This article demystifies Linux memory management by explaining why buffers and cache are not meant to be manually cleared, how the 'available' metric differs from 'free', and which sysctl parameters and cgroup settings you should tune to optimize performance and avoid OOM incidents.
This article explains the core principles of I/O read/write operations, detailing the data preparation and copying stages, the roles of kernel and user buffers, synchronization models, and performance optimizations such as double buffering, circular buffers, zero‑copy, read‑ahead, and delayed write.
This article explains the exact meaning of the “buffers” and “cached” fields shown by the Linux free command, detailing how they are derived from /proc/meminfo, the kernel source calculations, swap cache interactions, and provides verification experiments with code examples.
The article explains how the Linux free utility calculates the “buffers” and “cached” fields, detailing their definitions, the kernel source functions that produce them, the role of block‑device page cache versus ordinary file cache, and how to verify the numbers with simple commands.
This article demystifies the Linux free command’s “buffers” and “cached” fields by tracing their origins through /proc/meminfo, kernel source functions such as meminfo_proc_show, nr_blockdev_pages, and page‑cache mechanisms, and demonstrates the differences with practical experiments.
This section analytically derives the headroom size for loss‑less Ethernet links using IEEE 802.1Qbb priority flow control, detailing worst‑case delays, interface and cable latency, buffer cell sizing, Cisco Nexus configuration examples, and a comparison with Fibre Channel B2B primitives.
This article explains MySQL InnoDB's various buffers—including the buffer pool, change buffer, log buffer, and doublewrite buffer—detailing their purposes, internal mechanisms such as LRU variants, configuration options, and how they improve performance and ensure data integrity.
This article explains the purpose, recommended settings, and tuning tips for MyISAM‑related MySQL variables such as key_buffer_size, read_buffer_size, read_rnd_buffer_size, bulk_insert_buffer_size, myisam_sort_buffer_size, myisam_max_sort_file_size, myisam_repair_threads, and myisam_recover, helping DBAs optimize indexing and query performance.
This guide explains how to optimize Linux TCP performance by classifying and tuning kernel parameters related to connection establishment, packet reception, and packet transmission, covering queues, buffers, NIC bonding, multi‑queue IRQ affinity, RingBuffer settings, and offloading features.
This article explains how to interpret the Linux free command output, clarifies the roles of total, used, free, shared, buffers, and cached memory, describes the -/+ buffers/cache values, and provides commands for manually clearing swap and cache.
This article walks through common interview questions on Linux memory inspection and cache clearing, explains the fields shown by the free command, and then delves into SQL join types, performance bottlenecks, buffer settings, and practical optimization techniques for MySQL databases.
This article explains the core differences between Java NIO and traditional IO, introduces channels and buffers, details NIO’s underlying mechanisms, provides a complete code example, and compares NIO’s workflow with Netty’s model, highlighting performance and architectural distinctions.
This article explains the core differences between Java NIO and traditional IO, introduces the concepts of channels and buffers, describes buffer state management, provides a complete NIO selector code example, and compares the NIO workflow with Netty's model.
This guide explains how the Linux free command reports memory usage, clarifies the roles of total, used, free, buffers, and cache, describes the meaning of the -/+ buffers/cache line, and provides practical steps to clear swap and drop caches.
This guide explains how to interpret the Linux free command, clarifies the roles of total, used, free, shared, buffers, and cached memory, and provides practical commands to clear swap and drop caches for better system performance.
The article compares Java native arrays and Buffer types such as IntBuffer, showing through benchmarks that native arrays are typically over four times faster than Buffers, and discusses the memory management, performance trade‑offs, and practical implications of using each abstraction.
This guide explains how to interpret the Linux free command, distinguishes between used, free, buffers, and cache memory, describes common symptoms of memory pressure, and provides step‑by‑step commands to manually clear swap and drop caches for better system performance.
This article provides a comprehensive guide to Java I/O, covering traditional BIO streams, the differences between BIO, NIO and AIO, detailed explanations of byte and character streams, buffers, channels, selectors, and practical examples such as file copying and a simple client‑server chat implementation.
This article provides a comprehensive overview of Java IO, explaining the traditional blocking BIO model, the modern non‑blocking NIO architecture, the role of streams, buffers, channels, zero‑copy techniques, and selectors, and includes practical code examples for file copying and simple client‑server communication.
This article explains the distinction between Linux Buffers and Cache, how they appear in the free command, their representation in /proc/meminfo, and demonstrates practical experiments using vmstat and dd to observe their behavior during read and write operations, concluding with clear usage guidelines.
This guide explains Linux's memory architecture, how virtual memory (swap) works, and provides step‑by‑step commands to adjust swappiness, release page caches, and safely free swap space, helping you optimize system performance and avoid memory‑related issues.
This article explains Linux's memory architecture, the role of virtual memory and swap, the distinction between buffers and cache, and provides practical commands to adjust swappiness, clear caches, and safely release both RAM and swap space for improved system performance.
This article explains the fundamental differences between Java NIO and traditional IO, introduces channels and buffers, describes NIO's internal mechanisms, provides a complete code example, and compares NIO's workflow with Netty's model for high‑performance backend development.
This article explains the core differences between Java NIO and traditional IO, introduces the concepts of channels and buffers, details buffer state management, and provides sample NIO code along with a comparison to Netty's processing model.
This comprehensive guide walks developers through OpenGL fundamentals—including contexts, framebuffers, attachments, textures, vertex and index buffers, shader programs, per‑fragment operations, and buffer swapping—providing clear explanations and visual diagrams to help beginners grasp modern graphics programming.
This article explains how Linux memory management differs from Windows, clarifies the output of the free command—including buffers and cache—and demonstrates the performance benefits of caching through a simple 1 GB file read experiment.
Linux appears to consume most of a system’s RAM, but the free command’s output, including buffers and cache, actually reflects memory used for performance optimization; this article explains the distinction, how to interpret free’s columns, and demonstrates the impact with a 1 GB file read experiment.
Linux’s free command often shows high memory usage, leading many to think the OS consumes RAM, but understanding buffers, cache, and the distinction between used and free memory reveals that Linux efficiently utilizes idle memory to improve I/O performance, as demonstrated by simple read‑speed experiments.
This article explains why Linux appears to consume most of the memory, clarifies the meaning of the free command’s buffers/cache fields, and demonstrates through a simple experiment how Linux’s caching dramatically speeds up repeated file reads.
The article explains why Linux appears to consume most memory when using the free command, clarifies the roles of buffers and cache, shows how to interpret free’s output, and demonstrates through experiments how caching dramatically speeds up repeated file reads.
This article explains Java NIO introduced in Java 1.4, covering its core components—Channels, Buffers, and Selectors—detailing channel types, buffer operations, non‑blocking behavior, selector usage, and code examples such as FileChannel and Pipe, and compares NIO with classic IO.
This guide outlines comprehensive MySQL performance tuning techniques, covering architectural replication, system‑level hardware adjustments, MySQL configuration parameters, and application‑level query optimizations with specific recommended values for buffers, caches, and connection limits.
