This article explains MD5’s history, the four‑step algorithm that produces a 128‑bit hash, common uses such as data integrity and password storage, the critical security flaws like collisions, and why modern systems should switch to stronger hashes like SHA‑256 or SHA‑3.
Facing the challenge of importing billions of image assets, we redesigned the pipeline using Dataworks open‑API, clustered tables, data sharding, cube tables, and custom key generation, achieving faster parallel processing, fault tolerance, and flexible attribute storage, and share practical insights on scheduling, view parametrization, and output services.
This article reviews five widely used encryption algorithms—MD5, SHA‑256, DES, AES, and RSA—explaining their classifications, Java implementations, strengths, weaknesses, and how they combine in HTTPS to secure data transmission.
This article explains the value of short URLs, the HTTP redirection principle behind them, and provides detailed design and implementation strategies—including hash‑based and distributed‑ID approaches, base‑62 encoding, database storage, caching, indexing, and security measures—to build a scalable short‑link service.
This article explains the value, underlying HTTP redirect mechanism, and detailed design approaches—including hash‑based and distributed‑ID generation, base‑62 encoding, database storage, caching, indexing, sharding, and rate‑limiting—to build a scalable short‑link service.
This article explains the theory behind cryptographic hash functions and provides a complete PHP implementation of the SHA‑256 algorithm, detailing each processing step—from converting strings to binary to final compression—along with supporting helper functions and reference tables.
This article explains the principles of consistent hashing, its data‑skew issue, how virtual nodes mitigate that problem, and demonstrates the implementation and usage of ConsistentHashLoadBalance in Dubbo with detailed code analysis and practical load‑balancing examples.
This article explores the MD5 hashing algorithm in depth, detailing its fixed 128‑bit output, the padding and block processing steps defined in RFC 1321, the internal round functions, and the reasons it is considered irreversible yet vulnerable to collisions and various cracking techniques such as brute‑force, rainbow tables, and differential attacks.
This article walks through a classic interview problem of locating common URLs in two massive files, explains why a naïve O(m·n) approach fails, and presents a scalable solution using hash‑based divide‑and‑conquer and file partitioning techniques.
This article explains the background, design criteria, and practical implementations of horizontal database sharding—including range, hash, gene, routing‑table, and consistent‑hash methods—while discussing common pitfalls, data‑skew mitigation, and both doubling and consistent‑hash expansion techniques for MySQL clusters.
This article explains the drawbacks of a basic modulo hash algorithm for key distribution, demonstrates how consistent hashing resolves scaling and node‑failure issues, and discusses virtual‑node techniques to mitigate data skew and improve load balancing in distributed cache systems.
This article explains the concept of short URLs, compares three generation algorithms (auto‑increment ID, hash‑based, and random), analyzes their trade‑offs, and presents a complete backend design including database schema, caching strategy, redirection flow, and Java code examples for hash and base‑62 conversion.
This article provides an in‑depth analysis of Java’s ThreadLocal mechanism, covering its weak‑reference key, internal ThreadLocalMap structure, hash algorithm, collision resolution, cleanup strategies, expansion logic, source code walkthroughs, and practical usage scenarios such as trace‑ID propagation in distributed systems.
This article explains DBLE's hash‑based sharding algorithm that first computes a modulo to obtain a logical shard number and then directly maps it to a physical shard via a mapping table derived from partitionLength and partitionCount arrays, including configuration steps, development tips, operational guidance, and a comparison with MyCat.
The article explains how to use a perceptual hash algorithm to generate image fingerprints, compare them to assess UI screen similarity, and integrate this method with UIAutomator for automated decision‑making in the 360 testing project, reducing computational complexity compared to naive double‑loop approaches.
This article explains the fundamentals of binary operations, why hashCode is used, how Java's String hashCode is implemented, the rationale behind using the multiplier 31, and the detailed workings of HashMap's hash function, index calculation, capacity choices, and custom sizing recommendations.
