This guide explains how to design the database, modify product detail, cart, and order pages, and use PHP and Ajax to enforce stock‑based purchase quantity limits in an online store, ensuring users cannot exceed available inventory and improving overall shopping experience.
This article explains PHP's native JSON functions—json_encode and json_decode—showing how to convert PHP variables to JSON strings and back, and demonstrates a practical cURL example for fetching and processing JSON data from a remote API.
This article explains the Chain of Responsibility design pattern, its core concepts, characteristics, and problems it solves, then demonstrates how to combine it with the Strategy pattern in Java using Spring, complete with detailed code examples and execution flow.
This article examines the rise of microservice architecture and compares major communication mechanisms—RESTful APIs, gRPC, and message queues—guiding developers on selecting the most suitable approach based on business requirements, system scale, and team expertise.
This article introduces the XXL‑JOB open‑source distributed scheduler, compares it with Quartz and other solutions, and provides a step‑by‑step tutorial for server deployment, executor configuration, task development, execution, logging, and the underlying Netty‑based communication design, complete with code examples.
This article explains why Maven dependency analysis is essential for Java backend projects, demonstrates how to run the analysis with Maven and IntelliJ IDEA, interprets the warnings about used undeclared and unused declared dependencies, and provides best‑practice timing, risks, and shortcuts for maintaining clean dependency trees.
This tutorial explains PHP's array_slice() function, covering its syntax, parameters, and practical examples—including extracting specific elements, preserving keys, and using it for pagination—while highlighting that it returns a new array without altering the original.
This guide explains the fundamentals of CORS, walks through typical misconfigurations such as HeaderDisallowedByPreflightResponse, Nginx header ordering, and Origin‑Credentials conflicts, and provides complete Nginx examples to reliably enable cross‑origin requests.
ThinkPHP 8.1.2 introduces a host of improvements such as enhanced event subscription, new validation utilities, route grouping options, cookie handling fixes, multi‑module view rendering, language auto‑detect, and a brand‑new debugging library that supports local and remote debugging via Composer.
This article explains PHP's rename() function, covering its syntax, required source and target parameters, boolean return values, practical code examples for renaming files and directories, and important considerations such as permission constraints.
This article explains the PHP str_replace function, shows its syntax, and provides three practical examples demonstrating simple replacement, multiple replacements using arrays, and character deletion, helping developers efficiently manipulate strings in their backend code.
This article explains why monolithic applications become problematic as they scale, outlines the key advantages of microservice architectures, provides a step‑by‑step migration guide—including planning, service boundary definition, infrastructure setup, data decoupling, and communication—and illustrates the process with a fintech company case study.
This article investigates why an RPC interface with an average execution time of 1.5 ms still experiences numerous 100 ms+ timeouts, analyzes the root causes such as GC and I/O jitter, and proposes an elastic timeout optimization to improve service reliability.
This article explains the Chain of Responsibility design pattern, its core concepts, characteristics, and problems it solves, then demonstrates how to combine it with the Strategy pattern through detailed Java code examples that illustrate a product‑up‑shelf validation workflow and a generic request‑handling scenario.
This guide walks you through installing Spring Boot CLI, explains its Groovy‑based features, demonstrates creating and running a Hello World web app, shows how to use @Grab for dependencies, test with spring test, package into executable JARs, and explore init and shell commands.
This article explains the PHP trim() function, its parameters, default behavior, and demonstrates how to remove leading and trailing whitespace or custom characters from strings with clear code examples and output results.
This article explains how PHP’s built‑in is_object function can be used to determine whether a variable is an object, demonstrates its syntax, provides a complete code example with both an object and an array, and clarifies the distinction between objects and arrays.
This article explains how to efficiently read large files in PHP line by line with the fread function, provides a complete code example, and discusses additional techniques such as buffering, fseek positioning, and adjusting memory limits to avoid memory overflow.
This extensive tutorial series provides step‑by‑step video guides covering the design and implementation of an e‑commerce core order system, promotional processes, distributed services, a high‑concurrency seckill platform, performance tuning techniques, microservice architecture with Spring Cloud Alibaba, and cloud‑native deployment using Docker, Kubernetes, Prometheus, and Grafana.
This roundup highlights twelve standout Baidu Geek articles from 2024, covering breakthroughs in search personalization, high‑performance Go services, transaction reconciliation, login system evolution, AI‑native applications, microservice governance, caching algorithms, RLHF optimization, ClickHouse deployment, and more, each with concise recommendation reasons.
This article presents a comprehensive collection of written‑test and interview questions covering Java basics, Spring MVC annotations, JVM memory, garbage collection, database design, transaction management, distributed systems, version control, and development workflow, aimed at helping candidates prepare for small‑company technical interviews.
This article describes the background, problem definition, recursive algorithm design, Java implementation, deduplication logic, performance considerations, and business impact of a SKU‑level order merging solution for JD Logistics' inbound-to-warehouse process.
This article introduces the URule rule engine, explains its core concepts and library types, shows how to install and configure it within a Spring Boot project, demonstrates rule set and decision‑table creation, and provides complete Java code examples for practical usage.
Spiral Framework is a modern PHP framework that promises up to ten times faster execution than Laravel or Symfony, offers built‑in security features, extensive scalability, PSR compatibility, and provides a quick‑start guide with installation, server launch, and access instructions.
This guide shows how to integrate the Drools rule engine into a Spring Boot application to calculate e‑commerce discounts dynamically, covering Maven dependencies, configuration, model definitions, DRL rule creation, service and controller layers, and a simple test scenario demonstrating rule‑driven discount computation.
This article presents a real‑world case study of a high‑concurrency data‑processing interface whose response time was reduced from 30 seconds to under one second by diagnosing SQL bottlenecks, applying PostgreSQL array aggregation, moving logic to the database, and introducing Caffeine caching, with detailed code examples and performance analysis.
This article explains how Redisson leverages Redis, Lua scripts, and Pub/Sub to implement a robust distributed lock in Java, covering lock characteristics, client creation, acquisition, renewal, and release mechanisms with code examples.
This article explains the PHP in_array() function, detailing its syntax, optional strict mode parameter, and provides three clear code examples that demonstrate checking for values, enforcing type comparison, and retrieving keys associated with specific values in arrays.
This article reviews the most popular programming languages that can serve as alternatives to PHP for web development, evaluating each option’s performance, ecosystem, and suitability for server‑side projects, and offers guidance on selecting the best replacement based on project requirements.
This article explains the syntax and parameters of PHP's array_multisort() function, demonstrates its usage with a concrete example sorting names, ages, and scores, and shows the resulting ordered arrays, highlighting how to sort multiple arrays simultaneously.
The article reviews a Java veteran's 20‑year experience to identify backend technologies such as JSP, Struts, Hibernate, Servlet, Applet, Swing, JDBC and XML that are now outdated or less essential, and recommends focusing on Spring MVC, MyBatis and a deep understanding of Servlets for modern development.
This article compares three real‑time data update methods—short and long polling, WebSocket, and Server‑Sent Events—explaining their principles, advantages, drawbacks, and providing practical code examples so developers can choose the most suitable solution for their web applications.
This article analyzes the "write‑after‑immediate‑read" challenge in multi‑active disaster‑recovery setups, breaks down solution directions, presents a three‑city five‑center case study, and outlines a four‑step model—distinguish scenarios, mark written data, assess latency, and enable near‑by access—to achieve consistent, low‑latency reads.
This article presents a comprehensive set of practical techniques—including batch processing, asynchronous execution, caching, pre‑processing, pooling, parallelization, indexing, transaction management, pagination, SQL tuning, and lock granularity—to significantly reduce API latency and improve overall backend performance, illustrated with Java code examples and diagrams.
This article explains Netty's powerful asynchronous architecture, compares classic multithread, Reactor, select, poll, and epoll I/O multiplexing models, demonstrates JNI integration for native performance, and provides complete example code for building a high‑performance epoll‑based server in Java.
This article explains the PHP curl_init() function, covering its syntax, optional URL parameter, return values, and provides a complete example demonstrating initialization, option setting, execution, error handling, and response processing for HTTP API requests.
This article introduces ten essential PHP built‑in functions—including array_map, array_filter, array_reduce, json_encode/decode, and string utilities—explaining their purpose and providing clear code examples to help developers write more concise and efficient backend code.
This guide explains how to install the workerman/rabbitmq package, set up producer and consumer scripts for both Workerman and PHP‑FPM environments, and run asynchronous RabbitMQ messaging using detailed PHP code examples and configuration options.
This article explains how PHP's array_pop function removes and returns the last element of an array, provides its syntax, demonstrates its usage with a complete code example, shows the resulting output, and highlights its usefulness for array manipulation in backend development.
This article explains PHP's array_slice() function, detailing its parameters, return value, and usage through multiple code examples that demonstrate extracting subsets of arrays, preserving keys, and omitting length to retrieve remaining elements, plus practical notes for pagination.
This article examines the principles of microservice decomposition and composition, analyzes the risks of improper service splitting such as communication overhead, dependency loops, and chaotic call chains, and offers concrete governance strategies to achieve a balanced, maintainable architecture.
This article explains PHP's throw keyword, covering exception fundamentals, the try‑catch mechanism, the exception class hierarchy, and provides detailed code examples demonstrating how to throw and handle both built‑in and custom exceptions for robust error management.
This article introduces Elasticvue, a free open‑source Elasticsearch GUI that supports ES 7.x/8.x, explains how to install it via Docker, demonstrates its features such as cluster monitoring, index and shard management, document search, and REST queries using a real e‑commerce project example.
This guide explains how to create a dynamic IP blacklist that blocks malicious crawlers or users by configuring Nginx with Lua scripts and a Redis store, covering requirements, environment setup, design choices, configuration files, Lua code, and advanced usage scenarios.
This article details how Instagram migrated its massive Python 2/Django codebase to Python 3, covering the motivations, custom Django extensions, migration strategy, technical pitfalls such as Unicode handling, pickle compatibility, iterator behavior, and the resulting CPU and memory improvements.
This guide explains Nginx's regular‑expression syntax, the five location prefix types, their matching priority, and provides concrete configuration examples with code snippets and diagrams to help you correctly route requests in a single‑node Nginx v1.23.2 setup.
This guide explains how to install pytest, create a module with a function that calls an external API, and use unittest.mock fixtures and helper functions to mock requests.get for both successful and failing responses, then run the tests with pytest.
This article explains how to build a highly available distributed e‑commerce system by using load‑balancing, redundant servers, rate‑limiting techniques, circuit‑breaker patterns, and graceful degradation methods, and provides concrete Spring Cloud and Java code examples for each strategy.
This article explains the fundamentals of workflow engines, compares process and rule engines, discusses why and how to use message queues (including delay levels and popular MQ products), and details Redis data structures and memory‑eviction policies, providing practical guidance for backend system design.
China Railway’s 12306 trial of an automatic ticket‑ordering feature lets users pre‑select up to 60 trains, set priority and pre‑pay the highest fare for Spring Festival travel, with the system submitting orders automatically, handling refunds, and addressing priority sorting, scheduling, payment accuracy, and server load through extensive stress testing and a gray‑release strategy.
This article explains why proper exception handling is essential for building robust PHP applications, covering the advantages of exceptions over error codes, how to throw, catch, and create custom exceptions, set up global handlers, convert errors to exceptions, and log them effectively.
China Railway's 12306 pilot introduces an automatic ticket order submission system for Spring Festival travel, allowing users to pre‑fill up to 60 train options, set priorities, pre‑pay, and rely on backend scheduling and fairness mechanisms to improve ticket acquisition during peak demand.
This article introduces several Chinese open‑source AI platforms, shows how to import their Java SDKs, obtain API keys, run test demos, encapsulate a reusable AI module with Spring Boot configuration, and apply prompt‑engineering techniques to generate AI‑driven questionnaire content.
The article details a nine‑month rewrite of a fragmented 23‑interface news‑plugin integration layer into a single trpc‑go service, showing how unified architecture cut development effort by half, boosted stability above 99.99 %, slashed resource costs, raised test coverage to 66 %, and provides practical criteria for deciding when to refactor.
This article explains the PHP in_array() function, covering its syntax, parameter details, return values, and provides three practical code examples—including basic usage, strict mode comparison, and searching within multidimensional arrays—to help developers efficiently check element existence in arrays.
This article explains how PHP closures—anonymous functions that capture external variables—can be used to encapsulate reusable code blocks, demonstrates practical examples including data processing callbacks and integration with object‑oriented classes, and shows how this approach enhances code reuse, maintainability, and flexibility.
This article compares monolithic and microservice architectures, outlining their advantages, disadvantages, and ideal use‑cases, helping developers decide which approach aligns best with project size, team structure, scalability needs, and long‑term maintenance goals.
This article explores an unconventional Go switch‑true pattern used for checking systemd service status, compares it with equivalent if‑else logic, examines the generated assembly, and discusses when this style is advantageous for handling multiple string‑prefix conditions.
This article explains how to prevent duplicate data submissions in a Spring Boot application by designing an idempotent mechanism using AOP and Redis, covering the concept, design strategy, custom annotation, aspect implementation, and a simple test controller.
This article details how a legacy reporting module suffering from slow page loads was refactored by archiving log data, caching hourly counts in Redis, and using scheduled synchronization to dramatically improve query performance without adding new middleware.
This article introduces Java Stream API introduced in JDK 8, explains its pipeline concept, and demonstrates practical operations such as traversal, filtering, deduplication, type conversion, collection‑to‑map transformations, pagination, matching, and parallel processing with clear code examples.
This article reviews five leading Go frameworks and libraries—Gin, Beego, Echo, Buffalo, and GORM—detailing their core features, typical use cases, and reasons to choose each, helping developers select the most suitable tools for modern backend and full‑stack development in 2024.
This guide explains how to create a scalable PHP queue and ticket‑calling system using the high‑performance Webman framework and GatewayWorker, covering the system’s purpose, core components, step‑by‑step installation, configuration, startup commands, and sample log output.
This guide explains how to configure Nginx access and error logs, customize log formats with log_format, manage log files using access_log and error_log directives, and automate daily log rotation with a Bash script and cron job.
This article presents Liteflow, a lightweight yet powerful rule engine for Java Spring Boot applications, covering its architecture, supported rule formats, component types, EL rule files, data context handling, configuration options, and a practical e‑commerce workflow example, while providing Maven dependency snippets and usage code.
This article explains how to make Spring AOP logging configurable at runtime by dynamically adding or removing Advice objects through custom endpoints, event listeners, and plugin management code, and demonstrates the approach with a complete example including service, controller, and aspect jar.
This article explains how PHP's password_hash function creates cryptographically strong, salted password hashes, demonstrates its usage with example code, and shows how to verify passwords securely using password_verify, emphasizing best practices for backend security.
This article explains the PHP setcookie function, detailing its syntax, parameters, and practical examples for setting cookies with various attributes such as expiration time, path, domain, security, and HttpOnly flags.
The article examines the performance impact of excessive logging in large‑scale Java systems and proposes request‑level sampling with cross‑thread identifier propagation, offering practical component‑based solutions, implementation considerations, and a concrete code example for backend developers.
Fast‑Retry is a high‑throughput Java retry library that enables asynchronous, non‑blocking retries for massive task volumes, offering programmable and annotation‑based APIs, custom retry policies, and significant performance gains over traditional synchronous frameworks like Spring‑Retry and Guava‑Retry.
This article explains how the PHP curl_multi_add_handle() function can be used to add multiple cURL handles to a single session, improving network request efficiency and code maintainability, and provides a complete example with detailed code walkthrough.
This article explains the PHP basename() function, detailing its syntax, parameters, and behavior, and demonstrates its usage through multiple code examples that extract file names from absolute and relative paths, optionally removing specified suffixes, while noting OS-specific considerations.
This article explains the five major Elasticsearch query limits—including result size, max clause count, field data, join operations, and query throughput—provides concrete code examples, and offers practical optimization strategies to improve performance and ensure cluster stability.
A developer investigates why an RPC service suddenly rejected many requests, discovers that a Guava RateLimiter with a limit of only ten calls per minute caused thread‑pool saturation, and explains the misinterpretations, monitoring data, and steps taken to pinpoint the root cause.
This article explains the architectural changes introduced in RocketMQ 5.0, including the new stateless Proxy layer, the POP consumption model, message‑level load balancing, and the Controller mode for automatic master‑slave failover, providing detailed diagrams and resource links.
This article breaks down Nginx’s high‑concurrency architecture, covering the Master‑Worker process model, event‑driven non‑blocking I/O with epoll, asynchronous request handling, and performance‑boosting features like caching and Gzip compression.
This article explains how to replace Shiro with jCasbin for permission management in Spring Boot, covering Maven dependency setup, configuration files, Enforcer initialization, custom policy handling, and a simple servlet filter for runtime authorization checks.
This article explains the PHP array_keys() function, detailing its syntax and optional parameters, and provides three clear code examples that demonstrate how to retrieve keys from indexed, associative, and multidimensional arrays.
This article explains the concept of URL encoding and decoding, introduces PHP's urldecode() function with its prototype, provides step‑by‑step example code showing how to encode a string with urlencode() and then decode it back using urldecode(), and notes its limitations and the alternative rawurldecode() function.
PHP 8.4 brings a collection of developer‑friendly enhancements—including readonly independent properties, string‑key array unpacking, JIT performance gains, typed class constants, improved error messages, an upgraded type system, and stronger Fiber support—aimed at making code cleaner, faster and more maintainable.
This article explores the design and implementation of time wheel algorithms in Netty and Kafka, comparing their single‑layer and multi‑layer approaches, analyzing performance trade‑offs, and detailing how these systems achieve O(1) scheduling for massive delayed tasks while avoiding empty ticks.
This article explains what constitutes a large file, contrasts its upload challenges with ordinary files, outlines the chunked upload workflow for both front‑end and back‑end, and provides practical code examples and optimization techniques such as resumable uploads, instant upload, progress tracking, and pause/resume functionality.
This article explains what constitutes a large file, contrasts its upload challenges with ordinary files, and provides a complete chunked upload solution—including frontend slicing code, backend merging logic, breakpoint resume, instant transfer, progress handling, and references to mature libraries.
This article explains PHP's array_unique() function, detailing its syntax, parameters, and return value, and provides clear examples showing how to remove duplicate elements from arrays and optionally sort them using the $sort_flag parameter.
This article explains the PHP 7.3+ array_key_first() function, shows its syntax and a practical example for obtaining the first key of an associative array, and provides a fallback method using array_keys() for older PHP versions.
This guide explains PHP 8's named arguments feature, showing how they improve code readability, allow skipping optional parameters, make argument order irrelevant, and provide practical examples and best‑practice recommendations for writing clearer, more maintainable backend code.
This article explains the PHP str_replace function, its syntax, and demonstrates through three examples how to perform simple replacements, replace multiple substrings, and delete characters in strings, while also mentioning additional options and linking to further learning resources.
This article walks through the design and implementation of symmetric AES encryption for both GET and POST API endpoints in a Spring Boot application, covering requirement analysis, data model definition, custom RequestBodyAdvice and ResponseBodyAdvice, serialization challenges with FastJSON vs Jackson, and final configuration to ensure consistent JSON output across encrypted and non‑encrypted responses.
LinkedIn’s message search system stores messages in RocksDB, builds Lucene inverted indexes on demand, partitions them by user, keeps indexes in memory, and uses a coordinator with D2/Zookeeper for node routing, enabling rapid, cost‑effective searches while minimizing write overhead.
This article compares seven practical approaches—DelayQueue, database polling, Redis queues, Redis key expiration callbacks, RabbitMQ delayed messages, scheduled task frameworks, and event‑stream processing—for automatically cancelling unpaid orders, outlining their suitable scenarios, code examples, advantages, disadvantages, and optimization tips.
The article introduces the Cool Request IDEA plugin, explains its tracing capabilities for arbitrary packages, automatic MyBatis function monitoring, customizable timing colors, script-based environment manipulation, and provides a Java code example for handling responses, highlighting its usefulness for backend developers.
This article compiles detailed backend interview notes covering salary expectations, OS stack vs heap differences, process and thread concepts, DNS resolution, ping protocol, MySQL indexing and locking mechanisms, Redis performance characteristics, Kafka throughput optimizations, and Docker's underlying implementation.
This article presents twelve practical MyBatis‑Plus optimization techniques—ranging from avoiding null checks and specifying select fields to batch operations, safe ordering, pagination, logical deletion, optimistic locking, and performance tracking—each illustrated with code examples and clear explanations to help backend developers write cleaner, faster, and more maintainable Java ORM queries.
This article explains ten common mistakes when using Java thread pools—such as unbounded queues, wrong thread counts, missing shutdown, and ignored exceptions—and provides concrete code examples and best‑practice solutions to help developers write safer, more efficient concurrent code.
This article explains how to implement hot‑pluggable AOP in Spring by letting users enable or disable logging advice at runtime, covering prerequisite concepts, core logic, and a complete code‑first demonstration with dynamic proxy management.
The article examines monolithic architecture’s early popularity, its simplicity and deployment ease, then details its scalability and maintenance drawbacks, and explains how distributed architectures—through decoupling, redundancy, scalability, and mechanisms like caching and load balancing—address these issues, outlining practical migration steps.
This article explains Spring's transaction management, covering ACID principles, transaction propagation types, isolation levels, timeout settings, read‑only flags, rollback behavior, and the effect of asynchronous execution, supplemented with practical code examples and common pitfalls.
This article introduces Java's Optional class, explains why null checks cause clutter, demonstrates how to replace traditional three‑level null‑checking with concise Optional chains, and provides detailed examples of all core Optional methods such as empty, of, ofNullable, isPresent, get, ifPresent, filter, map, flatMap, orElse, orElseGet, and orElseThrow.
This article explains the PHP array_merge() function, its simple syntax, and demonstrates how to merge indexed, multiple, and associative arrays with clear code examples, showing the resulting output and highlighting key behaviors such as key overriding.
A high‑concurrency service quickly saturated its 100 Mbps upstream because each GET request carried a 1.68 KB TLS handshake, but switching to plain HTTP or enabling HTTP keep‑alive can slash request size by 70 % and dramatically reduce bandwidth and CPU usage.
