{"id":35091,"date":"2019-10-31T22:02:18","date_gmt":"2019-10-31T19:02:18","guid":{"rendered":"https:\/\/prohoster.info\/blog\/19-golov-gidry-bolshoj-obzor-programmy\/"},"modified":"2019-10-31T22:02:18","modified_gmt":"2019-10-31T19:02:18","slug":"19-golov-gidry-bolshoj-obzor-programmy","status":"publish","type":"post","link":"https:\/\/prohoster.info\/cs\/blog\/administrirovanie\/19-golov-gidry-bolshoj-obzor-programmy","title":{"rendered":"19 hlav hydry. Velk\u00fd p\u0159ehled programu","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"<p>Ve dnech 11-12 \u010dervence se v Petrohrad\u011b uskute\u010dn\u00ed konference <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/?utm_source=habr&amp;utm_medium=453832\">Hydra<\/a><\/noindex>, zam\u011b\u0159en\u00e1 na v\u00fdvoj paraleln\u00edch a distribuovan\u00fdch syst\u00e9m\u016f. V\u00fdhodou Hydry je, \u017ee spojuje skv\u011bl\u00e9 v\u011bdce (kter\u00e9 obvykle lze naj\u00edt pouze na zahrani\u010dn\u00edch v\u011bdeck\u00fdch konferenc\u00edch) a zn\u00e1m\u00e9 praktikuj\u00edc\u00ed in\u017een\u00fdry do jednoho velk\u00e9ho programu na pomez\u00ed v\u011bdy a praxe.<\/p>\n<p><\/p>\n<p>Hydra je jednou z na\u0161ich nejd\u016fle\u017eit\u011bj\u0161\u00edch konferenc\u00ed za posledn\u00edch n\u011bkolik let. P\u0159ipravovala se na ni velmi d\u016fkladn\u011b, byl proveden v\u00fdb\u011br p\u0159edn\u00e1\u0161ej\u00edc\u00edch a p\u0159\u00edsp\u011bvk\u016f. Minul\u00fd t\u00fdden o tom <noindex><a rel=\"nofollow\" href=\"https:\/\/habr.com\/ru\/company\/jugru\/blog\/453952\/\">vy\u0161lo habrointerview<\/a><\/noindex> s \u0159editelem spole\u010dnosti JUG.ru Group, Alexejem Fedorovem (<noindex><a rel=\"nofollow\" href=\"https:\/\/habr.com\/ru\/users\/23derevo\/\" class=\"user_link\">23derevo<\/a><\/noindex>). <\/p>\n<p><\/p>\n<p>Jsme <noindex><a rel=\"nofollow\" href=\"https:\/\/habr.com\/ru\/company\/jugru\/blog\/445730\/\">u\u017e mluvili<\/a><\/noindex> o t\u0159ech v\u00fdznamn\u00fdch \u00fa\u010dastn\u00edc\u00edch, zakladatel\u00edch teorie distribuovan\u00fdch syst\u00e9m\u016f - Leslie Lamportovi, Maurice Herlihym a Michaelu Scottovi. Nyn\u00ed je \u010das pod\u00edvat se podrobn\u011b na cel\u00fd program!<\/p>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/55b262908f46159cbd3638f00772215c.jpeg\" style=\"display:block;margin: 0 auto;\" \/><\/p>\n<p><noindex><a rel=\"nofollow\" name=\"habracut\"><\/a><\/noindex><\/p>\n<h2 id=\"motivaciya\">Motivace<\/h2>\n<p><\/p>\n<p>Pokud se zab\u00fdv\u00e1te programov\u00e1n\u00edm, tak \u010di onak se setk\u00e1v\u00e1te s v\u00edcevl\u00e1knovost\u00ed a distribuovan\u00fdmi v\u00fdpo\u010dty. Odborn\u00edci v p\u0159\u00edslu\u0161n\u00fdch oblastech s nimi pracuj\u00ed p\u0159\u00edmo, ale distribuovanost se na n\u00e1s neust\u00e1le d\u00edv\u00e1: v ka\u017ed\u00e9m v\u00edcejadrov\u00e9m po\u010d\u00edta\u010di nebo distribuovan\u00e9 slu\u017eb\u011b najdete n\u011bco, co sou\u010dasn\u011b prov\u00e1d\u00ed v\u00fdpo\u010dty.<\/p>\n<p><\/p>\n<p>Existuje mnoho konferenc\u00ed, kter\u00e9 odhaluj\u00ed ur\u010dit\u00e9 aspekty aplikovan\u00e9ho programov\u00e1n\u00ed. Na druh\u00e9 stran\u011b spektra m\u00e1me speci\u00e1ln\u00ed v\u011bdeck\u00e9 \u0161koly, kter\u00e9 ve form\u00e1tu p\u0159edn\u00e1\u0161ek odhaluj\u00ed obrovsk\u00e9 objemy slo\u017eit\u00e9 teorie. Nap\u0159\u00edklad paraleln\u011b s Hydrou prob\u00edh\u00e1 v Petrohrad\u011b <noindex><a rel=\"nofollow\" href=\"https:\/\/sptdc.ru\/?utm_source=habr&amp;utm_medium=453832\">\u0161kola SPTDC<\/a><\/noindex>. <strong>Na konferenci Hydra jsme se sna\u017eili spojit drsnou praxi, v\u011bdu a v\u0161e, co je na jejich pomez\u00ed.<\/strong> <\/p>\n<p><\/p>\n<p>Zamyslete se nad t\u00edmto: \u017eijeme v \u00fa\u017easn\u00e9 dob\u011b, kdy m\u016f\u017eete osobn\u011b potkat zakladatele oblasti v\u011bdy a in\u017een\u00fdrstv\u00ed, kterou se zab\u00fdv\u00e1me. Fyzi\u010dt\u00ed v\u011bdci nemohou potkat ani Newtona, ani Einsteina - vlak u\u017e odjel. Ale vedle n\u00e1s st\u00e1le \u017eij\u00ed ti, kdo vytvo\u0159ili z\u00e1klady teorie distribuovan\u00fdch syst\u00e9m\u016f, vymysleli popul\u00e1rn\u00ed programovac\u00ed jazyky a poprv\u00e9 to v\u0161echno p\u0159etvo\u0159ili do funk\u010dn\u00edch prototyp\u016f. Tito lid\u00e9 nezanechali svou pr\u00e1ci na p\u016fli cesty, pr\u00e1v\u011b te\u010f se zab\u00fdvaj\u00ed aktu\u00e1ln\u00edmi probl\u00e9my na celosv\u011btov\u011b zn\u00e1m\u00fdch univerzit\u00e1ch a spole\u010dnostech a jsou nejv\u011bt\u0161\u00edmi zdroji znalost\u00ed a zku\u0161enost\u00ed v sou\u010dasnosti. <\/p>\n<p><\/p>\n<p>Na druhou stranu, p\u0159\u00edle\u017eitost se s nimi setkat obvykle z\u016fst\u00e1v\u00e1 \u010dist\u011b teoretick\u00e1: m\u00e1lokdo z n\u00e1s m\u016f\u017ee neust\u00e1le sledovat ve\u0159ejn\u00e9 akce na n\u011bjak\u00e9 univerzit\u011b v Rochesteru, aby pak mohl rychle vyrazit do USA a zp\u011bt na p\u0159edn\u00e1\u0161ku k Michaelu Scottovi. Nav\u0161t\u00edvit v\u0161echny \u00fa\u010dastn\u00edky Hydra by st\u00e1lo po\u0159\u00e1dnou sumu, nemluv\u011b o ztracen\u00e9m \u010dase (i kdy\u017e to zn\u00ed jako zaj\u00edmav\u00fd \u00fakol).<\/p>\n<p><\/p>\n<p>Na druhou stranu m\u00e1me spoustu p\u0159edn\u00edch in\u017een\u00fdr\u016f, kte\u0159\u00ed pr\u00e1v\u011b te\u010f pracuj\u00ed na aktu\u00e1ln\u00edch probl\u00e9mech distribuovan\u00fdch syst\u00e9m\u016f, a ti ur\u010dit\u011b maj\u00ed co \u0159\u00edct. Ale probl\u00e9m je ten \u2014 oni <em>pracuj\u00ed<\/em>, a jejich \u010das je drah\u00fd. Ano, pokud jsi zam\u011bstnanec Microsoftu, Google nebo JetBrains, \u0161ance potkat jednoho z zn\u00e1m\u00fdch \u0159e\u010dn\u00edk\u016f na intern\u00ed akci se v\u00fdrazn\u011b zvy\u0161uje, ale jinak \u2014 ne, to se nest\u00e1v\u00e1 ka\u017ed\u00fd den.<\/p>\n<p><\/p>\n<p>Tak\u017ee konference Hydra pln\u00ed d\u016fle\u017eit\u00fd \u00fakol, kter\u00fd v\u011bt\u0161ina z n\u00e1s nem\u016f\u017ee ud\u011blat sama \u2014 v jednom m\u00edst\u011b a v jednom \u010dase spojuje lidi, jejich\u017e my\u0161lenky nebo komunikace mohou zm\u011bnit v\u00e1\u0161 \u017eivot. P\u0159ipou\u0161t\u00edm, \u017ee zdaleka ne v\u0161ichni pot\u0159ebuj\u00ed distribuovan\u00e9 syst\u00e9my, n\u011bjak\u00e9 slo\u017eit\u00e9 fundament\u00e1ln\u00ed z\u00e1le\u017eitosti. M\u016f\u017eete po cel\u00fd \u017eivot programovat CRUD aplikace v PHP a b\u00fdt docela \u0161\u0165astn\u00ed. Ale pro ty, kte\u0159\u00ed to pot\u0159ebuj\u00ed \u2014 to je va\u0161e \u0161ance.<\/p>\n<p><\/p>\n<p>Od prvn\u00edho ozn\u00e1men\u00ed konference Hydra na Habr\u00fa uplynulo u\u017e dost \u010dasu. B\u011bhem t\u00e9 doby byla odvedena obrovsk\u00e1 pr\u00e1ce \u2014 a te\u010f m\u00e1me seznam t\u00e9m\u011b\u0159 v\u0161ech p\u0159edn\u00e1\u0161ek. \u017d\u00e1dn\u00e9 mdl\u00e9 jednoprvkov\u00e9 algoritmy, jen \u010dist\u00fd distribuovan\u00fd hardcore! Poj\u010fme p\u0159estat s obecn\u00fdmi slovy a pod\u00edvejme se, co nyn\u00ed m\u00e1me na stole.<\/p>\n<p><\/p>\n<h2 id=\"keynouty\">\u00davodn\u00ed p\u0159edn\u00e1\u0161ky<\/h2>\n<p><\/p>\n<p>\u00davodn\u00ed p\u0159edn\u00e1\u0161ky za\u010d\u00ednaj\u00ed a kon\u010d\u00ed dny konference. Obvykle smysl \u00favodn\u00ed p\u0159edn\u00e1\u0161ky je nastavit celkov\u00e9ho ducha a sm\u011br konference. Z\u00e1v\u011bre\u010dn\u00e1 p\u0159edn\u00e1\u0161ka shrnuje a vysv\u011btluje, jak s nabyt\u00fdmi znalostmi a dovednostmi v pr\u016fb\u011bhu konference \u017e\u00edt. Za\u010d\u00e1tek a konec: to, co si zapamatujeme nejl\u00e9pe, a m\u00e1 zvl\u00e1\u0161tn\u00ed v\u00fdznam.<\/p>\n<p><\/p>\n<h3 id=\"cliff-click--the-h2o-distributed-kv-algorithmhttpshydraconfru2019talks1urihjc39wzahcg3lbxbtqutm_sourcehabrutm_medium453832\">Cliff Click \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/1urihjc39wzahcg3lbxbtq\/?utm_source=habr&amp;utm_medium=453832\">Algoritmus H2O distribuovan\u00e9ho K\/V<\/a><\/noindex><\/h3>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/2a1b4f1e305a3c4f32dc88e84cfe504f.jpeg\" style=\"display:block;margin: 0 auto;\" \/> Cliff je legenda sv\u011bta Javy. Na konci 90. let napsal pro svou dizerta\u010dn\u00ed pr\u00e1ci dokument s n\u00e1zvem <noindex>\"Kombinov\u00e1n\u00ed anal\u00fdz, kombinov\u00e1n\u00ed optimalizac\u00ed\"<\/noindex>, kter\u00e1 se po chv\u00edli stala z\u00e1kladem pro HotSpot JVM Server Compiler. O dva roky pozd\u011bji u\u017e pracoval ve spole\u010dnosti Sun Microsystems na JVM a uk\u00e1zal cel\u00e9mu sv\u011btu, \u017ee JIT m\u00e1 pr\u00e1vo na existenci. Cel\u00fd tento p\u0159\u00edb\u011bh o tom, \u017ee Java je jedn\u00edm z nejrychlej\u0161\u00edch modern\u00edch runtime s nejchyt\u0159ej\u0161\u00edmi a nejrychlej\u0161\u00edmi optimalizacemi, za\u010dal pr\u00e1v\u011b s Cliffem Clickem. Na za\u010d\u00e1tku se m\u011blo za to, \u017ee pokud je n\u011bco dostupn\u00e9 statick\u00e9mu kompil\u00e1toru, nem\u00e1 smysl to ani zkou\u0161et JIT-ovat. D\u00edky pr\u00e1ci Cliffa a jeho t\u00fdmu za\u010daly b\u00fdt v\u0161echny nov\u00e9 jazyky vytv\u00e1\u0159eny s my\u0161lenkou na JIT-kompilaci jako v\u00fdchoz\u00ed nastaven\u00ed. Bezpochyby to byla pr\u00e1ce ne pro jednoho \u010dlov\u011bka, ale Cliff v n\u00ed hr\u00e1l velmi d\u016fle\u017eitou roli.<\/p>\n<p><\/p>\n<p>V \u00favodn\u00edm keynote p\u0159edstav\u00ed Cliff sv\u00e9 dal\u0161\u00ed podnik\u00e1n\u00ed \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/github.com\/h2oai\/h2o-3\">H2O<\/a><\/noindex>, in-memory platformu pro distribuovan\u00e9 a \u0161k\u00e1lovateln\u00e9 strojov\u00e9 u\u010den\u00ed pro pr\u016fmyslov\u00e9 vyu\u017eit\u00ed. P\u0159esn\u011bji \u0159e\u010deno \u2014 o distribuovan\u00e9m \u00falo\u017ei\u0161ti p\u00e1r \u201ekl\u00ed\u010d-hodnota\u201c uvnit\u0159 n\u00ed. Je to velmi rychl\u00e9 \u00falo\u017ei\u0161t\u011b s mnoha zaj\u00edmav\u00fdmi vlastnostmi (p\u0159esn\u00fd seznam je v <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/1urihjc39wzahcg3lbxbtq\/?utm_source=habr&amp;utm_medium=453832\">popisu<\/a><\/noindex>), kter\u00e9 umo\u017e\u0148uj\u00ed pou\u017e\u00edvat podobn\u00e1 \u0159e\u0161en\u00ed v matematice streamov\u00e1n\u00ed velk\u00fdch dat.<\/p>\n<p><\/p>\n<p>Dal\u0161\u00ed p\u0159edn\u00e1\u0161ka, se kterou vystoup\u00ed Cliff \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/2jix5mst7iduyp9linqhfj\/?utm_source=habr&amp;utm_medium=453832\">Zku\u0161enosti s hardwarovou transak\u010dn\u00ed pam\u011bt\u00ed Azul<\/a><\/noindex>. Dal\u0161\u00ed \u010d\u00e1st jeho biografie \u2014 deset let <noindex>pr\u00e1ce v Azul<\/noindex>, kde aktualizoval a zlep\u0161il mnoho aspekt\u016f hardwaru a technologick\u00e9ho stacku Azul: JIT-kompil\u00e1tory, runtime, model vl\u00e1ken, zpracov\u00e1n\u00ed chyb, pr\u00e1ce se z\u00e1sobn\u00edkem, hardwarov\u00e1 p\u0159eru\u0161en\u00ed, na\u010d\u00edt\u00e1n\u00ed t\u0159\u00edd a tak d\u00e1le \u2014 no, ch\u00e1pete.<\/p>\n<p><\/p>\n<p>Nejzaj\u00edmav\u011bj\u0161\u00ed \u010d\u00e1st za\u010dala, kdy\u017e vytvo\u0159ili hardware pro velk\u00fd byznys \u2014 superpo\u010d\u00edta\u010d pro b\u011bh Java. Byla to docela inovativn\u00ed v\u011bc, konkr\u00e9tn\u011b navr\u017een\u00e1 pro Java, kter\u00e1 m\u00e1 zvl\u00e1\u0161tn\u00ed po\u017eadavky \u2014 pam\u011b\u0165ov\u00e9 bari\u00e9ry pro \u010dten\u00ed pro n\u00edzko-pauzov\u00e9 garbage collection, pole s kontrolou hranic, virtu\u00e1ln\u00ed vol\u00e1n\u00ed\u2026 Jednou z nejzaj\u00edmav\u011bj\u0161\u00edch technologi\u00ed byla hardwarov\u00e1 transak\u010dn\u00ed pam\u011b\u0165. Cel\u00fd L1 jak\u00e9hokoli z 864 jader mohl \u00fa\u010dastnit transak\u010dn\u00edho z\u00e1pisu, co\u017e je obzvl\u00e1\u0161\u0165 d\u016fle\u017eit\u00e9 pro pr\u00e1ci s blokacemi v Java (synchronized bloky mohou pracovat paraleln\u011b, dokud nedojde k re\u00e1ln\u00e9mu konfliktu v pam\u011bti). Ale kr\u00e1sn\u00e1 my\u0161lenka se rozpadla na drsnou realitu \u2014 a v t\u00e9to p\u0159edn\u00e1\u0161ce Cliff vysv\u011btl\u00ed, pro\u010d HTM a STM p\u0159\u00edli\u0161 dob\u0159e nevyhovuj\u00ed praktick\u00fdm pot\u0159eb\u00e1m v\u00edcetherm\u00e1ln\u00edch v\u00fdpo\u010dt\u016f.<\/p>\n<p><\/p>\n<h3 id=\"michael-scott--dual-data-structureshttpshydraconfru2019talkslnhqpq8cz5kzgjmhlqpicutm_sourcehabrutm_medium453832\">Michael Scott \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/lnhqpq8cz5kzgjmhlqpic\/?utm_source=habr&amp;utm_medium=453832\">Dvojit\u00e9 datov\u00e9 struktury<\/a><\/noindex><\/h3>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/5270050098dc1230d469e60362b6930a.jpeg\" style=\"display:block;margin: 0 auto;\" \/> <noindex><a rel=\"nofollow\" href=\"https:\/\/en.wikipedia.org\/wiki\/Michael_L._Scott\">Michael Scott<\/a><\/noindex> \u2014 profesor po\u010d\u00edta\u010dov\u00fdch v\u011bd na Univerzit\u011b v Rochesteru, se kter\u00fdm osud spojil jeho <noindex>u\u017e 34 let<\/noindex>, a na sv\u00e9 alma mater Wisconsin\u2013Madison byl d\u011bkanem p\u011bt let. Zam\u011b\u0159uje se na v\u00fdzkum paraleln\u00edho a distribuovan\u00e9ho programov\u00e1n\u00ed a design jazyk\u016f a vyu\u010duje to studenty.<\/p>\n<p><\/p>\n<p>Cel\u00fd sv\u011bt zn\u00e1 Michaela d\u00edky u\u010debnici <noindex><a rel=\"nofollow\" href=\"https:\/\/www.amazon.com\/Programming-Language-Pragmatics-Michael-Scott\/dp\/0124104096\/ref=sr_1_1?crid=265ZYWXFSUF4&amp;keywords=programming+language+pragmatics&amp;qid=1558916067&amp;s=gateway&amp;sprefix=Programming+Language+Pragmatics%2Caps%2C324&amp;sr=8-1\">\u201eProgramming Language Pragmatics\u201c<\/a><\/noindex>, posledn\u00ed vyd\u00e1n\u00ed vy\u0161lo relativn\u011b ned\u00e1vno \u2014 v roce 2015. Jeho pr\u00e1ce <noindex><a rel=\"nofollow\" href=\"http:\/\/web.mit.edu\/6.173\/www\/currentsemester\/readings\/R06-scalable-synchronization-1991.pdf\">\u201eAlgorithms for scalable synchronization on shared-memory multiprocessors\u201c<\/a><\/noindex> obdr\u017eela <noindex><a rel=\"nofollow\" href=\"https:\/\/ru.wikipedia.org\/wiki\/%D0%9F%D1%80%D0%B5%D0%BC%D0%B8%D1%8F_%D0%94%D0%B5%D0%B9%D0%BA%D1%81%D1%82%D1%80%D1%8B\">z\u00edskala Dijkstraovu cenu<\/a><\/noindex> jako jedna z nejzn\u00e1m\u011bj\u0161\u00edch v oblasti distribuovan\u00fdch v\u00fdpo\u010dt\u016f a <noindex><a rel=\"nofollow\" href=\"https:\/\/www.cs.rochester.edu\/u\/scott\/papers\/1991_TOCS_synch.pdf\">otev\u0159en\u011b le\u017e\u00ed<\/a><\/noindex> v online knihovn\u011b Rochesterovy univerzity. Tak\u00e9 ho m\u016f\u017eete zn\u00e1t jako autora toho slavn\u00e9ho algoritmu Michael-Scott z <noindex><a rel=\"nofollow\" href=\"https:\/\/www.cs.rochester.edu\/u\/scott\/papers\/1996_PODC_queues.pdf\">\u201eSimple, Fast, and Practical Non-Blocking and Blocking Concurrent Queue Algorithms\u201c<\/a><\/noindex>.<\/p>\n<p><\/p>\n<p>Pokud jde o sv\u011bt Javy, zde je situace zvl\u00e1\u0161tn\u00ed: spolu s Dougem Leou vyvinuli tyto neblokuj\u00edc\u00ed algoritmy a synchronn\u00ed fronty, na kter\u00fdch funguj\u00ed knihovny Javy. O tomto a bude keynote \u201eDvojit\u00e9 datov\u00e9 struktury\u201c \u2014 implementace t\u011bchto struktur v Java SE 6 umo\u017enila desetin\u00e1sobn\u00e9 zlep\u0161en\u00ed v\u00fdkonu <code>java.util.concurrent.ThreadPoolExecutor<\/code>. Pokud v\u00e1s dop\u0159edu zaj\u00edm\u00e1, co jsou tyto \u201eDvojit\u00e9 datov\u00e9 struktury\u201c, budi\u017e zde <noindex><a rel=\"nofollow\" href=\"https:\/\/www.cs.rochester.edu\/research\/synchronization\/pseudocode\/duals.html\">p\u0159\u00edslu\u0161n\u00e1 pr\u00e1ce<\/a><\/noindex>. <\/p>\n<p><\/p>\n<h3 id=\"maurice-herlihy--blockchains-and-the-future-of-distributed-computinghttpshydraconfru2019talks6ayncxk5m9q7g6dn80b7bcutm_sourcehabrutm_medium453832\">Maurice Herlihy \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/6ayncxk5m9q7g6dn80b7bc\/?utm_source=habr&amp;utm_medium=453832\">Blockchainy a budoucnost distribuovan\u00e9ho po\u010d\u00edta\u010dstv\u00ed<\/a><\/noindex><\/h3>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/807a70783be0a9825a85eca0e73b6a70.jpeg\" style=\"display:block;margin: 0 auto;\" \/> <noindex><a rel=\"nofollow\" href=\"https:\/\/en.wikipedia.org\/wiki\/Maurice_Herlihy\">Maurice Herlihy<\/a><\/noindex> \u2014 dr\u017eitel dvou Dijkstraov\u00fdch cen. Prvn\u00ed \u2014 za pr\u00e1ci na <noindex><a rel=\"nofollow\" href=\"https:\/\/cs.brown.edu\/~mph\/Herlihy91\/p124-herlihy.pdf\">\u201eWait-Free Synchronization\u201c<\/a><\/noindex> (Brown University), a druh\u00e1, nov\u011bj\u0161\u00ed \u2014 <noindex><a rel=\"nofollow\" href=\"http:\/\/courses.cs.vt.edu\/cs5204\/fall09-kafura\/Papers\/TransactionalMemory\/Architecture-Support.pdf\">\u201eTransactional Memory: Architectural Support for Lock-Free Data Structures\u201c<\/a><\/noindex> (Virginia Tech University). Dijkstraova cena se ud\u011bluje za pr\u00e1ce, jejich\u017e v\u00fdznam a vliv byly patrn\u00e9 po dobu alespo\u0148 deseti let, a je z\u0159ejm\u00e9, \u017ee Maurice je jedn\u00edm z nejzn\u00e1m\u011bj\u0161\u00edch odborn\u00edk\u016f v oboru. V sou\u010dasn\u00e9 dob\u011b pracuje jako profesor na Brownov\u011b univerzit\u011b a m\u00e1 \u0159adu \u00fasp\u011bch\u016f, kter\u00e9 by zabraly cel\u00fd odstavec.<\/p>\n<p><\/p>\n<p>V t\u00e9to z\u00e1v\u011bre\u010dn\u00e9 keynote Maurice promluv\u00ed o teorii a praxi blockchainov\u00fdch distribuovan\u00fdch syst\u00e9m\u016f z pohledu klasiky distribuovan\u00fdch v\u00fdpo\u010dt\u016f a o tom, jak to zjednodu\u0161uje \u0159adu souvisej\u00edc\u00edch probl\u00e9m\u016f. Tento p\u0159edn\u00e1\u0161ka se v\u00fdhradn\u011b v\u011bnuje t\u00e9matu konference \u2014 rozhodn\u011b ne o miningov\u00e9m hype, ale sp\u00ed\u0161e o tom, jak na\u0161e znalosti lze p\u0159ekvapiv\u011b efektivn\u011b a relevantn\u011b vyu\u017e\u00edt v r\u016fzn\u00fdch \u00faloh\u00e1ch.<\/p>\n<p><\/p>\n<p>V \u010dervenci 2017 u\u017e Maurice p\u0159ijel do Ruska na \u0161kolu SPTDC, z\u00fa\u010dastnil se meetupu JUG.ru, a z\u00e1znam si m\u016f\u017eete prohl\u00e9dnout na YouTube:<\/p>\n<p>\n<center><div class=\"youtube-placeholder\" data-id=\"S3Fx-7avfs4\" onclick=\"loadVideo(this)\">\r\n        <img decoding=\"async\" src=\"https:\/\/img.youtube.com\/vi\/S3Fx-7avfs4\/hqdefault.jpg\" alt=\"P\u0159ehr\u00e1t video\" loading=\"lazy\" width=\"480\" height=\"360\" style=\"width:100%;height:auto;\">\r\n        <div class=\"play-button\"><\/div>\r\n    <\/div><\/center><\/p>\n<h2 id=\"osnovnaya-programma\">Hlavn\u00ed program<\/h2>\n<p><\/p>\n<p>N\u00e1sledovat bude stru\u010dn\u00fd p\u0159ehled p\u0159edn\u00e1\u0161ek za\u0159azen\u00fdch do programu. N\u011bkter\u00e9 p\u0159edn\u00e1\u0161ky jsou zde pops\u00e1ny podrobn\u011b, jin\u00e9 stru\u010dn\u011bji. Dlouh\u00e1 popisy byly v\u011bt\u0161inou p\u0159id\u011bleny anglick\u00fdm p\u0159edn\u00e1\u0161k\u00e1m, kter\u00e9 vy\u017eaduj\u00ed odkazy na v\u011bdeck\u00e9 pr\u00e1ce, term\u00edny na Wikipedii atd. \u00dapln\u00fd seznam m\u016f\u017eete <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/#schedule\">vid\u011bt na webu konference<\/a><\/noindex>. Seznam na webu bude aktualizov\u00e1n a dopl\u0148ov\u00e1n. <\/p>\n<p><\/p>\n<h3 id=\"leslie-lamport--q--ahttpshydraconfru2019talks6evatt1mvwvpnwfxxveivwutm_sourcehabrutm_medium453832\">Leslie Lamport \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/6evatt1mvwvpnwfxxveivw\/?utm_source=habr&amp;utm_medium=453832\">Q &amp; A<\/a><\/noindex><\/h3>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/4c6d5928be31af95cd3e2a7812e86854.jpeg\" style=\"display:block;margin: 0 auto;\" \/> Leslie Lamport je autorem z\u00e1sadn\u00edch prac\u00ed v distribuovan\u00e9m v\u00fdpo\u010dtu. <noindex><a rel=\"nofollow\" href=\"https:\/\/en.wikipedia.org\/wiki\/LaTeX\">\u00abLaTeX\u00bb<\/a><\/noindex> se p\u0159ekl\u00e1d\u00e1 jako \u00abLamport TeX\u00bb. To on poprv\u00e9, u\u017e v roce 1979, zavedl pojem <noindex><a rel=\"nofollow\" href=\"http:\/\/lamport.azurewebsites.net\/pubs\/multi.pdf\">sekven\u010dn\u00ed konzistence<\/a><\/noindex>, a jeho \u010dl\u00e1nek <noindex><a rel=\"nofollow\" href=\"http:\/\/lamport.azurewebsites.net\/pubs\/time-clocks.pdf\">\u00abHow to Make a Multiprocessor Computer That Correctly Executes Multiprocess Programs\u00bb<\/a><\/noindex> z\u00edskal Dijkstraovu cenu.<\/p>\n<p><\/p>\n<p>To je nejneobvyklej\u0161\u00ed \u010d\u00e1st programu, proto\u017ee to nen\u00ed ani p\u0159edn\u00e1\u0161ka, ale sezen\u00ed ot\u00e1zek a odpov\u011bd\u00ed. Kdy\u017e je zna\u010dn\u00e1 \u010d\u00e1st publika ji\u017e obezn\u00e1mena (nebo se m\u016f\u017ee sezn\u00e1mit) se v\u0161emi mo\u017en\u00fdmi pracemi zalo\u017een\u00fdmi na \u00abLamportov\u011b teorii\u00bb, jeho vlastn\u00edmi \u010dl\u00e1nky a p\u0159edn\u00e1\u0161kami, je velmi d\u016fle\u017eit\u00e9 vyu\u017e\u00edt ve\u0161ker\u00fd dostupn\u00fd \u010das na p\u0159\u00edmou komunikaci.<\/p>\n<p><\/p>\n<p>My\u0161lenka je jednoduch\u00e1 \u2014 zhl\u00e9dnete na YouTube dv\u011b p\u0159edn\u00e1\u0161ky: <noindex><a rel=\"nofollow\" href=\"https:\/\/youtu.be\/6QsTfL-uXd8\">\u00abProgramming Should Be More Than Coding\u00bb<\/a><\/noindex> a <noindex><a rel=\"nofollow\" href=\"https:\/\/www.heidelberg-laureate-forum.org\/blog\/video\/lecture-monday-september-24-2018-leslie-lamport\/\">\u201ePokud nep\u00ed\u0161ete program, nepou\u017e\u00edvejte programovac\u00ed jazyk\u201c<\/a><\/noindex> a p\u0159iprav\u00edte si alespo\u0148 jeden dotaz, na kter\u00fd Leslie odpov\u00ed.<\/p>\n<p><\/p>\n<p>Prvn\u00ed z t\u011bchto dvou vide\u00ed jsme u\u017e <noindex><a rel=\"nofollow\" href=\"https:\/\/habr.com\/ru\/company\/jugru\/blog\/454898\/\">p\u0159etvo\u0159ili na hubro \u010dl\u00e1nek<\/a><\/noindex>. Pokud nem\u00e1te hodinu \u010dasu na sledov\u00e1n\u00ed videa, m\u016f\u017eete si to rychle p\u0159e\u010d\u00edst v textov\u00e9 podob\u011b.<\/p>\n<p><\/p>\n<p>Na v\u011bdom\u00ed: na YouTube je mnohem v\u00edce vide\u00ed s Lesliem Lamportem. Nap\u0159\u00edklad existuje skv\u011bl\u00fd <noindex><a rel=\"nofollow\" href=\"https:\/\/www.youtube.com\/watch?v=p54W-XOIEF8&amp;list=PLWAv2Etpa7AOAwkreYImYt0gIpOdWQevD\">kurz o TLA+<\/a><\/noindex>. Offline verze cel\u00e9ho tohoto kurzu je na <noindex><a rel=\"nofollow\" href=\"http:\/\/lamport.azurewebsites.net\/video\/videos.html\">domovsk\u00e9 str\u00e1nce autora<\/a><\/noindex>, a na YouTube ho zve\u0159ejnil pro pohodln\u011bj\u0161\u00ed zhl\u00e9dnut\u00ed na mobiln\u00edch za\u0159\u00edzen\u00edch.<\/p>\n<p><\/p>\n<h3 id=\"martin-kleppmann--syncing-data-across-user-devices-for-distributed-collaborationhttpshydraconfru2019talks6i4lkw8pwjnadgff5ylr11utm_sourcehabrutm_medium453832\">Martin Kleppmann \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/6i4lkw8pwjnadgff5ylr11\/?utm_source=habr&amp;utm_medium=453832\">Synchronizace dat nap\u0159\u00ed\u010d u\u017eivatelsk\u00fdmi za\u0159\u00edzen\u00edmi pro distribuovanou spolupr\u00e1ci<\/a><\/noindex><\/h3>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/09af25ab1ce915ba13ec6ee1013878f6.jpeg\" style=\"display:block;margin: 0 auto;\" \/> Martin Kleppmann je v\u00fdzkumn\u00edk na Univerzit\u011b v Cambridge, kter\u00fd pracuje na CRDT a form\u00e1ln\u00ed verifikaci algoritm\u016f. Kniha Martina <noindex>\u00abDesigning Data-Intensive Applications\u00bb<\/noindex>, publikovan\u00e1 v roce 2017, se uk\u00e1zala jako velmi \u00fasp\u011b\u0161n\u00e1 a dostala se na seznamy bestseller\u016f v oblasti ukl\u00e1d\u00e1n\u00ed a zpracov\u00e1n\u00ed dat. Kevin Scott, CTO ve spole\u010dnosti Microsoft, <noindex><a rel=\"nofollow\" href=\"https:\/\/martin.kleppmann.com\/2017\/03\/27\/designing-data-intensive-applications.html\">jednou \u0159ekl<\/a><\/noindex>: \u201eTato kniha by m\u011bla b\u00fdt nezbytn\u00e1 pro in\u017een\u00fdry v\u00fdvoj\u00e1\u0159e. Je to vz\u00e1cn\u00fd zdroj, kter\u00fd spojuje teorii a praxi, pom\u00e1h\u00e1 v\u00fdvoj\u00e1\u0159\u016fm l\u00e9pe navrhovat a realizovat infrastrukturu a syst\u00e9my zpracov\u00e1n\u00ed dat.\u201c N\u011bco podobn\u00e9ho \u0159\u00edkal i tv\u016frce Kafky a CTO Confluent, Jay Kreps.<\/p>\n<p><\/p>\n<p>P\u0159ed zah\u00e1jen\u00edm akademick\u00e9ho v\u00fdzkumu Martin pracoval v pr\u016fmyslu a stal se spoluzakladatelem dvou \u00fasp\u011b\u0161n\u00fdch startup\u016f:<\/p>\n<p><\/p>\n<ul>\n<li>Rapportive, zam\u011b\u0159en\u00e9ho na zobrazen\u00ed soci\u00e1ln\u00edho profilu kontakt\u016f z va\u0161\u00ed e-mailov\u00e9 po\u0161ty, kter\u00fd LinkedIn koupil v roce 2012;<\/li>\n<li>Go Test It, slu\u017eba pro automatizovan\u00e9 testov\u00e1n\u00ed webov\u00fdch str\u00e1nek v r\u016fzn\u00fdch prohl\u00ed\u017ee\u010d\u00edch, kterou RedGate koupil v roce 2009.<\/li>\n<\/ul>\n<p><\/p>\n<p>Celkov\u011b vzato, Martin je sice m\u00e9n\u011b zn\u00e1m\u00fd ne\u017e na\u0161i keynote speak\u0159i, ale ji\u017e p\u0159isp\u011bl k rozvoji distribuovan\u00fdch v\u00fdpo\u010dt\u016f i pr\u016fmyslu.<\/p>\n<p><\/p>\n<p>V t\u00e9to p\u0159edn\u00e1\u0161ce bude Martin hovo\u0159it o t\u00e9matu, kter\u00e9 je mu bli\u017e\u0161\u00ed k jeho akademick\u00e9mu v\u00fdzkumu. V Google Docs a podobn\u00e9m softwaru pro spolupr\u00e1ci na dokumentech znamen\u00e1 \u201espolupr\u00e1ce\u201c \u00falohu replikace: ka\u017ed\u00fd u\u017eivatel m\u00e1 vlastn\u00ed replikovan\u00fd dokument, kter\u00fd pot\u00e9 upravuje, a v\u0161echny zm\u011bny se \u0161\u00ed\u0159\u00ed po s\u00edti ostatn\u00edm \u00fa\u010dastn\u00edk\u016fm. Zm\u011bny dokument\u016f offline vedou k do\u010dasn\u00e9 nekonzistenci dokumentu v\u016f\u010di ostatn\u00edm \u00fa\u010dastn\u00edk\u016fm, a znovu-synchronizace vy\u017eaduje \u0159e\u0161en\u00ed konflikt\u016f. Pro toto existuj\u00ed <noindex><a rel=\"nofollow\" href=\"https:\/\/en.wikipedia.org\/wiki\/Conflict-free_replicated_data_type\">Conflict-free Replicated Data Types<\/a><\/noindex> (CRDT), v podstat\u011b docela nov\u00e1 v\u011bc, jej\u00ed\u017e podstata byla formulov\u00e1na teprve v roce 2011. V t\u00e9to p\u0159edn\u00e1\u0161ce se diskutuje, co se od t\u00e9 doby stalo ve sv\u011bt\u011b CRDT, jak\u00e9 jsou nejnov\u011bj\u0161\u00ed \u00fasp\u011bchy, a diskutuje se p\u0159\u00edstup k vytv\u00e1\u0159en\u00ed aplikac\u00ed local-first obecn\u011b a pou\u017eit\u00ed open-source knihovny <noindex><a rel=\"nofollow\" href=\"https:\/\/github.com\/automerge\/automerge\">Automerge<\/a><\/noindex> specificky.<\/p>\n<p><\/p>\n<blockquote><p>P\u0159\u00ed\u0161t\u00ed t\u00fdden zve\u0159ejn\u00edme na Habru velk\u00fd rozhovor s Martinem, bude to zaj\u00edmav\u00e9.<\/p><\/blockquote>\n<p><\/p>\n<h3 id=\"pedro-ramalhete--wait-free-data-structures-and-wait-free-transactionshttpshydraconfru2019talks1jwmdzkmjcalsclwavttxkutm_sourcehabrutm_medium453832\">Pedro Ramalhete \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/1jwmdzkmjcalsclwavttxk\/?utm_source=habr&amp;utm_medium=453832\">Struktury dat bez \u010dek\u00e1n\u00ed a transakce bez \u010dek\u00e1n\u00ed<\/a><\/noindex><\/h3>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/be9b98f5ab95d0f6646dfcb4cee38978.jpeg\" style=\"display:block;margin: 0 auto;\" \/> Pedro pracuje ve spole\u010dnosti Cisco a vyv\u00edj\u00ed paraleln\u00ed algoritmy u\u017e asi deset let, v\u010detn\u011b mechanism\u016f synchronizace, lock-free a wait-free datov\u00fdch struktur, a v\u0161eho, co si m\u016f\u017eete na toto t\u00e9ma p\u0159edstavit. Jeho sou\u010dasn\u00e9 v\u011bdeck\u00e9 a in\u017een\u00fdrsk\u00e9 z\u00e1jmy jsou zam\u011b\u0159eny na univerz\u00e1ln\u00ed konstrukce, software transak\u010dn\u00ed pam\u011b\u0165, persistentn\u00ed pam\u011b\u0165 a podobn\u00e9 technologie, kter\u00e9 umo\u017e\u0148uj\u00ed vytv\u00e1\u0159et spr\u00e1vn\u00e9, \u0161k\u00e1lovateln\u00e9 a odoln\u00e9 aplikace. A tak\u00e9 je autorem \u0161iroce zn\u00e1m\u00e9ho blogu v \u00fazk\u00fdch kruz\u00edch. <noindex><a rel=\"nofollow\" href=\"http:\/\/concurrencyfreaks.blogspot.com\/\">Concurrency Freaks<\/a><\/noindex>.<\/p>\n<p><\/p>\n<p>Na paraleln\u00edch datov\u00fdch struktur\u00e1ch dnes pracuje v\u011bt\u0161ina v\u00edcetrhu aplikac\u00ed, po\u010d\u00ednaje pou\u017e\u00edv\u00e1n\u00edm front zpr\u00e1v mezi akt\u00e9ry a kon\u010de indexovan\u00fdmi datov\u00fdmi strukturami v key-value \u00falo\u017ei\u0161t\u00edch. V Java JDK funguj\u00ed \u00fasp\u011b\u0161n\u011b ji\u017e mnoho let, a do C++ se pomalu p\u0159id\u00e1vaj\u00ed.<\/p>\n<p><\/p>\n<p>Nejjednodu\u0161\u0161\u00ed zp\u016fsob, jak realizovat paraleln\u00ed datovou strukturu, je sekven\u010dn\u00ed (jedno vl\u00e1knov\u00e1) implementace, kde jsou metody chr\u00e1n\u011bny mutexy. To je dostupn\u00e9 jak\u00e9mukoli juniorovi, ale m\u00e1 z\u0159ejm\u00e9 probl\u00e9my se \u0161k\u00e1lovatelnost\u00ed a v\u00fdkonem. Z\u00e1rove\u0148 v\u0161ak, lock-free a wait-free datov\u00e9 struktury nejen l\u00e9pe zvl\u00e1daj\u00ed chyby, ale maj\u00ed tak\u00e9 lep\u0161\u00ed profil v\u00fdkonnosti \u2014 av\u0161ak jejich v\u00fdvoj vy\u017eaduje hlubokou odbornost a p\u0159izp\u016fsoben\u00ed konkr\u00e9tn\u00edmu zp\u016fsobu pou\u017eit\u00ed. Jedin\u00fd \u0161patn\u00fd \u0159\u00e1dek k\u00f3du sta\u010d\u00ed, aby to v\u0161echno zkolabovalo.<\/p>\n<p><\/p>\n<p>Jak ud\u011blat, aby i ne-expert mohl navrhovat a implementovat takov\u00e9 datov\u00e9 struktury? Je zn\u00e1mo, \u017ee jak\u00fdkoli sekven\u010dn\u00ed algoritmus lze u\u010dinit vl\u00e1knov\u011b bezpe\u010dn\u00fdm bu\u010fto <noindex><a rel=\"nofollow\" href=\"https:\/\/hal.inria.fr\/hal-01397265v1\/document\">univerz\u00e1ln\u00ed konstrukc\u00ed<\/a><\/noindex>, nebo transak\u010dn\u00ed pam\u011bt\u00ed. Tyto p\u0159\u00edstupy mohou sn\u00ed\u017eit vstupn\u00ed pr\u00e1h pro \u0159e\u0161en\u00ed t\u00e9to \u00falohy. Nicm\u00e9n\u011b, ob\u011b \u0159e\u0161en\u00ed obvykle vedou k neefektivn\u00ed implementaci. Pedro pov\u00ed o tom, jak se jim poda\u0159ilo u\u010dinit tyto konstrukce efektivn\u011bj\u0161\u00edmi a jak je lze pou\u017e\u00edt pro vlastn\u00ed algoritmy.<\/p>\n<p><\/p>\n<h3 id=\"heidi-howard---liberating-distributed-consensushttpshydraconfru2019talks5z2xknkq9mozvqzhhgfoeiutm_sourcehabrutm_medium453832\">Heidi Howard \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/5z2xknkq9mozvqzhhgfoei\/?utm_source=habr&amp;utm_medium=453832\">Liberating distributed consensus<\/a><\/noindex><\/h3>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/09dd05684fde1015a87818f0b6804680.jpeg\" style=\"display:block;margin: 0 auto;\" \/> Heidi Howard \u2014 stejn\u011b jako Martin, je v\u00fdzkumnic\u00ed v oblasti distribuovan\u00fdch syst\u00e9m\u016f na Cambridgesk\u00e9 univerzit\u011b. Jej\u00ed specializace zahrnuje konzistenci, odolnost, v\u00fdkon a distribuovan\u00fd konsensus. Je nejv\u00edce zn\u00e1m\u00e1 zobecn\u011bn\u00edm algoritmu Paxos nazvan\u00fdm <noindex><a rel=\"nofollow\" href=\"https:\/\/fpaxos.github.io\/\">Flexible Paxos<\/a><\/noindex>. <\/p>\n<p><\/p>\n<p>P\u0159ipom\u00edn\u00e1me, \u017ee <noindex><a rel=\"nofollow\" href=\"https:\/\/en.wikipedia.org\/wiki\/Paxos_(computer_science)\">Paxos<\/a><\/noindex> \u2014 rodina protokol\u016f pro \u0159e\u0161en\u00ed konsenzu v s\u00edti nespolehliv\u00fdch v\u00fdpo\u010detn\u00edch uzl\u016f, jej\u00ed\u017e z\u00e1klady byly polo\u017eeny pracemi Leslieho Lamporta. N\u011bkte\u0159\u00ed na\u0161i p\u0159edn\u00e1\u0161ej\u00edc\u00ed tedy pracuj\u00ed na probl\u00e9mech, kter\u00e9 p\u016fvodn\u011b navrhli jin\u00ed na\u0161i p\u0159edn\u00e1\u0161ej\u00edc\u00ed \u2014 a to je skv\u011bl\u00e9.<\/p>\n<p><\/p>\n<p>Mo\u017enost dos\u00e1hnout konsenzu mezi n\u011bkolika hostiteli \u2014 p\u0159i adresaci, v\u00fdb\u011bru l\u00eddra, zablokov\u00e1n\u00ed nebo koordinaci \u2014 je z\u00e1kladn\u00ed ot\u00e1zkou modern\u00edch distribuovan\u00fdch syst\u00e9m\u016f. Paxos je nyn\u00ed hlavn\u00edm zp\u016fsobem, jak \u0159e\u0161it \u00falohy nalezen\u00ed konsenzu, a kolem n\u011bj se prov\u00e1d\u00ed mnoho v\u00fdzkum\u016f zam\u011b\u0159en\u00fdch na roz\u0161\u00ed\u0159en\u00ed a optimalizaci algoritmu pro r\u016fzn\u00e9 praktick\u00e9 pot\u0159eby. <\/p>\n<p><\/p>\n<p>V t\u00e9to prezentaci p\u0159ehodnot\u00edme teoretick\u00fd z\u00e1klad Paxos, oslaben\u00edm p\u016fvodn\u00edch po\u017eadavk\u016f a zobecn\u011bn\u00edm algoritmu. Uvid\u00edme, \u017ee Paxos je vlastn\u011b jen jedn\u00edm z mo\u017enost\u00ed v \u0161irok\u00e9 \u0161k\u00e1le p\u0159\u00edstup\u016f k konsenzu, a \u017ee dal\u0161\u00ed body v tomto spektru jsou tak\u00e9 velmi u\u017eite\u010dn\u00e9 pro budov\u00e1n\u00ed dobr\u00fdch distribuovan\u00fdch syst\u00e9m\u016f.<\/p>\n<p><\/p>\n<h3 id=\"alex-petrov--reduce-your-storage-costs-with-transient-replication-and-cheap-quorumshttpshydraconfru2019talks6eb39udg8bxsgmimkexd6jutm_sourcehabrutm_medium453832\">Alex Petrov \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/6eb39udg8bxsgmimkexd6j\/?utm_source=habr&amp;utm_medium=453832\">Sni\u017ete sv\u00e9 n\u00e1klady na \u00falo\u017ei\u0161t\u011b pomoc\u00ed p\u0159echodn\u00e9 replikace a levn\u00fdch kv\u00f3r.<\/a><\/noindex><\/h3>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/178a1db3cf49b5ff73a0c9101ab3845c.jpeg\" style=\"display:block;margin: 0 auto;\" \/> Alex je odborn\u00edk na datab\u00e1ze a \u00falo\u017en\u00e9 syst\u00e9my, a co je pro n\u00e1s nejd\u016fle\u017eit\u011bj\u0161\u00ed \u2014 committer v <noindex><a rel=\"nofollow\" href=\"https:\/\/en.wikipedia.org\/wiki\/Apache_Cassandra\">Cassandra<\/a><\/noindex>. Spole\u010dn\u011b s O'Reilly aktu\u00e1ln\u011b pracuje na knize Database Internals.<\/p>\n<p><\/p>\n<p>Pro syst\u00e9my s <noindex><a rel=\"nofollow\" href=\"https:\/\/en.wikipedia.org\/wiki\/Eventual_consistency\">eventual consistency<\/a><\/noindex> (v \u010desk\u00e9 terminologii \u2013 \u201ekonsistenc\u00ed nakonec\u201c), po p\u00e1du uzlu nebo rozd\u011blen\u00ed s\u00edt\u011b, je t\u0159eba vy\u0159e\u0161it n\u00e1sleduj\u00edc\u00ed dilema: bu\u010f pokra\u010dovat ve zpracov\u00e1n\u00ed po\u017eadavk\u016f, na \u00fakor konsistence, nebo odm\u00edtnout jejich zpracov\u00e1n\u00ed a ob\u011btovat dostupnost. V takov\u00e9m syst\u00e9mu kv\u00f3ra, p\u0159ekr\u00fdvaj\u00edc\u00ed podmno\u017einy uzl\u016f a zaji\u0161\u0165uj\u00edc\u00ed, \u017ee alespo\u0148 jeden uzel bude obsahovat nejnov\u011bj\u0161\u00ed hodnotu, se mohou st\u00e1t dobr\u00fdm hrani\u010dn\u00edm \u0159e\u0161en\u00edm. M\u016f\u017eete p\u0159e\u017e\u00edt selh\u00e1n\u00ed a ztr\u00e1tu p\u0159ipojen\u00ed k n\u011bkter\u00fdm uzl\u016fm, p\u0159i\u010dem\u017e budete i nad\u00e1le odpov\u00eddat nejnov\u011bj\u0161\u00edmi hodnotami.<\/p>\n<p><\/p>\n<p>Evidentn\u011b m\u00e1 v\u0161echno svou cenu. Kv\u00f3rumov\u00e1 sch\u00e9ma replikace znamen\u00e1 vy\u0161\u0161\u00ed n\u00e1klady na ukl\u00e1d\u00e1n\u00ed: je nutn\u00e9 uchov\u00e1vat redundantn\u00ed data na n\u011bkolika uzlech sou\u010dasn\u011b, aby bylo zaji\u0161t\u011bno dostate\u010dn\u00e9 mno\u017estv\u00ed dostupn\u00fdch kopi\u00ed v p\u0159\u00edpad\u011b probl\u00e9m\u016f. Ukazuje se, \u017ee nen\u00ed nutn\u00e9 uchov\u00e1vat v\u0161echna data na v\u0161ech replik\u00e1ch. Z\u00e1t\u011b\u017e na \u00falo\u017ei\u0161t\u011b lze sn\u00ed\u017eit, pokud uchov\u00e1v\u00e1te data pouze na \u010d\u00e1sti uzl\u016f, a pro sc\u00e9n\u00e1\u0159e zpracov\u00e1n\u00ed chyb pou\u017e\u00edt speci\u00e1ln\u00ed uzly (Transient Replica).<\/p>\n<p><\/p>\n<p>B\u011bhem prezentace se zam\u011b\u0159\u00edme na <noindex><a rel=\"nofollow\" href=\"http:\/\/citeseerx.ist.psu.edu\/viewdoc\/download?doi=10.1.1.146.3429&amp;rep=rep1&amp;type=pdf\">Witness Replicas<\/a><\/noindex>, sch\u00e9ma replikace pou\u017e\u00edvan\u00e9 v <noindex><a rel=\"nofollow\" href=\"https:\/\/en.wikipedia.org\/wiki\/Spanner_(database)\">Spanner<\/a><\/noindex> a <noindex><a rel=\"nofollow\" href=\"http:\/\/cidrdb.org\/cidr2011\/Papers\/CIDR11_Paper32.pdf\">Megastore<\/a><\/noindex>, a implementaci tohoto konceptu v Apache Cassandra pod n\u00e1zvy <noindex><a rel=\"nofollow\" href=\"https:\/\/jira.apache.org\/jira\/browse\/CASSANDRA-14404?subTaskView=all\">Transient Replication &amp; Cheap Quorums<\/a><\/noindex>.<\/p>\n<p><\/p>\n<h3 id=\"dmitriy-vyukov---goroutines-exposedhttpshydraconfru2019talks7336ginp0kke7n4yxxjvldutm_sourcehabrutm_medium453832\">Dmitry Vyukov \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/7336ginp0kke7n4yxxjvld\/?utm_source=habr&amp;utm_medium=453832\">Goroutines exposed<\/a><\/noindex><\/h3>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/94ce38f8cc366bbd2ee53b9636e4650d.jpeg\" style=\"display:block;margin: 0 auto;\" \/> Dmitry je v\u00fdvoj\u00e1\u0159 v Googlu, kter\u00fd pracuje na dynamick\u00e9m testov\u00e1n\u00ed C\/C++ a Go \u2014 Address\/Memory\/ThreadSanitizer a podobn\u00fdch n\u00e1stroj\u00edch pro j\u00e1dro Linuxu. P\u0159isp\u011bl k roz\u0161\u00ed\u0159iteln\u00e9mu pl\u00e1nova\u010di gorutin, s\u00ed\u0165ov\u00e9mu polleru a paraleln\u00edmu sb\u011bra\u010di odpadk\u016f v Go. Je odborn\u00edkem na v\u00edcerozm\u011brnost, autorem des\u00edtky nov\u00fdch bezblokovac\u00edch algoritm\u016f a dr\u017eitelem <noindex><a rel=\"nofollow\" href=\"https:\/\/software.intel.com\/en-us\/blackbelt\">\u010cern\u00e9ho p\u00e1sku<\/a><\/noindex> Intel.<\/p>\n<p><\/p>\n<p>Te\u010f trochu o samotn\u00e9 prezentaci. V jazyce Go existuje nativn\u00ed podpora v\u00edcerozm\u011brnosti v podob\u011b gorutin (lehk\u00fdch vl\u00e1ken) a kan\u00e1l\u016f (FIFO front). D\u00edky t\u011bmto mechanism\u016fm je pro u\u017eivatele velmi snadn\u00e9 a p\u0159\u00edjemn\u00e9 ps\u00e1t modern\u00ed v\u00edcerozm\u011brn\u00e9 aplikace, co\u017e vypad\u00e1 jako magie. Jak ch\u00e1peme, \u017e\u00e1dn\u00e1 magie zde nen\u00ed. V t\u00e9to prezentaci se Dmitry pod\u00edv\u00e1 na detaily fungov\u00e1n\u00ed pl\u00e1nova\u010de Go a uk\u00e1\u017ee tajemstv\u00ed realizace t\u00e9to \u201emagie\u201c. Na za\u010d\u00e1tku poskytne p\u0159ehled hlavn\u00edch komponent pl\u00e1nova\u010de a vysv\u011btl\u00ed, jak funguje. Pot\u00e9 se pod\u00edv\u00e1me podrobn\u011bji na jednotliv\u00e9 aspekty, jako jsou strategie parkov\u00e1n\u00ed\/rozparkov\u00e1n\u00ed a zpracov\u00e1n\u00ed blokuj\u00edc\u00edch syst\u00e9mov\u00fdch vol\u00e1n\u00ed. Nakonec Dmitry tak\u00e9 pov\u00ed n\u011bco o mo\u017en\u00fdch vylep\u0161en\u00edch v pl\u00e1nova\u010di.<\/p>\n<p><\/p>\n<h3 id=\"dmitriy-bugaychenko---uskoryaem-raspredelennyy-analiz-grafov-s-pomoschyu-veroyatnostnyh-sketchey-i-ne-tolkohttpshydraconfru2019talks1po7b00j6m4vst3df7aqtoutm_sourcehabrutm_medium453832\">Dmitry Bugaychenko \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/1po7b00j6m4vst3df7aqto\/?utm_source=habr&amp;utm_medium=453832\">Zrychlen\u00ed distribuovan\u00e9 anal\u00fdzy graf\u016f pomoc\u00ed pravd\u011bpodobnostn\u00edch skic a nejen to<\/a><\/noindex><\/h3>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/f963ef8ac1a37011aa387016dc938b3c.jpeg\" style=\"display:block;margin: 0 auto;\" \/> Dmitry t\u00e9m\u011b\u0159 9 let pracoval v outsourcingu, p\u0159i\u010dem\u017e neztratil kontakt s univerzitou a v\u011bdeck\u00fdm prost\u0159ed\u00edm. Anal\u00fdza velk\u00fdch dat v Odnoklassnik\u00e1ch se pro n\u011bj stala jedine\u010dnou p\u0159\u00edle\u017eitost\u00ed spojit teoretickou p\u0159\u00edpravu a v\u011bdeck\u00fd z\u00e1klad s v\u00fdvojem skute\u010dn\u00fdch, \u017e\u00e1dan\u00fdch produkt\u016f.<\/p>\n<p><\/p>\n<p>Distribuovan\u00e1 anal\u00fdza graf\u016f byla a z\u016fst\u00e1v\u00e1 slo\u017eit\u00fdm \u00fakolem: kdy\u017e vznikne pot\u0159eba z\u00edskat informace o vazb\u00e1ch sousedn\u00edho vrcholu, \u010dasto je t\u0159eba p\u0159ev\u00e1d\u011bt data mezi stroji, co\u017e vede ke zv\u00fd\u0161en\u00ed doby prov\u00e1d\u011bn\u00ed a z\u00e1t\u011b\u017ei s\u00ed\u0165ov\u00e9 infrastruktury. V t\u00e9to prezentaci uvid\u00edme, jak lze dos\u00e1hnout v\u00fdznamn\u00e9ho zrychlen\u00ed zpracov\u00e1n\u00ed pomoc\u00ed pravd\u011bpodobnostn\u00edch datov\u00fdch struktur nebo fakt\u016f, jako je symetri\u010dnost grafu p\u0159\u00e1telstv\u00ed v soci\u00e1ln\u00ed s\u00edti. To v\u0161e je ilustrov\u00e1no p\u0159\u00edklady k\u00f3du v Apache Spark.<\/p>\n<p><\/p>\n<h3 id=\"denis-ryscov--reduce-your-storage-costs-with-transient-replication-and-cheap-quorumshttpshydraconfru2019talks5e3yibth8vha0jbyoywpm6utm_sourcehabrutm_medium453832\">Denis Ryscov \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/5e3yibth8vha0jbyoywpm6\/?utm_source=habr&amp;utm_medium=453832\">Sni\u017ete sv\u00e9 n\u00e1klady na \u00falo\u017ei\u0161t\u011b pomoc\u00ed p\u0159echodn\u00e9 replikace a levn\u00fdch kv\u00f3r.<\/a><\/noindex><\/h3>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/700bfb1a35280932f654a9c34413e2d4.jpeg\" style=\"display:block;margin: 0 auto;\" \/> Denis je v\u00fdvoj\u00e1\u0159 <noindex><a rel=\"nofollow\" href=\"https:\/\/en.wikipedia.org\/wiki\/Cosmos_DB\">Cosmos DB<\/a><\/noindex>, odborn\u00edk v oblasti ov\u011b\u0159ov\u00e1n\u00ed konzistenc\u00ed model\u016f, v konsenzu\u00e1ln\u00edch algoritmech a v distribuovan\u00fdch transakc\u00edch. Nyn\u00ed pracuje v Microsoftu, a p\u0159edt\u00edm se zab\u00fdval distribuovan\u00fdmi syst\u00e9my v Amazonu a Yandexu.<\/p>\n<p><\/p>\n<p>V t\u00e9to prezentaci se sezn\u00e1m\u00edme s protokoly distribuovan\u00fdch transakc\u00ed, kter\u00e9 byly vyvinuty v posledn\u00edch n\u011bkolika letech, kter\u00e9 je mo\u017en\u00e9 implementovat na stran\u011b klienta nad jak\u00fdmkoli \u00falo\u017ei\u0161t\u011bm dat podporuj\u00edc\u00edm podm\u00edn\u011bn\u00e9 aktualizace (compare and set). Podstatou je, \u017ee \u017eivot nekon\u010d\u00ed dvouf\u00e1zov\u00fdm potvrzen\u00edm; transakce lze p\u0159idat nad jak\u00e9koli datab\u00e1ze \u2014 na \u00farovni aplikace, ale r\u016fzn\u00e9 protokoly (2PC, Percolator, RAMP) maj\u00ed r\u016fzn\u00e9 obchodn\u00ed \u00fastupky a nejsou n\u00e1m d\u00e1v\u00e1ny zadarmo.<\/p>\n<p><\/p>\n<h3 id=\"aleksey-zinovev--ne-vse-ml-algoritmy-popadayut-v-raspredelennyy-rayhttpshydraconfru2019talks3jd0bgsoa0qtcijgblidjsutm_sourcehabrutm_medium453832\">Alexej Zinovjev \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/3jd0bgsoa0qtcijgblidjs\/?utm_source=habr&amp;utm_medium=453832\">Ne v\u0161echny ML algoritmy se dostanou do distribuovan\u00e9ho r\u00e1je<\/a><\/noindex><\/h3>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/eb412d59dec5dcc4a04f603b32d12575.jpeg\" style=\"display:block;margin: 0 auto;\" \/> Alexej (<noindex><a rel=\"nofollow\" href=\"https:\/\/habr.com\/ru\/users\/zaleslaw\/\" class=\"user_link\">zaleslaw<\/a><\/noindex>) je na\u0161\u00edm dlouholet\u00fdm \u0159e\u010dn\u00edkem a \u010dlenem programov\u00fdch v\u00fdbor\u016f na jin\u00fdch konferenc\u00edch. Praktikuj\u00edc\u00ed lektor ve spole\u010dnosti EPAM Systems a s Hadoop\/Spark a dal\u0161\u00ed velk\u00fdmi daty se p\u0159\u00e1tel\u00ed od roku 2012.<\/p>\n<p><\/p>\n<p>V t\u00e9to prezentaci Alexej pov\u00ed o probl\u00e9mech p\u0159izp\u016fsoben\u00ed klasick\u00fdch algoritm\u016f strojov\u00e9ho u\u010den\u00ed pro prov\u00e1d\u011bn\u00ed v distribuovan\u00e9m re\u017eimu na z\u00e1klad\u011b sv\u00fdch zku\u0161enost\u00ed s Apache Spark ML, Apache Mahout, Apache Flink ML a zku\u0161enostmi s vytv\u00e1\u0159en\u00edm Apache Ignite ML. Alexej tak\u00e9 pov\u00ed o implementaci distribuovan\u00fdch ML algoritm\u016f v t\u011bchto r\u00e1mc\u00edch.<\/p>\n<p><\/p>\n<p>A na z\u00e1v\u011br \u2014 dv\u011b prezentace od spole\u010dnosti Yandex o Yandex Database.<\/p>\n<p><\/p>\n<h3 id=\"vladislav-kuznecov--yandex-database--kak-my-obespechivaem-otkazoustoychivosthttpshydraconfru2019talksmuxomfgqembsb3st7i3ciutm_sourcehabrutm_medium453832\">Vladislav Kuzn\u011bcov \u2014 <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/muxomfgqembsb3st7i3ci\/?utm_source=habr&amp;utm_medium=453832\">Yandex Database \u2014 jak zaji\u0161\u0165ujeme odolnost v\u016f\u010di poruch\u00e1m<\/a><\/noindex><\/h3>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/3bdb3bec0ec0eb71db373e85afad6260.jpeg\" style=\"display:block;margin: 0 auto;\" \/> Vladislav je v\u00fdvoj\u00e1\u0159 v Yandexu v t\u00fdmu distribuovan\u00fdch platforem. Yandex Database je horizont\u00e1ln\u011b \u0161k\u00e1lovateln\u00e1 geo-distribuovan\u00e1 odoln\u00e1 datab\u00e1ze, kter\u00e1 odol\u00e1v\u00e1 selh\u00e1n\u00ed disk\u016f, server\u016f, stojan\u016f a datov\u00fdch center bez naru\u0161en\u00ed konzistence. Pro zaji\u0161t\u011bn\u00ed odolnosti proti selh\u00e1n\u00ed se pou\u017e\u00edv\u00e1 vlastn\u00ed algoritmus pro dosa\u017een\u00ed distribuovan\u00e9ho konsensu, stejn\u011b jako \u0159ada technick\u00fdch \u0159e\u0161en\u00ed, kter\u00e1 jsou podrobn\u011b projedn\u00e1na v p\u0159edn\u00e1\u0161ce. P\u0159edn\u00e1\u0161ka m\u016f\u017ee b\u00fdt zaj\u00edmav\u00e1 jak pro v\u00fdvoj\u00e1\u0159e datab\u00e1z\u00ed, tak pro v\u00fdvoj\u00e1\u0159e aplika\u010dn\u00edch \u0159e\u0161en\u00ed zalo\u017een\u00fdch na datab\u00e1z\u00edch.<br clear=\"all\">\n<\/p>\n<p><\/p>\n<h3 id=\"semen-checherinda--raspredelennye-tranzakcii-v-ydbhttpshydraconfru2019talks3ubxfwi4ikpxdjcdqswjihutm_sourcehabrutm_medium453832\">Semen \u010cechorin <noindex><a rel=\"nofollow\" href=\"https:\/\/hydraconf.ru\/2019\/talks\/3ubxfwi4ikpxdjcdqswjih\/?utm_source=habr&amp;utm_medium=453832\">Distribuovan\u00e9 transakce v YDB<\/a><\/noindex><\/h3>\n<p><\/p>\n<p><img decoding=\"async\" alt=\"19 hlav hydry. Velk\u00fd p\u0159ehled programu\" src=\"\/wp-content\/uploads\/2019\/06\/0cf2b40fcabfba1a774f00c9f245b8f1.jpeg\" style=\"display:block;margin: 0 auto;\" \/> Semen je v\u00fdvoj\u00e1\u0159 v t\u00fdmu distribuovan\u00fdch platforem v Yandexu a pracuje na mo\u017enosti v\u00edceseznamov\u00e9ho vyu\u017eit\u00ed instalace YDB.<\/p>\n<p><\/p>\n<p>Yandex Database je ur\u010dena pro OLTP dotazy a spl\u0148uje po\u017eadavky ACID pro transak\u010dn\u00ed syst\u00e9m. V p\u0159edn\u00e1\u0161ce se pod\u00edv\u00e1me na algoritmus pl\u00e1nov\u00e1n\u00ed transakc\u00ed, kter\u00fd tvo\u0159\u00ed z\u00e1klad transak\u010dn\u00edho syst\u00e9mu YDB. Prozkoum\u00e1me, jak\u00e9 entity se pod\u00edlej\u00ed na transakc\u00edch, kdo ur\u010duje glob\u00e1ln\u00ed po\u0159ad\u00ed transakc\u00ed, jak se dosahuje atomick\u00e9ho chov\u00e1n\u00ed transakc\u00ed, spolehlivost a p\u0159\u00edsn\u00e1 \u00farove\u0148 izolace. Na p\u0159\u00edkladu b\u011b\u017en\u00e9ho \u00fakolu si uk\u00e1\u017eeme realizace transakc\u00ed pomoc\u00ed dvouf\u00e1zov\u00e9ho potvrzen\u00ed a deterministick\u00fdch transakc\u00ed. Probereme jejich rozd\u00edly.<\/p>\n<p><\/p>\n<h2 id=\"chto-dalshe\">Co d\u00e1l?<\/h2>\n<p><\/p>\n<p>Program konference se st\u00e1le dopl\u0148uje nov\u00fdmi p\u0159edn\u00e1\u0161kami. Zejm\u00e9na o\u010dek\u00e1v\u00e1me p\u0159edn\u00e1\u0161ku od <strong>Nikita Kovalenko<\/strong> (<noindex><a rel=\"nofollow\" href=\"https:\/\/habr.com\/ru\/users\/ndkoval\/\" class=\"user_link\">ndkoval<\/a><\/noindex>) z JetBrains a <strong>Oleg Anast\u00e1ziev<\/strong> (<noindex><a rel=\"nofollow\" href=\"https:\/\/habr.com\/ru\/users\/m0nstermind\/\" class=\"user_link\">m0nstermind<\/a><\/noindex>) ze spole\u010dnosti Odnoklassniki. Nikita se v\u011bnuje algoritm\u016fm pro korutiny v t\u00fdmu Kotlin, zat\u00edmco Oleg vyv\u00edj\u00ed architekturu a \u0159e\u0161en\u00ed pro vysoce zat\u00ed\u017een\u00e9 syst\u00e9my na platform\u011b spole\u010dnosti Odnoklassniki. Krom\u011b toho je zde je\u0161t\u011b 1 podm\u00edn\u011bn\u011b pr\u00e1zdn\u00fd slot, kter\u00fd je v sou\u010dasnosti ve vyjedn\u00e1v\u00e1n\u00ed s uchaze\u010di programov\u00fdm v\u00fdborem.<\/p>\n<p><\/p>\n<p>Konference Hydra se bude konat 11-12. \u010dervence v Petrohrad\u011b. Vstupenky je mo\u017en\u00e9 <noindex>zakoupit na ofici\u00e1ln\u00edch str\u00e1nk\u00e1ch<\/noindex>. Upozor\u0148ujeme na mo\u017enost online vstupenek \u2014 pokud se z n\u011bjak\u00e9ho d\u016fvodu nem\u016f\u017eete t\u011bchto dn\u016f dostavit osobn\u011b do Petrohradu.<\/p>\n<p><\/p>\n<p>Uvid\u00edme se na Hyd\u0159e!<\/p>\n<p>Zdroj: <a content=\"nofollow\" rel=\"nofollow\" href=\"https:\/\/habr.com\/ru\/company\/jugru\/blog\/453832\/\">habr.com<\/a><\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"<p>11-12 \u0438\u044e\u043b\u044f \u0432 \u0421\u0430\u043d\u043a\u0442-\u041f\u0435\u0442\u0435\u0440\u0431\u0443\u0440\u0433\u0435 \u0441\u043e\u0441\u0442\u043e\u0438\u0442\u0441\u044f \u043a\u043e\u043d\u0444\u0435\u0440\u0435\u043d\u0446\u0438\u044f Hydra, \u043f\u043e\u0441\u0432\u044f\u0449\u0435\u043d\u043d\u0430\u044f \u0440\u0430\u0437\u0440\u0430\u0431\u043e\u0442\u043a\u0435 \u043f\u0430\u0440\u0430\u043b\u043b\u0435\u043b\u044c\u043d\u044b\u0445 \u0438 \u0440\u0430\u0441\u043f\u0440\u0435\u0434\u0435\u043b\u0435\u043d\u043d\u044b\u0445 \u0441\u0438\u0441\u0442\u0435\u043c. \u0424\u0438\u0448\u043a\u0430 \u0413\u0438\u0434\u0440\u044b \u0432 \u0442\u043e\u043c, \u0447\u0442\u043e \u043e\u043d\u0430 \u043e\u0431\u044a\u0435\u0434\u0438\u043d\u044f\u0435\u0442 \u043a\u0440\u0443\u0442\u044b\u0445 \u0443\u0447\u0451\u043d\u044b\u0445 (\u043a\u043e\u0442\u043e\u0440\u044b\u0445 \u043e\u0431\u044b\u0447\u043d\u043e \u043c\u043e\u0436\u043d\u043e \u043d\u0430\u0439\u0442\u0438 \u0442\u043e\u043b\u044c\u043a\u043e \u043d\u0430 \u0437\u0430\u0440\u0443\u0431\u0435\u0436\u043d\u044b\u0445 \u043d\u0430\u0443\u0447\u043d\u044b\u0445 \u043a\u043e\u043d\u0444\u0435\u0440\u0435\u043d\u0446\u0438\u044f\u0445) \u0438 \u0438\u0437\u0432\u0435\u0441\u0442\u043d\u044b\u0445 \u043f\u0440\u0430\u043a\u0442\u0438\u043a\u0443\u044e\u0449\u0438\u0445 \u0438\u043d\u0436\u0435\u043d\u0435\u0440\u043e\u0432, \u0432 \u043e\u0434\u043d\u0443 \u0431\u043e\u043b\u044c\u0448\u0443\u044e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0443 \u043d\u0430 \u0441\u0442\u044b\u043a\u0435 \u043d\u0430\u0443\u043a\u0438 \u0438 \u043f\u0440\u0430\u043a\u0442\u0438\u043a\u0438. Hydra \u2014 \u043e\u0434\u043d\u0430 \u0438\u0437 \u0441\u0430\u043c\u044b\u0445 \u0432\u0430\u0436\u043d\u044b\u0445 \u043d\u0430\u0448\u0438\u0445 \u043a\u043e\u043d\u0444\u0435\u0440\u0435\u043d\u0446\u0438\u0439 \u0437\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0438\u0435 \u043d\u0435\u0441\u043a\u043e\u043b\u044c\u043a\u043e [&hellip;]<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":26388,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[688],"tags":[],"class_list":["post-35091","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-administrirovanie"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 5.0.3 - aioseo.com -->\n\t<meta name=\"description\" content=\"11-12 \u0438\u044e\u043b\u044f \u0432 \u0421\u0430\u043d\u043a\u0442-\u041f\u0435\u0442\u0435\u0440\u0431\u0443\u0440\u0433\u0435 \u0441\u043e\u0441\u0442\u043e\u0438\u0442\u0441\u044f \u043a\u043e\u043d\u0444\u0435\u0440\u0435\u043d\u0446\u0438\u044f Hydra, \u043f\u043e\u0441\u0432\u044f\u0449\u0435\u043d\u043d\u0430\u044f \u0440\u0430\u0437\u0440\u0430\u0431\u043e\u0442\u043a\u0435 \u043f\u0430\u0440\u0430\u043b\u043b\u0435\u043b\u044c\u043d\u044b\u0445 \u0438 \u0440\u0430\u0441\u043f\u0440\u0435\u0434\u0435\u043b\u0435\u043d\u043d\u044b\u0445.\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<meta name=\"author\" content=\"Yuri Gagarin\"\/>\n\t<link rel=\"canonical\" href=\"https:\/\/prohoster.info\/cs\/blog\/administrirovanie\/19-golov-gidry-bolshoj-obzor-programmy\" \/>\n\t\t<meta name=\"generator\" content=\"All in One SEO (AIOSEO) 5.0.3\" \/>\n\t\t<meta property=\"og:locale\" content=\"cs_CZ\" \/>\n\t\t<meta property=\"og:site_name\" content=\"ProHoster | \u041a\u0443\u043f\u0438\u0442\u044c \u043d\u0430\u0434\u0435\u0436\u043d\u044b\u0439 \u0445\u043e\u0441\u0442\u0438\u043d\u0433 \u0434\u043b\u044f \u0441\u0430\u0439\u0442\u043e\u0432 \u0441 \u0437\u0430\u0449\u0438\u0442\u043e\u0439 \u043e\u0442 DDoS, VPS VDS \u0441\u0435\u0440\u0432\u0435\u0440\u044b\" \/>\n\t\t<meta property=\"og:type\" content=\"article\" \/>\n\t\t<meta property=\"og:title\" content=\"\ud83e\udd4719 \u0433\u043e\u043b\u043e\u0432 \u0433\u0438\u0434\u0440\u044b. \u0411\u043e\u043b\u044c\u0448\u043e\u0439 \u043e\u0431\u0437\u043e\u0440 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u044b | ProHoster\" \/>\n\t\t<meta property=\"og:description\" content=\"11-12 \u0438\u044e\u043b\u044f \u0432 \u0421\u0430\u043d\u043a\u0442-\u041f\u0435\u0442\u0435\u0440\u0431\u0443\u0440\u0433\u0435 \u0441\u043e\u0441\u0442\u043e\u0438\u0442\u0441\u044f \u043a\u043e\u043d\u0444\u0435\u0440\u0435\u043d\u0446\u0438\u044f Hydra, \u043f\u043e\u0441\u0432\u044f\u0449\u0435\u043d\u043d\u0430\u044f \u0440\u0430\u0437\u0440\u0430\u0431\u043e\u0442\u043a\u0435 \u043f\u0430\u0440\u0430\u043b\u043b\u0435\u043b\u044c\u043d\u044b\u0445 \u0438 \u0440\u0430\u0441\u043f\u0440\u0435\u0434\u0435\u043b\u0435\u043d\u043d\u044b\u0445.\" \/>\n\t\t<meta property=\"og:url\" content=\"https:\/\/prohoster.info\/cs\/blog\/administrirovanie\/19-golov-gidry-bolshoj-obzor-programmy\" \/>\n\t\t<meta property=\"og:image\" content=\"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg\" \/>\n\t\t<meta property=\"og:image:secure_url\" content=\"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg\" \/>\n\t\t<meta property=\"og:image:width\" content=\"350\" \/>\n\t\t<meta property=\"og:image:height\" content=\"350\" \/>\n\t\t<meta property=\"article:published_time\" content=\"2019-10-31T19:02:18+00:00\" \/>\n\t\t<meta property=\"article:modified_time\" content=\"2019-10-31T19:02:18+00:00\" \/>\n\t\t<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/prohoster\" \/>\n\t\t<meta property=\"article:author\" content=\"https:\/\/www.facebook.com\/prohoster\" \/>\n\t\t<!-- All in One SEO -->\n\n","aioseo_head_json":{"title":"\ud83e\udd4719 hlav hydry. 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