Moni! Ndikufuna ndikuuzeni m'mawu osavuta zamakanikidwe akuba mkati mwa makina enieni komanso zazinthu zina zosadziwikiratu zomwe tidakwanitsa kuzipeza pakufufuza kwake, zomwe ndidayenera kulowamo ngati woyang'anira zaukadaulo wa nsanja yamtambo. . Pulatifomu imayenda pa KVM.
CPU kuba nthawi ndi nthawi yomwe makina pafupifupi salandira zothandizira purosesa kuti aphedwe. Nthawi ino imangowerengedwa m'machitidwe ogwiritsira ntchito alendo m'malo owonetsera. Zifukwa za komwe chuma choperekedwa kwambirichi chimapita, monga m'moyo, sichidziwika bwino. Koma tinaganiza kuti tiganizire, ndipo ngakhale tinayesa zingapo. Sikuti tsopano tikudziwa zonse zokhudza kuba, koma tikuuzani chinthu chosangalatsa tsopano.
1. Kuba ndi chiyani
Chifukwa chake, kuba ndi metric yomwe ikuwonetsa kusowa kwa nthawi ya purosesa pamakina enieni. Monga tafotokozera Stealth ndi nthawi yomwe hypervisor ikuchita njira zina pa OS yomwe ili nayo ngakhale idayimitsa makina opangira makina kuti aphedwe. Ndiko kuti, kuba kumawerengedwa ngati kusiyana pakati pa nthawi yomwe ndondomekoyi yakonzeka kuchitidwa ndi nthawi yomwe ndondomekoyi imaperekedwa nthawi ya purosesa.
Makina enieni a kernel amalandira metric kuba kuchokera ku hypervisor. Nthawi yomweyo, hypervisor sinatchule ndendende njira zina zomwe zikuyenda, zimangonena kuti "ndikakhala wotanganidwa, sindingathe kukupatsani nthawi." Pa KVM, chithandizo chowerengera chakuba chawonjezedwa . Pali mfundo ziwiri zofunika apa:
- Makina enieni amaphunzira za kuba kuchokera ku hypervisor. Ndiko kuti, pakuwona zotayika, pamakina omwe ali pamakina enieniwo ndi muyeso wosalunjika womwe ungakhale wopotoka mosiyanasiyana.
- Hypervisor sagawana zambiri ndi makina enieni pazomwe akuchita - chinthu chachikulu ndikuti sichipatula nthawi. Chifukwa cha izi, makina enieniwo sangathe kuwona kupotoza kwa chizindikiro chakuba, chomwe chingayesedwe ndi chikhalidwe cha mpikisano.
2. Zomwe zimakhudza kuba
2.1. Kuba kuwerengera
Kwenikweni, kuba kumawerengedwa pafupifupi mofanana ndi nthawi yogwiritsira ntchito CPU. Palibe zambiri zokhudza momwe kubwezereranso kumaganiziridwa. Mwina chifukwa anthu ambiri amaona funso limeneli nβlodziwikiratu. Koma palinso mbuna pano. Kuti mudziwe bwino ndondomekoyi, mukhoza kuwerenga : muphunzira za ma nuances ambiri powerengera kagwiritsidwe ntchito komanso zanthawi yomwe kuwerengeraku kudzakhala kolakwika pazifukwa izi:
- Purosesa imatentha kwambiri, zomwe zimapangitsa kuti kuzungulira kudumpha.
- Yambitsani / zimitsani turbo boost, yomwe imasintha liwiro la wotchi ya purosesa.
- Kusintha kwa kutalika kwa kagawo ka nthawi komwe kumachitika mukamagwiritsa ntchito matekinoloje opulumutsa mphamvu a purosesa monga SpeedStep.
- Vuto pakuwerengera pafupifupi: kuyerekeza kugwiritsa ntchito mphindi imodzi pa 80% kumatha kubisala kuphulika kwakanthawi kochepa kwa 100%.
- Kutsekera kozungulira kumapangitsa kuti purosesa ibwezedwe, koma wogwiritsa ntchito sawona kupita patsogolo kulikonse pakukwaniritsidwa kwake. Zotsatira zake, kugwiritsa ntchito purosesa yowerengeka ndi ndondomekoyi kudzakhala zana limodzi, ngakhale kuti ndondomekoyi sichitha nthawi ya purosesa.
Sindinapeze nkhani yofotokoza kuwerengera kofanana kwa kuba (ngati mukudziwa, gawani mu ndemanga). Koma, potengera magwero, njira yowerengera ndiyofanana ndi yobwezeretsanso. Mwachidule, kauntala ina imawonjezedwa mu kernel, mwachindunji pa njira ya KVM (makina enieni), omwe amawerengera nthawi ya KVM kudikirira nthawi ya CPU. Kauntala imatenga zidziwitso za purosesa kuchokera pazomwe ili ndikuyang'ana ngati nkhupakupa zake zonse zimagwiritsidwa ntchito ndi makina enieni. Ngati ndizo zonse, ndiye kuti timaganiza kuti purosesayo idangokhala ndi makina enieni. Kupanda kutero, timadziwitsa kuti purosesa ikuchita china, kuba kudawonekera.
Kuwerengera kwakuba kumakhala ndi zovuta zofanana ndi kuwerengera kobwerezabwereza. Osati kunena kuti mavuto oterowo amawonekera kaΕ΅irikaΕ΅iri, koma amawoneka olefula.
2.2. Mitundu ya virtualization pa KVM
Kunena mwachidule, pali mitundu itatu ya virtualization, yomwe imathandizidwa ndi KVM. Kachitidwe kakuba kumachitika kutengera mtundu wa virtualization.
Kutsatsa. Pankhaniyi, kugwiritsa ntchito makina ogwiritsira ntchito makina okhala ndi zida za hypervisor zakuthupi kumachitika motere:
- Makina ogwiritsira ntchito alendo amatumiza lamulo ku chipangizo chake cha alendo.
- Woyendetsa chipangizo cha alendo amalandira lamulo, amapanga pempho la chipangizo cha BIOS ndikuchitumiza kwa hypervisor.
- Njira ya hypervisor imamasulira lamulo kulamula chipangizo chakuthupi, kupangitsa kuti, mwa zina, kukhala otetezeka kwambiri.
- Woyendetsa chipangizo chakuthupi amavomereza lamulo losinthidwa ndikulitumiza ku chipangizocho chokha.
- Zotsatira zakuchita malamulo zimabwerera m'njira yomweyo.
Ubwino womasulira ndikuti umakupatsani mwayi wotsanzira chipangizo chilichonse ndipo sikutanthauza kukonzekera kwapadera kwa kernel ya opaleshoni. Koma muyenera kulipira izi, choyamba, mwachangu.
Kusintha kwa Hardware. Pankhaniyi, chipangizo pa mlingo hardware amamvetsa malamulo kuchokera opaleshoni dongosolo. Iyi ndiye njira yachangu komanso yabwino kwambiri. Koma, mwatsoka, sichimathandizidwa ndi zida zonse zakuthupi, ma hypervisors ndi machitidwe opangira alendo. Pakadali pano, zida zazikulu zomwe zimathandizira kukhazikitsidwa kwa hardware ndi mapurosesa.
Paravirtualization. Njira yodziwika kwambiri yosinthira zida pa KVM komanso njira yodziwika bwino yogwiritsira ntchito alendo. Chodabwitsa chake ndikuti kugwira ntchito ndi ma hypervisor subsystems (mwachitsanzo, ndi netiweki kapena disk stack) kapena kugawa masamba amakumbukiro kumachitika pogwiritsa ntchito hypervisor API, osamasulira malamulo otsika. Choyipa cha njira iyi ndikuti makina ogwiritsira ntchito alendo ayenera kusinthidwa kuti athe kulumikizana ndi hypervisor pogwiritsa ntchito API iyi. Koma izi nthawi zambiri zimathetsedwa mwa kukhazikitsa madalaivala apadera pa makina opangira alendo. Mu KVM API iyi imatchedwa .
Ndi paravirtualization, poyerekeza ndi kuwulutsa, njira yopita ku chipangizo chakuthupi imachepetsedwa kwambiri potumiza malamulo molunjika kuchokera ku makina enieni kupita ku njira ya hypervisor pa wolandila. Izi zimakupatsani mwayi wofulumizitsa kutsata malangizo onse mkati mwa makina enieni. Mu KVM, izi zimachitika ndi virtio API, yomwe imagwira ntchito pazida zina, monga network kapena disk adapter. Ichi ndichifukwa chake madalaivala a virtio amayikidwa mkati mwa makina enieni.
Choyipa cha kuthamangitsa uku ndikuti sizinthu zonse zomwe zimayenda mkati mwa makina omwe amakhalabe mkati mwake. Izi zimapanga zotsatira zapadera zomwe zingayambitse kuba. Ndikupangira kuyamba kuphunzira mwatsatanetsatane za nkhaniyi ndi .
2.3. "Fair" kupanga
Makina enieni pa hypervisor ndi njira wamba yomwe imamvera malamulo okonzekera (kugawa kwazinthu pakati pa njira) mu Linux kernel, kotero tiyeni tiwone bwinobwino.
Linux imagwiritsa ntchito chotchedwa CFS, Completely Fair Scheduler, chomwe chakhala chosasintha kuyambira pa kernel 2.6.23. Kuti mumvetse algorithm iyi, mutha kuwerenga Linux Kernel Architecture kapena code source. Chofunikira cha CFS ndikugawa nthawi ya purosesa pakati pa njira kutengera nthawi ya kuphedwa kwawo. Kuchuluka kwa CPU nthawi yomwe ndondomeko imafuna, m'pamenenso imalandira nthawi yochepa ya CPU. Izi zimatsimikizira kuti njira zonse zimachitidwa "mwachilungamo" - kotero kuti ndondomeko imodzi sichikhala ndi mapurosesa onse, ndipo njira zina zingathenso kuchita.
Nthawi zina paradigm iyi imatsogolera kuzinthu zosangalatsa. Ogwiritsa ntchito a Linux anthawi yayitali mwina amakumbukira kuzizira kwa mkonzi wanthawi zonse pakompyuta pomwe akuyendetsa ntchito zogwiritsa ntchito zinthu monga compiler. Izi zidachitika chifukwa ntchito zosagwiritsa ntchito kwambiri pakompyuta pakompyuta zimapikisana ndi ntchito zofunikira kwambiri, monga wopanga. CFS ikuganiza kuti izi sizachilungamo, chifukwa chake imayimitsa nthawi ndi nthawi ndikulola purosesa kuti agwire ntchito za wopanga. Izi zidakonzedwa pogwiritsa ntchito makina , koma zina zambiri za kugawa nthawi ya purosesa pakati pa ntchito zidatsalira. Kwenikweni, iyi si nkhani yonena za kuipa kwa chirichonse mu CFS, koma kuyesa kukopa chidwi chakuti kugawa βkoyeneraβ kwa nthawi ya purosesa si ntchito yaingβono kwambiri.
Mfundo ina yofunika mu scheduler ndi preemption. Izi ndizofunikira kuti muchotse njira yowotchera kuchokera ku purosesa ndikulola ena kuti agwire ntchito. Njira ya ejection imatchedwa kusintha kwa nkhani. Pankhaniyi, nkhani yonse ya ntchitoyi imasungidwa: chikhalidwe cha stack, zolembera, ndi zina zotero, pambuyo pake ndondomekoyi imatumizidwa kuti idikire, ndipo wina amatenga malo ake. Iyi ndi ntchito yokwera mtengo kwa OS ndipo siigwiritsidwa ntchito kawirikawiri, koma palibe cholakwika ndi izo. Kusintha kwanthawi zambiri kumatha kuwonetsa vuto mu OS, koma nthawi zambiri kumakhala kosalekeza ndipo sikuwonetsa chilichonse makamaka.
Nkhani yayitali yotere ikufunika kuti tifotokoze mfundo imodzi: momwe ma processor amathandizira kuti azigwiritsa ntchito mwachilungamo Linux scheduler, imayimitsidwa mwachangu kuti njira zina zigwirenso ntchito. Kaya izi ndi zolondola kapena ayi ndi funso lovuta lomwe lingathe kuthetsedwa mosiyana pansi pa katundu wosiyana. Mu Windows, mpaka posachedwa, wokonza mapulaniwo adangoyang'ana kwambiri pakukonza mapulogalamu apakompyuta, zomwe zingayambitse kuzizira. Sun Solaris anali ndi makalasi asanu osiyanasiyana okonzekera. Titayambitsa virtualization, tidawonjezera yachisanu ndi chimodzi, , chifukwa zisanu zapitazo sizinagwire ntchito mokwanira ndi Solaris Zones virtualization. Ndikupangira kuyamba kuphunzira mwatsatanetsatane nkhaniyi ndi mabuku ngati kapena .
2.4. Kodi kuwunika kuba?
Kuyang'anira kuba mkati mwa makina enieni, monga ma metric ena aliwonse a purosesa, ndikosavuta: mutha kugwiritsa ntchito chida chilichonse cha purosesa. Chinthu chachikulu ndi chakuti makina enieni ali pa Linux. Pazifukwa zina Windows sapereka chidziwitsochi kwa ogwiritsa ntchito. π
Kutulutsa kwa lamulo lapamwamba: tsatanetsatane wa katundu wa purosesa, kumanja kwenikweni - kuba
Vuto limakhalapo poyesa kupeza izi kuchokera kwa hypervisor. Mungayesere kulosera kuba pamakina ochitira alendo, mwachitsanzo, pogwiritsa ntchito Load Average (LA) parameter - mtengo wapakati wa kuchuluka kwa njira zomwe zikudikirira pamzere wophedwa. Njira yowerengera chizindikirochi si yophweka, koma kawirikawiri, ngati LA yokhazikika ndi chiwerengero cha ulusi wa purosesa ndi yoposa 1, izi zikusonyeza kuti seva ya Linux yadzaza ndi chinachake.
Kodi njira zonsezi zikudikirira chiyani? Yankho lodziwikiratu ndi purosesa. Koma yankho siliri lolondola kwathunthu, chifukwa nthawi zina purosesa imakhala yaulere, koma LA imachoka pamlingo. Kumbukirani . Zomwezo zitha kuchitika ndi disk ndi zida zina zolowetsa / zotulutsa. Koma kwenikweni, njira zimatha kuyembekezera kutha kwa loko iliyonse, kaya yakuthupi, yolumikizidwa ndi chipangizo cha I / O, kapena zomveka, monga mutex. Izi zikuphatikizanso kutseka pamlingo wa hardware (mayankhidwe omwewo kuchokera ku diski), kapena malingaliro (omwe amatchedwa zoyambira zotsekera, zomwe zimaphatikizapo gulu lazinthu, mutex adaptive ndi spin, semaphores, zosintha zamakhalidwe, zotsekera za rw, zotsekera za ipc. ...).
Mbali ina ya LA ndikuti imatengedwa ngati avareji ya machitidwe opangira. Mwachitsanzo, njira 100 zikupikisana pa fayilo imodzi, ndiyeno LA=50. Mtengo waukulu woterewu ungawoneke kuti ukuwonetsa kuti makina ogwiritsira ntchito ndi oipa. Koma kwa ma code ena mokhotakhota, izi zikhoza kukhala zachilendo, ngakhale kuti ndizoipa zokha, ndipo njira zina zogwirira ntchito sizivutika.
Chifukwa cha izi (ndipo pasanathe mphindi imodzi), kudziwa chilichonse ndi chizindikiro cha LA si ntchito yopindulitsa kwambiri, yomwe imakhala ndi zotsatira zosatsimikizika pazochitika zinazake. Ngati muyesa kuzilingalira, mupeza kuti zolemba za Wikipedia ndi zina zomwe zilipo zimangofotokoza zophweka, popanda kufotokoza mozama za ndondomekoyi. Nditumizanso aliyense amene ali ndi chidwi, - tsatani maulalo pansipa. Ndani ali waulesi kuyankhula Chingerezi - .
3. Zotsatira zapadera
Tsopano tiyeni tione nkhani zazikulu zakuba zimene tinakumana nazo. Ndikuuzani momwe amatsatira kuchokera pamwambazi komanso momwe akugwirizanirana ndi zizindikiro pa hypervisor.
Kubwezeretsanso. Chosavuta komanso chodziwika bwino: hypervisor yagwiritsidwanso ntchito. Zowonadi, pali makina ambiri ogwiritsira ntchito makina, kugwiritsa ntchito kwambiri purosesa mkati mwawo, mpikisano wambiri, kugwiritsa ntchito LA kumaposa 1 (yokhazikika ndi ulusi wa purosesa). Chilichonse chomwe chili mkati mwa makina onse owoneka bwino chimachepa. Kuba komwe kumachokera ku hypervisor kukukulanso, ndikofunikira kugawanso katunduyo kapena kuzimitsa munthu. Kawirikawiri, zonse ndi zomveka komanso zomveka.
Paravirtualization vs. Single Instances. Pali makina amodzi okha pa hypervisor amadya gawo laling'ono, koma amapanga katundu wamkulu wa I / O, mwachitsanzo pa disk. Ndipo kuchokera kwinakwake kuba pang'ono kumawonekera mmenemo, mpaka 10% (monga momwe zasonyezedwera ndi zoyesera zingapo).
Nkhaniyi ndi yosangalatsa. Kuba kumawoneka apa ndendende chifukwa chotsekereza pamlingo wa madalaivala omwe ali ndi paravirtualized. Kusokoneza kumapangidwa mkati mwa makina enieni, okonzedwa ndi dalaivala ndikutumizidwa kwa hypervisor. Chifukwa cha kusokoneza kasamalidwe pa hypervisor, kwa makina enieni amawoneka ngati pempho lotumizidwa, ali okonzeka kuphedwa ndipo akuyembekezera purosesa, koma samapatsidwa nthawi ya purosesa. Mtsikana weniweni akuganiza kuti nthawi ino yabedwa.
Izi zimachitika panthawi yomwe buffer imatumizidwa, imapita mu kernel space ya hypervisor, ndipo timayamba kuyembekezera. Ngakhale, kuchokera pamalingaliro a makina enieni, ayenera kubwerera mwamsanga. Chifukwa chake, malinga ndi algorithm yowerengera kuba, nthawi ino imawonedwa ngati yabedwa. Nthawi zambiri, muzochitika izi pakhoza kukhala njira zina (mwachitsanzo, kukonza mafoni ena a sys), koma sayenera kukhala osiyana kwambiri.
Scheduler motsutsana ndi makina odzaza kwambiri. Pamene makina enieni akuvutika ndi kuba kwambiri kuposa ena, izi zimachitika chifukwa cha ndandanda. Ntchito ikadzaza purosesa, m'pamenenso wokonza mapulani amathamangitsa kuti enawo athe kugwira ntchito. Ngati makina owoneka bwino amadya pang'ono, sangawone kuba: njira yake moona mtima idakhala ndikudikirira, tiyenera kuyipatsa nthawi yochulukirapo. Ngati makina enieni atulutsa katundu wambiri pazitsulo zake zonse, nthawi zambiri amachotsedwa pa purosesa ndipo amayesa kuti asapereke nthawi yochuluka.
Zimakhala zoipitsitsa kwambiri pamene njira mkati mwa makina enieni zimayesa kupeza purosesa yambiri chifukwa sangathe kuthana ndi kukonza deta. Ndiye makina opangira pa hypervisor, chifukwa cha kukhathamiritsa moona mtima, adzapereka nthawi yocheperapo ya purosesa. Izi zimachitika ngati chigumukire, ndipo kuba kumalumphira kumwamba, ngakhale makina ena enieni sangazindikire. Ndipo ma cores ambiri, makina okhudzidwawo amayipa kwambiri. Mwachidule, makina odzaza kwambiri okhala ndi ma cores ambiri amavutika kwambiri.
Low LA, koma pali kuba. Ngati LA ili pafupifupi 0,7 (ndiko kuti, hypervisor ikuwoneka kuti yatsitsidwa), koma kuba kumawonedwa mkati mwa makina enieni:
- Njira yokhala ndi paravirtualization yafotokozedwa kale pamwambapa. Makina enieni amatha kulandira ma metric omwe akuwonetsa kuba, ngakhale hypervisor ndiyabwino. Malinga ndi zotsatira za zoyeserera zathu, njira yakuba iyi sipitilira 10% ndipo siyenera kukhala ndi vuto lalikulu pakugwira ntchito kwa mapulogalamu mkati mwa makina enieni.
- Parameter ya LA imawerengedwa molakwika. Kunena zowona, pa mphindi iliyonse amawerengedwa molondola, koma ngati awerengeredwa mopitilira mphindi imodzi amakhala kuti sawerengedwa mochepera. Mwachitsanzo, ngati makina pafupifupi gawo limodzi mwa magawo atatu a hypervisor amadya mapurosesa ake onse ndendende theka la miniti, ndiye LA pamphindi pa hypervisor adzakhala 0,15; makina anayi otere omwe amagwira ntchito nthawi imodzi adzapereka 0,6. Ndipo kuti kwa theka la miniti pa aliyense wa iwo panali kuba zakutchire pa 25% malinga ndi chizindikiro cha LA sikungathenso kutulutsidwa.
- Apanso, chifukwa cha wokonza mapulani amene adaganiza kuti wina akudya kwambiri ndikusiya kuti wina adikire. Pakadali pano, ndisintha zomwe zikuchitika, kuwongolera zosokoneza ndikusamalira zinthu zina zofunika padongosolo. Zotsatira zake, makina ena enieni sawona vuto lililonse, pomwe ena amawonongeka kwambiri.
4. Zosokoneza zina
Pali zifukwa zina miliyoni zosokoneza kubwerera koyenera kwa nthawi ya purosesa pamakina enieni. Mwachitsanzo, hyperthreading ndi NUMA zimabweretsa zovuta pakuwerengera. Amasokoneza kotheratu kusankha kwa kernel kuti akwaniritse njirayi, chifukwa wokonza ndondomeko amagwiritsa ntchito ma coefficients - zolemera, zomwe zimapangitsa kuwerengera kukhala kovuta kwambiri posintha nkhaniyo.
Pali zosokoneza chifukwa cha matekinoloje monga turbo boost kapena, mosiyana, njira yopulumutsira mphamvu, yomwe, powerengera kagwiritsidwe ntchito, imatha kuwonjezera kapena kuchepetsa ma frequency kapena gawo la nthawi pa seva. Kuthandizira turbo boost kumachepetsa magwiridwe antchito a ulusi umodzi wa purosesa chifukwa cha kuchuluka kwa magwiridwe antchito a wina. Panthawiyi, chidziwitso chokhudza mafupipafupi a purosesa sichiperekedwa ku makina enieni, ndipo amakhulupirira kuti wina akubera nthawi yake (mwachitsanzo, anapempha 2 GHz, koma analandira theka).
Kawirikawiri, pangakhale zifukwa zambiri zosokoneza. Mukhoza kupeza china pa dongosolo linalake. Ndi bwino kuyamba ndi mabuku omwe ndidapereka maulalo pamwambapa, ndikubweza ziwerengero kuchokera ku hypervisor pogwiritsa ntchito zinthu monga perf, sysdig, systemtap, zomwe. .
5. Mapeto
- Kubera kwina kumatha kuchitika chifukwa cha paravirtualization, ndipo kumatha kuonedwa ngati kwachilendo. Amalemba pa intaneti kuti mtengo uwu ukhoza kukhala 5-10%. Zimatengera ntchito zomwe zili mkati mwa makina enieni komanso katundu omwe amayika pazida zake zakuthupi. Apa ndikofunikira kulabadira momwe mapulogalamu amamvera mkati mwa makina enieni.
- ChiΕ΅erengero cha katundu pa hypervisor ndi kuba mkati mwa makina pafupifupi nthawi zonse sizigwirizana momveka bwino;
- Wokonza mapulani ali ndi malingaliro oyipa panjira zomwe zimafunsa zambiri. Iye amayesetsa kupereka zochepa kwa amene amamupempha zambiri. Makina akuluakulu enieni ndi oipa.
- Kuba pang'ono kungakhale chizolowezi ngakhale popanda paravirtualization (poganizira katundu mkati mwa makina pafupifupi, makhalidwe a katundu wa anansi, katundu kugawa pa ulusi ndi zinthu zina).
- Ngati mukufuna kudziwa kuba mu dongosolo linalake, muyenera kufufuza njira zosiyanasiyana, kusonkhanitsa ma metrics, kuwasanthula mosamala ndikuganizira momwe mungagawire katunduyo mofanana. Zopatuka pazochitika zilizonse ndizotheka, zomwe ziyenera kutsimikiziridwa moyesera kapena kuyang'ana mu kernel debugger.
Source: www.habr.com