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.
This article explains how to achieve idempotent order creation and update by using unique order IDs, database primary‑key constraints, Redis flags, and a version‑column mechanism to detect and prevent duplicate submissions and ABA anomalies in distributed systems.
This article explains how to use PHP's str_split function to divide a string into an array of characters, covering basic syntax, specifying element length, handling multibyte characters, and providing practical code examples with output demonstrations.
This article explains how to use PHP's session_regenerate_id function to securely regenerate session IDs, discusses the reasons for doing so, provides sample code, and outlines important precautions such as starting the session, using HTTPS, and avoiding excessive regeneration.
Using JDK 21’s standardized Virtual Threads, this guide explains how to design and implement robust asynchronous batch processing, covering common pitfalls like CPU spikes and OOM, best‑practice concurrency controls, task queue architecture, and practical code illustrations.
Learn how to set up Nginx as a front‑end load balancer for web applications, define upstream servers and proxy_pass directives, and apply round‑robin, least‑connected, ip‑hash, weight, timeout, and backup server options to optimize traffic distribution and reliability.
This article details the three‑stage evolution of Ctrip's vacation product log system—from a simple single‑table DB approach, through a platform‑based ES + HBase solution, to a scalable V3.0 architecture that improves storage, search, and business empowerment while handling billions of log entries.
This article explains PHP's fgetc() function for reading a single character from an opened file or standard input, demonstrates how to open files with fopen(), shows example code for looping through file contents, and provides a user input example with a switch statement.
This article explains the motivations for creating a custom PHP framework—such as meeting specific needs, learning opportunities, long‑term maintenance, performance optimization, ease of use, and security—and provides a detailed chapter and section outline for a self‑study course.
This guide explains how to activate SpringBoot DevTools for hot deployment, integrate Lombok to reduce boilerplate code, and configure the Spring Configuration Processor for property metadata, including necessary Maven dependencies, IDE settings, and build plugin adjustments.
This article provides a comprehensive guide to using MyBatis dynamic SQL tags—including foreach, if, choose, trim, selectKey, and sql fragments—explaining their attributes, usage scenarios, and offering detailed Java and XML code examples to improve query flexibility and reduce errors.
PayPal’s rapid growth forced a shift from simple hardware upgrades to a sophisticated, actor‑based architecture built on Akka, enabling efficient resource utilization, fault tolerance, and high‑throughput processing, ultimately allowing the company to handle billions of daily transactions using only eight virtual machines.
This article outlines the design and implementation of a unified WebSocket communication service, covering background motivations, project goals, core architecture, message reliability mechanisms using RabbitMQ, message classification, API specifications, and unified message formats to enable efficient, decoupled real‑time messaging across backend applications.
This article examines PHP's DateTime class, analyzing its mutable design drawbacks, the benefits of the immutable DateTimeImmutable alternative, and offers practical guidelines and best‑practice strategies for developers to write safer, more maintainable date‑handling code.
During a recent iteration, adding a simple log statement triggered a system exception because Fastjson automatically invoked a custom getter that returned null, leading to an NPE; the article details the root cause, the serialization process, and practical solutions to prevent similar issues.
This tutorial walks through installing FastDFS on a Linux server, configuring its tracker and storage nodes, integrating it with Nginx via the FastDFS‑nginx module, and exposing the service publicly using the cpolar tunneling tool, providing complete commands and configuration snippets for each step.
This article provides a comprehensive guide to using MyBatis dynamic SQL tags such as foreach, if, choose, trim, selectKey, and sql fragments, illustrating best practices with detailed code examples for building flexible, error‑free queries and updates in Java backend applications.
This article explains the PHP array_unique() function, its syntax and parameters, demonstrates how to remove duplicate values from arrays with practical code examples, and shows how the optional $sort_flag argument can affect sorting behavior.
This article introduces the new array helper functions added in PHP 8.4, demonstrates how to use them with practical examples, and shows equivalent implementations in Laravel using the Arr and Collection classes to simplify array operations.
MyPerf4J is a high‑performance, non‑intrusive Java Agent that records millions of method calls per second with nanosecond precision, offering real‑time metrics, low memory overhead, and comprehensive monitoring for both development and production environments.
This article presents a practical guide for backend developers to troubleshoot Linux performance problems, covering essential analysis tools, a systematic diagnosis method, and detailed checklists for CPU, memory, disk I/O, and network I/O issues.
This article analyzes real‑world search query characteristics, breaks down a typical search system architecture, classifies cacheable data, compares result‑level, intermediate‑value and multi‑layer caches, discusses update, prefetch and placement strategies, and highlights common pitfalls such as cache miss, consistency, and resource overhead.
This guide walks through installing Viper, creating common and environment‑specific YAML configuration files, mapping them to Go structs, setting up a global configuration holder, and initializing the config with live watching, providing a complete, runnable example for Go backend projects.
This article explains what AI agents are, why they matter, the essential soft and hard skills needed, and provides a detailed step‑by‑step roadmap for anyone aspiring to become an AI agent developer in the emerging AI‑driven software landscape.
This article recounts how developer Saki discovered a PDO extension incompatibility after PHP 8.1 upgrade, submitted detailed bug reports and pull requests, added unit tests, resolved further SQL Server issues, and ultimately became a PHP core contributor, illustrating the open‑source contribution process.
Livewire v3 introduces the #[Validate] attribute, enabling developers to define validation rules directly on component properties, which reduces boilerplate, improves readability, and offers advanced features such as custom messages, multiple rules, and conditional validation for PHP/Laravel applications.
This article explains how to use the Strategy pattern combined with a simple factory in a Spring‑based Java backend, showing interface definition, multiple arithmetic strategy implementations, a factory that registers them in a map, a service that selects a strategy at runtime, and a REST controller for testing.
The author recounts switching from Gson to Fastjson, encountering a date‑formatting bug that only appears on Linux due to an outdated Fastjson version, explores a circular‑reference $ref issue, and shares debugging steps, GitHub issue references, and practical fixes for reliable JSON serialization.
This article explains the three common server‑to‑client push techniques—polling, WebSocket, and Server‑Sent Events—detailing their advantages, drawbacks, suitable business scenarios, and provides step‑by‑step demo code for both frontend and Node.js backend implementations.
This article explains how to achieve seamless code updates for SpringBoot applications by allowing two processes to share the same port, detailing the underlying servlet container mechanics, the role of DispatcherServlet, and providing a complete Java implementation with step‑by‑step instructions and code samples.
Redis has launched a multi‑threaded query engine that vertically scales its in‑memory database, dramatically increasing query throughput and lowering latency for vector similarity searches, thereby addressing the performance demands of real‑time retrieval‑augmented generation in generative AI applications.
This article demonstrates how Java 8’s functional interfaces—such as Supplier, Consumer, Runnable, and Function—can replace repetitive if‑else statements for exception handling and branch logic, providing clear code examples, custom interfaces, and utility methods to simplify backend development.
This article walks through a real‑world cache consistency bug in a high‑traffic push service, explains cache penetration, breakdown, and avalanche, compares strong and eventual consistency models, and presents practical cache update and invalidation strategies to prevent data mismatches.
Learn how to install the Viper library in Go, read and parse YAML, JSON, TOML, and ENV files, and leverage features like default values, automatic reload, environment variable binding, merging configs, dynamic updates, and struct unmarshalling through clear code examples.
This article explains the challenges of large‑scale Kafka clusters and introduces a lightweight Kafka‑Proxy layer that provides seamless cluster switching, traffic monitoring, online offset reset, and flow‑control mechanisms, ultimately improving availability, throughput, and operational efficiency.
This article outlines nine practical methods—caching, parallel processing, batch handling, data compression, lock‑free design, sharding, request avoidance, pooling, and asynchronous processing—illustrated with Redis, MySQL, Go, and Kafka examples, showing how they collectively cut latency and improve throughput.
This article presents a typical multi‑layer system architecture, examines the theoretical performance limits of each component—including load balancers, HTTP servers, Redis, message queues, relational databases and network bandwidth—and evaluates whether the combined stack can sustain one million concurrent requests.
The article explains how interface‑level faults—where the system stays up but business performance degrades—can be mitigated through four core techniques (degradation, circuit breaking, rate limiting, and queuing), detailing their principles, implementation patterns, and practical trade‑offs for backend services.
This article provides a comprehensive overview of Nginx's high‑performance architecture, including its core, basic and third‑party modules, master‑worker process model, asynchronous event handling with epoll, FastCGI and PHP‑FPM integration, as well as detailed configuration and optimization techniques for production deployments.
This article walks through extending a simple Prometheus Exporter into a full-featured API monitoring solution using Gin-Vue-Admin, detailing backend task scheduling, database schema, multi-protocol checks (HTTP, TCP, DNS, ICMP), dynamic cron management, and frontend integration for managing and visualizing health metrics.
This article explains how SpringBoot interceptors work, demonstrates custom interceptor implementation, shows how misuse of ThreadLocal can cause memory leaks and OOM errors, and provides a fix by moving cleanup logic to afterCompletion, complete with code samples and performance screenshots.
This article introduces Liteflow, a lightweight yet powerful Java rule engine built on Spring Boot, explains its architecture, usage patterns, component types, EL rule files, data context handling, configuration options, and demonstrates a real‑world e‑commerce workflow, while also containing promotional material for related services.
This article explains PHP's ceil() function, shows its syntax, and provides three code examples demonstrating how to round floating‑point numbers and integers upward, illustrating the returned smallest integer greater than or equal to the given value.
This article explains critical pitfalls, proper shutdown handling, event loss during startup, suitable business scenarios, reliability guarantees, and best‑practice patterns for employing Spring Event in high‑traffic backend systems, providing concrete code examples and operational recommendations.
This article explains RocketMQ’s batch processing concepts, walks through the early batch model, the index‑build pipeline refactor, the BatchCQ and AutoBatch models, and presents benchmark results that show dramatic throughput gains and lower latency compared to Kafka.
This article explains the challenges of loading historical chat messages in an instant‑messaging app and demonstrates why traditional offset pagination fails, then introduces cursor‑based pagination with SQL examples and best‑practice guidelines for reliable incremental loading.
This article introduces PHP's array_slice() function, explains its parameters and syntax, and provides three practical code examples demonstrating how to extract subsets of an array, preserve keys, and use it for pagination.
This article explores the concept of traffic hijacking, compares front‑end and back‑end interception methods, and provides practical proxy‑based implementations for fetch, XMLHttpRequest, and ReadableStream to achieve seamless request and response manipulation in a unified authentication system.
This article explains how Nginx processes regular expressions and location directives, details the syntax and priority of different location prefixes, and provides concrete configuration examples with code snippets and diagrams to help developers correctly match request URIs.
This article walks through six common Go interview mistakes—incorrect function brace placement, map initialization without make, unexported struct fields for JSON, ineffective slice iteration, array versus slice parameter passing, and variable shadowing with :=—explaining each issue and providing the correct code examples.
This article explains the PHP array() function, demonstrates how to create both indexed and associative arrays with clear examples, outlines important usage notes, and provides sample code for various array types to help developers master array creation in PHP.
This article explains PHP's in_array() function, covering its basic syntax, parameters, return values, and demonstrates both normal and strict comparisons with clear code examples, helping developers efficiently check for values within arrays.
This article describes a complete solution for creating a PDF contract electronic signature system using Vue for the front‑end rendering, pdfjs‑dist to extract predefined form fields, and pdf‑lib on the back‑end to generate a signed PDF, covering field extraction, coordinate conversion, canvas overlay, and server‑side PDF manipulation.
This article explains the challenges of multiple product logins, reviews traditional session mechanisms, discusses session sharing solutions in clustered environments, and presents a CAS‑based single sign‑on implementation with Java code examples, highlighting differences between CAS and OAuth2 for secure authentication.
The article explains interface‑level failures in business systems and presents four mitigation strategies—degradation, circuit breaking, rate limiting, and queuing—detailing their principles, implementation methods, and algorithmic choices such as fixed and sliding windows, token bucket and leaky bucket.
This article explains the history, key technologies, benefits, drawbacks, and practical recommendations for adopting a frontend‑backend separation architecture, especially for startups seeking scalable, maintainable, and efficient web applications.
A detailed post‑mortem of a three‑time service outage reveals how hidden bugs, frequent FullGC, a saturated connection pool, and an unindexed slow SQL query crippled a Spring Boot backend, and shows the step‑by‑step troubleshooting, temporary fixes, and lasting improvements applied.
The interview discusses various routing and blocking strategies of the xxl-job distributed task scheduling framework, explains how it addresses task overlap, idempotency issues, and provides practical solutions such as single‑machine execution, locking mechanisms, and using a business date to avoid date‑related problems.
This article analyzes typical thread‑pool misuses that caused a production outage, explains why tasks may slow down under load, and provides concrete recommendations such as pagination, timeout handling, proper pool sizing, avoiding shared pools, ThreadLocal cleanup, and cautious use of parallel streams.
This article explains the PHP array_filter() function, its parameters, and demonstrates how to filter numeric arrays and associative arrays with practical code examples, helping developers efficiently remove unwanted elements based on custom callback logic.
This article explains how the PHP file() function reads a file's contents into an array, details its syntax and parameters, demonstrates basic and flag‑based usage with code examples, and highlights important behavior such as line handling and newline removal.
Node.js v22.6.0 introduces the experimental --experimental-strip-types flag, enabling developers to execute TypeScript files directly, but it only strips type annotations at runtime and imposes several usage constraints such as mandatory type‑only imports and explicit file extensions.
This article outlines the business background, detailed payment workflow, associated product and coupon management, and practical implementation tips for designing a robust payment system, covering process decomposition, sequence diagrams, data structures, transaction handling, and key technical considerations such as transaction management, locking, and settlement accuracy.
This article explains how PHP's array_pop function removes and returns the last element of an array, shows its syntax, provides a complete code example with expected output, and summarizes its usefulness for handling array data in backend development.
This article explains PHP's array_flip() function, detailing its syntax, behavior with duplicate values, and practical uses such as reversing associative arrays and looking up keys by value, illustrated with clear code examples and output demonstrations.
This article recounts a small startup’s journey from selecting uni‑app for cross‑platform mobile development and egg.js for the backend, through mid‑project adjustments, hiring challenges, and practical team‑management advice, highlighting lessons to avoid common pitfalls.
This article explains how to use PHP's urldecode function to decode URL-encoded parameters and full URLs, provides practical code examples, demonstrates the relationship with urlencode, and highlights best practices for handling special characters in web development.
This article introduces PHP 7.4's Foreign Function Interface (FFI), explains how to enable it, demonstrates basic usage and advanced examples for calling C functions, discusses performance considerations, security best practices, troubleshooting, and future directions for PHP developers.
This article demonstrates how to transform overly complex Spring Boot controllers—filled with repetitive validation, try‑catch blocks, and business logic—into clean, maintainable implementations by applying @Valid annotations, streamlined validation, and a centralized global exception handler.
This article explains PHP's array_fill() function, detailing its purpose, parameters, return behavior, and provides clear code examples—including simple and two‑dimensional array fills—to help developers quickly master array creation and population in backend development.
Introduced in PHP 7.3, the array_key_first() function returns the first key of an array or null for an empty array, and this article explains its syntax, demonstrates usage with code examples, and discusses practical scenarios such as retrieving the first key and checking if an array is empty.
This guide explains how to integrate JSON Schema validation into a Spring Boot application, covering dependency setup, schema definition, bean configuration, service implementation, controller handling, and testing with curl examples to ensure JSON payloads conform to the defined rules.
This guide walks through initializing a Spring Boot project, handling IDE licensing hurdles, ensuring compatible Spring Cloud, Spring Boot, and Kafka versions, leveraging Maven for dependency management, and integrating essential utilities like global exception handling, logging, CORS, Swagger, and helpful development tools.
This article explains how to quickly test MyBatis SQL statements by bypassing the Spring container, using a minimal MyBatis configuration, adding support for PageHelper pagination and MyBatis‑Plus plugins, and provides code examples and a plugin recommendation for efficient backend development.
This article explains how to implement product purchase quantity limits in a PHP‑based online store by designing a stock field in the database, updating product detail, cart, and order pages, using Ajax for dynamic updates, and handling inventory adjustments during order processing to improve user experience and operational efficiency.
This article explains PHP's array_replace_recursive() function, detailing its syntax, recursive merging behavior, example usage with code, output interpretation, important considerations, and compares it with array_merge_recursive() for effective backend array handling in PHP development.
This article details the design, architecture, and Java implementation of a WebSocket‑based backend that enables real‑time, multi‑player quiz battles, covering entity definitions, message handling, matchmaking logic, error handling, game flow, and supporting utilities such as Redis‑based state management.
This article explains how to quickly develop an AI‑native application using Spring AI, covering core features such as chat models, prompt templates, function calling, structured output, image generation, embedding, vector stores, and Retrieval‑Augmented Generation (RAG), and provides end‑to‑end Java code examples for building a simple AI‑driven service.
The article demonstrates how to transform overly complex Spring Boot controllers—filled with repetitive validation and business logic—into clean, maintainable code by using @Valid annotations, concise validation rules, and a centralized exception handler, effectively halving the code size and improving readability.
This article explains how to leverage Java 8's @FunctionalInterface, including Supplier, Consumer, Runnable, and Function, to eliminate repetitive if…else branches, handle exceptions, and simplify branch logic with concise lambda‑based utilities.
This article explains the PHP str_replace function, its syntax, and demonstrates three practical examples—simple replacement, replacing multiple words with an array, and deleting characters—showing the resulting output and highlighting additional options available in the official documentation.
This article explains how to refactor Spring MVC controller layers by introducing a unified response wrapper, handling String conversion issues with ResponseBodyAdvice, applying JSR‑303 validation for request parameters, creating custom validation annotations, and implementing custom exceptions with a global exception handler to produce clean, maintainable backend code.
