This article explains the drawbacks of traditional high‑latency timeout centers and presents a Redis‑based low‑latency design, detailing task storage, scheduling, topic and queue structures, two‑phase consumption, retry control, and the resulting performance and reliability benefits.
This article explains why duplicate requests—especially write operations—can cause serious issues, outlines common duplication scenarios, and presents a complete server‑side solution using unique request IDs with Redis as well as business‑parameter hashing with MD5 to achieve reliable idempotency in Java back‑end systems.
This article provides a step‑by‑step guide to integrating GitHub and QQ third‑party OAuth2 login in a Spring Boot backend, covering app registration, required URLs, state handling to prevent CSRF, and complete Java code for authorization, token exchange, and user info retrieval.
This article explains the fundamental differences between RPC and HTTP services, covering the OSI model, RPC architecture, synchronous vs asynchronous calls, and popular open‑source RPC frameworks such as gRPC, Thrift, and Dubbo, to help developers choose the right approach for large‑scale systems.
The article outlines various OpenWhisk serverless use cases—including microservices, web and mobile back‑ends, IoT data pipelines, API services, data processing, and cognitive applications—highlighting its modular scalability, language flexibility, and advantages for building lightweight, cost‑effective cloud‑native solutions.
This article compiles a wide range of practical PHP knowledge—including function‑parameter ordering, proper salt storage, newline handling, string‑operator precedence, http_build_query quirks, OpCache basics, the HTTPOXY vulnerability, operator precedence nuances, instanceof behavior, array_map tricks, performance considerations for array functions, type‑juggling pitfalls, comparison changes in PHP 8, and different ways to merge arrays—providing code examples and references for each topic.
This tutorial explains how to install Docker, pull and run a FastDFS Docker image, verify the service, add the fastdfs-client dependency to a Spring Boot project, configure the client, implement a utility class for file operations, and test the integration with sample code.
When a Java application throws IllegalArgumentException: Request header is too large, the issue stems from oversized HTTP headers, and you can resolve it by increasing the server's max‑http‑header‑size setting in Spring Boot or by moving large data from headers to the request body.
This article outlines a comprehensive technical architecture for internet services, covering DNS resolution (including traditional and HttpDNS), load balancing strategies and algorithms, API gateway functions and configurations, push notification mechanisms, and microservice communication patterns, providing practical references for building scalable, reliable backend systems.
This article presents an interview‑style walkthrough of HTTP request methods, detailing the eight methods defined by HTTP/1.1, focusing on GET and POST, their functional differences, URL length limits, parameter formatting, security considerations, and packet behavior.
This article chronicles the step‑by‑step evolution of a workflow engine, detailing how simple sequential approvals grew into a tree‑structured system supporting parallel, conditional, proxy, and timed nodes, complete with state management, nesting, and progress metrics.
This article explains the technical architecture of an internet company, covering DNS, load balancing, long connections, API gateways, push notifications, microservices, distributed transactions, and the supporting foundational services, providing a comprehensive reference for learners.
This article explains how zero‑copy techniques such as mmap, sendfile, and splice reduce CPU involvement in data transfer by avoiding memory copies between kernel and user spaces, and shows how Java NIO and Netty implement these mechanisms for high‑performance backend I/O.
This article explains how Nginx runs as a daemon with a master process and multiple worker processes, why it prefers a multi‑process asynchronous non‑blocking architecture over threads, and details the key internal data structures such as connections, requests, arrays, queues, lists, strings, memory pools, hash tables, and red‑black trees that enable its high‑performance HTTP handling.
The article introduces load balancing as a vital solution for high‑traffic systems, explains vertical and horizontal scaling, classifies balancers by hardware, layer and algorithm, and details common algorithms—random, weighted, round‑robin, least‑active, IP‑hash, and consistent hash—with code examples and usage guidance.
This article explains the purpose of Spring's @Transactional annotation, how it leverages AOP and dynamic proxies to manage transactions, and walks through the core source‑code components—including BeanPostProcessor, advisors, TransactionInterceptor, and the transaction lifecycle—illustrated with concrete code examples.
This article explains how Zhihu built a highly available, low‑latency read‑filtering service for its homepage, detailing the system’s design goals, architecture components such as proxy, cache and storage, massive data scale, migration from MySQL to TiDB, and performance results after adopting TiDB 3.0.
This article curates thirteen high‑quality Spring Boot open‑source projects—ranging from e‑commerce platforms and microservice frameworks to payment systems and HR tools—providing star counts, repository links, brief feature overviews, and demo screenshots to help Java developers choose valuable reference implementations.
This comprehensive guide explains Nginx’s core concepts—including reverse and forward proxy, load balancing, static‑dynamic separation, common commands, configuration blocks, and high‑availability setup with keepalived—providing step‑by‑step examples, diagrams, and practical tips for deploying scalable, high‑performance web services.
The article explains why simple sharding and database partitioning cannot achieve unlimited scaling in backend systems, analyzes the problem of excessive RPC‑to‑DB connections, and proposes a unitization approach that limits each service to a single database to enable true horizontal expansion.
This guide shows three practical ways—using the queryset query attribute, Django's connection object, and the Django Debug Toolbar—to inspect the raw SQL generated by Django ORM, helping developers optimize database performance and troubleshoot queries effectively.
This article explains a confusing PHP error where a method expects an instance of int but receives an integer, analyzes three common causes—including an incorrect use statement, outdated PHP version, and unnecessary type hint—and provides concise solutions for each.
Gaode’s new serverless/FaaS platform, built on Alibaba Cloud Function Compute with custom C++, Go, and Node.js runtimes, now processes over 100 000 QPS, enabling a unified client‑cloud codebase, rapid feature iteration, automatic scaling and cost savings, while supporting extensive monitoring, Dapr integration, and future edge‑computing enhancements.
This article analyzes the typical evolution from monolithic to RPC-based services, explains why sharding and database partitioning cannot alone achieve unlimited scaling due to connection limits, and introduces a unitization approach that assigns each application to a specific database shard to overcome those constraints.
mcrypt_encrypt encrypts plaintext using a specified cipher, key, mode, and optional IV, returning the ciphertext as a string or FALSE on failure, with detailed explanations of each parameter—including cipher name, key length requirements, data padding, mode options, and IV usage—provided for PHP developers.
Learn how to set up basic Nginx load balancing with a minimal nginx.conf, create multiple Node.js services, and explore common strategies like round-robin, weighted round-robin, and IP hash, complete with code examples and testing results to ensure even request distribution.
The article explains common causes of order loss and duplicate submissions in payment workflows, distinguishes external and internal loss, and provides concrete backend strategies such as intermediate payment states, timeout queries, idempotent handling, retry mechanisms, and Redis‑based deduplication to ensure reliable order processing.
This article explains cache‑database consistency challenges, outlines three classic caching patterns, compares delete‑versus‑update strategies, discusses operation ordering, and presents three practical solutions—including delayed double delete, retry mechanisms, and binlog‑based asynchronous eviction—to help maintain data integrity in distributed systems.
This guide explains how to define and use Elasticsearch index templates, manage index aliases, configure the _source field, and understand the roles of master, data, and coordinating nodes in a 7.8 cluster, with practical API examples and visual illustrations.
This article explains Spring's Lifecycle and SmartLifecycle interfaces, shows how to implement custom beans that react to container start and stop events, provides complete code examples, and demonstrates the automatic startup and ordered shutdown behavior of SmartLifecycle in a Spring Boot application.
This article explains the Nacos architecture, the principles of service registration and discovery, and how Spring Cloud integrates with Nacos through the ServiceRegistry interface, auto‑configuration, heartbeat mechanisms, and both Open API and SDK approaches for managing microservice instances.
This article compares popular Python web frameworks, highlights the speed advantages of async frameworks—especially Sanic—through benchmark data, explains why asynchronous I/O matters, and discusses Sanic's ecosystem, production readiness, documentation, and community support.
This article examines common performance pitfalls in Elasticsearch—including slow queries, cluster architecture bottlenecks, and business‑scenario challenges—and provides practical guidance such as caching key fields, data pre‑heating, hot‑cold separation, avoiding joins, and using tribe nodes to improve accuracy and response time.
This article presents a comprehensive collection of PHP interview questions covering topics such as directory creation, Smarty template features, safe mode restrictions, file handling, regular expressions, MVC concepts, and includes complete code examples for each solution.
This guide explains how to extend the moco API with request‑hit monitoring, demonstrates building a lightweight test service, and shows achieving over 50,000 QPS using FunTester, while detailing the available assertion methods and their practical code examples.
This article walks through Spring Boot 2.5.0's redesigned DataSource script initialization, clarifies deprecated properties, introduces the new SqlInitializationProperties class, and provides a complete example with Maven dependencies, configuration settings, SQL scripts, and best‑practice recommendations for automated database setup.
This article explains the fundamentals of online advertising business, outlines its technical challenges such as high concurrency, complex logic, and massive data handling, and then details a practical architecture—including data storage, indexing, retrieval, billing, and reporting—offering actionable insights for building robust ad platforms.
This tutorial walks through setting up iText dependencies, creating a Word‑based PDF template, configuring Adobe Acrobat form fields, and implementing a Spring Boot utility class and endpoint to generate and download customized PDF documents with embedded images.
This article explains PHP 8's named parameters, how they allow flexible argument ordering, skipping defaults, variadic usage, and demonstrates the new match expression with strict typing and constructor property promotion examples.
This article explains the role of a service registry in micro‑service architectures, compares Zookeeper (CP) and Eureka (AP) in terms of design, consistency, and availability, and provides detailed code and configuration examples for deploying both solutions in a high‑availability cluster.
Spring Boot 2.5.0 (alongside 2.4.6 and 2.3.11) introduces Java 16 support, Gradle 7 compatibility, enhanced Docker image building, a new datasource loading mechanism, dark‑mode documentation, and several important configuration and security changes for backend developers.
This article explains process and thread fundamentals, describes Node.js's single‑threaded nature, and provides detailed guidance on using the child_process module (spawn, fork, exec, execFile) and the cluster module to create, manage, and communicate between multiple Node.js processes for scalable, high‑concurrency applications.
The article explains why Java 8 Stream API is still valuable despite SQL offering similar functions, detailing Stream creation, terminal and intermediate operations, collectors, matching, and practical scenarios where Streams simplify data processing across microservices.
To improve debugging speed and reduce issue resolution time, the article recommends defining a unified LogObject structure with fields such as eventName, traceId, msg, costTime, request, and response, using JSON serialization, and discusses adding traceId, consolidating request/response logs, and implementation examples in Java.
This guide explains why the ThinkPHP controller Index class may not be found in a multi‑app setup, lists common causes, and provides three step‑by‑step solutions—including installing the think‑multi‑app extension, adjusting configuration files, and using full‑path URLs—along with the necessary code changes.
This article details a practical implementation of the FunTester distributed performance testing framework, covering its master‑slave‑server architecture, Docker image creation with a Groovy base, and full code examples for the master scheduler, slave agent, and test server.
This article provides a comprehensive guide for startups on choosing and assembling a backend technology stack, covering language choices, core components such as project management, DNS, load balancing, CDN, RPC frameworks, service discovery, databases, NoSQL, messaging, logging, monitoring, configuration, deployment, and operational best‑practice recommendations.
This guide outlines the essential components of a startup’s backend architecture, covering language choices, middleware, databases, messaging, monitoring, CI/CD, and deployment, and provides practical recommendations for selecting open‑source and cloud services to build a reliable, scalable system from scratch.
This article explains how Hystrix implements resiliency patterns such as bulkhead, circuit breaker, retry, and degradation for microservice calls, details its execution workflow, core components, dynamic configuration, isolation strategies, metrics collection, and practical usage, and discusses future alternatives and extensions.
This article explains the concepts of microkernel architecture, why it improves extensibility, its component structure of core system and plugins, and demonstrates how Java's JDK SPI mechanism implements a plug‑in model with detailed code examples and analysis of its use in JDBC drivers.
This article examines why local locks fail in distributed systems, introduces Redis‑based distributed locking, and walks through five progressive solutions—from a simple SETNX implementation to atomic Lua scripts—highlighting each approach's drawbacks and how to mitigate them.
Tomcat 10.0.x targets Jakarta EE 9, requiring developers to replace the javax package with jakarta, and version 10.0.5 introduces proper JNDIRealm escaping, updated HandlesTypes handling, and a refactored, IoC‑friendly WebSocket creation process to ease migration from earlier Tomcat releases.
This article explains the limitations of traditional REST APIs, introduces GraphQL as a more flexible and efficient alternative, details its core concepts, execution model, schema design, type system, and provides guidance on server and client implementations, popular services, and tooling.
This article explains PHP floating-point precision issues, demonstrates common arithmetic errors, and shows how to use the bcmath extension and various rounding functions such as floor, ceil, round, and number_format to achieve accurate numeric calculations in backend development.
This guide walks through creating a SpringBoot multi‑module project integrated with MyBatis and Shiro, covering Maven module setup, dependency versions, bean scanning nuances, unit‑test annotations, custom Realm configuration, common pitfalls, and provides a demo repository for reference.
This article analyzes the causes of data backlog in an ActiveMQ message queue, demonstrates how synchronized locks and default prefetch settings limit throughput, and presents three optimization phases—including removing the lock, adjusting queuePrefetch, and redesigning queue handling—to achieve over 30‑fold performance improvement.
This guide walks you through setting up RocketMQ Console 2.0 on a RocketMQ 4.8.0 cluster, configuring its properties, building and running the service, and testing message sending and receiving using a Spring Boot application, including topic creation tips.
This article explains the Same Origin Policy, introduces the CORS standard, details required response headers, and provides three practical Spring implementations—global config, filter, and annotation—to enable cross‑origin requests efficiently.
This article examines common RESTful API design mistakes—such as using verbs in URIs, embedding version numbers, and inconsistent case—provides corrected examples, discusses versioning strategies, and outlines best‑practice guidelines for building clean, resource‑oriented backend services.
This article provides a comprehensive overview of the Spring framework, covering its core modules, version compatibility, core concepts such as IoC and AOP, proxy implementations, bean factories, lifecycle management, transaction handling, MVC architecture, Spring Boot, Spring Cloud, and common annotations for Java backend development.
This article provides an in‑depth overview of microservice architecture, covering its definition, historical development, differences from monolithic and SOA approaches, core characteristics, practical implementation concerns such as API gateways, inter‑service communication, service discovery, fault tolerance, common design patterns, advantages, drawbacks, and a shift in thinking required for successful adoption.
This article traces the progression of web application architecture from tightly coupled JSP/Servlet MVC models through half‑separated Ajax‑driven approaches to fully separated front‑end/back‑end designs, highlighting how Node.js middle‑layer solutions improve adaptability, performance, and maintainability.
This tutorial explains how to create a lightweight PHP class for generating OSS direct‑upload signatures, describes the advantages of client‑side uploads without server bandwidth, provides the full source code, and highlights common pitfalls such as bucketHost configuration and policy newline handling.
This article explains the concepts of blocking (BIO), non‑blocking (NIO) and asynchronous (AIO) I/O in Java, introduces the principle of I/O multiplexing, provides a complete Java example with server and client code, and compares system calls like select, poll, and epoll.
A practical guide warns developers to breathe, verify servers, back up data, and follow strict habits when using risky commands like rm -rf, chmod, dd, and MySQL to prevent catastrophic data loss in production environments.
This article explains Java's proxy pattern, compares static and dynamic proxies, and provides detailed examples of JDK dynamic proxy, CGLIB, Javassist, and ASM implementations, highlighting their mechanisms, code samples, and practical considerations for backend development.
This tutorial explains how to replace traditional REST APIs with GraphQL by building a Spring Boot application, defining Java entities, writing GraphQL schema, implementing query resolvers, configuring the endpoint, and testing queries using tools like Altair.
Explore the key features, strengths, and trade‑offs of the three leading Java microservice frameworks—Spring Boot, Dropwizard, and Micronaut—to help you choose the right tool for building fast, lightweight, and scalable services in modern cloud environments.
This article presents a comprehensive guide to improving Laravel application performance by covering configuration caching, route caching, class map optimization, autoload optimization, session storage with Memcached, professional cache drivers, database query tuning, dataset caching, JIT compilers, and front‑end asset bundling.
This article explains Sentinel's flow control rule definition, the attributes of the FlowRule class, and how the FlowSlot, FlowRuleChecker, and related components evaluate and enforce these rules, including code examples and a discussion of different flow control strategies and node types.
This article explores how Java's method area stores object behavior, how the java.lang.instrument.Instrumentation API enables runtime class redefinition, and how tools like ASM, BTrace, and Arthas empower developers to inject bytecode, trace methods, and debug production systems without source changes.
This article explains why browsers enforce the same‑origin policy, defines cross‑origin requests, outlines the restrictions of non‑same‑origin interactions, and presents five practical methods—including a global CorsFilter, WebMvcConfigurer, @CrossOrigin annotation, manual header setting, and a custom filter—to implement CORS in Java Spring backends.
This article explains the dangers of using the kill -9 command on Java services, illustrates how it can cause data loss, and presents several graceful shutdown techniques for Spring Boot—including SIGTERM, Actuator endpoints, custom Tomcat shutdown hooks, and @PreDestroy backups—complete with code examples and screenshots.
This article examines why caching is needed for MySQL, discusses consistency challenges, and compares four Redis‑based solutions—including expiration, synchronous updates, Kafka‑mediated async updates, and binlog replication—offering guidance on selecting the appropriate approach based on latency and reliability requirements.
This article explains the necessity of distributed locks in multi‑node applications, outlines the essential properties a distributed lock must satisfy, and compares three common implementation methods—database‑based exclusive locks, Redis‑based locks, and Zookeeper‑based locks—highlighting their advantages, drawbacks, and usage patterns.
This article explains how to efficiently export large datasets to CSV files using PHP, describing the CSV format, why a simple streaming approach outperforms PHPExcel, performance expectations for 200,000 rows, and provides a complete PHP function that handles encoding, buffering, and memory‑friendly output.
The article recounts a production incident caused by an ungraceful RocketMQ consumer shutdown, analyzes the root cause involving Spring's bean destruction order and ShutdownHook behavior, and presents two solutions—using the official Spring‑Boot starter with SmartLifecycle or handling ContextClosedEvent—to achieve orderly termination.
This article details Ximalaya's evolution from a Tomcat‑based gateway to a Netty‑driven, fully asynchronous architecture, covering design challenges, performance bottlenecks, traffic management features, monitoring, and future HTTP/2 plans that enabled handling over 200 billion daily calls with high QPS.
This article explains the structure and meaning of HTTP status codes, detailing each of the five response classes (1xx informational, 2xx success, 3xx redirection, 4xx client error, 5xx server error) and providing concise descriptions for the most common codes within each class.
This article analyzes the root causes of MySQL 'wait_timeout' related exceptions in a backend system using MHA read/write separation, explains how oversized connection pool timeout settings and MySQL wait_timeout lead to idle connections being closed, and provides practical Druid configuration adjustments and alternative solutions to eliminate the errors.
This article systematically explains why thread pools are needed, how to create them, the types of pools Executors can build, key parameters, underlying principles, rejection policies, blocking queues, core‑thread settings, pool states, thread reuse, the difference between submit() and execute(), and practical usage tips for Java developers.
This guide explains why Spring Boot’s default @ControllerAdvice cannot catch servlet‑level errors, introduces the ErrorPageFilter mechanism, and shows how to replace the BasicErrorController with a custom ExceptionController that rethrows errors for unified handling across the application.
This article explains Elasticsearch’s three pagination methods—From + size, search_after, and Scroll—detailing their definitions, code examples, advantages, disadvantages, and suitable scenarios, while also discussing max_result_window limits, PIT views, and best practices for handling large result sets.
This article introduces the importance of web development frameworks and provides an overview of several popular Python frameworks—including CherryPy, Tornado, BIK, Flask, and Cuicweb—detailing their key features, advantages, and typical use cases for building efficient backend applications.
This article explains the concept, technical solutions, workflow diagrams, and database schema for implementing unified multi‑account login using username/password, mobile verification, and third‑party OAuth2 integrations, providing practical design guidance without detailed source code.
This article walks through the challenges of implementing a complex e‑commerce search interface, compares a naïve SQL solution with optimized multi‑query and Redis‑based approaches, and demonstrates how to use Redis sets, sorted sets, and transactions to achieve efficient querying, pagination, and data updates.
This article explains why PageHelper pagination yields incorrect totals when list operations are performed before or after pagination, analyzes the underlying cause that startPage only affects subsequent SQL, and provides a step‑by‑step solution that processes the list after pagination and returns a correctly populated PageInfo object.
This guide walks through the four‑layer backend architecture—language, components, processes, and systems—and offers practical recommendations for selecting project management, DNS, load balancing, CDN, RPC frameworks, databases, messaging, CI/CD, logging, monitoring, configuration, and deployment tools tailored to early‑stage companies.
zip_entry_filesize() is a PHP function that returns the actual size of a specified zip entry, taking a zip entry resource obtained via zip_read() as its argument and providing the entry’s size in bytes.
This article explains how Java's ReadWriteLock works, compares it with mutex locks, shows caching strategies for high‑concurrency scenarios, illustrates thread‑contention problems, and discusses lock upgrade and downgrade nuances to help developers write safe, performant backend code.
Spanning three decades, this article traces the evolution of web development from Tim Berners‑Lee’s 1991 static page through the rise of HTML, CSS, JavaScript, PHP, AJAX, SPA frameworks, server‑side rendering, Node.js, and emerging trends like React Server Components, illustrating how each breakthrough addressed the limitations of its predecessors.
This article explains what the Linux Load Average metric means, how the three numbers are calculated, and walks through each line of the top command output—including CPU, memory, swap, and process details—to help you diagnose server load issues effectively.
This article explains how to create a reusable backend foundation for new Spring Boot projects by assembling common utilities such as Swagger API documentation, MyBatis‑Plus code generation, unified response objects, pagination helpers, custom exception handling, multi‑environment Maven and Spring profiles, logback configuration, and a Jenkins pipeline.
This article investigates how Spring Boot’s connectionTimeout parameter behaves by conducting three experiments—controller‑side delay, HttpURLConnection requests, and raw socket connections—revealing that the timeout only applies after a client establishes a connection and remains idle, not to the overall request processing time.
This article outlines a comprehensive backend technology stack for startup companies, detailing language choices, essential components, processes, system tools, and best‑practice recommendations across areas such as project management, DNS, load balancing, databases, messaging, CI/CD, monitoring, and deployment.
This article examines the business context and collection workflow of a BOS‑integrated service, dissects the distributed lock logic and its execution sequence, and conducts a thorough structured code review that reveals logical, exception, non‑functional, and testability issues while offering concrete improvement recommendations.
This article explains what rate limiting is, why it is needed, the typical actions taken when limits are reached, compares single‑node and distributed architectures, reviews four classic limiting algorithms, and provides a practical Redis‑Lua token‑bucket implementation with code examples.
This article explains why optimizing Nginx HTTPS latency matters for instant search, describes how TLS handshakes add round‑trip delays, and provides step‑by‑step Nginx TLS configuration changes—such as enabling HTTP/2, adjusting ciphers, enabling OCSP stapling, tuning buffer sizes and session cache—that together reduced request latency by about 30% in a real‑world search service.
This article explains why local in‑memory locks fail in distributed environments, introduces the concept of distributed locks, and walks through five progressive Redis‑based lock implementations—bronze, silver, gold, platinum, and diamond—detailing their principles, code examples, advantages, and shortcomings.
This article explains how the Laravel PHP framework and the Vue.js progressive JavaScript library complement each other, highlighting their popularity, ease of integration, event‑driven architecture, virtual DOM performance, and faster learning curve, making them an ideal stack for new web projects.
