Is file append atomic in UNIX?
In general, what can we take for granted when we append to a file in UNIX from multiple processes? Is it possible to lose data (one process overwriting the other's changes)? Is it possible for data to get mangled? (For example, each process is appending one line per append to a log file, is it possible that two lines get mangled?) If the append is not atomic in the above sense, then what's the bes
今度ã“ã絶対ã‚ãªãŸã«ç†è§£ã•ã›ã‚‹Paxos - Qiita
Paxosã¨ã¯ä½•ã‹ 分散システムã®é‡‘å—å¡”ã¨ã‚‚呼ã°ã‚Œã€Leslie Lamport大先生ã®è¼ã‹ã—ã„æˆæžœã®ä¸€ã¤ã¨ã—ã¦çŸ¥ã‚‰ã‚Œã‚‹åˆ†æ•£åˆæ„アルゴリズムPaxos。 æ—¢å˜ã®è§£èª¬ 実ã¯ã™ã§ã«å˜åœ¨ã™ã‚‹Paxosã®è§£èª¬ã¯å……分ã«è³ªãŒé«˜ã„ Wikipediaã®é …ç›®ã«ã‚‚çµæ§‹é•·ã€…ã¨æ›¸ã‹ã‚Œã¦ã„ã¦ã€ã“れをèªã‚“ã§ç†è§£ã§ããŸäººã¯ã‚‚ã†åƒ•ã®è¨˜äº‹ã‚’èªã‚€å¿…è¦ã¯ãªã„。 åŒæ§˜ã«PFIã®ä¹…ä¿ç”°ã•ã‚“ã«ã‚ˆã‚‹è§£èª¬ã‚¹ãƒ©ã‚¤ãƒ‰ã‚‚ã‚ã‚Šã€ã“れも良ã書ã‘ã¦ã„ã‚‹ã—ã€ã“れをèªã‚“ã§ç†è§£ã§ããŸäººã‚‚ã“れ以上記事をèªã‚€å¿…è¦ã¯ãªã„。 minghaiæ°ã«ã‚ˆã‚‹ãƒ–ãƒã‚°è¨˜äº‹ã®ã“ã‚Œã¨ã‹ç‰¹ã«ã“ã£ã¡ãªã‚“ã‹ã¯ã‹ãªã‚Šç´å¾—æ„ŸãŒã‚ã‚Šã€ã“れらをèªã‚“ã§ç†è§£ã§ããŸäººã‚‚（ä¸ç•¥ï¼‰ tyonekuraæ°ã«ã‚ˆã‚‹ã‚¹ãƒ©ã‚¤ãƒ‰ã‚‚良ãã‹ã‘ã¦ã„ã¦(ä¸ç•¥) ã“ã®è¨˜äº‹ã¯ã“れらã®èª¬æ˜Žã«ç›®ã‚’通ã—ã¦ã‚‚ãªãŠç†è§£ã§ããªã‹ã£ãŸäººã€ã‚‚ã—ãã¯ã“れらã®èª¬æ˜Žã‚’ã“ã‚Œã‹ã‚‰èªã‚‚ã†ã¨æ€ã£ã¦ã„る人ã«å‘ã‘ã¦æ›¸ãã€Paxosアルゴリズムã®è©³ç´°ãªèª¬æ˜Žè‡ªä½“
Should I Rust, or Should I Go
“Should I stay, or should I go?†Great song by the band The Clash. I’m listening to it, right now, while I’m writing this article. The song debuted back in 1982, a long time ago. Back then, I was just a kid exploring a new hobby — programming my Atari 2600. The first video game I ever wrote was written using 6502 Assembly for that console. The compiler for it cost about $65, if I recall, which at
How we're building a business to last
CockroachDB was inspired by frustration with the available open source databases and cloud DBaaS offerings. It was never conceived of as anything but open source software. In late 2014, with encouraging interest from the GitHub community and concomitant inquiries from some forward-looking venture capitalists, it was decision time: should we start a company to accelerate CockroachDB development? On
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Photo by Jon S 長らã日本ã®ã‚¨ãƒ³ã‚¸ãƒ‹ã‚¢ã¯åœ°ä½ãŒä½Žã„ã¨è¨€ã‚れ続ã‘ã¦ã„ã¾ã™ãŒã€æµ·å¤–ã®ã‚¨ãƒ³ã‚¸ãƒ‹ã‚¢ã¯æœ¬å½“ã«åœ°ä½ãŒé«˜ã„ã®ã§ã—ょã†ã‹ã€‚海外ã®ã‚¨ãƒ³ã‚¸ãƒ‹ã‚¢ã¯å¹´åŽ1,000万円以上稼ãã¨ã„ã†è©±ã‚‚よã言ã‚ã‚Œã¾ã™ãŒã€ã©ã“ã¾ã§ãŒæœ¬å½“ãªã®ã§ã—ょã†ã‹ã€‚ 海外ã®äº‹ä¾‹ã‚’紹介ã™ã‚‹éš›ã«è‰¯ã„é¢ã—ã‹ç´¹ä»‹ã—ã¦ãŠã‚‰ãšã€Œå®Ÿä½“ã¯æ—¥æœ¬ã¨ä¸€ç·’ã€ã¨ã„ã†äº‹ã‚‚考ãˆã‚‰ã‚Œãªãã¯æœ‰ã‚Šã¾ã›ã‚“。ãã“ã§ä»Šå›žã¯ã€æµ·å¤–ã®ã‚¨ãƒ³ã‚¸ãƒ‹ã‚¢ã®å¹³å‡å¹´åŽã€ä»–è·ç¨®ã¨æ¯”ã¹ãŸå ´åˆã®æ—¥æœ¬ã®æ°´æº–を調ã¹ã¦ã¿ã¾ã—ãŸã€‚ ■物価ã€è·ç¨®ã€åœ°åŸŸã«ã‚ˆã‚‹æ¯”較 ã“ã‚Œã¾ã§ã‚‚よãã‚ã£ãŸã‚¨ãƒ³ã‚¸ãƒ‹ã‚¢ã®å¹´åŽã«ã¤ã„ã¦ã®è¨˜äº‹ã«ãŠã‘ã‚‹å•é¡Œç‚¹ã¯ä¸‹è¨˜ã®3ã¤ã§ã¯ãªã„ã‹ã¨è€ƒãˆã¦ã„ã¾ã™ã€‚ 物価を考慮ã—ã¦ã„ãªã„ ä»–ã®è·ç¨®ã¨ã®æ¯”較ã—ã¦ã„ãªã„ アメリカ(シリコンãƒãƒ¬ãƒ¼)ã¨ã®æ¯”較ã—ã‹ã—ã¦ã„ãªã„ â—†1．物価を考慮ã—ã¦ã„ãªã„ よãã‚ã‚‹ã®ãŒã€å˜ç´”ã«ã‚·ãƒªã‚³ãƒ³ãƒãƒ¬ãƒ¼ãªã©ã®ã‚¨ãƒ³ã‚¸ãƒ‹ã‚¢ã®ã¿ã®å¹´åŽã‚’å–り上ã’ã¦æ—¥æœ¬ã¨æ¯”較ã™ã‚‹ã‚‚ã®ã§ã™ãŒã€ãã‚Œ
Simplify Repairing your ScyllaDB Cluster with ScyllaDB Manager
We are happy to announce the first release of our new product, ScyllaDB Manager, a management system that automates maintenance tasks on a ScyllaDB cluster. In this release, we now provide a managed repair feature that will automatically run repairs on a cluster. A Smarter Repair Repairing a full cluster is not an easy task and multiple strategies exist. We provide a dedicated solution that levera
On Disk IO, Part 2: More Flavours of IO
If you like the series, check out my upcoming book on Database Internals! Series consist of 5 pieces: Flavors of IO: Page Cache, Standard IO, O_DIRECTMore Flavors of IO: mmap, fadvise, AIOLSM TreesAccess Patterns in LSM TreesB-Trees and RUM ConjectureA new series on Distributed System concepts in Databases can be found here. Memory MappingMemory mapping (mmap) allows you to access a file as if it
Difference between POSIX AIO and libaio on Linux?
On linux, the two AIO implementations are fundamentally different. The POSIX AIO is a user-level implementation that performs normal blocking I/O in multiple threads, hence giving the illusion that the I/Os are asynchronous. The main reason to do this is that: it works with any filesystem it works (essentially) on any operating system (keep in mind that gnu's libc is portable) it works on files wi
Linuxã§aio - （ã²ï¼‰ãƒ¡ãƒ¢
実装ãŒ2ã¤ã‚る。以下ã€ã‚ãã¾ã§ä»Šã®æ™‚点ã§ã®Linuxã®å ´åˆã®çŠ¶æ³/実装ã®ãŠã¯ãªã—。 POSIX aio aio_read(3) ã¨ã‹ aio_write(3), aio_error(3), aio_return(3) ã¨ã‹ã€‚ インターフェースã¯POSIXã§å®šç¾©ã•ã‚Œã¦ã„ã‚‹ã®ã¨åŒã˜ã€‚ システムコールã˜ã‚ƒãªãã¦ãƒ©ã‚¤ãƒ–ラリ関数（librt） è£ã§pthreadã¤ãã£ã¦ãŒã‚“ã°ã£ã¦ã‚‹ã’。 libaio http://lse.sourceforge.net/io/aio.html http://ftp.jaist.ac.jp/pub/Linux/Fedora/development/source/SRPMS/libaio-0.3.106-3.2.src.rpm ã¨ã‹ io_prep_pread(2), io_prep_pwrite(2), io_submit(2), io_queue_init(2),
「ユーザーã®å£°ã€ã‚’上手ã«èžã方法｜ã‘ã‚“ã™ã†
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Mistaeks I Hav Made: Visualising Test Terminology
Good judgement is the result of experience ... Experience is the result of bad judgement. — Fred Brooks In our book, Growing Object-Oriented Software, Guided by Tests, we describe the different kinds of tests we use to drive the design of a computer system and show how they guide the evolution of the system's structure towards the Ports and Adapters architecture. The Ports and Adapters architectur
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How do I accomplish lightweight transactions with linearizable consistency?
GitHub - rqlite/rqlite: The lightweight, distributed relational database built on SQLite.
Light Weight Transactions Under Stress (Christopher Batey, The Last Pickle) | Cassandra Summit 2016
Light Weight Transactions Under Stress (Christopher Batey, The Last Pickle) | Cassandra Summit 2016
Reddit - Dive into anything
http://voyage.hiroono.com/2018/02/08/falcon-heavy/
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