This guide walks through practical Linux commands—including xargs, background execution, resource monitoring, multitail, continuous ping logging, netstat analysis, and SSH port forwarding—to help sysadmins write concise scripts, troubleshoot performance, and automate routine tasks effectively.
This article traces the historical development of Ethernet—from its 1973 inception and early coaxial media through successive IEEE standards such as 10BASE‑T, Fast Ethernet, Gigabit Ethernet, and 10 GbE—detailing cable types, wiring schemes, fiber optics, transceiver modules, and auto‑negotiation mechanisms that underpin modern networking.
This article examines how data center operators and the supply chain are advancing toward 400 Gbps Ethernet, detailing the technical innovations, market forces, and future challenges that shape high‑speed networking, optical modules, and ASIC development for ultra‑large scale data centers.
The article shares a developer’s experience interviewing at over 30 Chinese tech firms, breaking down three main interview focuses—data structures and algorithms, operating‑system and core‑technology knowledge, and project experience—while also offering practical advice on networking questions, open‑source tools, and how to evaluate a company's interview process.
The article shares the author’s interview experiences at over 30 companies and provides a comprehensive guide covering data‑structure and algorithm questions, core C++ concepts, operating‑system fundamentals, networking protocols, open‑source tools, project‑experience expectations, and practical advice for evaluating both technical and non‑technical aspects of potential employers.
DPVS is an open‑source, DPDK‑based user‑space load balancer that achieves line‑rate throughput by assigning each worker to a dedicated CPU core and NIC queue, provides lock‑free per‑CPU data structures and multiple forwarding modes including NAT64, and simplifies maintenance while supporting IPv4/IPv6 in large‑scale production deployments.
Using a vivid Journey to the West allegory, this article walks through cloud networking fundamentals—from regions, availability zones, and VPCs to BGP routing, DNS resolution, TCP handshakes, TLS encryption, load balancing, and micro‑service communication—illustrating each concept with clear diagrams and analogies.
This article provides a detailed overview of operations engineering, covering the definition of ops and game ops, interactions with product teams, server management strategies, RAID levels, load‑balancing technologies (LVS, Nginx, HAProxy), caching solutions, middleware, MySQL troubleshooting, backup methods, Keepalived, Linux security, networking layers, and practical shell scripts for monitoring and automation.
This article explains the principles of caching, compares memory and disk storage, demonstrates several iOS persistence methods, and details how YYCache combines memory and disk layers with LRU optimization and network synchronization to improve performance in a real‑world mobile app.
The article shares a detailed, step‑by‑step account of eight backend interview experiences, covering written tests, system‑design questions, networking fundamentals, Python/Django coding tasks, and practical advice for job seekers aiming to land offers at top tech companies.
This article provides a comprehensive overview of the HTTP protocol, covering its relationship with DNS/TCP/IP, request/response structure, methods, design principles, persistent connections, cookies, compression, caching, status codes, and the enhancements introduced in HTTP/2.
This comprehensive tutorial walks through capturing HTTP traffic with Wireshark and tcpdump, decodes raw TCP packets, explains request and response structures, explores encoding, MIME types, methods, status codes, and advanced topics such as proxies, caching, cookies, redirection, and connection management, giving developers a solid understanding of how HTTP works under the hood.
This comprehensive guide explains the concepts, architecture, and operation principles of Linux Virtual Server (LVS) load‑balancing clusters, details the NAT, DR, and Tun modes, compares scheduling algorithms, and provides step‑by‑step scripts and commands for setting up high‑availability LVS environments with keepalived.
This tutorial shows how to create a Python client‑server pair that randomly generates a new Windows login password on a target machine, sends it over a socket to your server, and demonstrates how to revert the change using built‑in commands.
This article provides a comprehensive overview of InfiniBand technology, covering its open‑standard architecture, history, OFED software stack, protocol layers, performance advantages over traditional storage networks, and its primary use cases in high‑performance computing and data‑center environments.
This article provides a comprehensive overview of Ethernet switching, covering data‑link layer functions, IEEE 802.3 family standards, duplex modes, MAC/IP addressing, auto‑negotiation, flow‑control mechanisms, VLAN concepts, broadcast‑storm mitigation, trunking, and mainframe storage interfaces such as ESCON and FICON.
This article traces the historical development of Ethernet—from its 1973 inception and early 2.94 Mbps implementations through successive IEEE standards such as 10 Mbps DIX, Fast Ethernet, Gigabit Ethernet, 10 GbE, and 100 GbE—detailing the physical media, cabling types, connector standards, and auto‑negotiation mechanisms that have shaped modern networking.
The article investigates intermittent TCP connection failures during application server startup caused by the Linux kernel ARP queue length parameter unres_qlen, reproduces the issue with a concurrent connection test, analyzes kernel internals, and recommends increasing unres_qlen for kernels prior to 3.3.
This article provides a comprehensive guide to DNS, covering its purpose, hierarchical query process, server roles, record types, and practical command‑line tools like dig, host, and nslookup, enabling readers to fully understand and troubleshoot domain name resolution.
A seasoned CTO shares concrete advice for junior developers, covering tool selection, goal setting, continuous learning, communication skills, networking, and choosing the right company, all aimed at maximizing growth and long‑term career value during the critical early years.
This article explains the concept of load balancing, compares HTTP redirection, DNS‑based balancing, reverse‑proxy solutions, and Linux Virtual Server techniques (LVS‑NAT, LVS‑DR, LVS‑TUN), detailing their mechanisms, advantages, limitations, and practical configuration commands for building scalable, high‑performance server farms.
This guide demonstrates how to enable communication between hosts on different subnets within the same VLAN across two three‑layer switches by configuring VLANs, assigning IP addresses to Vlanif interfaces, and adding static routes on each device.
This article presents a set of 14 multiple‑choice and short‑answer questions covering database indexing, locking mechanisms, DELETE behavior, network protocols, OSPF LSA types, Linux signals, port inspection, list deduplication, Python data structures, class inheritance, HTTP GET/POST differences, site reliability improvements, and hash function evaluation.
This article explains how the protocol formerly known as HTTP-over-QUIC was officially renamed to HTTP/3, outlines the role of the IETF QUIC working group, the distinction between iQUIC and gQUIC, and highlights key interoperability milestones and resources.
A comprehensive collection of Linux commands and shell scripts covering mounting Windows shares, monitoring HTTP concurrency, network sniffing, log analysis, file system checks, boot sequence, link types, partition handling, FTP modes, and various automation tasks for effective system administration.
This tutorial walks through designing a network topology, configuring static and DHCP IPs, disabling the default firewall, installing and initializing iptables and DHCP services, setting up NAT and port forwarding, and persisting the configuration on a Linux server.
This guide walks you through Python's built‑in open() function, file modes, reading and writing techniques, directory traversal with os.walk, and a series of practical scripts including a triangle printer, number‑guessing game, log analysis, IP counting, prime number generator, command‑line argument handling, web page fetching, process memory aggregation, port monitoring, and SNMP‑based CPU and network traffic monitoring.
Netty is a high‑performance, asynchronous, event‑driven NIO framework that supports TCP, UDP and file transfer, offering robust, customizable, and scalable networking solutions widely adopted across internet, big‑data, gaming and telecom industries, with detailed analysis of its architecture, I/O model, threading, serialization, reliability, traffic shaping, graceful shutdown, and security features.
A comprehensive collection of Linux commands, shell one‑liners, and multi‑line scripts covering file sharing, network monitoring, process inspection, disk management, boot sequence, link types, user creation, FTP modes, and service automation to help sysadmins work efficiently.
This article presents a comprehensive set of Linux interview questions covering basic file handling, process management, networking, security concepts, HTTP protocols, load balancing, and Python scripting, providing clear tasks and explanations for each topic.
This guide explains how to use the Linux wget utility for reliable, automated file downloads, covering basic syntax, essential options for background execution, recursive mirroring, bandwidth limiting, proxy handling, logging, and a dozen practical examples that demonstrate common scenarios such as resuming interrupted transfers and downloading entire websites.
This article explains Linux's separation of user and kernel address spaces, details the five classic network I/O models—blocking, non‑blocking, I/O multiplexing, signal‑driven, and asynchronous—and introduces zero‑copy techniques such as mmap, sendfile and splice to reduce data copying overhead.
A comprehensive collection of Linux operations interview questions and answers covering topics such as system maintenance, networking, load balancing, RAID, MySQL, scripting, security, and troubleshooting, providing practical guidance for candidates seeking high‑pay Linux sysadmin roles.
This article explains why load balancing is essential for high‑traffic systems, describes its underlying principles and classifications from layer‑2 to layer‑7, outlines common software implementations, and presents typical scenarios such as scaling, high availability, and disaster recovery.
Alibaba showcased its cutting‑edge network research at SIGCOMM 2018, highlighting programmable hardware, integrated software‑hardware designs, AI‑driven operations, the Hyper‑scale Edge Network vision, hierarchical network lifecycle management, large‑scale RDMA deployment, and advanced network visualization, positioning itself alongside leading global tech firms.
This article provides a comprehensive introduction to Docker, covering its open‑source origins, client‑server architecture, networking and storage solutions, integration with PaaS/IaaS platforms, impact on DevOps practices, and its pivotal role in enabling modern microservice architectures.
This article walks through fundamental networking concepts such as routing tables, ifconfig, and ARP, demonstrates how a ping request is processed across subnets and gateways, shows real‑world packet captures, and explains how a misconfigured HSRP caused intermittent connectivity issues, offering practical troubleshooting steps.
This article explains the fundamental differences between GET and POST requests, the dual TCP/UDP usage of DNS, the meaning of idempotence, the contrast between cookies and sessions, causes and solutions for TCP packet fragmentation, the three‑way handshake and four‑way termination, the complete HTTP request flow, long‑connection handling, TCP reliability mechanisms, detailed HTTP structure, the distinction between URI and URL, and how HTTPS secures data transmission.
This article uses simple animations and analogies to demystify TCP’s three‑way handshake, data transmission nuances, and the four‑way connection termination, explaining key states like SYN_SENT, SYN_RCVD, and TIME_WAIT while also covering retransmission, duplicate‑ack handling, and window sizing.
This article traces the evolution of Ethernet from its 1973 inception through successive IEEE standards, explains the various copper and fiber media types, describes cabling categories and wiring schemes, and outlines auto‑negotiation and optical module technologies used in modern networking.
While both GET and POST are HTTP request methods built on TCP, they differ in how parameters are transmitted, caching behavior, URL length limits, security implications, and the number of TCP packets exchanged, with GET sending data via the URL and POST via the request body.
This guide explains the fundamentals of DNS, how hostnames map to IP addresses, and provides step‑by‑step instructions for installing BIND on Linux, configuring master, slave, and cache servers, defining zones, and managing common DNS record types.
This article explains how a unified, cross‑platform long‑connection component built on libuv, mbedTLS and WebSocket was refactored into a plug‑in architecture that decouples layers, uses double‑linked structures and function pointers, and dramatically improves flexibility and maintainability.
This article describes the motivation, layered architecture, protocol implementation details, and a plug‑in refactoring approach for a cross‑platform long‑connection component that unifies iOS, Android, and WebSocket communication using libuv, mbedTLS, and C interfaces.
This article presents a concise 14‑question quiz covering key concepts in database indexing, locking, Linux signals, network protocols, Python data structures, and hash functions, plus open‑ended discussion prompts on system reliability and hash evaluation.
This article explains the basic principles of the TCP protocol, covering its purpose in ensuring reliable data transmission, packet size limits, sequence numbering, how packets are reassembled by the operating system, the slow‑start mechanism with ACK handling, and methods for detecting and retransmitting lost packets.
An in‑depth look at the evolution of the TCP/IP protocol suite, covering its origins, key pioneers like Vint Cerf and Bob Kahn, early ARPANet experiments, the protocol’s impact on modern internet infrastructure, and how it continues to shrink global communication distances.
This article explains how the Internet is built and operates by detailing the layered architecture of computer networks, comparing the OSI and TCP/IP models, and describing the functions, protocols, and key concepts of each layer from the physical medium up to the application layer.
Archie, created in 1989 by Peter Deutsch at McGill University, was the first internet search tool that indexed FTP sites, while WAIS, developed by Brewster Kahle at Thinking Machines, extended searchable databases worldwide, both highlighting early challenges in managing large communication traffic and user-friendly interfaces.
This article delivers a comprehensive, experiment‑driven guide to IPv6, covering its 128‑bit address scheme, Linux kernel stack, practical setups such as stateless autoconfiguration and web services, various transition mechanisms like dual‑stack, tunneling and NAT64/DNS64, and detailed socket‑programming considerations for developers.
This article compiles a comprehensive set of NetEase interview questions covering computer science fundamentals, networking, operating systems, Linux commands, databases, and short‑answer problems, providing candidates with a practical resource to assess and improve their technical knowledge.
This article explains how the Internet works by breaking the Internet Protocol Suite into a simplified five‑layer model, covering the physical, link, network, transport, and application layers, their protocols, addressing schemes, and how data moves from hardware to user applications.
This article provides a comprehensive introduction to container technology—covering Docker's architecture, networking models, storage solutions, integration with PaaS/IaaS platforms, orchestration tools, and its impact on DevOps, micro‑services, and cloud computing ecosystems.
NVMe over Fabrics, leveraging PCIe and RDMA, replaces legacy SCSI and SAS protocols to deliver vastly higher bandwidth and lower latency for SSDs, enabling massive parallel I/O queues, and reshaping data‑center storage architectures through both FC‑NVMe and Ethernet‑based implementations.
This guide walks you through configuring a Python development environment, installing essential libraries, handling network and binary operations, and using powerful tools like pwntools to build security and exploit scripts efficiently.
This article compiles 35 Linux operations interview questions—including multiple‑choice, coding, and essay topics—along with detailed answers covering VLANs, system calls, IP addressing, TCP/UDP, process handling, data structures, and networking fundamentals to help candidates prepare effectively.
This article outlines three increasingly complex Envoy deployment patterns for service‑mesh environments—service‑to‑service, service with a front‑proxy, and service‑to‑service with front‑proxy and double‑proxy—detailing listener configurations, external service handling, discovery integration, and provided configuration templates.
This article explains the concept of load balancing in distributed systems, outlines its benefits for throughput and reliability, compares common architectural layers, evaluates key algorithmic considerations, and provides Python implementations of round‑robin, weighted, random, hash‑based, and least‑connection strategies along with deployment options.
Envoy is a cloud‑native L7 proxy and communication bus designed for modern service‑oriented architectures, offering out‑of‑process deployment, language‑agnostic operation, modern C++11 implementation, extensive L3/L4 and HTTP L7 filtering, HTTP/2, gRPC, database protocol support, service discovery, health checking, advanced load balancing, edge proxy capabilities, observability, and dynamic configuration.
This article provides a comprehensive overview of core Linux concepts, including the GNU project and GPL license, common distributions, swap partitions, GRUB bootloader, buffer vs cache, TCP three-way handshake, filesystem hierarchy, hard and soft links, and RAID technology.
This article explains the fundamentals of load balancing, compares layer‑2 to layer‑7 approaches, reviews popular software solutions such as LVS, Nginx and HAProxy, and details both static and dynamic balancing algorithms with practical implementation guidance.
This article explains the principles of TCP long connections, compares NIO and BIO models, and describes how Android applications can implement and share persistent connections using AIDL, process sharing, and a dedicated SDK to support push, IM, and other real‑time services.
This guide explains how to use the powerful Linux ip command—replacing ifconfig—to configure IP addresses, manage routing tables, view network statistics, monitor netlink messages, handle ARP entries, and control interfaces, with practical examples and code snippets for system administrators and developers.
This article explains why Weave's FastDb mode can cause network interruptions on CentOS 7 VMs, analyzes the underlying kernel bugs and UDP PMTU probing issues, and provides practical solutions such as kernel upgrades, disabling UFO, and adjusting MTU settings.
This article documents the step‑by‑step conversion of a Python 2.6 script that uses socket.inet_aton() and MD5 hashing to Python 3.4, explaining the differences in return types, required byte‑string handling, and the final optimized solution.
This article explains the fundamentals of DNS, details the Qunar DNS architecture and its intelligent DNS, EDNS, and HTTP-DNS features, and describes how these technologies improve resolution speed, balance traffic, enable automatic failover, and prevent DNS hijacking.
This article provides concise answers to common Linux interview questions, covering GPL and free software concepts, distro selection, essential startup services, system optimization steps, runlevels, boot process, link types, partition planning, file deletion, vi usage, user management commands, grep and sed options, crontab syntax, important directories, shutdown/reboot commands, sudoers configuration, permission management, SecureCRT shortcuts, log auditing solutions, network troubleshooting, shell quoting, startup configuration files, and a list of useful Linux commands.
The article explains how RDMA (Remote Direct Memory Access) reduces CPU involvement, lowers latency, and increases bandwidth in data‑center networks, describes JD.com’s practical deployments across AI, big‑data, storage, and HPC workloads, and highlights industry trends toward broader RDMA adoption.
This article compiles essential Linux environment variable settings, TCP characteristics, three‑handshake rationale, proxy implementation, TCP vs UDP pros and cons, OOP vs procedural differences, HTTP request flow, status codes, deadlock causes and prevention, TCP close_wait and time_wait states, and common IPC mechanisms, providing concise answers for operations interview preparation.
This guide details how to configure a Huawei AR2220 router with a single WAN port to enable PPPoE dial‑up, set up default routing, NAT, and DHCP services so that internal LAN users can access the Internet using the specified credentials.
The article explains TCP as a connection‑oriented protocol, contrasts it with UDP, details the three‑way handshake and four‑way termination processes using clear steps and analogies, and includes illustrative diagrams to aid comprehension.
This article compiles a comprehensive set of 19 Linux, security, networking, and Python interview questions covering basic commands, file handling, process management, load balancing, HTTP headers, cookies vs sessions, TCP handshakes, and common security vulnerabilities, providing a solid study guide for system administrators and DevOps engineers.
Learn how TCP’s three-way handshake and four-way termination work in detail, illustrated with Wireshark packet captures, and understand why each step is necessary through clear explanations and real‑world analogies that demystify network connection establishment and closure.
This article walks you through the fundamentals of DNS, explains the role of /etc/hosts, describes the three types of DNS servers, shows how to install BIND on Red Hat or Debian systems, and provides detailed configuration examples for master, slave, and cache zones along with essential record types and troubleshooting commands.
The common belief that a machine can only handle 65,536 TCP connections is a misconception; in theory and practice a server or client can manage far more connections, depending on IP, port, and system limits.
This article compiles a wide range of interview questions and answers covering MySQL escaping, JavaScript memory leaks, PHP garbage collection, concurrency control, networking fundamentals, and system design, aiming to warn developers about knowledge gaps and encourage deeper technical learning.
This guide outlines how operations engineers can elevate their professional image by pursuing key certifications, mastering deep technical topics, favoring niche tools over mainstream ones, writing scripts with awk/sed, embracing unconventional operating systems, and strategically networking within the industry.
This guide compiles 28 practical Linux commands and shell scripts covering file system mounting, network monitoring, process inspection, password generation, log analysis, link handling, boot sequence, FTP modes, and service management, providing concise examples for everyday system administration tasks.
This guide outlines the ten core toolsets—ranging from Linux basics and network services to scripting, firewalls, monitoring, clustering, and backup—that aspiring Linux operations engineers need to master for effective system administration.
This article explains the role of TCP within the Internet protocol stack, details packet size limits, sequence numbering, assembly, slow‑start and ACK mechanisms, and how TCP ensures reliable, ordered data transmission despite packet loss.
This article presents a comprehensive collection of 76 multiple‑choice questions covering Linux shell commands, networking fundamentals, and server management topics, each with four options and the correct answer provided, making it an ideal study resource for system administrators and IT students.
This article provides a comprehensive overview of InfiniBand technology, covering its history, performance advantages over traditional interconnects, architectural concepts, layered protocol specifications, and typical use cases in high‑performance computing and data‑center environments.
This article explains why and how to expose a locally running server to the public internet using ngrok, demonstrates installation and usage steps including region configuration, compares it briefly with the open‑source localtunnel tool, and notes security considerations for development testing.
This article explains the concept of load balancing, compares HTTP redirection, DNS‑based balancing, reverse‑proxy methods, and Linux Virtual Server techniques (LVS‑NAT, LVS‑DR, LVS‑TUN), detailing their mechanisms, performance trade‑offs, configuration commands, and practical deployment considerations for scalable server infrastructures.
This guide presents practical Linux and server administration commands, covering log cleanup, nginx IP analysis, tcpdump capture, Python date formatting and string reversal, subprocess execution, multiprocessing, iptables port forwarding, cron scheduling, file relocation, RAID concepts, Oracle backup strategies, port checking, Apache MPM modes, and monitoring tool comparisons.
The article details Hujiang's practical experience deploying microservices with Docker, evaluating orchestration tools, network and storage solutions, monitoring approaches, and automatic scaling, and demonstrates how Docker improves deployment density, QPS, and resource efficiency compared to traditional architectures.
This article provides a comprehensive overview of Linux Virtual Server (LVS) load‑balancing clusters, detailing core concepts, packet‑flow mechanisms, key terminology, NAT/DR/TUN modes, scheduling algorithms, step‑by‑step configuration scripts, and high‑availability setup with keepalived, all illustrated with diagrams and command examples.
This guide explains how to install the ip utility, configure and delete IP addresses, view and modify routing tables, display interface statistics, monitor netlink messages, manage ARP entries, and obtain help, providing practical command examples for Linux system administrators.
This article provides a comprehensive guide to common Linux commands, covering internal vs external classification, help lookup methods, command syntax, practical examples for file management, system monitoring, compression, shutdown, pipelines, quoting, and best learning habits.
Google’s internal Maglev load balancer, described in a recent research paper, bypasses the kernel to operate directly on the NIC, uses ECMP routing, consistent hashing, and memory‑shared queues to achieve sub‑microsecond packet processing while scaling horizontally across clusters.
This article provides a comprehensive, command‑by‑command tutorial for installing and configuring the OpenStack Neutron networking service on the controller, network, and compute nodes, covering package installation, database setup, Keystone integration, ML2 plugin configuration, and service startup.
This guide explains why policy routing is essential for servers with two ISP lines, and provides step‑by‑step commands for configuring persistent policy routes on CentOS 6.5 and FreeBSD 10.3, including iproute2 tables, pf rules, and Nginx listen directives with setfib.
This article enumerates and briefly describes the 18 open‑source iOS libraries and components that were used during the development of the NetEase News iOS application, covering networking, UI, audio, image handling, and utility functions.
This article explains the TCP three‑way handshake, four‑way termination, and related state transitions, illustrates uncommon scenarios such as simultaneous open and close, discusses half‑open connections, fd‑leak effects, and presents Linux‑based experiments with client.go and server.go code samples.
This article provides a comprehensive introduction to TCP, covering its header structure, optional fields, the role of MSS and TSO, mechanisms for reliability and retransmission, as well as detailed explanations of flow control, sliding windows, and congestion control algorithms.
The article explains why TCP’s TIME_WAIT state is essential for reliable data delivery, describes how excessive TIME_WAIT sockets can exhaust port resources in high‑concurrency short‑connection servers, and offers principled and practical mitigation techniques such as kernel sysctl tweaks and careful use of SO_LINGER.
This article uses a playful campus love story to illustrate how messages travel over a network, explaining the role of IP addresses, MAC addresses, broadcast domains, and the ARP protocol in translating an IP to a physical address so data can reach the recipient’s device.
This article explains Docker's native networking model, covering Linux namespaces, veth pairs, the docker0 bridge, container IP assignment, port exposure, Docker links, Libcontainer versus LXC, and the need for advanced network optimization solutions for complex cloud environments.
The article examines common misconceptions about game server performance, outlines essential message pipelines, introduces Gate as a reverse‑proxy for low‑latency scene synchronization, discusses integrating a message‑queue (MQ) for decoupled services, and presents a service‑oriented RPC framework with patterns to build maintainable, scalable multiplayer back‑ends.
The article explains the three LVS load‑balancing modes—NAT, IP tunnel, and direct routing—and details eight scheduling algorithms (Round‑Robin, Weighted Round‑Robin, Least‑Connection, Weighted Least‑Connection, Locality‑Based, Locality‑Based with Replication, Destination Hashing, and Source Hashing), describing their principles and use cases.
