This article demonstrates how to use Alibaba's open‑source Java diagnostic tool Arthas to quickly locate and fix high CPU usage in a Java application, covering installation, attaching to a JVM, using dashboard, thread, jad, watch, and ognl commands, and interpreting the results.
This article explains the common reasons why Redis performance degrades—such as network latency, high‑complexity commands, big keys, concentrated expirations, memory limits, fork overhead, huge pages, AOF settings, CPU binding, swap usage, and memory fragmentation—and provides detailed optimization and troubleshooting steps to restore low latency.
An in‑depth case study explains how a single Proxy machine’s message‑queue backlog was traced to a stuck HTTP download thread caused by an HttpClient bug, detailing the step‑by‑step investigation, root‑cause analysis, and the final fix that eliminated the issue.
This article explains the common causes of network packet loss—from hardware NIC issues and driver problems to kernel stack and TCP/UDP layer faults—provides step‑by‑step diagnostic commands, and offers practical solutions to quickly identify and resolve packet loss in Linux environments.
This article explains the typical reasons why a Redis instance becomes slow—such as high latency, expensive commands, big keys, concentrated expirations, memory limits, fork overhead, huge pages, AOF settings, CPU binding, swap usage, and memory fragmentation—and provides concrete diagnostics and optimization steps to resolve each issue.
This article enumerates typical system performance problems such as slow response time, insufficient throughput, resource bottlenecks, database slowness, memory leaks, platform differences, network latency, security overhead, scalability limits, and provides practical optimization and mitigation strategies for each.
This guide explains why Docker network IP address conflicts occur and provides step‑by‑step commands to locate duplicate IPs, stop conflicting containers, manually reassign IPs, and fully clean and restart the Docker environment to eliminate the issue.
When a pod crashes and continuously restarts, kubelet logs may miss the output, but using the kubectl --previous flag lets you access the logs of the prior container instance by reading the symlinked files under /var/log/pods, enabling effective troubleshooting of Kubernetes crashes.
This guide walks you through practical Linux commands—tail, head, cat, grep, sed, wc, and pagination tools—to quickly locate, filter, and examine specific error entries within large log files, boosting troubleshooting efficiency for system administrators.
This article explains the common video screen artifacts—flower screen, flashing, green screen, and black screen—covers the end‑to‑end RTC video pipeline, and provides a step‑by‑step method to locate and diagnose the root cause across sending, server, and receiving stages.
Understanding container exit codes—from 0 for normal termination to 255 for unknown errors—helps diagnose pod failures in Docker and Kubernetes, covering each code’s meaning, typical causes, and step‑by‑step troubleshooting actions to resolve issues such as command errors, permission problems, signals, and resource limits.
This guide walks operators and developers through diagnosing and resolving frequent Kubernetes issues such as ImagePullBackOff, CrashLoopBackOff, OOMKilled, BackoffLimitExceeded, and probe failures, providing key kubectl commands, secret handling tips, and best‑practice recommendations to keep clusters stable.
Improper initialization of multiple identical Dubbo References can flood ZooKeeper with duplicate consumer nodes, causing instability and service outages, but adjusting jute.maxbuffer, upgrading Dubbo, and using MSE ZooKeeper's rate‑limiting and monitoring can resolve the issue.
This guide walks through eight frequent Kubernetes networking problems in Tencent Cloud Kubernetes Service—such as cross‑VPC NodePort timeouts, low load‑balancer CPS, DNS resolution delays, apiserver access lag, mis‑configured resolv.conf, liveness‑probe failures, and externalTrafficPolicy = Local timeouts—explaining their root causes and providing concrete kernel, iptables, DNS, and configuration fixes.
This article explains how to verify whether OceanBase's freeze mechanism and memstore dump processes are functioning correctly by querying internal tables, inspecting logs, and checking related metrics such as active_memstore_used, major_freeze_trigger, and MemTable reference counts.
This article explains a MySQL master‑slave synchronization failure caused by a corrupted relay log, walks through the replication principles, analyzes slave status and GTID differences, and provides step‑by‑step commands to skip the problematic GTID and restore replication.
When a Linux server suddenly spikes in load and alerts flood your phone, you can pinpoint the cause within a minute by using ten powerful commands from Netflix's performance engineering team to quickly assess CPU, memory, disk I/O, and network metrics.
This guide walks through Wireshark's powerful features—including precise packet filtering, time‑display adjustments, absolute sequence numbering, exporting filtered captures, traffic statistics, decoding mixed logs, TCP stream tracing, and MAC‑address vendor lookup—to help engineers troubleshoot and analyze network traffic efficiently.
When a production container suddenly hit 90% CPU, the author traced the issue to abnormal JVM garbage‑collection activity, captured the problematic GC graphs, and used Linux tools, jstack, and code inspection to pinpoint a faulty Excel export loop that caused excessive GC and full‑GC cycles.
This guide explains how to fix common Composer dependency errors in a Laravel project by backing up and removing the composer.lock file, reinstalling dependencies, and restoring the lock file, while also showing the typical error messages that may appear.
This article presents a comprehensive 40‑question and answer guide covering the essential safety conditions, key temperature definitions, diagnostic methods, common failure causes, and maintenance strategies for data‑center refrigeration system design and operation.
This article walks through a Python web‑crawler problem raised in a community, showing step‑by‑step how to start the project, troubleshoot terminal errors in PyCharm, and verify the directory structure using the tree command, providing a clear solution for beginners.
This article compiles frequent Flink job submission problems on YARN—including WordCount jar errors, HBase dependency conflicts, MySQL timeout, checkpoint restoration failures, parallelism limits, and unexpected container termination—provides root‑cause analysis and step‑by‑step remediation instructions.
This article walks through a common Python pip upgrade error, shows the error screenshots, explains why it occurs, and provides a concise two‑command solution that restores the Python environment, helping readers quickly resolve similar issues.
This article details a real‑world Kubernetes control‑plane outage where kube‑apiserver repeatedly OOM‑killed, examines cluster metrics, logs, heap and goroutine profiles, explores root‑cause hypotheses such as etcd latency and DeleteCollection memory leaks, and offers practical prevention steps.
This guide explains why a Calico pod shows "BIRD is not ready: BGP not established" in a Kubernetes cluster, identifies the missing node interface detection as the root cause, and provides step‑by‑step instructions to adjust the IP autodetection method and restore pod health.
This article explains the fundamentals of Linux network latency, demonstrates how to measure round‑trip time using ping, traceroute, hping3 and wrk, walks through a Docker‑based test setup, and shows how to analyze packet captures with tcpdump and Wireshark to uncover causes such as TCP delayed ACK.
This guide introduces four powerful network utilities—nali for IP geolocation, dig for DNS queries, mtr for combined traceroute and ping analysis, and tsunami for high‑speed UDP transfers—explaining their installation, key commands, options, and practical usage examples.
The article describes a MySQL 5.7.31 replication delay where Seconds_Behind_Master fluctuates between 0 and over 10,000 seconds, analyzes root causes such as single‑threaded replication, large or long‑running transactions, and provides preventive, diagnostic, and remediation steps including enabling parallel replication and using the infobin tool.
This guide explains key Linux networking commands—including ip, ifconfig, netstat, ping, traceroute, DNS utilities, and DHCP tools—showing how to view interfaces, check connectivity, trace routes, query DNS records, and manage DHCP leases for effective network troubleshooting.
This article explains how to identify Redis latency problems, measure baseline performance, monitor slow commands, and address common causes such as network RTT, forked RDB snapshots, transparent huge pages, swap usage, AOF configuration, key expiration bursts, and big keys, providing practical solutions and a checklist for remediation.
This article describes how to identify and fix Greenplum standby segment failures by inspecting segment status, comparing missing files, generating a recovery configuration, executing gprecoverseg commands, and verifying that all segments return to normal operation without service interruption.
This article provides a comprehensive overview of the ping command, explaining its basic usage, interpreting output fields such as bytes, time, and TTL, and detailing advanced options like -t, -a, -n, -l, -r, as well as batch ping techniques for network troubleshooting.
This article explains how to determine whether Redis is truly experiencing latency issues, outlines benchmark testing methods, identifies common causes such as network problems, high‑complexity commands, big keys, slow logs, memory limits, fork overhead, AOF configuration, swap usage, fragmentation, and provides practical troubleshooting and optimization steps.
This article details a step‑by‑step troubleshooting process for an OBproxy deployment error where a client loses connection to the OceanBase server due to an incorrect port in the root service list, including environment setup, command examples, log analysis, and the final resolution.
This guide walks through ten frequent Kubernetes problems—from service access failures and port‑mapping errors to image pull issues and CrashLoopBackOff—explaining root causes, showing exact error messages, and providing concise command‑line solutions to restore cluster health.
This article outlines the Kubernetes pod lifecycle, describes the five pod phases, enumerates 13 typical failure scenarios—including scheduling, image pull, dependency, init container, probe, and OOM issues—provides error states, root causes, and step‑by‑step kubectl commands for diagnosis and remediation.
This guide explains what port forwarding (port mapping) is, why it’s useful for remote access, and provides detailed instructions on configuring it on a router, using public IP or dynamic DNS, plus common troubleshooting tips to ensure external users can reach internal services.
After moving an application to a PaaS platform, intermittent 502 errors occur due to Nginx’s retry behavior, HTTP/1.1 connection reuse, and a mismatch between Ingress and uwsgi protocols, which can be diagnosed through error statistics and packet capture.
When starting a new Kafka consumer group, an unexpected SyncGroup error occurs due to a RecordTooLargeException, and the article walks through log inspection, identifies the oversized __consumer_offsets record, and resolves the issue by increasing the message.max.bytes configuration.
Real‑world Linux server failures show that missing PAM support in SSH prevents ulimit changes, misordered pam_faillock entries break cron authentication, and custom pam_script setups for Squid require careful configuration, highlighting that module order, thorough testing, and proper hardening are essential for reliable PAM authentication.
This article explains the types and formats of OceanBase logs, how to identify relevant log files, interpret log fields such as trace_id, lt, and dc, and provides step-by-step methods for using error codes and trace IDs to pinpoint the root cause of errors.
This article walks through a real‑world incident where a Redis cache big‑key caused service timeouts, explains how to identify the problem using cluster metrics, outlines detection tools and commands, and provides practical steps to delete big keys and prevent future occurrences.
This article presents a practical three‑step methodology—understanding, managing, and preventing—to troubleshoot Kubernetes deployments, explains how to leverage monitoring, observability, and incident‑response tools, and offers guidance on fostering team collaboration and building resilient, self‑healing cloud‑native systems.
On September 10 2021, a Kubernetes cluster experienced intermittent kubectl hangs caused by kube-apiserver OOM kills, leading to cascading control-plane failures; this article details the environment, observed metrics, log analysis, code inspection of DeleteCollection, and provides troubleshooting steps to prevent similar incidents.
This guide explains how to fix Chrome’s broken automatic translation after Google shut down its China services by locating the hosts file on Windows, macOS, Linux or Android, adding specific IP mappings, and using alternative IPs if needed.
This guide explains how to troubleshoot Filebeat failing to start due to an EOF error while loading registrar state, by inspecting logs, resetting the registry directory, and restarting the service on a Linux host.
This article explains how to set up remote debugging for services in sandbox or test environments, covering remote creation, locating debug ports, constructing JVM arguments, checking service status, stopping services, and useful alias commands to streamline the debugging process.
This article explains how to identify the root causes of increased network latency on Linux servers, covering tools such as ping, traceroute, hping3, and wrk, demonstrating packet analysis with tcpdump and Wireshark, and showing how TCP delayed ACK and socket options affect response times.
This article provides a comprehensive guide to diagnosing and fixing a wide range of Docker problems, including storage migration, disk space shortages, missing libraries, container corruption, network configuration, permission errors, image management, and timeout issues, with detailed command-line solutions and configuration examples.
A network engineer recounts a terrifying outage caused by a firmware‑related SSD bug that locks core switches after 28,224 hours of use, explains the emergency troubleshooting steps taken, and highlights the need for better vendor recall mechanisms to protect critical infrastructure.
This article explains what Docker container exit codes mean, how to view them using Kubernetes or Docker commands, and details the most common codes such as 0, 1, 137, 139, and 143, helping you diagnose why a container is not running.
This article explains how Dble validates its configuration files during startup, lists the main configuration file types, and walks through typical startup failure examples—such as port conflicts, syntax errors, and backend MySQL connectivity issues—providing step‑by‑step troubleshooting guidance for new users.
This guide explains why the “Address already in use” message appears, defines listening ports, and shows step‑by‑step how to use netstat, ss, and lsof commands to list, filter, and pinpoint the processes occupying specific ports on Linux and macOS systems.
This article walks through a real Git‑induced failure, explains how to reproduce and diagnose the nested process loop, analyzes the underlying commit‑graph and alternates interactions, and then details step‑by‑step how to seek help and contribute a fix to the Git open‑source community.
This article walks through a real‑world case of a private‑cloud service experiencing 504 and 499 errors due to cross‑continent latency, detailing step‑by‑step troubleshooting, log analysis, Nginx timeout parameter tuning, SLB configuration changes, and key concepts behind Nginx error codes and proxy settings.
This guide covers common Docker problems such as migrating storage directories, handling insufficient disk space, missing shared libraries, container deletion issues, network configuration, command usage, and provides step‑by‑step solutions with code examples.
This article analyzes MySQL replication anomalies caused by master failures or network interruptions that lead to incomplete transaction replay on slaves, demonstrates a reproducible experiment using network delay and iptables, and provides practical guidance for both recovering and permanently handling stalled slave IO threads.
This article explains the fundamentals of the ping utility, detailing its basic output fields, interpreting bytes, time, and TTL values, and demonstrates advanced switches such as -t, -a, -n, -l, -r, as well as batch ping techniques for network troubleshooting.
This article recounts a MySQL high‑availability incident in a dual‑master environment, explains how missing binary‑log index files caused replication failures, and details step‑by‑step troubleshooting, directory recreation, binlog position correction, and configuration improvements to restore reliable database operation.
This article walks through Dubbo’s RPC communication using a packet‑as‑narrator metaphor, detailing the thread models of Netty 3 and Netty 4, OS socket handling, and practical troubleshooting steps for latency and timeout issues in a clear, engaging style.
This guide explains how to identify when Redis is slow, measure baseline latency, monitor slow commands and latency, troubleshoot network, fork, huge pages, swap, AOF, expiration, and big keys, and provides a practical checklist of solutions.
The article investigates why read queries are sent to the master node when Dble is configured with rwSplitMode=3, analyzes reproductions on standard replication and MySQL Group Replication, identifies heartbeat and replication status issues, and provides troubleshooting steps and recommendations.
A Kafka cluster at vivo suffered a total traffic drop across a resource group when a broker’s disk failed, because the default producer partitioner still hashed keys to the failed partition, exhausting client buffers and blocking all healthy partitions, prompting recommendations to avoid keys or use custom partitioners.
The article investigates why two MySQL 5.7.32 installations on RedHat 7 show different client character sets—utf8 in the first batch and latin1 in the second—by reviewing MySQL charset settings, OS locale configuration, and providing corrective commands.
This article explains how to identify the root causes of Linux network latency—including transmission delays, kernel processing speed, and application handling—by using tools such as hping3, traceroute, wrk, tcpdump, and Wireshark, and offers practical steps to mitigate the delays.
This article provides a step‑by‑step methodology for troubleshooting online service failures by systematically examining CPU, disk, memory (including heap, OOM, stack overflow, and off‑heap), garbage collection, and network problems using tools such as ps, top, jstack, jmap, jstat, iostat, vmstat, strace, and tcpdump.
This guide explains how to configure and read Nginx access and error logs, covering log formats, file locations, per‑server settings, log level options, and practical commands for parsing log entries to aid troubleshooting and performance monitoring.
The article analyzes why a MySQL 5.7.32 instance’s monitoring thread remains in the Opening table state when querying information_schema.tables, discovers the involvement of the Federated storage engine, reproduces the issue with a non‑existent remote server, and confirms the root cause through controlled experiments.
This article presents eight common MySQL error scenarios—including forgotten passwords, password policy violations, case‑sensitivity issues, service startup failures, export/import restrictions, connection limits, binary log overflow, and primary‑key replication errors—along with detailed troubleshooting steps and configuration commands to resolve each problem.
The article details a step‑by‑step investigation of why HTTP request latency increased after moving a Go‑based service to new hardware, focusing on DNS resolution delays, the role of DNSmasq, Go's resolver implementation, and the experiments that led to fixing the issue.
This guide explains why a TiKV node remains pending offline after a scale‑out and scale‑in operation, walks through detailed log inspection, region checks, and command‑line troubleshooting, and provides a step‑by‑step solution to forcefully remove the problematic region and clean up the store.
This guide compiles twenty‑four common Docker problems—from oversized storage directories and disk‑space shortages to network misconfigurations, NFS lock errors, and container startup failures—providing clear explanations, step‑by‑step commands, and configuration tweaks to resolve each issue efficiently.
This guide explains why enabling .NET Framework may still leave applications unable to run, details the need to install both .NET Runtime and SDK for versions 5.0 and 6.0 in x86 and x64, and provides step‑by‑step troubleshooting with a real‑world example.
This article narrates a step‑by‑step troubleshooting process for a malfunctioning 128 GB USB flash drive, covering initial failure, diagnostics with Windows Disk Management, chip detection tools, firmware re‑flashing using mptools, speed testing with DiskMark, and final verification, offering practical tips for similar hardware repairs.
Learn how to diagnose the “Address already in use” error by listing listening ports on Linux and macOS using netstat, ss, and lsof, understand port concepts, interpret command output, filter results, and find which processes occupy specific ports.
This guide explains how to use tcpdump for network packet capture, covering basic usage, interface selection, host and port filtering, logical operators, saving captures to files, and real‑world troubleshooting scenarios with clear command examples.
The article examines the chaotic changes in Jira's newer API version, detailing six incompatible methods of passing issue status parameters, explains the mismatch between name and id fields, and provides Java helper functions to handle these inconsistencies effectively.
This guide walks through nineteen typical Kubernetes problems—from service access and port‑mapping errors to pod init failures, PVC issues, and helm installation glitches—explaining each root cause, providing concise troubleshooting steps, and showing the exact kubectl commands and code snippets needed to resolve them.
This article breaks down Kubernetes troubleshooting into three essential steps—understanding the failure, managing the response, and preventing recurrence—while mapping key monitoring, observability, and incident‑response tools to each phase for reliable cloud‑native operations.
This article demonstrates how to use the JDK’s native command‑line and graphical utilities—such as jps, jinfo, jvisualvm, jconsole, jstat, jstack and jcmd—to observe JVM metrics, troubleshoot memory and thread issues, and verify JVM parameters in Java applications.
This article explains how DNS operates inside Kubernetes, enumerates common failure causes, describes CoreDNS's built‑in observability plugins, introduces BPF‑based client‑side diagnostics, and provides a step‑by‑step troubleshooting workflow to identify and resolve DNS issues in cloud‑native environments.
This article explains why Redis latency spikes can cause system-wide outages, shows how to measure baseline performance, monitor slow commands, and address network, RDB, swap, AOF, expiration, and big‑key problems with practical solutions and a diagnostic checklist.
This article provides a step‑by‑step methodology for identifying why a Redis instance becomes slow, covering baseline latency testing, slow‑log analysis, big‑key detection, expiration patterns, memory limits, fork overhead, huge‑page effects, AOF configuration, CPU binding, swap usage, memory fragmentation, network saturation, and practical remediation techniques.
After migrating to a PaaS platform, intermittent 502 errors appeared on both GET and POST requests, and a detailed analysis of Nginx retry behavior, Ingress HTTP version settings, and uWSGI incompatibility reveals the root cause and a configuration fix.
This article explains how to detect Redis latency problems, measure baseline performance, monitor slow commands, and address common causes such as network round‑trip delays, fork‑generated RDB snapshots, transparent huge pages, swap usage, AOF settings, key expiration, and big‑key handling, providing practical troubleshooting steps and solutions.
This article analyzes a MySQL replication failure caused by stale GTID execution data and unsynchronized binlog persistence, explains the underlying mechanisms, demonstrates reproducible testing, and provides two practical remediation methods to skip duplicate-key errors and restore replication.
A Kubernetes pod appeared healthy but failed to receive heartbeats because its DNS search domain included a top‑level "HOST" entry, causing incorrect name resolution, and the article explains the root cause, analysis, and practical fixes such as using fully qualified names or adjusting ndots and dnsPolicy.
This article explains the relationship between kubelet, Docker, containerd, and runc, walks through a real‑world exec failure logged by dockerd, and shows how to pinpoint the faulty component, identify resource‑limit causes, and understand runc’s execution workflow.
This guide explains how to use Linux networking commands—including ip, ifconfig, netstat, ping, traceroute, host, dig, systemd-resolve, and dhclient—to inspect interfaces, check connectivity, trace routes, query DNS, and manage DHCP leases for effective troubleshooting.
Debugging microservices in a Kubernetes environment is challenging due to the abstraction of pods, network complexities, infrastructure issues, and application-level faults, but by monitoring at the service layer, aggregating data, and applying machine‑learning‑based anomaly detection, teams can effectively identify and resolve problems.
This article shares practical methods and real‑world case studies for IT professionals to analyze, locate, and fix system runtime issues, service timeouts, file‑handle leaks, JVM memory overflows, and performance bottlenecks, emphasizing hypothesis testing, boundary narrowing, and systematic post‑mortems.
Learn how to use essential Linux networking tools—including ip, ifconfig, netstat, ping, traceroute, host, dig, and dhclient—to view interface details, monitor connections, test reachability, query DNS, and manage DHCP leases, with command options and practical tips for effective system troubleshooting.
This guide explains how to diagnose the “Address already in use” error by listing listening ports with netstat, ss, and lsof, interpreting their output, filtering results, and locating the offending process on Linux and macOS systems.
This article details the investigation of frequent RocketMQ timeout errors in a company's procurement service, identifies misconfigured brokerIP2 and unstable master‑slave network as the root causes, and provides step‑by‑step remediation procedures to restore reliable message delivery.
The article explains that using the logical operator AND between column assignments in a MySQL UPDATE statement causes unexpected results, demonstrates the issue with sample data, and shows that multiple columns must be separated by commas to update them correctly.
During high‑traffic events like Double‑11, Linux systems often see load averages surge, affecting response times and command execution; this article explains what load averages represent, how the kernel computes them using exponential weighted moving averages, and outlines common causes and systematic methods for root‑cause analysis.
This article provides a systematic, step‑by‑step methodology for diagnosing Redis latency spikes, covering baseline performance testing, slow‑log analysis, high‑complexity commands, big‑key handling, expiration patterns, memory limits, fork overhead, huge‑page settings, AOF configurations, CPU binding, swap usage, memory fragmentation, network saturation, and practical monitoring tips.
This article explains why MySQL fails to start on Ubuntu due to AppArmor restrictions and provides two practical solutions: editing the AppArmor profile to grant MySQL directory access or switching AppArmor to complain mode, with full command examples and configuration snippets.
This guide provides a step‑by‑step troubleshooting workflow for common Kubernetes problems across Pods, Services, and Ingresses, explaining key concepts, diagnostic commands, typical failure states, and remediation links to help operators quickly identify and resolve cluster issues.
