Introducing full-stack Internet architecture technologies centered on Java
An investigation reveals that MySQL treats trailing spaces in VARCHAR values as insignificant during string comparison, causing queries like SELECT * WHERE name='Tom' to match rows with extra spaces, and demonstrates that using the BINARY keyword restores exact matching, highlighting a potential bug in MySQL 5.7.
This article explains MySQL deadlocks by creating a test table, running two concurrent transactions—one using SLEEP to hold a lock and another attempting the same resource—to reproduce a deadlock error, and discusses how this approach aids debugging and understanding of transaction conflicts.
This article explains various situations that cause MySQL indexes to become ineffective—such as leading wildcard LIKE queries, calculations on indexed columns, use of functions, data type mismatches, improper use of composite indexes, and character set differences—providing example SQL, execution plans, and practical testing steps.
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.
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.
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.
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.
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.
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.
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.
