This article analyzes a high‑concurrency flash‑sale scenario using SpringBoot, MySQL, and JMeter, demonstrates seven implementations—from service‑level locks to AOP, pessimistic/optimistic locks, and queue‑based designs—examines their trade‑offs with concrete code, test results, and practical recommendations.
The article uses everyday analogies to explain why multithreaded programming, especially when dealing with shared data, debugging, and performance optimization, is inherently difficult due to nondeterministic execution, combination explosion, and the challenges of lock granularity.
This article analyzes a thread‑pool exhaustion issue in JD's JSF framework during a Redis cache upgrade, detailing log evidence, stack‑trace analysis, lock contention caused by read/write locks and ForkJoinPool usage, and the steps taken to diagnose and resolve the problem.
Reentrant locks are thread‑safe synchronization tools that let the same thread acquire the same lock multiple times without deadlocking, tracking acquisition counts, and offering advantages over traditional synchronized blocks, with Java’s ReentrantLock providing flexible features such as interruptible and timed locking, illustrated by a complete code example.
This guide explains why standard Java collections are not thread‑safe, introduces their concurrent counterparts such as Vector, ConcurrentHashMap, and various BlockingQueue implementations, and provides concrete code examples and usage patterns for safe multi‑threaded programming.
This article explains how Java's ThreadLocal provides thread‑specific storage, enabling safe context management across thread pools, web request handling, database connections, logging, and global data propagation, thereby preventing interference and improving concurrency performance.
This article explains Java 21's virtual threads, their lightweight and auto‑managed nature, demonstrates basic usage and Spring Boot integration, compares performance against traditional threads, and offers additional Java performance tips for high‑concurrency applications.
This article explains the CSP concurrency model, compares it with the Actor model, discusses its advantages and limitations, and reviews Go's native support as well as several Python libraries and experimental projects that aim to bring CSP-style parallelism to Python.
The article explains the distinction between a data race—simultaneous unsynchronized memory access by goroutines—and a race condition—logic errors caused by timing dependencies—using Go code examples, demonstrates how to reproduce each issue, and shows how mutexes or atomic operations can resolve them.
This article explains the four standard Java ThreadPoolExecutor rejection policies—AbortPolicy, CallerRunsPolicy, DiscardOldestPolicy, and DiscardPolicy—detailing their behavior, suitable scenarios, and providing full code examples, plus guidance on creating custom policies.
This article explains Java's ThreadLocal mechanism, detailing its internal ThreadLocalMap structure, core set/get/remove operations with full code examples, and demonstrates how multiple ThreadLocal variables are stored per thread, providing a clear understanding of thread‑local storage in backend development.
This article explains the core concepts of Java’s AbstractQueuedSynchronizer (AQS), its exclusive and shared modes, the template‑method design it uses, and walks through the actual source code showing how ReentrantLock implements both fair and non‑fair locking, complete with diagrams and code snippets for interview preparation.
This article explains Java’s java.util.concurrent.Phaser class, compares it with CountDownLatch, details its core methods, demonstrates practical usage with code examples, and shows how to build a custom lightweight synchronization utility for performance testing scenarios.
This article explains the step‑by‑step decision process a Java thread pool follows when execute() adds a task, covering core and maximum pool sizes, queue handling, thread creation, rejection policies, and idle thread termination.
This article explains how Redisson leverages Redis, Lua scripts, and Pub/Sub to implement a robust distributed lock in Java, covering lock characteristics, client creation, acquisition, renewal, and release mechanisms with code examples.
This article breaks down the seven parameters of Java's ThreadPoolExecutor constructor, explaining corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, threadFactory, and handler, and provides practical tips on thread creation and rejection policies.
This article introduces twenty advanced Python concepts—including decorators, context managers, generators, metaclasses, multiple inheritance, coroutines, closures, magic methods, dynamic attributes, GIL, async IO, regular expressions, garbage collection, modules, virtual environments, SOLID principles, type annotations, IPC, memory management, and reflection—explaining their typical use cases and providing clear code examples for each.
This article explains how to protect time‑consuming business operations and critical data by designing a Redis‑based distributed lock using custom annotations, Spring AOP, and a ScheduledExecutorService that automatically extends the lock’s expiration to avoid premature release.
CountDownLatch and CyclicBarrier are two essential Java synchronization tools from java.util.concurrent, enabling threads to coordinate tasks; this guide explains their concepts, usage with code examples, advantages, disadvantages, and key differences, helping developers choose the right tool for thread coordination.
This article walks through Go's concurrency model, detailing how goroutines are scheduled across logical processors, how to control parallelism with GOMAXPROCS, detect and resolve race conditions using atomic operations, mutexes, and channels, and provides practical code examples for each concept.
This article explores Java's thread communication techniques—including the basic wait/notify mechanism, advanced Lock and Condition usage, and the thread‑safe BlockingQueue—providing detailed explanations, producer‑consumer examples, and additional concurrency utilities like CountDownLatch, illustrating how to coordinate threads efficiently in multithreaded applications.
This article demonstrates how to simulate a high‑concurrency flash‑sale scenario using SpringBoot, MySQL, Mybatis‑Plus and JMeter, analyzes the overselling problem caused by premature lock release, and presents seven solutions—including lock‑first strategies, AOP, pessimistic and optimistic locks, and queue‑based approaches—along with code samples and test results.
This article explains the purpose and usage of Java’s synchronized keyword, covering object locks, method locks, synchronized blocks, and class locks, along with detailed code examples that demonstrate how threads acquire and release locks to ensure data consistency in multithreaded environments.
In Java’s ThreadPoolExecutor, core threads remain alive even when idle unless the allowCoreThreadTimeOut flag is set to true, which then permits both core and non‑core threads to be reclaimed after exceeding the keepAliveTime threshold, a behavior that contradicts the pool’s design principle of minimizing thread creation overhead.
This article explains Go's Context concept, its role in managing Goroutine lifecycles, the standard library's context package API, how to create and cancel contexts, share values safely, and best practices for using Contexts in concurrent backend applications.
The article explains why using Thread.sleep in a loop causes busy‑waiting and performance problems, and demonstrates several Java scheduling alternatives—including Timer/TimerTask, ScheduledExecutorService, wait/notify, and CompletableFuture—to efficiently check a flag at fixed intervals.
This article outlines a comprehensive guide to Go's concurrency model, covering fundamental concepts, goroutine scheduling, synchronization primitives, channel communication, common patterns, deadlock avoidance techniques, and performance‑optimizing mechanisms with concrete code examples and step‑by‑step explanations.
This article explains why thread execution order is nondeterministic and presents eight Java techniques—join, single‑thread executor, CountDownLatch, CyclicBarrier, Semaphore, synchronized with wait/notify, and Lock with Condition—to reliably enforce sequential execution, complete with clear code examples for each method.
This article explains how Rust's memory safety, concurrency guarantees, explicit error handling, and modern tooling make it a safer and more maintainable alternative to C for developing Linux kernel modules.
This article explains the Fork/Join model and ForkJoinPool in Java, covering divide‑and‑conquer theory, RecursiveTask implementation, task submission methods, work‑stealing queues, common pool pitfalls, and performance testing with code examples to help developers choose and tune parallel execution strategies.
This article explains Java virtual threads, compares them with regular threads, shows how to enable them in SpringBoot, and presents performance tests that reveal up to a 200‑fold reduction in latency for IO‑bound workloads.
This article explains the challenges of thread synchronization in distributed systems, introduces the concept of distributed locks, compares common implementations such as Redis, Zookeeper, and databases, and provides robust Java and Lua solutions to ensure atomicity, avoid deadlocks, and support lock renewal.
This article outlines a Rust programming book that starts with fundamental syntax, variables, and memory management, then progressively explores ownership, lifetimes, error handling, concurrency, async programming, traits, macros, and practical examples, providing code snippets and core concepts for each topic.
This article explains the Java java.util.concurrent.locks.Lock interface and its ReentrantLock implementation, detailing the advantages of reentrancy, interruptibility, and timeout features, and provides practical code examples for blocking, interruptible, and timed lock acquisition along with best‑practice recommendations.
This article compares Java and Go across syntax, type systems, object‑oriented features, pointer usage, error handling, concurrency models, and reflection, providing code examples to illustrate the practical differences and trade‑offs for developers transitioning between the two languages.
This article explains the purpose, internal implementation, and correct usage patterns of Go's sync.Cond concurrency primitive, walks through its source code, demonstrates simple and advanced examples—including a custom concurrent waiting queue—and provides test cases to illustrate its behavior in real-world scenarios.
This article introduces Java 21 virtual threads, explains their lightweight, high‑concurrency and automatic management advantages, demonstrates basic and delayed usage with code examples, shows how to enable them in Spring Boot, and compares their performance against traditional threads in various scenarios.
This chapter introduces advanced Java multithreading concepts, explaining thread safety, the synchronized keyword, various synchronization techniques, and practical code examples such as object‑level, class‑level, method‑level synchronization and double‑checked locking to help solve concurrency problems in performance testing.
This article compares Java and Go across syntax simplicity, type systems, object‑oriented features, pointers, error handling, concurrency, reflection, and community culture, providing concrete code examples and practical insights to help Java developers transition smoothly to Go.
This article explains how Go's testing/synctest experiment speeds up cache expiration tests by using a virtual clock and bubble isolation, providing code examples that reduce a five‑second wait to milliseconds while ensuring reliable concurrent test execution.
This article explains the ABA concurrency issue in distributed systems and presents three practical solutions—using Redis locks, implementing optimistic locking with version fields, and leveraging ordered message queues—to ensure data consistency under concurrent updates.
This article explains why JDK 8's CompletableFuture lacks built‑in timeout interruption, analyzes common usage patterns and their limitations, and presents a custom asynchronous timeout solution that works in both JDK 8 and JDK 9 environments, complete with reusable utility code.
This article explains C++11’s memory model and atomic types, demonstrating how lock‑free concurrency, memory ordering, and synchronization primitives such as fences can be used to achieve high‑performance, race‑free multithreaded code for demanding backend systems like game servers.
Java developers should avoid ten common thread‑pool mistakes—such as using unbounded queues, misconfiguring thread counts, neglecting shutdown, ignoring rejection policies, swallowing task exceptions, submitting blocking work, overusing pools, lacking monitoring, and missing dynamic tuning—by configuring bounded queues, proper sizes, explicit policies, exception handling, and runtime adjustments.
This article explains ten common mistakes when using Java thread pools—such as unbounded queues, wrong thread counts, missing shutdown, and ignored exceptions—and provides concrete code examples and best‑practice solutions to help developers write safer, more efficient concurrent code.
This article walks through Java thread‑pool queue options—LinkedBlockingQueue, SynchronousQueue, LinkedBlockingDeque, and PriorityBlockingQueue—explaining their characteristics, demonstrating code examples, and showing how to build multi‑priority executors with concrete output analysis.
This article explains the segment‑mode ID generation strategy, analyzes its pros and cons, describes suitable application scenarios, and provides a complete Java implementation with database schema, supporting classes, and a multithreaded test case for high‑concurrency environments.
This article introduces the Disruptor in‑memory message queue, explains its architecture and core concepts such as Ring Buffer, Sequence, Sequencer, and Wait Strategies, and provides tuning guidance and a complete Java example for building low‑latency concurrent systems.
This article experimentally compares how a Java ExecutorService thread pool reacts to uncaught exceptions when tasks are submitted via execute versus submit, showing that execute removes the faulty thread and creates a new one while submit retains the thread and stores the exception in a Future.
This article examines how Java's ExecutorService thread pool reacts when a task throws an uncaught exception, comparing the behaviors of execute and submit methods, analyzing source code, and summarizing the impact on thread removal, creation, and exception retrieval.
This article examines why uncaught exceptions in Java thread pools cause runaway thread creation, then walks through five concrete strategies—try‑catch wrappers, Callable, afterExecute overrides, custom ThreadFactory, and a global default handler—each illustrated with runnable code and detailed analysis.
This article examines five Go implementations of a broadcast notifier—using sync.Cond, channels, context, sync.WaitGroup, and sync.RWMutex—detailing their code, execution flow, and trade‑offs so readers can understand how each primitive achieves notification broadcasting.
This article explains the limitations of Java's Future, introduces CompletableFuture with its rich API for non‑blocking asynchronous programming, demonstrates practical usage including task creation, result retrieval, chaining, exception handling, and shows how RocketMQ leverages CompletableFuture to coordinate disk flush and replica sync tasks efficiently.
To avoid performance degradation caused by simultaneous large‑scale data exports, this guide demonstrates building a fixed‑size FIFO export queue in Spring Boot, integrating EasyExcel for million‑row exports, handling asynchronous processing, and providing sample code for the queue, export service, and controller.
This article explains ten common Java thread‑pool pitfalls—such as using Executors shortcuts, misconfiguring thread counts, ignoring queue choices, and neglecting shutdown or monitoring—and provides concrete code examples and best‑practice solutions to help developers write safer, more efficient concurrent code.
Java's CompletableFuture, introduced in Java 8, replaces the blocking Future with a rich, non‑blocking API that supports asynchronous task creation, result retrieval via get/join, chaining callbacks, exception handling, task combination (AND/OR, allOf/anyOf), and recommends custom executors, timeouts, and proper saturation policies.
This article systematically dispels ten widespread myths about PHP—covering threading, project scale, security, modern relevance, usage scope, code quality, performance, object‑oriented support, learning depth, and scalability—showing that modern PHP remains a powerful, secure, and versatile backend technology.
This article explains Java 21's virtual threads, their lightweight and high‑concurrency advantages, demonstrates basic creation and Spring Boot integration, compares performance against traditional threads, and offers additional Java performance optimization techniques.
The article demonstrates how to implement a bounded FIFO export queue in a Spring Boot application, using synchronized wait/notify methods to limit concurrent large‑data exports to ten threads, integrating with an abstract EasyExcel exporter and a controller that spawns export tasks, while noting future enhancements such as persistent storage and Redis‑based queues.
This article thoroughly explains the design and implementation of Go's context package, covering its core interfaces, various concrete types, cancellation propagation, deadline handling, value storage, and the internal mechanisms that enable concurrent-safe control flow and data passing across context trees.
This article introduces Java 21 virtual threads, explains their lightweight and automatically managed nature, demonstrates basic creation and Spring Boot configuration, and presents performance experiments comparing traditional and virtual threads in both CPU‑bound and HTTP request scenarios.
This article explains why the standard Executors factory methods may be insufficient, details each ThreadPoolExecutor constructor parameter, demonstrates how to configure a custom pool for performance testing, and walks through multiple code examples that illustrate thread creation, queue behavior, and rejection policies.
The article analyses a large‑scale benchmark comparing Go, C, Rust, C# and other languages under single, 100 k and 1 M concurrent tasks, revealing how Go’s 64‑bit int array size and goroutine stack overhead cause dramatically higher memory consumption despite comparable CPU performance.
This article explains the concepts, creation methods, usage examples, and internal implementation details of fair and unfair locks in Java's ReentrantLock, comparing their performance characteristics and providing guidance on when to choose each type in multithreaded applications.
This article explains how Nginx handles concurrent connections, defines worker_processes and worker_connections, shows how to calculate the theoretical maximum concurrency, and provides practical configuration tips for achieving tens of thousands of simultaneous connections.
This article explains PHP 8.1 Fibers, describing their cooperative multitasking mechanism, how suspension and resumption affect the main script, why they do not provide true asynchronous execution, and how they can be combined with event loops for more efficient non‑blocking code in backend development.
This article explains Java thread pools, their performance benefits, and how to create and use FixedThreadPool and CachedThreadPool via the Executors utility, providing code examples, execution results, and guidance on selecting the appropriate pool for different concurrency scenarios.
This article introduces Cangjie, a lightweight, high‑performance programming language for HarmonyOS, detailing its core advantages, rapid environment configuration, distinctive language features such as flow expressions, lightweight threads, extensions, synchronization primitives, and demonstrates seamless interoperation with ArkTS, concluding with future development outlook.
Java's ThreadPoolExecutor provides four built‑in RejectedExecutionHandler strategies—AbortPolicy, CallerRunsPolicy, DiscardPolicy, and DiscardOldestPolicy—each suited to different overload scenarios, and this article explains their behavior, trigger conditions, and practical application guidelines for robust backend concurrency management.
This article provides a concise English recap of the 27 previously published InnoDB lock module articles, covering theoretical concepts such as table and row locks, lock waiting, deadlock handling, and practical scenarios like lock behavior during inserts and duplicate key operations.
This article explains the purpose, typical usage scenarios, and provides concrete code demonstrations of Java's CountDownLatch and CompletableFuture, comparing their synchronization versus asynchronous capabilities and guiding developers on selecting the appropriate tool for effective multithreaded programming.
This article explains HarmonyOS concurrency concepts, covering async patterns with Promise and async/await, the Actor model for multithreading, and practical usage of TaskPool, Worker, and the @Concurrent decorator with code examples to improve app responsiveness and performance.
singleflight, a Go concurrency primitive from the x/sync package, merges duplicate in‑flight requests to reduce server load, with detailed usage examples, source code analysis, and discussion of its differences from sync.Once and typical application scenarios such as cache‑penetration, remote calls, and task deduplication.
This article provides a comprehensive overview of operating systems, explaining their essence as software, detailing core functions such as process and memory management, device and file system handling, security, user interfaces, and describing key characteristics like concurrency, sharing, asynchrony, virtualization, as well as common OS classifications and architectural designs.
The author recounts a four‑year journey from UI automation to Java‑based performance testing, illustrating how mastering Java’s concurrency utilities and Groovy scripting can replace traditional tools like JMeter, enabling flexible, high‑throughput test scenarios and deeper control over test case design.
This article explains the concept of spin locks, compares them with mutexes, shows how to use the pthread API and C++ atomic_flag to implement them, outlines suitable scenarios, highlights CPU‑usage pitfalls, and provides practical code examples.
This article explains how to wrap Go goroutine execution in a reusable function that catches panics, logs stack traces, and automatically restarts the goroutine, discussing the underlying fault‑tolerance concepts, related design patterns, suitable use cases, and possible enhancements.
This article summarizes how to correctly declare, monitor, configure, and name Java thread pools, explains common mistakes such as unbounded queues and ThreadLocal contamination, and introduces dynamic tuning techniques and open‑source solutions for robust backend concurrency management.
This article compares coroutines and threads for high‑concurrency and I/O‑intensive workloads, summarizes multithreading fundamentals, presents performance‑critical code examples, and discusses JVM memory, locking, middleware, and various optimization techniques for backend systems.
This article explains the conditions that trigger Java thread‑pool rejection policies, describes the four built‑in policies (AbortPolicy, CallerRunsPolicy, DiscardPolicy, DiscardOldestPolicy), provides detailed code examples for each, and discusses suitable application scenarios for backend developers.
This article provides a detailed technical analysis of Go's runtime memory management, covering the initialization of the mheap structure, small‑object allocation via mcache, large‑object handling, the three‑color mark‑and‑sweep garbage collector, memory release mechanisms, and the optimization techniques that coordinate mcache and mheap for efficient concurrent execution.
This article provides a comprehensive overview of Linux memory barriers, explaining why they are needed for correct ordering of memory operations on modern multi‑core CPUs, describing the different barrier types (read, write, full), their implementation in the kernel and Java, and illustrating their use in synchronization primitives and lock‑free data structures with code examples.
This article explains how a PHP script uses a named semaphore for process mutual exclusion, demonstrates why a second concurrent process can acquire the semaphore after the first finishes, and clarifies that PHP automatically releases held semaphores when a process terminates.
This article reviews several Stage 2 ECMAScript proposals—including discard bindings using the void operator, iterator chunking for sliding windows and non‑overlapping sequences, phase‑based ESM imports for static worker initialization, extractors for custom destructuring, and structs with shared memory, mutexes, and unsafe blocks.
This article compiles an extensive Python reference covering Python 2 vs 3 differences, essential and advanced libraries, concurrency models, language internals, testing techniques, design patterns, data structures, algorithms, networking basics, MySQL and Redis insights, Linux I/O models, and performance‑optimization strategies, all illustrated with practical code snippets.
The article examines how frequent inventory adjustments in JD retail supply‑chain can suffer from concurrency issues, explains why traditional locking may fail, analyzes a real‑world case of lock misuse, and presents code‑level, database‑level, and architectural solutions to guarantee data consistency.
This article explains the bitmap (BitVec) data structure, its memory efficiency for handling billions of integers, real‑world applications such as bloom filters and permission flags, and walks through Go’s internal BitVec implementation with concrete code examples and performance insights.
This article offers a comprehensive overview of Java's lock mechanisms, detailing each lock type, its underlying principle, typical use cases, differences between synchronized and Lock, and practical code examples for implementing read‑write locks and optimizing concurrency.
This article demonstrates how to boost performance when exporting large datasets to Excel using EasyExcel, covering single‑batch, paginated, and concurrent writes, and explains multiple approaches—including annotations and custom WriteHandlers—to efficiently create merged cells in the generated spreadsheets.
This article demonstrates how to use EasyExcel to efficiently export large volumes of data to Excel by improving performance through pagination, concurrent queries, and custom cell‑merging strategies, including built‑in annotations and WriteHandler implementations, while providing complete Java code examples.
This article explains the treap data structure—its BST and heap properties, random priority balancing, and implementation details—then dives into Go's runtime semaRoot treap, showing step‑by‑step enqueue and dequeue algorithms with code, rotations, and performance reasoning.
This article presents a comprehensive guide to Python exception handling, covering basic try‑except usage, multiple exception capture, else/finally clauses, custom exceptions, exception chaining, logging, context managers, assertions, traceback, concurrent and asynchronous error handling, and testing techniques.
This article explains what Java virtual threads are, how they differ from regular OS threads, demonstrates configuring Spring Boot to use them, and presents performance benchmarks showing virtual threads dramatically outperform traditional threads in both async service calls and simple HTTP requests.
This article explains why Java’s Lock interface is still needed despite synchronized, covering non‑blocking tryLock, timed lock acquisition, interruptible locking, fair versus non‑fair locks, read‑write locks, and Condition objects, with code samples and execution logs illustrating each feature.
The article dissects glibc's ptmalloc implementation, explaining malloc_state, malloc_chunk, fastbins, bins, and top chunk, then analyzes lock contention and fragmentation in multithreaded scenarios through a custom stress test, and concludes with recommendations for high‑performance memory management.
This article explains why creating a thread for each task is inefficient, introduces thread pools as a solution, compares execution times with code examples, details ThreadPoolExecutor's core interfaces, constructors, execution flow, rejection policies, state transitions, and provides practical usage patterns and best‑practice recommendations for Java backend development.
This article outlines how to correctly create, monitor, and configure Java ThreadPoolExecutor instances, explains why using the Executors factory can cause OOM, recommends separate named pools per business, provides formulas for sizing CPU‑bound and I/O‑bound workloads, and highlights real‑world pitfalls and dynamic‑configuration solutions.
This article explores the origins of Java's JUC package, explains the core concepts of AbstractQueuedSynchronizer—including template methods, exclusive and shared acquisition, CLH queues, CAS, and LockSupport—and demonstrates how locks, conditions, and synchronization mechanisms are implemented and used in real-world Java concurrency.
Go 1.23 introduces a garbage‑collectable, synchronous timer channel implementation that eliminates resource leaks and race conditions, requiring code changes such as replacing len‑checks with non‑blocking selects and offering GODEBUG flags for toggling the new behavior during testing and production.
This article dissects Go's runtime GPM model and the lock‑free runq data structure, detailing its fields, core operations such as runqput, runqget, runqgrab, and their atomic implementations, while also comparing local and global queues and illustrating the code paths with concrete examples.
