This tutorial explains why RESTful API versioning is needed, presents four versioning strategies (URI, request parameter, custom header, and media type), provides Spring Boot code examples for each, and discusses factors to consider when choosing a versioning approach.
The article explains PHP's image2wbmp() function, detailing its parameters ($image, optional $filename, optional $threshold), return value, and how to output a WBMP image directly or save it to a file, and includes a complete code example.
The article traces the evolution of backend services from monolithic applications through RPC-based scaling and sharding, highlights the limitations of database connection counts, and proposes a unitized architecture that partitions databases per service to achieve true unlimited scaling while acknowledging added complexity.
This article examines how Nacos leverages Java's reflection mechanism to instantiate its NamingService, explains the fundamentals of reflection, compares alternative approaches, and analyzes the architectural reasons behind choosing reflection in the Nacos client design.
This guide explains how to install the MySQL driver for Python, establish a connection to a MySQL database using MySQLdb, execute queries, and optionally use ORM libraries such as SQLAlchemy or Peewee for higher‑level database interactions.
This article analyzes the limitations of Trip.com’s blocking‑IO servlet architecture for its email push service, proposes a reactive, non‑blocking redesign using EventLoop and NIO, details the thread‑model and code changes, and demonstrates performance gains through benchmark comparisons.
This article explains the complete kernel‑level implementation of the TCP three‑way handshake, covering server listen queue allocation, client connect state handling, SYN/SYN‑ACK processing, syncookie protection, timer management, socket creation, and the accept path, with detailed code examples.
This article explains how SpringBoot launches an embedded Tomcat server by walking through the main method, the SpringApplication.run workflow, context creation and refresh, and the internal Tomcat components such as Connector, Engine, Host, Context, and Wrapper, illustrated with code snippets and diagrams.
This article explains the PHP function image_type_to_extension, describing its purpose, parameters, return value, and provides a complete example showing how to obtain the correct file extension for a given IMAGETYPE constant when saving images.
This article explains what RPC is, walks through each step of a remote procedure call—including stubs, routing, load balancing, serialization, encoding, and network transmission—and analyzes where latency originates to guide backend developers in performance optimization.
This article demonstrates how to use Spring's BeanUtils.copyProperties method to copy properties between objects and provides a generic utility to convert a list of source objects into a list of target objects, illustrated with Java code examples for User and Employee classes.
This guide explains how to integrate Alipay’s new secure transfer API (alipay.fund.trans.uni.transfer) into a Java Spring application, covering SDK upgrade, certificate placement, configuration files, Maven dependency, bean injection, and utility classes with full code examples for payment and transfer operations.
This article explains the purpose and inner workings of Spring's @Transactional annotation, detailing how AOP creates proxy objects, the role of BeanPostProcessor, advisors, interceptors, and the TransactionInterceptor, and walks through key source code snippets that manage transaction boundaries.
getimagesizefromstring is a PHP function that extracts an image’s width and height from raw image data supplied as a string, mirroring getimagesize but accepting string input; the article explains its parameters, return values, and provides example code comparing file‑based and string‑based usage.
The article explains PHP's getimagesize() function, which determines the dimensions, type, and MIME information of various image formats, describes its return values, and provides a complete code example demonstrating how to retrieve image size and output the image with appropriate headers.
This article outlines the design principles, layered and cluster architecture, technical requirements, caching strategies, and payment integration of a cloud‑based shopping cart system, highlighting how distributed backend components ensure stability, high performance, elasticity, and anti‑fraud measures.
This article walks through the concepts, protocols, and complete Go code needed to implement both HTTP and HTTPS forward proxies, explaining request handling, header transformations, and TCP forwarding while providing clear diagrams and runnable examples.
This article examines the challenges faced by a search middle platform—such as inaccurate impact assessment, unstable underlying clusters, and missing process standards—and details a comprehensive quality‑assurance strategy that includes baseline test suites, stability practices, performance testing, emergency drills, and systematic monitoring to ensure reliable search services.
This article explains how to build a real‑time game leaderboard using Redis sorted sets, covering ranking categories, composite scoring formulas, dynamic updates, efficient data retrieval with pipelines, and provides a complete PHP class implementation.
This article traces the evolution of a high‑concurrency backend architecture from a single‑machine setup to cloud‑native microservices, detailing ten‑plus stages such as separating Tomcat and DB, adding caches, load‑balancing with Nginx/LVS, read‑write splitting, sharding, containerization, and finally deploying on public cloud, while also summarizing key design principles.
This article explains the simple factory pattern, compares its standard definition with Nacos's implementation, and walks through concrete Java examples showing how NacosFactory, NamingFactory, and related services create instances in the Nacos client.
The PHP scandir function returns an array of filenames and sub‑directories from a given directory, optionally sorted in ascending or descending order, and can accept a stream context, providing FALSE on failure and generating a warning if the path is not a directory.
This article outlines the step-by-step evolution of server‑side architecture from a single‑machine setup to a cloud‑native, micro‑service ecosystem, detailing concepts such as distribution, high availability, caching, load balancing, database sharding, containerization, and the principles guiding scalable, resilient backend systems.
This article introduces RabbitMQ's core concepts, compares AMQP with JMS, outlines its key features, and demonstrates four working patterns—work queue, routing, publish/subscribe, and wildcard—through detailed Java producer and consumer code examples.
RSocket is a binary, back‑pressure‑aware protocol that supports four interaction models—fire‑and‑forget, request‑response, request‑stream, and request‑channel—using multiplexed frames with odd/even stream IDs for true bidirectional communication, and provides a reactive, resumable API suitable for microservices, IoT, and broker‑based architectures.
This article details the design and implementation of a reactive API gateway built on RxNetty, covering its overall architecture, request dispatch, conditional routing for gray releases, API management, rate limiting, circuit breaking, security policies, and integrated monitoring and tracing capabilities.
This guide walks you through installing Django, creating an app, defining a custom user model with a manager, configuring AUTH_USER_MODEL, and migrating the database, enabling email‑based authentication and flexible user fields.
This article explains PHP's opendir function, which opens a directory handle for subsequent closedir, readdir, and rewinddir operations, details its parameters and return values, and provides a complete example script demonstrating how to read directory contents and output file names with their types.
This article explains the purpose, scenarios, and detailed implementations of common rate‑limiting algorithms—including counter (fixed window), sliding window, token bucket, and leaky bucket—highlighting their advantages, drawbacks, and sample Python code for each.
This article explains how to implement a simple multi‑way merge sort in PHP to sort a massive 1 GB file using only 100 MB of memory, detailing the file‑splitting, incremental merging steps, and providing a complete PHP code demo.
This article explains the background of RSocket and Dubbo 3.0, introduces the spring‑retrosocket project, and provides a detailed, code‑rich tutorial on creating an RSocket server and client in Spring Boot, including dependency setup, configuration, annotations, and testing examples.
This article walks through a rapid three‑day Go onboarding, covering installation, environment setup, core syntax, package management with Go modules, common development tools, and a simple producer‑consumer concurrency example, while comparing Go concepts to Java and JavaScript.
The article explains the PHP getcwd() function, its return values, permission considerations on Unix variants, and provides a clear code example demonstrating how to obtain and change the current working directory using echo and chdir.
This article explains how microservices communicate via inter‑process communication, covering interaction patterns (one‑to‑one, one‑to‑many, synchronous and asynchronous), API definition and evolution, strategies for handling partial failures, and the choice of messaging or request/response technologies such as REST and Thrift.
This article explains why Swagger‑Dubbo is needed, introduces Swagger, describes the Swagger‑Dubbo tool, provides step‑by‑step integration instructions with Maven dependencies and Java configuration code, demonstrates how to launch and test the generated API docs, and outlines additional integrations with Knife4j and YApi.
This article explains how to design and implement a task‑orchestration workflow using a directed acyclic graph (DAG) in Java, covering graph representation, core data structures, concurrency handling with executors, persistence to a database, and platform‑level visualisation.
The article examines how to prevent data inconsistency during cross‑service money transfers by using local transactions, two‑phase commit, and message‑queue based eventual consistency, providing detailed code examples, performance considerations, and practical solutions for large‑scale backend systems.
The article explains PHP's dir() function, detailing its parameters, return values, and providing a complete example that demonstrates opening a directory, retrieving its handle and path, iterating over entries, and closing the directory resource.
This guide explains Nginx's rate‑limiting feature, covering its leaky‑bucket algorithm, basic and advanced configurations—including limit_req_zone, limit_req, burst, nodelay, whitelisting, logging, and custom error codes—to help you protect upstream servers and mitigate abuse.
This article explains what coroutines are, compares them with threads, outlines when to use them, introduces the async‑capable httpx library, shows installation and sample code, and demonstrates a performance test where asynchronous requests cut execution time by about 73% compared to synchronous requests.
This article explains how adopting ten essential microservice best practices—such as single responsibility, independent data stores, asynchronous communication, circuit breakers, API gateways, backward‑compatible APIs, versioning, dedicated infrastructure, independent release pipelines, and organizational efficiency—helps build a loosely‑coupled, scalable, and maintainable backend system.
PHP 8.1 has entered Alpha, introducing enums, fsync/fdatasync, Fibers, expanded resource-to-object conversion, macOS process renaming, new hashing algorithms, enhanced Sodium encryption, inheritance cache, and performance tweaks, with a release schedule leading to a GA version expected by November 2021.
The PHP closedir function closes a directory handle opened by opendir, accepting a resource parameter and returning TRUE on success or FALSE on failure, with usage examples and parameter details for backend filesystem operations.
This guide walks through adding Spring Boot Actuator to a project, configuring default and custom endpoints, securing shutdown operations, and demonstrates practical code snippets and curl commands for monitoring and managing a Spring Boot application.
This article explains the core differences between Java NIO and traditional IO, introduces the concepts of channels and buffers, describes buffer state management, provides a complete NIO selector code example, and compares the NIO workflow with Netty's model.
This article explains how to design and deploy a highly available Redis architecture using Sentinel, covering failure scenarios, evaluation of common HA solutions, step‑by‑step configurations from a single‑node setup to a three‑Sentinel deployment, and practical tips such as using virtual IPs for seamless client access.
The article explains PHP's chroot function, detailing its purpose of changing the process root directory, required environment and permissions, parameters, return values, and provides a practical code example demonstrating its usage.
This article provides a detailed English overview of Netty's complete server lifecycle, covering service startup, connection establishment, data read/write handling, business logic processing, and the procedures for closing connections and shutting down the service.
At Meituan’s 63rd Tech Salon, experts detailed how the company is platformizing its in‑store operations—unifying supply‑chain, transaction, settlement and CRM systems across food delivery, hotels, tickets and lifestyle services—to achieve scalable, reusable, user‑friendly solutions, sharing hard‑won lessons and outlining future integration plans.
This article reviews the evolution of Vivo's e‑commerce promotion system, detailing why the original monolithic architecture failed, how a separate, highly extensible promotion service was designed, the technical challenges of scalability, high concurrency, and stability, and the practical lessons learned from Redis and hotspot key issues.
This article dives deep into the Linux kernel implementation of the listen system call, explaining how the kernel creates and initializes the full‑connection and half‑connection queues, how backlog and system parameters interact, and why these steps are essential before a server can accept client connections.
The article introduces the DCS_FunTester framework, explains its naming, provides Swagger API access, details local deployment steps, describes a header‑based authentication change, outlines asynchronous test execution, multi‑request handling, progress tracking, and includes relevant Java code snippets for building and running the system.
The article explains PHP's cal_days_in_month function, detailing its purpose, parameters (calendar, month, year), return value, and provides a complete example showing how to retrieve and display the number of days in a specific month of a given year.
This article explains the concept of idempotency in API design, why it matters, two main strategies to achieve it, and how global unique identifiers such as UUID and Snowflake can be used to guarantee single‑execution semantics while maintaining performance and scalability.
This article provides a comprehensive overview of e‑commerce order system roles, core modules, workflow design, process engine, state machine, and future architectural evolution, offering practical guidance for building scalable and maintainable order management platforms.
This article explains the PHP function unixtojd, which converts a given Unix timestamp into its corresponding Julian Day number, returning the current day's count when no timestamp is supplied, and details its parameter and return value.
This article explains the internal implementation of PHP arrays, detailing the _Bucket and _zend_array structures, hash table mechanics, packed versus hash arrays, and how PHP maintains element order through an auxiliary index table.
This article explains how Spring Cloud Gateway (Hoxton.SR11) initializes predicate factories, binds their Config objects from configuration, creates Route objects, caches them with CachingRouteLocator, and finally matches incoming requests by evaluating combined asynchronous predicates to locate the appropriate route.
This article explains how to implement a unified exception handling mechanism in Spring applications by using @ControllerAdvice, custom Assert utilities, and enum‑based error definitions to replace repetitive try‑catch blocks, improve code readability, and provide consistent error responses across controllers and services.
Learn how PHP's juliantojd function converts Julian calendar dates—valid from 4713 B.C. to 9999 A.D.—into Julian Day Numbers, including its signature, parameter ranges, historical context, and the meaning of its return value for developers.
This article explains Nacos's health‑check and heartbeat mechanism in detail, covering the client‑side heartbeat scheduling, metadata configuration, server‑side beat reception, instance health evaluation, and the periodic health‑check tasks that mark or remove unhealthy instances.
This article explains how to use Spring's built‑in StopWatch utility to record the start and end times of multiple code sections, generate a clear performance summary, and compares it with similar tools from Apache Commons and Guava.
This article explains the concept, characteristics, and multiple implementation approaches of distributed locks, focusing on Redis‑based locks and the Redlock algorithm, and provides complete Java code examples using Spring Boot and Redisson for acquiring and releasing locks safely.
The article explains the concept of gray release, outlines a basic architecture with strategy configuration, execution, and service registry components, describes common traffic-splitting strategies, and details practical implementations using Nginx, gateway services, and complex scenarios involving data synchronization and message queues.
This article explains Java's Iterator pattern, compares it with traditional loop approaches, shows how it abstracts collection traversal, details the Iterator interface methods, and walks through the internal ArrayList iterator implementation with code examples and diagrams.
This article provides a practical guide to tuning Linux kernel parameters and NGINX configuration directives—such as backlog queues, file descriptors, worker processes, keepalive connections, access‑log buffering, sendfile, limits, caching and compression—to achieve optimal web server performance for high‑traffic sites.
This article walks through redesigning a Go‑based log‑collection framework, introducing etcd for distributed configuration, demonstrating context for timeout and data propagation, and showing how to integrate Kafka consumers while improving concurrency handling and adding rate‑limiting mechanisms.
This tutorial explains how to use XPath in Python to extract free proxy IP addresses from kuaidaili.com, covering XPath basics, installing the XPath Helper Chrome extension, crafting extraction rules, and looping through pages to collect and display results.
This article explains Go's MPG scheduling model, detailing how Goroutine, M, and P interact during blocking, asynchronous and synchronous system calls, the role of the netpoller, and the sysmon coroutine that enables preemptive scheduling and runtime monitoring.
This article explains why CORS problems arise in front‑end/back‑end separation, introduces the CORS standard and request types, details the required response headers, and provides three concrete Spring Boot solutions—including global configuration, filter‑based handling, and the @CrossOrigin annotation—complete with code examples and migration notes.
This article explains how PHP's zend_array is implemented as either a packed array or a hash array, detailing the underlying struct fields, the role of the Bucket container, and how different key patterns affect memory layout and performance.
This article explains PHP 8’s internal array implementation, describing the zend_array (alias zend_array and HashTable) structure, its key‑value storage, ordering, and the detailed fields such as reference counting, flags, bucket data, and associated functions, providing code excerpts for deeper understanding.
This article explains the design goals and conventions of Java's Service Provider Interface (SPI), demonstrates a practical JDK SPI example with a Command interface, discusses its drawbacks, and shows how Dubbo extends and customizes SPI for protocol implementations.
This article describes the architecture and optimization of JD.com’s coupon platform, covering the JimDB distributed in‑memory database for core storage, a massive distributed task system for product coupons, high‑availability strategies for store coupons, and the overall middle‑platform design that ensures scalability, low latency, and data consistency across millions of daily transactions.
This article examines four common message middleware delivery models—Point-to-Point, Publish/Subscribe, Partition, and Transfer—explaining their core characteristics, differences, usage scenarios, and performance considerations, with practical examples from ActiveMQ, Kafka, RocketMQ, and NSQ in modern systems.
This article chronicles my step‑by‑step journey of learning Apache RocketMQ, from downloading the source and building it with Maven, configuring mirrors, launching NameServer, Broker, Producer and Consumer on Windows, to exploring the system’s architecture and design principles.
This article explains the difference between shallow and deep copying in Java, demonstrates how Apache Commons BeanUtils and Spring Framework BeanUtils perform property copying with code examples, highlights performance concerns, and recommends more efficient alternatives for backend development.
The article analyses a real‑world Node.js service outage caused by sudden 504 timeouts, explains how the asynchronous I/O model creates time‑slice contention under high QPS, presents load‑testing code and results for both I/O‑ and CPU‑bound requests, and offers practical mitigation strategies such as clustering, caching and resource scaling.
This tutorial walks through PHP 7.4’s internal zend_string and zval structures, explains their role in binary‑safe strings and copy‑on‑write memory management, and demonstrates step‑by‑step debugging with GDB to inspect variable states and reference counts.
This article introduces seven popular open‑source microservice projects, each with detailed descriptions of their architecture, technology stacks such as Spring Boot, Spring Cloud, Docker, and links to the repositories, helping developers quickly start practical microservice development.
The article examines the shortcomings of REST APIs—such as lack of standards, cumbersome pagination, fragile documentation, and heavy client‑server coordination—and explains how GraphQL’s typed schema, automatic validation, precise field selection, and strong tooling provide a more efficient and maintainable alternative for modern web and mobile applications.
Learn how to use Postman for practical API testing by walking through three hands‑on examples—searching Baidu, interacting with WeChat’s public API, and triggering alerts on a specialized radio communication system—covering request setup, parameter handling, assertions, and common pitfalls.
This article outlines the architecture of a high‑traffic user center system, detailing core requirements, distributed session and transaction handling, caching strategies with Redis and local caches, common challenges such as hot data and high‑frequency queries, and provides practical solutions and a concise summary.
This article explains the internal PHP7+ data structures such as _zval_struct, zend_value, and zend_string, detailing their fields, type definitions, memory layout, flexible array usage, and the associated allocation and release macros that enable efficient, binary‑safe string handling in the Zend Engine.
This article explains how etcd 3.x switched its external API to gRPC, the challenges of using its gRPC‑gateway for HTTP requests in Apache APISIX, the default message size limit causing sync failures, and the certificate configuration pitfalls that were fixed through a PR merged in v3.5.0.
After upgrading to MySQL 8.0, the Druid connection pool experiences severe performance degradation with many threads blocked due to repeated failed class loading of the removed MySQLConnection class, and the issue is resolved by upgrading Druid to a newer version.
This article explains how to use Redis bitmap operations to efficiently implement like, sign‑in, and other binary state features, covering bitmap fundamentals, common use cases, essential commands, Java code examples with Jedis, and range query techniques.
This article introduces Spring Cache as a framework‑agnostic caching abstraction that eliminates manual cache code, explains its core concepts, annotations, configuration options, and demonstrates practical usage with Redis and custom key, condition, and eviction strategies in Spring Boot applications.
This article introduces the PHP variable system by examining the Zend Engine's source code, covering variable naming rules, value types, reference and variable variables, file extensions in the PHP source tree, and a detailed walkthrough of the zend_types.h definitions, unions, structs, and memory‑alignment considerations.
This article explores the fundamental concepts of software architecture, illustrates scaling challenges with examples like Uber and Weibo, and details multi‑tier designs, caching strategies, service decomposition, monitoring, and operational practices for building and maintaining high‑performance, billion‑user backend systems.
This article explains the various ways to use Spring's @Autowired annotation, examines its underlying implementation via reflection, and provides detailed code examples illustrating field, constructor, setter, and collection injection, while also discussing annotation lifecycle and best practices.
This article breaks down Nginx’s high‑performance architecture, covering its modular design, event‑driven processing, multi‑stage asynchronous request handling, master‑worker process model, and memory‑pool strategy, and explains how each component contributes to scalability, low latency, and efficient resource utilization.
This article explains microservices architecture, contrasting it with monolithic systems, outlines the problems solved by microservices, lists their advantages and disadvantages, presents a practical API example with code, and discusses splitting strategies, design principles, and common migration patterns.
The jdmonthname function in PHP returns the name of a month based on a given Julian day number and a specified calendar mode, detailing its string return type, required integer parameters, and usage for different calendar systems.
The JDDayOfWeek PHP function returns the day of the week for a given Julian day number, offering numeric or English string results based on an optional mode parameter, making it useful for date calculations in backend development.
The article explains how Spring's automatic dependency injection initializes beans to avoid NullPointerExceptions, contrasting it with manual object creation using new, and provides example code demonstrating proper @Autowired usage versus manual instantiation.
This article explains the concept of Python coroutines, compares them with multithreading, outlines suitable and unsuitable scenarios, introduces the httpx library for asynchronous HTTP calls, and demonstrates performance gains through synchronous and asynchronous code examples.
This article provides an extensive set of regular expression patterns for validating numbers, characters, and special formats such as email, URLs, phone numbers, dates, IP addresses, and more, offering developers ready-to-use solutions for common data validation tasks across various programming contexts.
This article summarizes Nginx's high‑performance architecture, covering its modular design, event‑driven processing, multi‑stage asynchronous request handling, master‑worker process model, and memory‑pool strategy, while illustrating each concept with diagrams and practical observations from recent reading notes.
This article explains the concept of API idempotency, why it is needed, practical design approaches, and how to generate globally unique identifiers using methods such as UUID and Snowflake to ensure reliable, high‑performance backend services.
