Cluster | BestHub

IT Services Circle

Jun 11, 2025 · Databases

How to Count 100 Million Redis Keys Efficiently Without Crashing the Cluster

This article explains why the KEYS * command is dangerous for large Redis deployments and presents several practical alternatives—including SCAN, multithreaded SCAN, cluster‑wide parallel scans, built‑in counters, and real‑time incremental counting—along with code samples, performance comparisons, and guidance on choosing the right solution.

ClusterKey CountingRedis

0 likes · 10 min read

How to Count 100 Million Redis Keys Efficiently Without Crashing the Cluster

Full-Stack Internet Architecture

Jun 10, 2025 · Databases

Advanced Nacos: Service Cluster Setup, Configuration Loading Order, and Common Issues

This guide explains how to build a Nacos service cluster, configure providers and consumers, write the necessary Spring Cloud Nacos YAML and Java controller code, detail the steps for setting up multiple Nacos nodes, and troubleshoot typical startup errors.

ClusterConfigurationJava

0 likes · 7 min read

Advanced Nacos: Service Cluster Setup, Configuration Loading Order, and Common Issues

Full-Stack Internet Architecture

May 19, 2025 · Databases

Understanding MOVED and ASK Redirection in Redis Cluster

Redis clusters use two redirection commands—MOVED for permanently migrated hash slots and ASK for temporary redirects during slot migration—explaining their trigger conditions, typical scenarios, and step-by-step client interaction examples, including sample CLI output.

ASKClusterMOVED

0 likes · 4 min read

Understanding MOVED and ASK Redirection in Redis Cluster

Full-Stack Internet Architecture

May 15, 2025 · Databases

Understanding PFAIL and FAIL States in Redis Cluster Node Failure Detection

This article explains the PFAIL (possible fail) and FAIL (failed) states in Redis clusters, describes the state transition process, demonstrates node failure and automatic failover with command‑line examples, and provides practical insights into cluster health monitoring and recovery.

ClusterFAILNode Failure

0 likes · 5 min read

Understanding PFAIL and FAIL States in Redis Cluster Node Failure Detection

Full-Stack Internet Architecture

May 8, 2025 · Databases

Manual Slot Migration in Redis Cluster: Step-by-Step Guide

This article explains how to manually migrate a hash slot in a Redis cluster by checking cluster status, setting importing and migrating slots, retrieving keys, using the MIGRATE command, and updating slot assignments across nodes, with detailed command examples and explanations.

CLIClusterRedis

0 likes · 6 min read

Manual Slot Migration in Redis Cluster: Step-by-Step Guide

IT Xianyu

May 8, 2025 · Databases

Redis for DBAs: Quick Installation, Core Commands, Caching Design Patterns, and High‑Concurrency Practices

This article explains why Redis is becoming a DBA's favorite, provides a five‑minute installation guide, essential commands, cache‑design pitfalls and solutions, explores Redis data structures with Java examples, demonstrates distributed locking and flash‑sale implementations, and covers clustering, backup, monitoring, and performance tuning.

CachingClusterJava

0 likes · 9 min read

Redis for DBAs: Quick Installation, Core Commands, Caching Design Patterns, and High‑Concurrency Practices

Full-Stack Internet Architecture

Apr 30, 2025 · Databases

How to Reshard Slots in a Redis Cluster

This article explains the process of moving hash slots between nodes in a Redis cluster using the redis-cli --cluster reshard command, detailing the required parameters, interactive steps, and verification of successful slot migration.

ClusterData MigrationRedis

0 likes · 6 min read

Full-Stack Internet Architecture

Apr 29, 2025 · Databases

Essential Redis Cluster Configuration Parameters: Required and Optional Settings

This article explains the key Redis cluster configuration options found in redis.conf, detailing required settings such as cluster-enabled, cluster-config-file, and cluster-node-timeout, as well as optional parameters like cluster-slave-validity-factor, migration barrier, full coverage requirement, and read‑when‑down behavior.

ClusterConfigurationHigh Availability

0 likes · 5 min read

Essential Redis Cluster Configuration Parameters: Required and Optional Settings

Full-Stack Internet Architecture

Apr 28, 2025 · Databases

Understanding Epochs in Redis Cluster: currentEpoch and configEpoch

This article explains the concept of epochs in Redis Cluster, describing the two types—currentEpoch and configEpoch—their roles in versioning and conflict resolution, how they are updated and persisted, and provides example node listings and commands for inspection.

ClusterDistributed SystemsEpoch

0 likes · 5 min read

Understanding Epochs in Redis Cluster: currentEpoch and configEpoch

Full-Stack Internet Architecture

Apr 27, 2025 · Databases

Understanding the Redis Cluster Bus and Node Communication

This article explains how Redis cluster nodes use a TCP-based gossip protocol and a dedicated cluster bus to discover each other, detect failures, synchronize configuration, and automatically redirect client commands to the correct node, illustrated with practical command‑line examples.

ClusterNode CommunicationRedis

0 likes · 5 min read

Understanding the Redis Cluster Bus and Node Communication

Full-Stack Internet Architecture

Apr 25, 2025 · Databases

Essential Knowledge Points of Redis Cluster

Redis cluster relies on two ports per node, a hash‑slot based sharding scheme, a master‑slave replication model, and provides eventual consistency, making these four fundamentals essential knowledge for developers and operators to.

ClusterHigh AvailabilityMaster‑Slave

0 likes · 6 min read

Essential Knowledge Points of Redis Cluster

Full-Stack Internet Architecture

Apr 24, 2025 · Databases

How to Add and Remove Nodes in a Redis Cluster

This guide demonstrates how to horizontally scale a Redis cluster by adding nodes as masters or slaves, configuring them, using redis-cli commands to join or remove nodes, and handling special cases such as removing a failed node, all with practical code examples.

BackendClusterNode Management

0 likes · 7 min read

How to Add and Remove Nodes in a Redis Cluster

Full-Stack Internet Architecture

Apr 22, 2025 · Databases

Understanding Redis Cluster Node IDs and Their Fields

This article explains the immutable unique node IDs in a Redis cluster, the additional metadata each node maintains, provides a sample `cluster nodes` output, and details the meaning of every field in that output to help with monitoring and interview preparation.

ClusterDistributed SystemsNode ID

0 likes · 5 min read

Understanding Redis Cluster Node IDs and Their Fields

Full-Stack Internet Architecture

Mar 20, 2025 · Databases

Using Key Tags to Perform Multi-Key Operations in Redis Cluster

This guide explains how to use Redis cluster key tags to align multiple keys to the same slot, enabling multi-key commands like MGET, and includes step‑by‑step examples of connecting, setting keys, checking slots, encountering CROSSSLOT errors, and resolving them with tagged keys.

ClusterKey TaggingMulti-key Commands

0 likes · 4 min read

Using Key Tags to Perform Multi-Key Operations in Redis Cluster

Full-Stack Internet Architecture

Mar 17, 2025 · Databases

Understanding Redis Cluster Hash Slots: Concepts, Calculation, Allocation, and Dynamic Scaling

This article explains Redis cluster hash slots, how they partition data across 16,384 slots, the CRC16-based slot calculation, slot allocation to nodes, and demonstrates dynamic scaling operations such as adding, reshaping, and removing nodes with practical command‑line examples.

ClusterData ShardingDynamic Scaling

0 likes · 9 min read

Understanding Redis Cluster Hash Slots: Concepts, Calculation, Allocation, and Dynamic Scaling

Full-Stack Internet Architecture

Mar 14, 2025 · Databases

All About Redis Cluster: Architecture, Setup, Operations, and High‑Availability

This article provides a comprehensive guide to Redis Cluster, covering its background, overall architecture, deployment steps, configuration templates, cluster creation commands, basic key‑value operations, high‑availability testing, and how to manually assign master‑slave relationships for robust distributed caching.

ClusterConfigurationHigh Availability

0 likes · 14 min read

All About Redis Cluster: Architecture, Setup, Operations, and High‑Availability

Practical DevOps Architecture

Mar 7, 2025 · Cloud Native

Kubernetes DNS Resolution Issues and Troubleshooting Guide

This article explains common Kubernetes DNS resolution failures, both for external domains and internal service discovery addresses, and provides a step‑by‑step troubleshooting workflow that includes checking CoreDNS, examining resolv.conf, adjusting DNS settings, and recreating CoreDNS when necessary.

ClusterCoreDNSDNS

0 likes · 6 min read

Kubernetes DNS Resolution Issues and Troubleshooting Guide

Architect

Jan 26, 2025 · Databases

Optimizing Redis Cluster Slot Migration to Reduce Latency and Improve High Availability

This article analyzes the latency and availability problems of native Redis cluster slot migration, proposes a master‑slave synchronization based redesign that batches slot transfers, reduces ask‑move and topology‑change overhead, and validates the solution with performance tests showing smoother latency and higher reliability.

ClusterDatabase OptimizationHigh Availability

0 likes · 16 min read

Optimizing Redis Cluster Slot Migration to Reduce Latency and Improve High Availability

Lobster Programming

Nov 9, 2024 · Databases

How to Split Hot Keys in Redis Cluster to Avoid Single-Shard Bottlenecks

Redis can become a bottleneck when a hot key concentrates traffic on a single shard; this article explains how to split such hot keys into multiple sub‑keys, distribute them across cluster nodes using CRC16 slot mapping, and implement the approach in high‑concurrency scenarios like coupon grabs or real‑time leaderboards.

ClusterDatabase ScalingHigh Concurrency

0 likes · 6 min read

How to Split Hot Keys in Redis Cluster to Avoid Single-Shard Bottlenecks