Formerly called 'Code to 35'. Add our main WeChat ID to access a wealth of shared resources (algorithms, interview prep, tech stacks: Java, Python, Go, big data). We mainly share serious development techniques, focusing on output-driven input. Occasionally we post life snippets and gossip. Our aim is to attract precise traffic and test advertising opportunities.
The article explains Elasticsearch's disk watermark mechanism—low, high, and flood stage thresholds—detailing why they are crucial for preventing data loss and maintaining cluster stability, how they work, how to configure them in elasticsearch.yml, and best‑practice recommendations for monitoring and storage planning.
This article explains Java 8's StampedLock—its optimistic and pessimistic read/write modes, internal state handling, source‑code walkthrough, typical usage scenarios, and a performance comparison with ReentrantLock and ReentrantReadWriteLock—providing concrete code examples and detailed analysis for developers.
This article provides an in‑depth overview of Java’s Collections Framework, detailing the core interfaces (List, Set, Queue, Deque, Map), their major implementations, performance characteristics, thread‑safety considerations, iterator usage, utility classes, and concurrent collection options, illustrated with code examples and diagrams.
This article compiles a concise reference of fifty commonly used Linux commands, detailing each command’s purpose, typical usage syntax, concrete examples, and handy tips to help developers and system administrators quickly master essential command‑line operations.
This article explains how Java’s garbage collector interacts with the four reference types—Strong, Soft, Weak, and Phantom—detailing their behavior, typical use cases, and code examples that show when each reference allows an object to be reclaimed.
The article explains why MySQL 8 replaces fragmented, non‑transactional metadata files with a unified, InnoDB‑backed transactional data dictionary, details the information_schema views that expose it, and enumerates the resulting benefits such as atomicity, consistency, crash recovery, performance gains, simplified administration, reduced lock contention, smoother upgrades, improved DDL handling, and enhanced security.
This article explains Elasticsearch's post_filter mechanism, outlines scenarios where post‑query filtering is beneficial, provides DSL examples for filtering search hits and aggregations, and offers optimization tips to balance precision and query performance.
The article explains how Elasticsearch implements efficient search using an inverted index, detailing its components—posting list, term dictionary, and term index—illustrating the query flow with concrete examples, compression techniques, and the role of Lucene.
This article compiles twelve advanced Spring interview questions covering bean initialization and lifecycle, AOP implementation, transaction management, the differences between ApplicationContext and BeanFactory, type conversion mechanisms, dependency injection, circular dependency resolution with three‑level caches, the event system, @Transactional and @Async annotations, and the inner workings of DispatcherServlet.
The article systematically compares four major API styles—SOAP, REST, GraphQL, and RPC—detailing each one's core characteristics, advantages, limitations, and suitable use‑cases, and concludes with guidance on selecting the most appropriate protocol based on security, performance, complexity, and team expertise.
