This article examines the pitfalls of using SpringBoot's @ControllerAdvice and @ExceptionHandler for global exception handling, illustrates common issues across controller, service, and data layers, and proposes more precise logging and debugging strategies to improve error traceability and maintainability.
This article shares a Java developer’s six‑year experience with Arthas, detailing how vmtool, hot‑swap, OGNL filtering and various Arthas commands can dramatically improve problem‑diagnosis, reduce log noise, and accelerate debugging in production environments.
This article introduces the most frequent Python errors—including syntax, runtime, and logical mistakes—explains their typical causes, and provides practical solutions and debugging techniques such as using IDEs, print statements, and unit tests, complemented by a case study and useful tips.
The article details a week‑long investigation of a sandbox environment where Spring Boot APIs became unresponsive due to Redis connection pool blocking, describing the use of system tools, JVM thread analysis, and code inspection to identify mis‑configured pool settings and recommending proper connection handling with Spring's RedisTemplate.
This article explains a real‑world Java backend issue where the first call to MD5 hashing caused a massive latency spike, how the problem was diagnosed with Arthas tracing, and why replacing the Hutool MD5 implementation with a lightweight alternative resolved the slowdown.
This tutorial details how to set up a cross‑compilation toolchain on Ubuntu 20.04, install QEMU, build a BusyBox‑based root filesystem, compile and configure the ARM64 Linux kernel, create a simulated disk, share files between host and guest, and perform kernel debugging using GDB and Eclipse.
Docker announced three new hybrid tools at DockerCon—Next‑Gen Docker Build, which claims a 39‑fold speed boost by leveraging cloud resources; Docker Debug, a language‑agnostic toolbox for faster container debugging; and Docker Scout, an integrated security assistant—highlighting a shift toward combined local and cloud development workflows.
This article explains how to debug and optimize PHP database connections using PDO and mysqli, demonstrates error handling and logging techniques, and presents performance improvements such as persistent connections, connection pooling, and query optimization with practical code examples.
This article investigates why inserting the foreign_key_checks system variable into MySQL's my.cnf prevents the server from starting, explains the underlying NO_CMD_LINE flag mechanism, and provides a simple command‑line method to distinguish variables that can or cannot be set via configuration files.
The crash in asl::LooperObserverMan::notifyIdle was traced to a compiler‑level store‑store reordering that exposed an uninitialized observer pointer, causing an illegal memory access, and was fixed by inserting a memory barrier or using proper atomic ordering to enforce correct initialization order.
This article explores LangSmith, the experimental platform from the creators of LangChain, detailing how it tracks complex LLM reasoning, supports batch testing and evaluation of AI applications, and offers a community Hub for sharing prompts and chains, ultimately helping move LLM projects from prototype to production.
The article explains the origins, common misconceptions, and a rigorous definition of observability (o11y), highlights its importance in cloud‑native environments, and describes how high‑cardinality, high‑dimensional telemetry enables effective debugging, troubleshooting, and performance analysis of modern distributed systems.
This guide explains typical C memory‑allocation errors, practical ways to avoid them, and introduces a lightweight logging system that automatically records allocations and frees to help developers detect memory leaks during debugging.
This guide explores essential front‑end techniques—from efficiently handling massive data sets and adopting the Svelte framework, to containerizing deployments, mastering Chrome and VSCode debugging, applying clean architecture principles, and dissecting eight classic sorting algorithms—providing practical insights for modern web developers.
The article details how a sudden surge in goroutine and heap usage was traced to repeatedly creating gRPC clients instead of reusing a singleton, leading to blocked goroutines and TCP connections, and explains using pprof, stack traces, and tools like goleak to detect and prevent such leaks.
This guide provides participants with a comprehensive set of FAQs covering platform operation, debugging frame skips, random seed effects, code submission requirements, compilation issues, and competition rules to help them navigate Huawei Cloud's robot hackathon and achieve optimal results.
The article explains a real‑world issue where the first invocation of a MD5 hash in a Java backend took dozens of seconds, describes how the problem was traced using the Arthas diagnostic tool, reveals that the delay stemmed from BouncyCastle algorithm loading, and shows how replacing the library resolved the performance bottleneck.
This guide explains the advantages of using the Charles proxy tool for software testing—including network traffic monitoring, debugging, environment simulation, security testing, and automation support—followed by detailed instructions for downloading, installing, registering, and configuring the tool.
This quick‑start guide walks readers through ARM assembly development by teaching simple template functions, exposing typical parameter‑passing and register bugs with debugging tricks, and demonstrating a depthwise convolution written in assembly that delivers roughly 4.7× faster inference on a Huawei Mate40 Pro compared to its C++ counterpart, while also covering ARM32/ARM64 register conventions, vector instructions, and floating‑point handling.
The article walks through a real‑world FastJSON serialization failure caused by a newly added log statement, explains why FastJSON invokes certain getter methods during serialization, shows the ASM‑generated serializer internals, and proposes annotation‑based coding standards to avoid similar bugs.
This article investigates why inserting the foreign_key_checks variable into MySQL's my.cnf causes the server to fail to start, explains the underlying NO_CMD_LINE flag mechanism, and provides a simple command‑line method to distinguish variables that can or cannot be set via configuration files.
This article presents ten practical Python code examples demonstrating various garbage collection mechanisms and memory‑analysis tools, including reference counting, cyclic references, object inspection, tracemalloc, memory_profiler, pympler, and objgraph, to help developers understand and optimize memory usage.
This article presents ten advanced Python techniques—including assertions, interactive debugging, profiling, comprehensions, efficient data structures, caching, NumPy vectorization, parallel processing, and appropriate storage choices—to help developers improve code quality and execution speed.
IntelliJ IDEA 2023.2 introduces a suite of enhancements—including a Run‑window profiler, inline return breakpoints, automatic test reruns for Gradle/Maven/JPS, WSL‑based Tomcat debugging, TLS‑enabled gRPC requests, Swagger and OpenAPI support, shared index generation, and numerous UI and code‑completion upgrades—streamlining Java development workflows.
This article explains how to use the open‑source Java diagnostic tool Arthas to attach to a running JVM, view real‑time metrics, and employ the trace command to pinpoint and analyze time‑consuming methods without inserting manual timing code.
This article investigates a MySQL 8.0 TDSQL client experiencing connection interruptions during batch streaming, analyzes error 1161 (ER_NET_WRITE_INTERRUPTED) root causes in the MySQL source code, presents debugging steps with log and packet captures, and offers practical mitigation recommendations.
This article introduces the major enhancements of Python 3.11—including structural pattern matching, improved type hints, faster execution via PEP 659, richer error messages, the new | dictionary‑merge operator, built‑in breakpoint debugging, and other standard‑library additions—illustrated with concise code examples.
This guide explains why exec‑based pod debugging is limited and demonstrates how to use Kubernetes ephemeral containers to troubleshoot network issues, trace processes, and debug nodes without restarting the pod, including step‑by‑step commands and code examples.
Kelemetry, an open‑source tracing system from ByteDance, visualizes Kubernetes control‑plane events by treating each object as a span, linking audit logs, events, and component interactions to provide a unified, searchable view that simplifies debugging, performance analysis, and multi‑cluster observability.
The article explains a puzzling MySQL DELETE failure caused by a missing primary key, shows how Navicat adds an ESCAPE clause to the generated SQL, clarifies the purpose of ESCAPE in LIKE patterns, and reveals that the real issue was a mistaken condition order in the query.
This article explains how thorough code review, using tools like GoLand, Git plugins, and Postman, improves test case accuracy, data integrity, branch coverage, and overall software quality in Go projects, while offering practical tips on diff usage and highlighting the tangible benefits for testing teams.
The article recounts a production OutOfMemoryError incident caused by heap and metaspace exhaustion in a Java service, analyzes Mybatis's role in the memory leak, reproduces the issue with heavy SQL and multithreading, and offers concrete debugging and code‑optimization steps to prevent future crashes.
This article introduces the fundamentals of source-level debugging for WebAssembly, explains core debugging principles, discusses native and managed program debugging, examines various debugging information formats such as SourceMap and DWARF, and compares several practical debugging solutions—including Chrome DevTools, LLDB with wasmtime or iwasm, and WasmInspect.
This article explains the two primary PHP functions for displaying arrays—print_r() for readable output and var_dump() for detailed type and value information—provides syntax examples, and shows the resulting output of each function.
This article introduces several powerful Python libraries—Albumentations for image augmentation, MonkeyType for type inference, Bleach for HTML sanitization, Plotnine for data visualization, Returns for exception handling, ipdb for interactive debugging, and Virtualenv for environment isolation—detailing their use cases and providing example code for interface automation.
A Java backend service suffered a massive first‑request latency because the MD5 hashing library loaded heavy cryptographic algorithms on first use, and the author traced, diagnosed, and solved the issue by replacing the library and sharing lessons on performance debugging.
This article walks you through building a minimal Spring Boot demo, setting breakpoints, analyzing call stacks and logs, and tracing the @Transactional rollback logic in the framework source code to understand why certain methods roll back or commit.
This article walks through diagnosing V8FatalErrorCallback OOM crashes in an Electron‑based PC Taobao Live client, explores stack analysis, disables compilation cache, adjusts V8 heap limits, compiles a custom Electron without pointer compression, and uses Chrome DevTools Memory and Performance tools along with runtime monitoring to locate and fix the underlying memory leak.
The article details how the author traced V8FatalErrorCallback out‑of‑memory crashes in an Electron‑based Taobao Live client to an ever‑growing compilation cache and pointer‑compression limits, rebuilt Electron with those disabled, identified a JavaScript memory leak caused by unfiltered error logging, and implemented runtime heap monitoring to prevent future OOM failures.
This article details a real‑world Netty long‑connection memory‑leak case, explains how to reproduce the problem, uses Netty's advanced leak detection to pinpoint the faulty ByteBuf usage, and presents three practical remediation strategies to permanently fix the leak.
This article explains the root cause of the thread‑pool plugin enhancement failure in SkyWalking—duplicate AgentClassLoader instances—detailing the investigation steps, code changes, and two practical solutions to ensure reliable instrumentation of ThreadPoolExecutor.
This article explains the purpose, usage, constraints, and example code for several PHP magic methods—including __toString, __invoke, __set_state, __clone, __autoload, and __debugInfo—showing their effects, common pitfalls, and how they improve object handling and debugging in modern PHP applications.
The article recounts how a Java backend’s MD5‑based snapshot generation caused the first request to time out, details the investigation using Arthas to pinpoint the slow initialization of BouncyCastle algorithms, and explains the final fix by switching to a lightweight MD5 implementation.
The article recounts a production incident where a Java service’s CPU surged to 1200%, detailing how top, jstack, and jmap were used to trace the issue to a missing parameter that caused a full‑table scan, prolonged GC pauses, and ultimately a system freeze.
The article recounts a senior architect's investigation into FastJson's date formatting bug and circular reference handling, detailing version mismatches, GitHub issue tracking, feature flag usage, and lessons for backend developers on avoiding hidden serialization pitfalls.
This guide compiles 61 practical ADB commands covering device connection, app management, debugging tools, file transfer, input simulation, device control, and advanced operations, providing Android developers with a comprehensive cheat‑sheet for efficient testing and troubleshooting.
This article explains how to identify when a MySQL DDL operation is blocked, locate the blocking session using the sys.schema_table_lock_waits view, and resolve the issue by enabling necessary instruments and killing the appropriate connection, with examples for MySQL 5.7 and 8.0.
This article walks through the entire crash‑handling workflow for an Electron‑based Taobao Live client, covering why crashes occur, how to capture minidumps with Crashpad, report them to monitoring platforms, and analyze the dumps using Visual Studio or WinDbg.
This guide explains why dual-machine debugging is needed, outlines the two main scenarios (virtual machine and physical machine), and provides step‑by‑step instructions for configuring VirtualKD as well as network‑based kernel debugging on Windows systems, including common test cases and useful commands.
An engineer troubleshoots a .NET application login freeze by capturing a dump with WinDbg, discovers the thread blocked in MySQL SSL handshake, verifies the MySQL driver version, and resolves the issue by disabling SSL via the connection string, illustrating effective debugging without source code or logs.
The article analyzes why a sed command freezes while modifying a MySQL MHA installation script on a CentOS 6 system, identifies the charset conversion issue caused by GBK locale and missing spaces after comment symbols, and provides a step‑by‑step debugging and fix procedure.
A Java backend developer investigates sudden CPU spikes caused by hidden Nacos client threads, traces the issue through thread dumps and code analysis, explores Raft network partition behavior, and implements a fix that checks and recreates Nacos connections to prevent unnecessary thread creation.
The article explains why test engineers need solid programming skills, highlights Java's cross‑platform advantages, rich libraries, and simple syntax, and provides a step‑by‑step guide covering core concepts, development setup, coding standards, practice exercises, common APIs, debugging tips, and essential testing tools.
A seemingly harmless C bug caused a Windows build to ignore a ternary file‑creation expression because a stray backslash in a comment turned the following code into a comment, illustrating how tiny syntax errors can cripple cross‑platform programs.
This article walks through building a Spring @EventListener demo, explains how to decouple registration logic, shows step‑by‑step debugging of the event‑listener infrastructure, and explores the internal mechanisms that register and invoke listeners during application startup and runtime.
The article walks through a real‑world React‑Native white‑screen crash, explains how the Metro bundler transforms source code into a jsbundle, extracts two distinctive code‑feature patterns (e.default = v and return (0, l.default)(b,[{)), and demonstrates how these patterns can be used to locate the original component files responsible for the error.
This article explains how to evaluate the puzzling JavaScript expression console.log(([][[]] + [])[+!![]]+([]+{})[+!![]+ + !![]]), detailing the required knowledge of type coercion, unary operators, and implicit conversions to reveal why the output is “nb”.
This guide shows how to create a multi‑threaded C program on embedded Linux, set thread names with pthread_setname_np, and use the top command with the -H option to display each thread’s status, illustrating the difference when thread names are omitted.
This article describes how Meituan addresses the rapid growth of Flink SQL jobs by introducing fine‑grained TTL and concurrency settings, an editable execution plan for state migration, pre‑analysis compatibility checks, and a bytecode‑instrumented debugging system that captures operator data and streams it to Kafka for analysis.
This article details Meituan's implementation of Flink SQL at scale, covering fine‑grained job configuration, state‑TTL management, state‑migration techniques for job upgrades, a custom debugging tool for correctness issues, and future directions for Flink SQL enhancements.
A Python community member struggled with a regular expression that mishandled backslashes, but by converting the pattern to a raw string with an r prefix, the issue was resolved and the regex matched correctly, illustrating a common pitfall and its simple fix.
This guide explains what core dump files are, how to configure foreground and background processes to generate them on embedded Linux, and provides step‑by‑step commands and sample code for enabling core dumps and analyzing them with arm‑linux‑gnueabihf‑gdb.
The article introduces JupyterLab’s new visual debugger, explains why debugging is needed in Jupyter, provides installation commands for the front‑end extension and xeus‑python kernel, describes the debugger’s UI components and capabilities, and compares it with a VS Code visual debugging tool.
This article explains how ChatGPT, the popular AI chatbot, can boost developer productivity through testing, debugging, documentation, error detection, code completion, formatting, refactoring, search assistance, text classification, and summarization, while also highlighting its need for human oversight and risks such as plagiarism.
This article examines why a single Thread.currentThread().getStackTrace() call is insufficient for modern Android performance debugging, compares instrumentation and native stack‑capture approaches, and provides detailed step‑by‑step implementations, code snippets, and optimization tips for reliable stack tracing.
Learn a quick IntelliJ IDEA trick that lets you set a breakpoint to pause only when a loop reaches a particular iteration, eliminating the need to manually step through each cycle and speeding up Java debugging.
This guide shows programmers how to quickly locate errors in massive server logs using essential Linux commands such as tail, cat, grep, sed, and pagination tools, providing step‑by‑step examples and tips for efficient debugging.
This article explains common scenarios that cause CPU usage to soar above 200% in production, outlines step‑by‑step diagnosis and remediation for MySQL and Java processes, and shares real‑world case studies with command‑line tools, indexing, caching, and code adjustments to bring CPU load back to normal levels.
This article explains how to debug live Kubernetes pods using temporary (ephemeral) containers that share namespaces, covering cluster setup, creating workloads, diagnosing network problems, tracing processes, and accessing node shells without restarting the original pods.
This article walks through a real‑world incident where an update to a MySQL row was not visible to a subsequent read, explains how SkyWalking tracing revealed the exact timing of binlog writing, MQ delivery, and query execution, and offers practical mitigation strategies.
This guide walks through practical ways to make GDB debugging more efficient in the terminal, covering raw command‑line usage, the built‑in TUI mode, CGDB, Emacs GDB integration, and the browser‑based gdbgui, with configuration snippets and key bindings for each tool.
This article recounts a real‑world investigation of a MySQL high‑availability outage where HikariCP connections appeared to dead‑lock, detailing the architecture, observed symptoms, code analysis, thread‑dump findings, and the final fix of adding socket timeout parameters to the JDBC URL.
This guide walks you through installing VS Code on macOS, configuring essential C/C++ extensions, setting up the Clang/LLVM toolchain, creating a simple Hello World project, compiling, running, and debugging it using VS Code's tasks and launch configurations.
This article walks through a Python visualization issue raised in a community chat, shows the problematic code and error screenshots, explains the root cause identified by an expert, and provides the corrected implementation so readers can resolve similar problems themselves.
In this article, the author shares a real‑world pandas data‑processing problem caused by missing spaces, demonstrates the error, provides the corrected code snippet, and explains how the fix resolves the issue for fellow Python learners.
The article details a sudden CPU spike in a Java backend service using Nacos, walks through diagnosing the offending thread with top and jstack, analyzes Nacos client thread creation and scheduled gray‑config tasks, explains Raft network partition handling, and presents a fix that checks config health and avoids unnecessary thread creation.
This guide explains what crontab does, its syntax and options, provides practical examples, highlights typical problems such as environment variables, time misconfiguration, special characters and output redirection, and offers debugging tips and tools for reliable Linux task scheduling.
This comprehensive article explains what Android ANR (Application Not Responding) is, details its various causes and trigger scenarios, walks through the internal service‑side workflow, and presents practical monitoring solutions—including a watchdog thread and SIGQUIT signal interception—along with code samples, trace analysis methods, and mitigation strategies for developers.
This article investigates a MyBatis‑Plus bug where enum values with abstract methods become anonymous classes, causing the framework to fail to locate the correct TypeHandler, leading to SQL errors, and provides several practical solutions to avoid or fix the issue.
This article explains Android's Alarm mechanism, covering its overall architecture, the four alarm types, framework and kernel workflows, batch alignment, wake‑up handling, suspend processing, and a real‑world power‑debugging case to help developers optimize battery consumption.
This article demonstrates how to locate the source of abnormal MySQL connection traffic by identifying the offending socket, tracing its system‑call stack with strace, and correlating the activity to specific application logic such as create/drop database and workload tasks.
This guide explains what crontab does, how to write and manage user and system cron jobs, shows real‑world syntax examples, highlights typical pitfalls such as environment variables, time fields, special characters and output redirection, and provides debugging strategies including the crontab.guru online parser.
This article details several real‑world Flutter performance problems encountered at Soul—including excessive memory usage for emojis, iOS 14 debug launch restrictions, high CPU consumption of Lottie animations, background‑foreground flickering, and PlatformView memory leaks—and provides concrete mitigation strategies with code examples.
This guide walks you through turning the basic command‑line GDB into a far more efficient debugging environment by using GDB's built‑in TUI, custom .gdbinit scripts, the cgdb front‑end, Emacs gdb‑mode, and the browser‑based gdbgui, complete with key bindings, window layouts and practical tips.
This article explains the design, architecture, and evolution of Ant Cube Tool (ACT), a Node‑based CLI and VSCode‑enhanced solution that compiles, previews, and debugs Alipay Cube card DSLs, enabling efficient cross‑platform mobile dynamic content creation.
This article introduces Arthas, Alibaba's open‑source Java diagnostic tool, explains its installation, showcases common commands such as stack, jad, sc, watch, trace, jobs, logger, dashboard, and redefine, and demonstrates how to use them to monitor JVM status, trace method calls, inspect classes, and perform hot‑updates without restarting the application.
This article walks through a real‑world case of off‑heap memory leakage in the Dble proxy, detailing symptom observation, log analysis, monitoring, BTrace instrumentation, code review, and the eventual fix that delays buffer allocation until needed.
This article walks through a real‑world Python file‑handling problem, showing the initial mistake, the corrected approach using encoding, and the final working result, providing a practical example you can apply in your own projects.
This article explains what SIGKILL crashes are on iOS, how the operating system terminates a process, how to capture SIGKILL events using the MetricKit framework with code examples, the meaning of common termination codes, and practical fixes for typical SIGKILL scenarios in mobile apps.
The article details a step‑by‑step investigation of an intermittent deadlock occurring during session creation in a video‑conference system, explains how InnoDB lock types caused the conflict between DELETE and INSERT statements on the session and session_endpoint tables, reproduces the issue, debugs MySQL source code, and presents a simple code‑order fix to eliminate the deadlock.
The article explains how uncaught exceptions cause Electron app crashes on Windows, describes Windows’ user‑mode dump types, shows how Crashpad generates minidumps via a simple exception filter, demonstrates starting the built‑in crash reporter in JavaScript, and outlines uploading and analyzing dumps with Visual Studio or WinDbg, plus a watchdog restart strategy.
This guide walks through creating a React app, downloading the React source, building it, linking the packages, configuring webpack aliases, fixing import paths, disabling ESLint, adjusting environment variables, and resolving internal React errors so you can edit and debug the original React source directly in the browser.
A recent production incident caused by inserting a single log statement revealed how FastJSON's ASM‑generated serializer invokes methods like isChinaName(), leading to a NullPointerException, and the article dissects the root cause, serialization mechanics, and best‑practice annotations to prevent similar bugs.
This guide surveys essential frontend topics—including deep dives into lodash usage, iterator and generator concepts, Web3D visualizations, hybrid remote debugging, long‑task performance optimization, Chrome DevTools measurement, and creative image‑loading effects—offering practical insights for modern web developers.
A MySQL DBA recounts a 4‑TB InnoDB instance that stalled during startup, analyzes top, stack traces, and source code to pinpoint a bug involving truncate operations and the buf_flush_event, then presents three practical solutions—including adjusting innodb_flush_sync, using GDB to break the wait loop, or removing truncate logs—to restore normal operation.
This article outlines ten common developer missteps—from hoarding knowledge and skipping code reviews to weak testing and undocumented changes—and explains how avoiding them can transform you into a high‑value software engineer.
This article recounts a real‑world incident where a change to the Access‑Control‑Allow‑Origin header triggered CORS errors for credentialed requests, analyzes the CDN caching and Vary‑header issues that caused inconsistent responses, and outlines the steps taken to fix and prevent the problem.
Soul developed an Electron‑based hybrid app debugging tool that simulates H5 environments, bridges client‑side methods via CDP, and enables Chrome DevTools debugging of DOM, network, and touch events in webviews for effective troubleshooting.
This article explains how a Python web‑scraping request failed due to extra nested parameters, shows the step‑by‑step debugging process, and demonstrates that deleting trivial 0/1 values can restore the request, offering a practical tip for similar crawling issues.
This article compiles a series of frequent Go programming pitfalls—ranging from incorrect use of unsafe.Sizeof and variadic any parameters to slice expansion, pointer handling, closure capture, concurrency bugs, and serialization quirks—providing concrete code examples and safe alternatives to help developers write more reliable Go code.
