This guide explains the most important MySQL configuration variables—max_connections, max_user_connections, net_buffer_length, max_allowed_packet, and back_log—detailing how each affects concurrency, network efficiency, and overall database performance, with practical sizing recommendations.
This article compiles and translates a selection of the most popular DevOps blog posts from the first half of 2015, highlighting key tools such as Fabric, Ansible, Docker, and case studies from Amazon and Netflix, and provides links to the original English sources.
MyCat is an open‑source distributed database middleware that transparently shreds tables across multiple backend databases, solves connection overload, provides ER‑based sharding, global partitioning, AI‑driven catlets, and advanced read‑write separation, enabling low‑cost migration of single‑node databases to the cloud.
After a painful P1 incident caused by a kernel upgrade, this article outlines how to properly reboot a Linux server by documenting pre‑restart state, verifying post‑restart consistency with process and port snapshots, and using simple commands such as ps, netstat, diff, and last to ensure service continuity.
The article explains how Alibaba's Notify and MetaQ middleware achieve high‑performance, reliable distributed messaging and final consistency for massive e‑commerce transactions, detailing their architecture, design principles, scalability, fault‑tolerance, and the specific optimizations applied for the Double‑11 shopping festival.
This article explains essential software performance testing concepts—including QPS/TPS, concurrency, response time, throughput calculations, think time, and how to estimate daily traffic using real‑world examples from e‑commerce platforms—providing formulas and practical guidance for engineers, administrators, and developers to assess and optimize system capacity.
This guide walks through creating VLAN 10, assigning an IP address, setting up local AAA users, enabling telnet access, and activating the HTTP server on a Quidway switch, including file management commands and verification steps.
This article explains how WeChat introduced a global font setting and configuration‑driven UI parameters to adapt iOS interfaces across iPhone, iPad and split‑screen devices, handling logical resolutions, proportional scaling, and webview font adjustments.
This article explains MongoDB's three explain modes, details the fields returned by queryPlanner and executionStats, shows how IndexFilters influence the optimizer, and walks through practical examples that demonstrate how proper indexing eliminates collection scans and in‑memory sorts for faster query performance.
This article examines the problems and trade‑offs of metadata protection in cloud object storage, highlighting the importance of reliability, availability, and consistency, and comparing primary‑secondary and multi‑replica models, including the WRN algorithm and practical operational considerations.
This article explains how MySQL's Query Cache invalidation works, which tables are suitable for caching, how to control caching with the SQL_NO_CACHE and SQL_CACHE hints, and how to handle large result sets using the query_cache_limit setting.
This article presents a comprehensive overview of DSP advertising system architecture, covering real‑time bidding infrastructure, audience targeting, data processing pipelines using Hadoop, Spark and Storm, click‑through‑rate prediction models, and anti‑fraud mechanisms, offering practical insights for engineers building high‑performance ad platforms.
Understanding website traffic involves distinguishing IP (unique visitors) from PV (page views), interpreting their relationship, and using these metrics to estimate bandwidth needs, with formulas that factor in average page size, peak traffic multiples, and conversion from bytes to bits for accurate capacity planning.
This guide explains how to design a powerful user interview outline, manage question pacing, apply qualitative probing techniques, and use facilitation tricks such as preparation, flexible pacing, tone control, and visual aids to extract deep user insights.
This article shares eight practical insights on operations automation—from overall planning and standardization to continuous delivery, DevOps philosophy, leveraging testing, CMDB considerations, aiming for NoOps, and the real impact of Docker—offering a comprehensive guide for modern IT teams.
Since the 1970s databases have become essential middleware, and modern large‑scale parallel databases, designed for extreme parallelism on clustered hardware, face trade‑offs in performance, scalability, and fault tolerance, prompting a shift toward cloud‑native, micro‑service architectures and new hardware such as SSDs and memory‑centric designs.
The article explains how MySQL's Query Cache, while simple and fast, can incur CPU overhead from hash calculations, suffer frequent invalidations on table changes, and consume excessive memory, making its use potentially counter‑productive under high‑concurrency or volatile data scenarios.
The article shares practical support and communication principles, data handling guidelines, and internal best‑practice examples from Qunar to help newcomers avoid common pitfalls and improve operational efficiency by emphasizing sincere assistance, careful treatment of sensitive information, post‑mortem reviews, and appropriate use of tools such as mailing lists, QTALK, and encoding conversion.
The article explains the difference between upstream and downstream bandwidth on a server, describes how most servers primarily use upstream for downloads, notes that downstream is used for uploads, and warns that POST uploads can consume memory and cause I/O slowdown when concurrency is high.
This article explains the differences between long and short TCP/IP connections, outlines three major communication models (server/client, connection type, and send/receive mode), describes synchronous and asynchronous transmission, and reviews various message formats and read/write strategies to help developers design robust network programs.
