, and provides a complete Java implementation using Redis Lua scripts, distributed locks, and callback‑based stock initialization.
This guide explains SpringBoot's built‑in performance monitoring interceptors, demonstrates how to configure them with custom annotations, pointcuts, and advisors, and shows how to extend SimpleTraceInterceptor and CustomizableTraceInterceptor for detailed method‑execution logging and timing.
Learn step-by-step how to activate gzip compression in Nginx, configure compression level, buffer size, minimum file size, and proxy settings, and understand the impact of each directive on bandwidth reduction and page load speed for both static and dynamic content.
This article explains Java meta‑annotations—@Target, @Retention, @Documented, and @Inherited—detailing their purposes, possible values, and providing code examples to show how they control annotation scope, lifecycle, documentation inclusion, and inheritance in Java programs.
This article introduces JDFrame/SDFrame, a Java library that provides a DataFrame‑style, semantic API for stream processing, covering quick start, dependency setup, extensive examples of filtering, aggregation, distinct, grouping, sorting, joining, and utility functions, along with Maven coordinates and source repository links.
This article introduces the high‑performance Rust library quick-xml, explains its core features, shows how to install it, and provides detailed code examples for reading, writing, and advanced XML processing, helping developers efficiently handle XML data.
This document describes a web‑based contract and employee expense reimbursement system for small‑to‑medium enterprises, covering its BS architecture with a Vue front‑end, Django back‑end, MySQL database, deployment environment, registration/login procedures, and detailed modules for user, department, contract, reimbursement, and financial management.
This article details the architecture, core component design, and implementation techniques of 58.com’s invitation business system, covering background, technical challenges, modular backend design, event‑driven services, rule‑engine filtering, protocol conversion, and process orchestration to improve scalability, efficiency, and reusability.
This article explains how the PHP file_get_contents() function works, detailing its syntax, parameters, and examples for reading both local and remote files, while also highlighting its usefulness for further data processing.
This article explains the PHP file_exists() function, covering its syntax, return values, practical examples for checking local and remote files as well as directories, and important limitations to consider when using it in backend development.
PHP 8.4, released on November 21, 2024, introduces performance, usability, and security enhancements such as property hooks, a parenthesis‑free new operator, powerful array functions, an HTMLDocument class, new Sodium algorithms, a request parsing helper, stricter type declarations, JIT optimizations, and migration of several extensions to PECL.
This guide outlines a step‑by‑step method for recognizing critical APIs, evaluating their importance and complexity, assigning priority levels, and preparing the necessary people, tools, and CI/CD processes to implement effective API automation testing.
This article explains why Java ORM frameworks are essential for simplifying database access, outlines the critical criteria for selecting the right ORM, compares popular choices such as Hibernate, JPA, EclipseLink, and DataNucleus, and provides a step‑by‑step guide for successful implementation.
The guide equips candidates for backend interviews by covering essential networking (HTTP/HTTPS, TLS handshake, status codes, headers, OCSP, session resumption, CSRF), RPC frameworks, Java class-loading and JVM memory/GC, OS process/thread scheduling, Spring bean lifecycle, Redis caching pitfalls, and MySQL indexing and query optimization.
This article explains PHP's strlen() function, detailing its syntax, demonstrating how to calculate string lengths—including handling spaces and trimming—and highlighting important considerations such as character encoding and special characters, with clear code examples and output explanations.
This article introduces ten lesser‑known PHP tricks—including memory management, Composer dependency handling, the built‑in web server, anonymous classes, try‑catch error handling, generators, traits, built‑in functions, PDO, and namespaces—to help developers write more efficient, maintainable, and secure code.
This article explains PHP's array_column() function, available since version 5.5, showing its syntax, parameters, return values, and practical code examples for extracting specific keys from multidimensional arrays and optionally using an index key to create associative results.
This article explains the motivations for upgrading to JDK21, introduces Generational ZGC, details integration steps and monitoring setup, presents performance test results comparing ZGC and Generational ZGC, and outlines future plans for Java services at Zhaozhuan.
This article explains the PHP dirname() function, detailing its purpose, syntax, parameters, return values, and provides multiple code examples demonstrating how it extracts directory paths from absolute, relative, and Windows-style file paths, including handling of directory inputs.
This article explains PHP's shuffle() function, its syntax, behavior on indexed and associative arrays, and provides code examples demonstrating how to randomize array elements and handle the function's boolean return value in practice.
This guide walks through a complete set of Bash scripts for building, starting, stopping, upgrading, and rolling back a Go backend application, explains the required directory layout, and highlights signal handling to ensure reliable deployments.
This guide explains why .env files are used, how to install and configure the dotenv package, handle multiple environments, expand variables, and secure secrets with dotenvx, providing clear code examples and best‑practice recommendations for Node.js developers.
The article advises developers to avoid explicitly mentioning the use of scaffolding frameworks like RuoYi when describing project experience, suggesting they instead focus on the underlying implementation details and any custom improvements to demonstrate genuine technical contribution and avoid misconceptions about their capabilities.
This article provides a comprehensive collection of free, unlimited-use API endpoints covering diverse services such as phone number lookup, historical events, stock data, weather forecasts, identity verification, jokes, maps, and many others, offering developers ready-to-use resources for building data-driven applications.
This article explains PHP's rawurldecode() function, detailing its syntax, how it reverses URL encoding performed by urlencode(), provides a complete code example, demonstrates the output, and highlights the difference between rawurldecode() and urldecode() for full URL decoding.
This guide explains how to enable comprehensive request logging, use request/response wrappers, implement once‑per‑request filters, and define clean controller interfaces in Spring Boot 3.2.5, providing code examples and configuration tips for robust backend development.
This article explains PHP's count() function, its syntax and parameters, and provides step‑by‑step examples for counting simple and multidimensional arrays using both normal and recursive modes. It also shows how to output the results and highlights the differences between COUNT_NORMAL and COUNT_RECURSIVE.
Graceful Response is a Spring Boot component that offers one‑stop unified response packaging, global exception handling, and custom error code support, enabling developers to simplify controller code, reduce boilerplate, and improve readability and efficiency.
This article explains the principles and source‑code flow of Nacos configuration center’s long‑polling mechanism, detailing how the client initiates periodic tasks, how the server processes listener requests, and how configuration changes are detected and propagated through various internal classes and threads.
This article explains how to implement interface debounce in Java backend services, covering the concept, identifying suitable APIs, generating unique keys, and applying distributed locking mechanisms with Redis and Redisson, including code examples and practical testing results.
This guide walks through ten practical Python examples for parsing, constructing, validating, updating, deleting, and iterating JSON data via HTTP requests, including custom date serialization and schema validation, each demonstrated with complete code and expected outcomes.
This article explains RocketMQ's core components, including domain models, message transmission models, reliability mechanisms, the challenges of ordered messaging, practical usage scenarios, and the design and implementation of transactional messages in both open‑source and proprietary versions.
This article explains why the backend services were upgraded from JDK 8 to JDK 21, introduces the generational ZGC garbage collector, details its architecture, tuning parameters, integration steps, monitoring setup, and presents performance test results that demonstrate reduced allocation stalls, lower latency, higher throughput, and near‑zero GC pauses.
This article explains Java's EnumMap, covering its definition, key characteristics, how to create and use it with code examples, its efficient array‑based implementation, and practical test cases, demonstrating why EnumMap is a high‑performance map for enum keys in backend development.
This article explains how to integrate JSON Schema validation into a Spring Boot application, covering dependency setup, schema definition, bean configuration, service implementation, controller exposure, and testing with curl to ensure JSON payloads conform to the defined rules.
