This article explains how Redis Cluster distributes data using hash slots and consistent hashing, how nodes communicate via the gossip protocol, and how the Java Jedis client handles redirection and slot migration to achieve scalable, highly available Redis deployments.
This article compiles common Elasticsearch interview questions and detailed answers covering cluster architecture, inverted index fundamentals, index design, write/query optimizations, master election, document indexing flow, search process, Linux tuning, and Lucene internals, providing practical guidance for candidates.
This article explores how enterprises can effectively use Redis by partitioning clusters for independent or shared use, addressing key naming conflicts, implementing graceful scaling with Zookeeper, monitoring performance via Open-Falcon, and quickly isolating problematic business traffic to maintain system stability.
This article explains Redis as an in‑memory data store used for caching, database, and messaging, walks through its evolution from simple HTTP caching to dedicated servers, and details server‑side features like persistence, Sentinel, replication, clustering, as well as client‑side capabilities such as rich data types, transactions, Lua scripting, pipelining, and distributed locks.
This article walks through the evolution of Redis clustering—from early Replication+Sentinel setups, through Proxy‑based solutions, to modern Redis Cluster—detailing their architectures, advantages, drawbacks, and provides practical interview tips and high‑impact answers for candidates.
This article reviews the progression of Redis high‑availability solutions—from simple replication with Sentinel, through proxy‑based setups, to native Redis Cluster—explains their advantages and drawbacks, and provides practical interview Q&A tips for candidates.
The article explains the evolution from classic three‑tier Java web architecture to cluster, distributed, and microservice designs, detailing each model’s components, load‑balancing mechanisms, session sharing, and the trade‑offs of using technologies such as Tomcat, Nginx, Dubbo, and Spring Cloud.
This comprehensive guide explains Redis fundamentals, its rich data structures and common commands, then dives into performance optimization, replication, and clustering, offering practical examples and best‑practice recommendations for building reliable, high‑performance Redis deployments.
This article provides a comprehensive guide to Redis high‑availability solutions, detailing Sentinel principles, multiple HA architectures such as DNS‑based, VIP‑based, Keepalived, Redis Cluster, Twemproxy and Codis, and shares practical best‑practice recommendations for deployment and failover.
This guide walks through configuring static IP, netmask, gateway, and DNS for each node in a virtual‑machine cluster on Linux, showing exact file edits for the master and slave machines, testing connectivity with ping commands, and confirming the network setup is complete.
In this talk, Tencent Cloud senior engineer Zou Peng outlines cloud‑native best practices for Redis 4.0 clusters, detailing a smart‑proxy architecture with gossip‑based management, lazy‑scan big‑key handling, automatic fail‑over, the high‑performance CKV engine, and practical guidance on scaling, sharding, monitoring, and cost‑effective high‑availability deployment.
This article provides a comprehensive overview of the Quartz Java scheduling framework, detailing its architecture, core components such as Scheduler, Job, Trigger and JobDetail, typical use cases, Spring‑based cluster deployment configurations, monitoring techniques, and the underlying database‑lock synchronization mechanism.
This article reviews the common Redis deployment patterns—including single‑instance, master‑slave replication, Sentinel, Cluster and custom solutions—analyzes their strengths and weaknesses, and provides practical configuration tips and recommendations for building reliable, scalable Redis services in production environments.
This article examines five common Redis deployment patterns—single instance, master‑slave replication, Sentinel, Cluster, and custom high‑availability solutions—detailing their architectures, advantages, drawbacks, and practical configuration tips to help engineers choose the most suitable setup for their workloads.
Redis Cluster is a distributed system that partitions its keyspace into 16,384 hash slots across up to 16,384 nodes, enabling automatic sharding, slot migration, replication, and high‑availability features such as automatic node discovery, master‑slave election, and online resharding without service interruption.
Elasticsearch is an open‑source, scalable, high‑availability distributed full‑text search engine that operates in near real‑time, using clusters of nodes, indexes, documents, shards and replicas to efficiently store and retrieve large volumes of data.
This tutorial explains how to set up two Elasticsearch nodes on one machine by copying the installation directory, adjusting configuration files, starting each node, verifying cluster health with curl or Kibana, and addressing common pitfalls such as port conflicts and master‑node settings.
This tutorial explains how to set up a six‑node Redis cluster (three masters and three slaves) on one Linux VM by creating separate directories and configuration files for each instance, installing Ruby tools, starting the instances, and using the redis‑trib.rb script to create and verify the cluster.
This comprehensive guide explains Spark's ecosystem, execution principles, key features, deployment architectures, core concepts like RDD, Transformations, Actions, Jobs, Stages, Shuffle and Cache, as well as Spark Streaming mechanics and practical resource‑tuning tips for optimal big‑data processing.
This article compares several Redis cluster solutions—including Codis‑style architecture, Alibaba Cloud ApsaraCache, Baidu BDRP 2.0, JD's custom implementation, the official Redis Cluster, AWS ElasticCache, and Baidu Tieba's ksarch‑saas—detailing their components, sharding methods, migration strategies, and deployment scenarios.
This article walks readers through setting up MySQL replication, from the basic master‑slave model to a one‑master‑multiple‑slave cluster, covering configuration files, essential parameters, verification commands, performance tips, and common pitfalls for production deployments.
This guide walks you through editing the network interface file on a master node, replicating the settings on slave nodes, and verifying connectivity with ping commands, providing a complete step-by-step process to configure a clustered virtual machine network on Linux.
This guide shows how to use SRVCTL commands and SQL queries to view the status of Oracle RAC databases, instances, services, node applications, ASM instances, and disk groups, as well as how to start and stop the entire RAC cluster safely.
This article compares the three most common distributed cache solutions—Redis, Memcached, and Alibaba's Tair—across nine technical dimensions, then dives into Redis fundamentals, high‑availability setups with Sentinel, and cluster sharding to help engineers make informed cache‑selection decisions.
This article explains the origins of knowledge graphs, introduces the leading graph databases Neo4j and OrientDB, demonstrates their Java client usage, and compares their features to help developers select the most suitable technology for constructing effective knowledge graph solutions.
In this interview, Redis China User Group chair Zhang Donghong shares the database’s key features, version history, data types, high‑availability options, clustering mechanics, automation challenges, future trends, and practical advice for beginners, illustrating how Redis powers massive online services.
This guide explains why a Redis cluster is needed for large data sets, describes the hash‑slot architecture introduced in Redis 3.0, and provides step‑by‑step instructions—including directory creation, configuration changes, instance startup, Ruby gem installation, and cluster creation commands—to build a functional Redis cluster on a Mac.
This article explains how Node.js uses the Cluster module to create a master‑worker multi‑process architecture, detailing worker creation, inter‑process communication via socketpair, handling of shared ports, and provides practical code examples for master, slave, and low‑level libuv interactions.
This article explores Hadoop YARN’s evolution, multi‑tenant design, queue and node‑label scheduling, real‑world resource allocation challenges, and data‑driven tools that automate diagnostics and visualizations to optimize CPU and memory usage across massive clusters.
This article explains how high‑availability (HA) clusters provide redundancy for directors, RS‑servers, databases and storage, covering active‑passive node roles, resource stickiness, constraints, quorum voting, split‑brain avoidance, failure detection methods, and essential configuration tips.
This article explains how Node.js’s built‑in cluster module and external tools like PM2 can be used to improve stability and load capacity through three scaling strategies—cloning, decomposing, and splitting—allowing applications to fully leverage multi‑core CPUs and achieve zero‑downtime restarts.
Redis is an open-source, in-memory data store offering versatile structures and commands; this guide explains its fundamentals, key data types, essential commands, practical examples, performance optimization techniques, replication, clustering, and Java client choices to help you design robust, high-performance Redis solutions.
This article compares Redis and Memcached across data‑type support, memory management, persistence mechanisms, and clustering features, highlighting their architectural differences, performance trade‑offs, and suitable use‑cases to help developers choose the right in‑memory storage solution.
This article provides a step‑by‑step analysis of Dubbo’s cluster fault‑tolerance mechanism, explaining the roles of Directory, Router, and LoadBalance, illustrating the execution flow with diagrams, and clarifying how invokers are selected and balanced in a distributed Java RPC framework.
This article explains how server clusters manage shared storage using SCSI‑2 and SCSI‑3 reservation mechanisms, detailing their workflows, advantages, and limitations, and includes examples from Windows Server 2003 and 2008 clustering to ensure data integrity and high availability.
This comprehensive guide introduces Redis fundamentals, explores its rich data structures and essential commands, delves into performance optimization techniques, explains replication and clustering strategies, and compares popular Java clients, providing practical examples and best‑practice recommendations for reliable, high‑performance deployments.
This article explains Redis Cluster’s distributed architecture, the 16,384 hash slot mechanism, node addition and removal, decentralised request routing, fault‑tolerance through master‑slave replication, slot migration without service interruption, and the internal data structures that enable these features.
This article explains why Redis high‑availability is essential, details the inner workings of Redis Sentinel, compares several HA architectures—including Sentinel with DNS or VIP, client‑side Sentinel, Keepalived/Haproxy, Redis Cluster, Twemproxy, and Codis—lists their pros and cons, and shares practical best‑practice recommendations for building reliable Redis deployments.
This article explains Redis as an open‑source in‑memory data store, compares its main deployment modes—single instance, Redis Cluster, and Redis Sentinel—detailing their architectures, replication, sharding, failover mechanisms, client options, and backup strategies such as RDB and AOF.
This article provides a comprehensive guide to Inceptor Server HA, covering its high‑availability architecture, configuration steps, required parameters, connection strings, failover behavior, and the HA Tools utility for monitoring and managing master‑standby switches.
This article explains what an LVS cluster is, outlines its types (LB, HA, HP), details common LVS deployment modes (nat, dr, tun) and their features, describes scheduling algorithms, and provides practical ipvsadm commands and configuration examples for building and managing high‑availability Linux load‑balancing clusters.
This article explains MySQL's asynchronous, semi‑synchronous, and Group Replication mechanisms, compares their trade‑offs, details Group Replication’s certification‑based full‑sync workflow, lists its features and limitations, and provides a complete configuration and maintenance guide for a three‑node cluster.
This step‑by‑step guide walks you through installing Kafka, starting a single‑node broker, producing and consuming messages, configuring a multi‑node cluster with replication, testing fault tolerance, and using Kafka Connect to import and export data between files.
This guide walks through the principles of Keepalived, its VRRP‑based architecture, and step‑by‑step configuration of a dual‑master LVS high‑availability cluster, covering prerequisites, installation, keepalived setup, real server configuration, testing failover, and handling complete node failures.
This guide walks through the reasons for sharding in MongoDB, explains the sharding architecture, and provides detailed commands to configure config servers, shard servers, and mongos, add shards, enable sharding on databases and collections, insert test data, and verify successful data distribution across shards.
Learn how to quickly set up a multi‑node Hadoop cluster on a single machine using Docker containers, covering image preparation, SSH configuration, fixed IP assignment with pipework, and building custom Hadoop images, enabling a lightweight, cost‑effective big‑data environment for development and testing.
Learn how to build and manage a Redis cluster on Linux, covering the rationale for clustering, hash slot mechanics, node configuration, adding/removing nodes, resharding, and integrating master‑slave replicas, with step‑by‑step commands and practical examples.
This article reviews three mainstream MySQL clustering solutions—MHA master‑slave replication, Oracle's MySQL Cluster, and Alibaba's open‑source Cobar—detailing their architectures, advantages, drawbacks, and practical deployment considerations for high availability and scalability.
This article explains PostgreSQL's kernel architecture, from client connection handling through parsing, rewriting, planning, and execution, illustrates scan and join algorithms, shows how to extend the kernel and build clustered deployments, and introduces Foreign Data Wrappers for integrating external data sources.
This article explains how Redis Cluster automatically distributes data across nodes, how clients locate the correct node using slot hashing and hash tags, and how resharding and slot migration are performed without downtime, providing a detailed overview of the partitioning mechanism.
This guide explains why using a forced OS shutdown on an Oracle RAC cluster can leave services in an UNKNOWN state and provides a step‑by‑step, gentle procedure using crs_stat and srvctl commands to check status, shut down databases, ASM instances, and node services in the correct order, then restart them safely.
This guide explains how to build Docker images, configure Redis, and orchestrate containers to create a fully automated, one‑click Redis sharding cluster, covering preparation, scripting, configuration, and verification steps.
The article reviews common MySQL high‑availability solutions—including shared‑storage SAN, DRBD disk replication, keepalived/heartbeat, MHA, ZooKeeper‑based HA, Galera/PXC clusters, and proxy middleware—detailing their architectures, advantages, limitations, and suitability for different business and operational requirements.
This article reviews the main MySQL high‑availability architectures—including shared‑storage SAN, DRBD disk replication, keepalived/heartbeat, MHA, ZooKeeper‑based HA, Galera/PXC clustering, and middleware proxy solutions—detailing their principles, advantages, limitations, and suitability for different business scenarios.
This article provides a comprehensive, step‑by‑step tutorial for installing Go 1.4, compiling Codis from source, configuring Zookeeper, setting up Codis server, proxy, and dashboard, and deploying a three‑node Codis cluster on Linux, including all necessary environment variables and command examples.
This article explains IBM PowerHA (formerly HACMP) for AIX, covering its architecture, heartbeat‑based failover mechanisms, topology and resource components, dual‑active HyperSwap solutions, and the role of the HMC management console in providing enterprise‑grade high availability.
This article walks through configuring a MySQL high‑availability cluster using Pacemaker and Corosync, covering topology, environment setup, host preparation, NFS sharing, MySQL installation, HA resource definition, testing, and final considerations, all with detailed commands and screenshots.
This guide walks through setting up a highly available two‑node Nginx service on CentOS 7 using Corosync and Pacemaker, covering topology, environment preparation, host synchronization, HA component installation, NFS sharing, resource configuration with crmsh, and testing the failover behavior.
This step‑by‑step guide shows how to configure a three‑node MariaDB HA cluster on CentOS using NFS shared storage, corosync multicast heartbeat, pacemaker resource management, and a virtual IP, including installation, configuration files, and failover testing.
This article provides a comprehensive overview of Redis, covering its primary use cases, internal network and memory models, data consistency, supported data types, client libraries, replication mechanisms, read‑write separation, eviction policies, cluster architecture, node communication, redirection handling, online reconfiguration, and fault‑tolerance strategies.
Redis 3 now officially supports clustering, introducing hash slots and dynamic node management to simplify key distribution, scaling, and fault tolerance, allowing seamless read/write operations across multiple nodes without manual hashing, and offering features like online node addition, automatic slave monitoring, and performance‑aware key allocation.
This tutorial walks you through installing LVS on a Red Hat server, configuring the router, setting up virtual and real servers, adjusting ARP tables, and validating the cluster with ipvsadm, curl, and Tsung performance testing, all while ensuring high‑throughput static web delivery.
This article examines the inherent drawbacks of Redis Cluster—such as gossip overhead, upgrade challenges, client protocol complexities, and implementation gaps—and proposes a set of architectural enhancements, including proxy layers, dashboards, and agents, to improve scalability, reliability, and operational efficiency.
This article reviews real‑world Redis Cluster deployments from Youdao, Qihoo 360 and Mango TV, analyzes its architectural drawbacks, client challenges, implementation limitations, performance impact, and summarizes the overall advantages and disadvantages of using Redis Cluster as a distributed database solution.
This article walks through constructing a MySQL MHA high‑availability cluster using Docker, comparing traditional installation with two Docker‑based versions, detailing container setup, configuration steps, Dockerfile composition, pros and cons, and automation scripts for rapid, repeatable deployments.
Learn how to set up a fault‑tolerant MySQL environment by installing and configuring Corosync, Pacemaker, DRBD, and related resources across two servers, covering prerequisites, network sync, storage setup, resource definitions, and verification steps to achieve a fully operational HA cluster.
This article explains how to build a robust multi‑process Node.js server using the cluster module, covering round‑robin load balancing, graceful worker shutdown, process monitoring, and inter‑process communication with code examples for both master and worker processes.
This article examines Node.js’s early criticisms about reliability and single‑threaded limits, then explains how the built‑in cluster module and fork() enable multi‑process deployment, load balancing, and communication, illustrated with code demos, performance insights, and a look at nginx proxy integration.
This article recounts a series of July Redis incidents—including network‑card saturation, connection‑limit exhaustion, suspected split‑brain, Bgsave‑induced OOM, and master‑restart data loss—detailing the migration to Redis Cluster with a Smart Proxy, the challenges faced, and actionable remediation strategies.
The article analyzes the inherent drawbacks of Redis Cluster—such as its decentralized P2P design, gossip overhead, upgrade difficulty, lack of hot‑cold data separation, client protocol challenges, and implementation limits—and proposes architectural enhancements like proxy, dashboard, and agent components to improve scalability, manageability, and performance.
This article introduces MySQL Cluster’s share‑nothing architecture, explains the NDB storage engine’s advantages and drawbacks, describes the management, data, and API node roles, and provides a step‑by‑step configuration and deployment tutorial with command‑line examples.
The article explains MySQL Cluster as a real‑time, ACID‑compliant, in‑memory distributed database, describes its node architecture, transparent sharding for linear scalability, various SQL/NoSQL access methods, and presents a benchmark achieving 200 million queries per second on 32 data nodes.
This guide walks you through the complete process of adding a new master or slave node to an existing Redis cluster, covering configuration, startup, cluster integration, verification, and slot migration to ensure the new node operates correctly.
This guide explains how Redis 3’s native clustering works, details the hash‑slot mechanism, and provides step‑by‑step instructions for installing Redis and its Ruby dependencies, configuring multiple nodes, creating a six‑node cluster, and testing key distribution across the cluster.
This article explains the fundamentals of MySQL Cluster, its shared‑nothing architecture, NDB storage engine advantages and drawbacks, the roles of management, data, and API nodes, and provides a step‑by‑step guide with configuration files and commands to set up a high‑availability MySQL Cluster on multiple servers.
This guide explains the fundamentals of Linux Virtual Server (LVS), covering cluster concepts, types, scheduling algorithms, ipvsadm commands, and detailed configuration examples for NAT and DR models, culminating in a complete web‑server load‑balancing deployment with Discuz on CentOS.
This article explains what a Linux cluster is, contrasts it with distributed systems, outlines its two main characteristics—scalability and high availability—along with essential capabilities like load balancing and error recovery, and details common cluster types such as high‑availability, load‑balancing, and high‑performance computing clusters.
This comprehensive tutorial walks you through Redis Cluster fundamentals, including installation, hash slot sharding, node replication, fault tolerance, configuration files, cluster creation commands, and client testing, all without delving into complex distributed theory.
