This article outlines the essential preparations, strategic service granularity decisions, and practical splitting techniques—based on business logic, scalability, reliability, and performance—to guide teams in migrating monolithic systems to a robust microservice architecture.
This article walks through the evolution from a single‑server Tomcat setup to a multi‑layer architecture using Nginx, a gateway, and LVS, explaining dynamic/static request separation, high‑availability strategies, and the performance trade‑offs that guide scalable backend design.
This guide outlines why microservice architecture is preferred for large applications, presents a clear learning roadmap, and details each critical concern—such as Docker, orchestration, API gateways, load balancing, service discovery, event buses, logging, monitoring, tracing, persistence, caching, and cloud providers—along with recommended tools.
This article explains the concept of gray release, outlines a simple architecture with essential components, describes common traffic-splitting strategies, shows how to implement control in Nginx and service layers, and discusses complex scenarios such as multi‑service and data‑centric deployments.
This article provides a comprehensive, step‑by‑step guide on why and how to split monolithic applications, prepare for migration, execute database vertical and horizontal sharding, handle schema changes, ensure consistency, and maintain stability during and after the split, enriched with real‑world pitfalls and solutions.
This article explains why microservice architecture is preferred over monolithic applications, outlines a learning roadmap, and details essential components such as Docker, container orchestration, API gateways, load balancing, service discovery, event buses, logging, monitoring, distributed tracing, data persistence, caching, and cloud providers.
This article explains the background, concepts, resource granularity, rule definition, calculation logic, and implementation steps for rate limiting and circuit breaking in microservice architectures, using examples from Spring Cloud, Kong, and Alibaba Sentinel to guide practical design decisions.
This article explains why message queues are used, outlines core interview questions, analyzes interviewers' expectations, compares major MQ products, and provides practical guidance on selecting the right queue for different scenarios.
The article explains how a supply‑chain system originally relied on tight microservice coupling for product queries, encountered performance and reliability issues, and then adopted data‑redundancy and a message‑driven decoupled synchronization architecture—using Bifrost—to improve query speed, consistency, and service independence.
This article analyzes the challenges of building a flash‑sale system—such as overselling, massive concurrent requests, URL exposure, and database strain—and presents a comprehensive backend design that includes separate databases, dynamic URLs, Redis clustering, Nginx load balancing, rate‑limiting, asynchronous order processing, and service degradation strategies.
This article details how Haro Mobility built a search‑driven ride‑matching platform using ElasticSearch and Flink, covering the business background, architectural evolution, data‑sync challenges, performance tuning, stability measures, and the resulting improvements in order completion and user engagement.
Vivo’s rapid development platform, built in two phases—a 2017 configuration platform offering visual form design, intelligent delivery, cloud control and smart push, followed by the 2021 low‑code “Houyi” system with visual composition, multi‑portal support and standardized storage—dramatically accelerates backend development, improves R&D efficiency, and sets the stage for future enhancements in configurability, usability, and complex backend handling.
The article shares practical experiences from evolving a mobile app store backend, comparing three API versioning models, detailing challenges of multi‑version client support, describing a two‑stage migration to compatible versioning, and offering design guidelines for scalable, maintainable service interfaces.
This talk outlines the evolution of Kuaishou's video infrastructure—from its early service‑oriented design through workflow‑engine and FaaS upgrades, to fine‑grained ROI‑driven resource management and infrastructure promotion, highlighting lessons shared with Netflix and Facebook and future functional‑declaration directions.
This article explains how to design and optimize backend server architecture for high‑concurrency scenarios, covering load balancing, database master‑slave clusters, NoSQL caching, concurrency testing tools, caching strategies, message‑queue based async processing, layered and distributed designs, redundancy, automation, and service‑oriented approaches.
The article explains how to design a high‑concurrency system by planning server architecture, load balancing, master‑slave databases, NoSQL clusters, caching layers, message‑queue based asynchronous processing, static‑content CDN, and automated redundancy to ensure scalability and reliability.
This article summarizes SOLID and component design principles, explains how to evaluate and balance component stability, coupling, and abstraction, and describes source‑code, library, and service‑level decoupled deployment strategies for building maintainable backend architectures.
This article presents a comprehensive guide to designing high‑concurrency backend systems, covering server architecture, load balancing, database and NoSQL clustering, caching strategies, concurrency testing tools, message‑queue solutions, first‑level cache, static data handling, layering, distribution, asynchronous processing, redundancy and automation.
This article demystifies message queues by comparing them to parcel lockers, explains their role in asynchronous processing and system decoupling, details point‑to‑point and publish‑subscribe models, introduces JMS, AMQP, RabbitMQ, ActiveMQ, RocketMQ, and Kafka, and outlines their architectures and high‑availability mechanisms.
This article explains six typical system architecture designs, focusing on the first three—single‑database single‑app, content‑delivery, and read‑write separation—detailing their structures, advantages, disadvantages, and practical implementation steps for modern backend development.
The article explains the typical live‑streaming architecture, its core modules, the impact of CDN integration, and three major challenges—video‑stream pressure, low‑latency interactive protocols, and high‑concurrency pulse traffic—while showing how Alibaba Cloud PTS can be used for realistic performance testing.
This article explains how to design a robust e‑commerce shopping‑cart service by separating business, system, and technical architectures, applying DDD, strategy and chain‑of‑responsibility patterns, and choosing Redis data structures for high‑performance storage.
This article examines the importance of resource isolation in distributed systems, covering thread, process, cluster, data‑read/write, static, and crawler isolation, and illustrates practical implementations with Netty, Dubbo, Tomcat, and Hystrix, including code snippets and configuration tips.
This article presents a comprehensive guide to designing high‑concurrency systems, covering server architecture, load balancing, database clustering, caching strategies, message‑queue based async processing, static data offloading, service‑oriented design, redundancy, automation, and practical implementation examples for large‑scale web applications.
The article details Ctrip Business Travel's order system architecture, outlining its background, challenges of the original vertical‑only design, and the layered, process‑driven, and snapshot design principles that guide its evolution toward modular backend services, data consolidation, configurable messaging, and service orchestration.
This article explains how a user‑behavior data dashboard originally built on a daily T+1 batch process was redesigned to achieve real‑time T+0 updates by introducing message‑queue notifications, a dedicated aggregation service, and MongoDB storage, improving data freshness and user experience.
This article explains the concepts, characteristics, and architectural design of a flash‑sale (秒杀) system, covering rate‑limiting, peak‑shaving, asynchronous processing, caching, scalability, and concrete Redis‑based implementation details for handling massive concurrent requests.
This article examines the challenges of building a flash‑sale system—such as overselling, massive concurrent requests, URL exposure, and database pressure—and presents a comprehensive backend design that includes dedicated databases, dynamic URLs, static pages, Redis clustering, Nginx load balancing, SQL optimization, token‑bucket rate limiting, asynchronous order processing, and service degradation techniques.
This article explains the origin, definition, and strategic role of the mid‑platform (Zhongtai) in enterprises, compares it with platformization, outlines front‑middle‑back distinctions, offers practical construction tips, discusses common pitfalls, organizational considerations, and future trends, providing a comprehensive guide for backend architects.
The article analyzes flash‑sale business flow, outlines the technical challenges of massive concurrent requests, and presents a comprehensive backend architecture—including request isolation, queueing, caching, sharding, replication, optimistic locking, and overload protection—to ensure correctness, scalability, and availability of seckill services.
This article provides a comprehensive overview of microservices architecture, covering its definition, key characteristics, advantages and drawbacks, suitable organizational contexts, core components such as service discovery, gateways, configuration centers, monitoring, circuit breaking, as well as containerization and orchestration technologies.
This article examines the challenges of evolving data models in large applications, explains the Command Query Responsibility Segregation (CQRS) pattern, and outlines when to adopt or avoid it to balance read/write performance, scalability, and system complexity.
This article details Dada's journey from identifying costly business‑configuration pain points to designing and deploying an automated configuration center that isolates business settings, improves system stability, enhances robustness, accelerates development, secures data, and delivers measurable performance gains.
This article details how a legacy e‑commerce supply‑chain system was re‑architected using Domain‑Driven Design, Hexagonal architecture, CQRS, and an EventStore solution to resolve unclear boundaries, inventory inaccuracies, and scalability issues while improving testability and operational efficiency.
This article analyses the business flow, unique characteristics, technical challenges, architectural principles, layer‑wise design, database strategies, high‑concurrency issues, cheating defenses, and data‑safety mechanisms required to build a reliable flash‑sale system capable of handling tens of thousands of simultaneous requests.
This article details how a tangled, legacy supply‑chain system was re‑engineered using domain‑driven design, hexagonal architecture, CQRS, and an EventStore solution, resulting in accurate inventory, clearer boundaries, easier extensions, and a reusable event‑driven component for future e‑commerce projects.
This article describes how Keep leveraged Domain‑Driven Design, hexagonal architecture, CQRS and EventStore to restructure a legacy supply‑chain system, solve inventory inaccuracies, improve modularity, and achieve scalable, maintainable backend services for its e‑commerce platform.
This article explains DataVisor's risk‑control system architecture, outlines the business challenges such as complex logic, massive data, high QPS and low latency, and demonstrates how OpenResty (Nginx + Lua) is used for high‑performance gateways, micro‑service style calls, hot‑loaded scripts, automatic circuit‑breakers, and progressive architectural evolution toward service‑mesh designs.
Using Taobao as a case study, this article traces the architectural evolution from a single-server setup handling hundreds of requests to a multi-layered, distributed system capable of supporting millions of concurrent users, detailing each stage’s challenges, technologies such as caching, load balancing, microservices, and cloud deployment.
This article describes how to design, implement, and evaluate a scalable backend that can simulate 10 billion WeChat red‑envelope requests by supporting up to 1 million concurrent users and handling 30 k–60 k QPS per server using Go, Linux tools, and custom monitoring.
This article analyzes common like‑system business scenarios, derives functional requirements, proposes three architectural solutions (Redis‑based priority queue, relational database, and a hybrid cache‑MQ‑DB design), presents detailed implementation code, and evaluates each approach with extensive performance tests to guide practical backend design choices.
The article analyzes why a company's clusters were unstable—unstable release process, missing monitoring and logging, insufficient documentation, and unclear request routing—and proposes a comprehensive solution built around Kubernetes‑centric CI/CD, a federated Prometheus monitoring platform, Elasticsearch logging, centralized documentation, and Kong/Istio traffic management.
This article explores the importance of resource isolation in distributed systems, detailing thread, process, cluster, data‑center, read/write, static, and crawler isolation techniques, with practical code examples from Netty, Dubbo, and Tomcat, and discusses trade‑offs such as thread‑pool versus semaphore isolation.
This article describes the background, requirements, architecture, script language selection, performance testing, and future plans of a rule engine used to send notifications to couriers in Dada Logistics, highlighting the trade‑offs among Groovy, MVEL, SpEL and Aviator.
To meet Baidu Chinese’s need for sub‑200 ms responses on multi‑hop queries across millions of dictionary entities, the team replaced MySQL with the open‑source HugeGraph graph database backed by RocksDB, deploying a multi‑master, REST‑enabled architecture with caching, bulk loading, and a data‑intervention platform to ensure fast, reliable traversal of semantic relationships.
The article explains the role, evolution, business logic, user requirements, and design principles of a payment operations platform, detailing its architecture, interaction model, permission system, and technical stack to support internal staff with secure, efficient, and easy‑to‑use services.
This article presents a comprehensive design for a high‑availability message center that targets 10,000 messages per second inbound throughput and 1,000 messages per second outbound delivery, detailing technical goals, functional requirements, technology selection, architectural diagrams, and implementation guidelines using RocketMQ, Elasticsearch, Spring Cloud Gateway, MySQL, Docker, and Kubernetes.
This article explains the design and implementation of a modular, configurable pricing engine that handles real‑time and simulated price calculations for complex e‑commerce promotions, addressing rule fragmentation, extensibility, priority conflicts, and transaction‑level precision while ensuring high performance and reliability.
The article explains message queues, their primary use cases—async processing, system decoupling, and traffic peak shaving—compares five mainstream products (ActiveMQ, RabbitMQ, Kafka, RocketMQ, Pulsar), and examines core design principles such as architecture, storage choices, push/pull models, and consumer groups, highlighting broader relevance to distributed systems.
The article examines Kuaishou Y‑tech's server‑side effects platform, detailing its background, technical challenges, exploration of open‑source workflow and serverless frameworks, architectural adjustments for non‑blocking APIs, and future development directions while highlighting recruitment opportunities.
This article explains how Kuaishou's Y‑Tech team designs a server‑side video‑effects platform that tackles high computational load, real‑time constraints, and resource limits by adopting asynchronous workflows, task‑queue scheduling, and cloud‑native serverless frameworks such as Netflix Conductor and Knative.
This article outlines the technical and business goals, design architecture, technology selection, and operational considerations for creating a message center capable of handling 10,000 messages per second upstream and 1,000 downstream, while ensuring 100% high availability and easy integration with third‑party push services.
This article examines the challenges of implementing a flash‑sale (秒杀) system—such as overselling, massive concurrency, request flooding, URL exposure, and database strain—and presents a comprehensive backend design that includes dedicated databases, dynamic URLs, static page rendering, Redis clustering, Nginx load balancing, optimized SQL, token‑bucket rate limiting, asynchronous order processing, and service degradation strategies.
This article explains the fundamental message exchange patterns—including publish‑subscribe, fanout, unidirectional and bidirectional streaming, as well as unicast, broadcast, multicast, and anycast routing—detailing their structures, use‑cases, and typical implementations in modern backend systems.
This article explains how Domain‑Driven Design provides a systematic approach to modeling complex business domains, guiding microservice decomposition, service boundaries, bounded contexts, and layered architectures, while addressing software complexity through strategic and tactical patterns such as SOLID, aggregates, and hexagonal design.
The article details Youzan’s Return Shipping Fee insurance service, explaining its consumer and merchant benefits, end‑to‑end workflow, integrated risk‑control mechanisms, insurance‑product specifications, and a layered technical architecture—business, domain, component, and dependency services built with domain‑driven design—to enable scalable, reusable e‑commerce insurance solutions.
Meituan’s Pike 2.0 replaces the Shark‑dependent Pike 1.0 with a four‑layer, TunnelKit‑based bidirectional messaging service that offers shared or independent channels, heartbeat‑driven keep‑alive, aggregated high‑QPS delivery, ordering guarantees, extensive monitoring, and plans for IoT and QUIC enhancements, achieving over 5 billion daily messages with sub‑220 ms latency.
This article walks through the evolution of a web service architecture—from a single Tomcat server to a multi‑node setup with load balancers, gateways, static‑dynamic separation, and finally a combined LVS‑Nginx solution with DNS load balancing and CDN integration—explaining each component and its impact on scalability and reliability.
This article explains the design and evolution of Baidu's word‑list service for content moderation, covering its background, multi‑layer architecture, management platform, strategy loading, matching workflow, performance optimizations for large texts, and future enhancements such as special‑character support and per‑business‑line deployment.
The article outlines the challenges of real‑time messaging in live‑streaming education, presents a multi‑stage backend architecture—including AccessServer, MessageServer, and specialized services—along with caching, clustering, and future enhancements such as connection migration and QUIC to achieve high reliability, low latency, and massive concurrency.
This comprehensive guide explores microservice architecture—from its historical roots and core characteristics to ten vital design patterns such as database per service, event sourcing, CQRS, Saga, BFF, API gateway, Strangler, circuit breaker, externalized configuration, and consumer‑driven contract testing—detailing their advantages, drawbacks, and practical usage scenarios.
This article explores how Domain‑Driven Design (DDD) was applied to redesign a rapidly evolving retail store system, detailing the challenges of legacy monoliths, the step‑by‑step migration through versions 1.0, 2.0 and 3.0, and the resulting architectural, tactical and operational benefits for backend development.
This article explains why message queues are used in system architecture, outlines their advantages such as decoupling, asynchronous processing, and traffic shaping, discusses their drawbacks, and compares four popular MQ solutions—Kafka, ActiveMQ, RabbitMQ, and RocketMQ—to help candidates ace interview questions.
This article explains the challenges of flash‑sale traffic spikes and presents a multi‑layered backend architecture—using CDN‑cached static pages, read‑write split Redis, Lua scripts for atomic stock deduction, and Redis‑based message queues—to achieve high concurrency, stability, and fairness.
This article introduces key microservice architecture design patterns—including Database per Service, Event Sourcing, CQRS, Saga, BFF, API Gateway, Strangler, Circuit Breaker, Externalized Configuration, and Consumer‑Driven Contract Testing—explaining their advantages, drawbacks, appropriate usage scenarios, and example technologies to guide scalable, resilient system design.
This article explains microservices architecture, contrasting it with monolithic systems, outlines the problems it solves, lists its advantages and disadvantages, provides a concrete service example with code, and discusses strategies, principles, and patterns for splitting and evolving microservices.
This article analyzes the large‑scale architecture of WeChat Moments, detailing image and video traffic characteristics, hardware and software safeguards, disaster‑recovery mechanisms, capacity assessment, and a series of flexible strategies such as compression format changes, bitrate reduction, buffer pools, and timeline throttling to handle holiday spikes.
The article outlines Vivo Mall’s new independent promotion system architecture—introducing a unified discount model, flexible pricing engine, and scalable, high‑concurrency design—while detailing technical solutions such as Redis caching, batching, hot‑cold separation, rate‑limiting, idempotency, circuit‑breaker safeguards, and lessons learned from Redis SCAN and hot‑key issues.
This article explains the purpose of aggregates in Domain‑Driven Design, illustrates common pitfalls with database‑centric and naïve OO models, and provides practical heuristics and implementation guidelines—including lifecycle, domain, and scenario consistency—to help developers design clean, consistent aggregates.
This article explains the differences between in‑process caches and external cache services like Redis, outlines the drawbacks of process‑level caching in distributed systems, and provides concrete criteria and strategies for deciding when to migrate to a dedicated cache service.
The article explains why traditional two‑phase commit fails in microservice architectures, introduces the Saga pattern as a solution, compares choreography and orchestration implementations, illustrates a step‑by‑step e‑commerce example, and discusses rollback handling, benefits, and drawbacks.
The article proposes a comprehensive microservice‑based caching solution for low‑frequency static data such as vehicle models and user profiles, detailing why caching is needed, why Redis and persistent queues are chosen, how consistency checks work, and the trade‑offs compared with simple expiration strategies.
This article explains key microservice design patterns—including Database per Service, Event Sourcing, CQRS, BFF, API Gateway, Strangler, Circuit Breaker, Externalized Configuration, and Consumer‑Driven Contract Testing—detailing their advantages, disadvantages, suitable scenarios, and example technologies for building scalable, resilient backend systems.
To solve the scalability, visibility, and debugging challenges of heterogeneous asynchronous calls after Alibaba Momma’s advertising services shifted to micro‑services, the team created the AMB (Alibaba Momma Application Message Bus), a console‑driven, bus‑style platform with layered connectors, reusable components, isolated JStorm topologies, and centralized monitoring that turns hours‑long coding into rapid visual workflow configuration.
This article explains the essence of DDD aggregates, why they are needed to enforce business consistency, how to identify proper aggregate boundaries using lifecycle, domain, and scenario‑frequency rules, and provides practical implementation guidance with code examples and architectural tips.
This article explains the evolution from monolithic to microservice architectures, defines microservices, compares Spring Cloud and Dubbo solutions, and provides a detailed overview of Spring Cloud’s core components such as Eureka, Ribbon, Feign, Hystrix, Zuul, Gateway, Config, Bus, OAuth2, and Sleuth, illustrated with diagrams.
This article explains the definition of microservices, outlines the core challenges and standard components required for a microservice architecture, and discusses why Spring Cloud and Spring Cloud Alibaba are popular choices for building and managing such systems.
This article explains Apache RocketMQ's high‑performance distributed messaging architecture, detailing its core components—Producer, Broker, Consumer, and Namesrv—along with routing metadata, message ordering, priority handling, parallelism, and essential concepts such as topics, groups, tags, and reliability mechanisms.
This article explains how to design backend architectures that meet the "three high" goals—high concurrency, high performance, and high availability—by using load balancing, connection pooling, traffic filtering, multi‑level caching, log optimization, and failover strategies.
This article presents a comprehensive guide to designing service‑center interfaces and data models, covering the Facade pattern, DTO usage, and eleven practical service design principles such as contract‑first, cohesion, granularity, redundancy elimination, statelessness, naming, and operation design, illustrated with code examples and diagrams.
This article provides an in‑depth overview of microservices, covering its origins, core principles, advantages and drawbacks, adoption criteria, architectural stages, prerequisite infrastructure, design patterns, service decomposition strategies, and a comparison of popular frameworks such as Spring Cloud, Dubbo, Service Mesh, and related tooling.
This article explains the design of a low‑latency timeout center, compares it with traditional high‑latency approaches, and details a Redis‑based solution that uses sorted sets, topic partitioning, and multi‑stage queues to achieve fast, reliable, and at‑least‑once message processing.
This article explains the drawbacks of traditional synchronous request handling, introduces message queues as a solution for asynchronous processing, decoupling services, and traffic shaping, and then details the common MQ challenges—duplicate messages, data inconsistency, loss, ordering, backlog, and added system complexity—along with practical mitigation strategies.
This article presents a detailed case study of Zhihu's read‑service architecture, describing its high‑availability, high‑performance, and easy‑scalability design goals, key components such as Proxy, Cache and TiDB storage, performance metrics, and the migration from MySQL to TiDB with practical lessons learned.
This article examines whether Service and DAO layers in Java backend projects require interfaces, arguing that with dependency‑injection frameworks like Spring the interfaces are often unnecessary, while outlining development workflows, project structures, and scenarios where interfaces remain useful.
This article details how Lakala built a distributed, cloud‑native messaging platform using Apache Pulsar, covering functional requirements, architectural advantages, performance testing, and real‑world integration scenarios such as OGG adapters, TiDB pipelines, OpenMessaging, custom sources, functions, Flink connectors, and future plans.
The article describes how the Tongtian Tower activity platform adopted a serverless Function-as-a-Service (FaaS) architecture to improve development flexibility, reduce integration costs, enable local function execution, and support rapid iteration across multiple channels, while outlining its core components, features, SDK design, and future directions.
This article examines JD Daojia's order fulfillment system, detailing the challenges of high‑volume prompt‑sound queries, the division of responsibilities among Redis, MySQL, and Elasticsearch, the adoption of Canal for asynchronous data replication, deployment practices with Kafka and Zookeeper, and the key operational lessons learned.
The article details the step‑by‑step architectural evolution of a cloud classroom replay generation platform, from a quick third‑party‑based implementation to a self‑developed, CDN‑integrated solution that now reliably produces nearly 90,000 class videos daily while reducing cost and operational complexity.
This article explains the role of an order system in traditional e‑commerce enterprises, outlines its main functional modules, describes its upstream and downstream relationships, details core processes such as order creation, payment, fulfillment, and returns, and discusses future architectural evolution and state‑machine design.
Vivo’s live‑streaming IM system combines short‑polling and long‑connection techniques, Redis SortedSet storage, priority‑based routing, protobuf compression, and discard strategies to deliver a fault‑tolerant, high‑concurrency messaging backbone that scales with growing traffic and diverse message types.
This article explores the essence of system architecture, illustrating how large‑scale services like Uber and Weibo handle massive traffic, data storage, service decomposition, multi‑level caching, and monitoring, and offers practical design principles for building robust, high‑performance backend systems.
This article details Zhihu's read‑service architecture, covering its business requirements, high‑availability and high‑performance design goals, key components such as Proxy, Cache and Storage, extensive performance metrics, the migration from MySQL to TiDB, and the benefits brought by TiDB 3.0 features.
DiDi’s Bay Flow platform transforms its service‑side API into a configurable, layered “travel middle‑platform” that routes front‑end requests through a flow layer and reusable ability components, using the Dukang framework’s transports, steps, and factors to support dozens of ride‑hailing categories across PHP and Go while ensuring isolation and high reuse.
The article explains the CQRS (Command Query Responsibility Segregation) pattern, showing how separating command and query models addresses diverse data view needs, improves query flexibility, discusses synchronization methods, compares with microservices and caching, and outlines its benefits and trade‑offs.
This talk explains JD.com’s order‑fulfillment workflow, the underlying storage stack of Redis, MySQL and Elasticsearch, the challenges of high‑traffic alert‑sound queries, the adoption of Canal for data heterogeneity, and a 4R‑based complexity‑oriented design methodology for building resilient backend systems.
This article breaks down the design and source‑code implementation of RocketMQ's NameServer, detailing its core responsibilities, component interactions, and the seven Java classes that together provide network handling, connection management, routing, configuration, and startup logic.
This article analyzes the challenges of building a flash‑sale system—such as overselling, massive concurrent requests, URL exposure, and database pressure—and presents a comprehensive backend architecture that combines Redis clustering, Nginx load balancing, token‑bucket rate limiting, asynchronous order processing, and service degradation techniques.
From its 2016 debut to the present, Baidu’s Fengjing APM system has evolved through four major releases—moving from invasive jar‑based probes to non‑invasive bytecode agents, adding modular hot‑swap plugins, scaling to thousands of containers, handling billions of daily metrics via Kafka, Doris, and SIA TSDB, while solving probe upgrade downtime, data‑ingestion volume, and call‑graph query latency.
This article explains microservice architecture, its key characteristics, advantages and disadvantages, and presents ten essential design patterns—including database per service, event sourcing, CQRS, Saga, BFF, API gateway, Strangler, circuit breaker, externalized configuration, and consumer‑driven contract testing—while offering guidance on when to apply each pattern.
