Moni, Habr! Ndine Artem Karamyshev, wamkulu wa gulu loyang'anira dongosolo . Takhala ndi zotsatsa zambiri zatsopano chaka chatha. Tinkafuna kuwonetsetsa kuti ntchito za API ndizovuta, zololera zolakwika, komanso zokonzekera kukula mwachangu kwa ogwiritsa ntchito. Pulatifomu yathu imakhazikitsidwa pa OpenStack, ndipo ndikufuna ndikuuzeni mavuto omwe tidayenera kuthana nawo kuti tipeze dongosolo lololera zolakwika. Ndikuganiza kuti izi zikhala zosangalatsa kwa iwo omwe amapanganso zinthu pa OpenStack.
Kulekerera kwa zolakwika zonse papulatifomu kumakhala ndi kulimba kwa zigawo zake. Chifukwa chake tidzadutsa pang'onopang'ono magawo onse omwe tidazindikira zoopsa ndikuzitseka.
Kanema wa nkhaniyi, gwero lalikulu lomwe linali lipoti pamsonkhano wa Uptime day 4, wokonzedwa ndi , mukuwona .
Kukhazikika kwa zomangamanga
Gawo lagulu la mtambo wa MCS tsopano lakhazikitsidwa m'magawo awiri a data a Tier III, pakati pawo pali ulusi wake wakuda, wosungidwa pamlingo wakuthupi ndi njira zosiyanasiyana, ndi 200 Gbit / s. Gawo lachitatu limapereka mulingo wofunikira wololera zolakwika pazachilengedwe.
Ulusi wakuda umasungidwa pamlingo wakuthupi komanso womveka. Njira yosungitsa tchanelo inali yobwerezabwereza, mavuto adabuka, ndipo tikuwongolera nthawi zonse kulumikizana pakati pa malo opangira data.
Mwachitsanzo, posachedwapa, pogwira ntchito pachitsime pafupi ndi malo osungiramo deta, wofukula anathyola chitoliro, ndipo mkati mwa chitolirochi munali chingwe chachikulu ndi chosungirako. Njira yathu yolankhulirana yolakwika ndi malo opangira data idakhala pachiwopsezo nthawi ina, pachitsime. Chifukwa chake, tataya gawo lina la zomangamanga. Tidazindikira ndikuchita zingapo, kuphatikiza kukhazikitsa ma optics owonjezera pachitsime chapafupi.
M'malo opangira ma data pali malo opezeka opereka mauthenga omwe timawawululira ma prefixes athu kudzera pa BGP. Pamayendedwe aliwonse a netiweki, metric yabwino kwambiri imasankhidwa, yomwe imalola makasitomala osiyanasiyana kuti apatsidwe mawonekedwe abwino kwambiri olumikizirana. Ngati kulumikizana kudzera mwa wothandizira m'modzi kutsika, timapanganso njira yathu kudzera mwa omwe amapereka.
Ngati wothandizira alephera, timasinthiratu kupita kwina. Pakachitika kulephera kwa malo amodzi a data, tili ndi kope lagalasi la mautumiki athu mu data center yachiwiri, yomwe imatenga katundu wonse.
Kukhazikika kwa zomangamanga
Zomwe timagwiritsa ntchito pakulekerera zolakwika pamlingo wa pulogalamu
Ntchito yathu imamangidwa pazigawo zingapo za opensource.
ExaBGP ndi ntchito yomwe imagwiritsa ntchito zingapo pogwiritsa ntchito protocol ya BGP-based dynamic routing protocol. Timagwiritsa ntchito mwachangu kutsatsa ma adilesi athu a IP ovomerezeka omwe ogwiritsa ntchito amapeza API.
Hapo ndi yolemetsa yolemetsa kwambiri yomwe imakupatsani mwayi wokonza malamulo osinthika osinthira magalimoto pamagawo osiyanasiyana amtundu wa OSI. Timagwiritsa ntchito moyenera pamaso pa mautumiki onse: nkhokwe, otumizira mauthenga, mautumiki a API, mautumiki apa intaneti, mapulojekiti athu amkati - chirichonse chiri kumbuyo kwa HAProxy.
Pulogalamu ya API - pulogalamu yapaintaneti yolembedwa mu python, yomwe wogwiritsa ntchitoyo amayang'anira zomangamanga zake ndi ntchito yake.
Ntchito ya antchito (ogwira ntchito pano) - mu ntchito za OpenStack, iyi ndi daemon ya zomangamanga yomwe imakupatsani mwayi wofalitsa malamulo a API ku zomangamanga. Mwachitsanzo, kupanga disk kumachitika mwa wogwira ntchito, ndipo pempho la chilengedwe limapezeka mu API yogwiritsira ntchito.
Standard OpenStack Application Architecture
Ntchito zambiri zomwe zimapangidwira OpenStack zimayesa kutsatira paradigm imodzi. Ntchito nthawi zambiri imakhala ndi magawo awiri: API ndi ogwira ntchito (oyang'anira kumbuyo). Monga lamulo, API ndi ntchito ya WSGI mu python, yomwe imayambitsidwa ngati njira yodziyimira pawokha (daemon), kapena kugwiritsa ntchito seva yapaintaneti ya Nginx kapena Apache. API imayang'anira pempho la wogwiritsa ntchito ndikupereka malangizo ena ku ntchito kuti agwire ntchito. Kusamutsa kumachitika pogwiritsa ntchito meseji broker, nthawi zambiri RabbitMQ, enawo samathandizidwa bwino. Mauthenga akafika kwa broker, amasinthidwa ndi antchito ndipo, ngati kuli kofunikira, abweze yankho.
Paradigm iyi imaphatikizapo zolephera zomwe zadziwika: RabbitMQ ndi database. Koma RabbitMQ imasiyanitsidwa ndi ntchito imodzi ndipo, mwachidziwitso, ikhoza kukhala payekha pa ntchito iliyonse. Chifukwa chake ku MCS timalekanitsa mautumikiwa momwe tingathere; pa projekiti iliyonse timapanga nkhokwe yapadera, RabbitMQ yosiyana. Njirayi ndi yabwino chifukwa pakachitika ngozi pamalo omwe ali pachiwopsezo, sintchito yonse yomwe imawonongeka, koma gawo lake lokha.
Chiwerengero cha ntchito za ogwira ntchito chilibe malire, kotero API imatha kuwongolera mozungulira kumbuyo kwa owerengera kuti iwonjezere magwiridwe antchito ndi kulolerana kolakwa.
Ntchito zina zimafuna kugwirizanitsa mkati mwa ntchitoyo pamene zovuta zotsatizana zimachitika pakati pa ma API ndi ogwira ntchito. Pachifukwa ichi, malo amodzi ogwirizanitsa amagwiritsidwa ntchito, ndondomeko yamagulu monga Redis, Memcache, etcd, yomwe imalola wogwira ntchito wina kuti auze wina kuti ntchitoyi yapatsidwa kwa iye ("chonde musatenge"). Timagwiritsa ntchito etcd. Monga lamulo, ogwira ntchito amalumikizana mwachangu ndi database, kulemba ndi kuwerenga zambiri kuchokera pamenepo. Timagwiritsa ntchito mariadb ngati nkhokwe, yomwe ili mgulu la multimaster.
Ntchito yachikale iyi imakonzedwa m'njira yovomerezeka ya OpenStack. Itha kuonedwa ngati njira yotsekedwa, yomwe njira zowonjezera ndi kulolerana zolakwa ndizodziwikiratu. Mwachitsanzo, chifukwa cha kulekerera zolakwika za API, ndikwanira kuyika balancer patsogolo pawo. Kuchulukitsa ogwira ntchito kumatheka powonjezera chiwerengero chawo.
Malo ofooka mu dongosolo lonse ndi RabbitMQ ndi MariaDB. Zomangamanga zawo zikuyenera kukhala ndi nkhani ina.M'nkhaniyi ndikufuna kuyang'ana kwambiri kulekerera zolakwika za API.
Openstack Application Architecture. Kulinganiza ndi kulolerana kolakwa kwa nsanja yamtambo
Kupanga HAProxy balancer yolekerera zolakwika pogwiritsa ntchito ExaBGP
Kuti tipangitse ma API athu kukhala owopsa, othamanga komanso olekerera zolakwika, timayika cholemetsa patsogolo pawo. Tinasankha HAProxy. Malingaliro anga, ili ndi makhalidwe onse ofunikira pa ntchito yathu: kugwirizanitsa pamagulu angapo a OSI, mawonekedwe a kasamalidwe, kusinthasintha ndi scalability, njira zambiri zogwirizanitsa, zothandizira matebulo a gawo.
Vuto loyamba lomwe limayenera kuthetsedwa linali kulolerana kolakwika kwa balancer palokha. Kungoyika balancer kumapangitsanso kulephera: chowerengera chimasweka ndikuwonongeka kwa ntchito. Kuti izi zisachitike, tidagwiritsa ntchito HAProxy molumikizana ndi ExaBGP.
ExaBGP imakupatsani mwayi wogwiritsa ntchito njira yowunikira momwe ntchito ikuyendera. Tinagwiritsa ntchito njirayi kuti tiwone momwe HAProxy imagwirira ntchito ndipo, pakagwa mavuto, zimitsani ntchito ya HAProxy kuchokera ku BGP.
ExaBGP + HAProxy scheme
- Timayika mapulogalamu ofunikira, ExaBGP ndi HAProxy, pa maseva atatu.
- Timapanga mawonekedwe a loopback pa seva iliyonse.
- Pa maseva atatu onsewa timapereka adilesi yoyera ya IP ku mawonekedwe awa.
- Adilesi yoyera ya IP imalengezedwa pa intaneti kudzera pa ExaBGP.
Kulekerera zolakwika kumatheka potsatsa adilesi yomweyo ya IP kuchokera ku maseva onse atatu. Kuchokera pamawonedwe a netiweki, adilesi yomweyo imapezeka kuchokera ku ma hop atatu otsatirawa. Router imawona njira zitatu zofanana, imasankha zomwe zili patsogolo kwambiri potengera ma metric ake (izi nthawi zambiri zimakhala zofanana), ndipo magalimoto amapita ku imodzi mwa ma seva.
Pakakhala zovuta ndi ntchito ya HAProxy kapena kulephera kwa seva, ExaBGP imasiya kulengeza njirayo, ndipo magalimoto amasinthira ku seva ina.
Chifukwa chake, tapeza kulolerana kolakwa kwa balancer.
Kulekerera zolakwika kwa HAProxy balancers
Chiwembucho chinakhala chopanda ungwiro: tinaphunzira kusunga HAProxy, koma sitinaphunzire kugawa katundu mkati mwa mautumiki. Chifukwa chake, tidakulitsa chiwembuchi pang'ono: tidapitilira kuwongolera pakati pa ma adilesi angapo oyera a IP.
Kusanja kutengera DNS kuphatikiza BGP
Nkhani yoyezera katundu kwa HAProxy yathu sinathe. Komabe, zitha kuthetsedwa mosavuta, monga tachitira pano.
Kuti musinthe ma seva atatu mudzafunika ma adilesi atatu oyera a IP ndi DNS yabwino yakale. Iliyonse mwa ma adilesi awa imatsimikiziridwa pa mawonekedwe a loopback a HAProxy iliyonse ndikutsatsa pa intaneti.
Mu OpenStack, kuyang'anira zothandizira, bukhu lautumiki limagwiritsidwa ntchito, lomwe limatchula mapeto a API a ntchito inayake. Mu bukhuli timalembetsa dzina lachidziwitso - public.infra.mail.ru, lomwe limathetsedwa kudzera pa DNS ndi ma adilesi atatu a IP. Zotsatira zake, timapeza kugawa pakati pa ma adilesi atatu kudzera pa DNS.
Koma popeza polengeza ma adilesi oyera a IP sitiwongolera zosankhidwa za seva, izi sizikuyenda bwino. Nthawi zambiri, seva imodzi yokha ndiyo idzasankhidwa kutengera kukula kwa ma adilesi a IP, ndipo ena awiriwo azikhala opanda pake chifukwa palibe ma metric omwe atchulidwa mu BGP.
Tinayamba kutumiza maulendo kudzera pa ExaBGP ndi ma metric osiyanasiyana. Balancer aliyense amatsatsa ma adilesi onse atatu oyera a IP, koma imodzi mwa izo, yomwe ndi yayikulu pa balancer iyi, imalengezedwa ndi metric yocheperako. Choncho pamene ma balancer atatu onse akugwira ntchito, kuyitana ku adilesi yoyamba ya IP kumapita ku balancer yoyamba, kuyitanira kwa wachiwiri mpaka kwachiwiri, ndikuyitanira wachitatu mpaka wachitatu.
Kodi chimachitika ndi chiyani m'modzi mwa olinganiza akagwa? Ngati balancer iliyonse ilephera, adilesi yake yayikulu imalengezedwabe kuchokera ku ena awiriwo, ndipo magalimoto amagawidwanso pakati pawo. Chifukwa chake, timapatsa wogwiritsa ma adilesi angapo a IP nthawi imodzi kudzera pa DNS. Mwa kusanja ndi DNS ndi ma metric osiyanasiyana, timapeza kugawa kofanana kwa katundu pa ma balancer onse atatu. Ndipo panthawi imodzimodziyo sitimataya kulolerana kolakwa.
Kuyanjanitsa HAProxy kutengera DNS + BGP
Kuyanjana pakati pa ExaBGP ndi HAProxy
Chifukwa chake, tidakhazikitsa kulolerana kwa zolakwika ngati seva ichoka, kutengera kuyimitsa kulengeza kwa njira. Koma HAProxy ikhoza kutseka pazifukwa zina kusiyana ndi kulephera kwa seva: zolakwika za kayendetsedwe ka ntchito, zolephera mkati mwa utumiki. Tikufuna kuchotsa balancer yosweka kuchokera pansi pa katundu muzochitika izi, ndipo timafunikira njira ina.
Chifukwa chake, kukulitsa chiwembu cham'mbuyomu, tidakhazikitsa kugunda kwamtima pakati pa ExaBGP ndi HAProxy. Uku ndikukhazikitsa pulogalamu yolumikizirana pakati pa ExaBGP ndi HAProxy, pomwe ExaBGP imagwiritsa ntchito zolemba zachikhalidwe kuti ziwone momwe ntchito zilili.
Kuti muchite izi, muyenera kukonza wowunika zaumoyo mu ExaBGP config, yomwe ingayang'ane momwe HAProxy ilili. Kwa ife, tidakonza zam'mbuyo zaumoyo ku HAProxy, ndipo kuchokera kumbali ya ExaBGP timayang'ana ndi pempho losavuta la GET. Chilengezochi chikasiya kuchitika, ndiye kuti HAProxy sichigwira ntchito ndipo palibe chifukwa cholengeza.
HAProxy Health Check
HAProxy Peers: kulumikizana kwa gawo
Chotsatira chinali kugwirizanitsa magawo. Pogwira ntchito yogawa ma balancers, zimakhala zovuta kukonzekera kusungidwa kwa chidziwitso cha magawo a kasitomala. Koma HAProxy ndi imodzi mwa owerengeka ochepa omwe angathe kuchita izi chifukwa cha machitidwe a Anzako - kutha kusamutsa matebulo a gawo pakati pa njira zosiyana za HAProxy.
Pali njira zofananira zosiyanasiyana: zosavuta monga , ndi kuwonjezereka, pamene gawo la kasitomala likumbukiridwa, ndipo nthawi iliyonse amathera pa seva yomweyo monga kale. Tinkafuna kukhazikitsa njira yachiwiri.
HAProxy amagwiritsa ntchito matebulo kuti asunge magawo a kasitomala pamakinawa. Amasunga adilesi yoyambirira ya kasitomala, adilesi yosankhidwa (backend) ndi zina zambiri zautumiki. Nthawi zambiri, matebulo omatira amagwiritsidwa ntchito kusungira gwero-IP + kopita-IP pair, yomwe imakhala yothandiza kwambiri kwa mapulogalamu omwe sangathe kusamutsa gawo la ogwiritsa ntchito posinthira ku balancer ina, mwachitsanzo, mu RoundRobin kusanja mode.
Ngati tebulo la ndodo likuphunzitsidwa kusuntha pakati pa njira zosiyana za HAProxy (pakati pa zomwe kusanja kumachitika), olinganiza athu adzatha kugwira ntchito ndi dziwe limodzi la matebulo a ndodo. Izi zipangitsa kuti zitheke kusintha maukonde a kasitomala ngati m'modzi mwa owerengera alephera; kugwira ntchito ndi magawo amakasitomala kumapitilira pazomwe zidasankhidwa kale.
Kuti mugwiritse ntchito moyenera, vuto la magwero a IP adilesi ya balancer yomwe gawolo linakhazikitsidwa liyenera kuthetsedwa. Kwa ife, iyi ndi adilesi yosinthika pa mawonekedwe a loopback.
Zolondola ntchito anzawo zimatheka pokhapokha zinthu zina. Ndiko kuti, nthawi ya TCP iyenera kukhala yayikulu mokwanira kapena kusinthana kuyenera kukhala kofulumira kotero kuti gawo la TCP lisakhale ndi nthawi yothetsa. Komabe, zimalola kusintha kosasinthika.
Mu IaaS tili ndi ntchito yomangidwa pogwiritsa ntchito ukadaulo womwewo. Izi , yomwe imatchedwa Octavia. Zimakhazikitsidwa ndi njira ziwiri za HAProxy ndipo poyamba zimaphatikizapo kuthandizira anzawo. Iwo asonyeza kuti ndi abwino kwambiri mu utumiki umenewu.
Chithunzichi chikuwonetsa kusuntha kwa matebulo a anzawo pakati pa zochitika zitatu za HAProxy, kasinthidwe kakukonzedwa momwe izi zingakhazikitsire:
HAProxy Peers (kalunzanitsidwe gawo)
Ngati mumagwiritsa ntchito chiwembu chomwecho, ntchito yake iyenera kuyesedwa mosamala. Sizowona kuti zidzagwira ntchito mofananamo 100% ya nthawiyo. Koma simudzataya matebulo mukafunika kukumbukira IP ya kasitomala.
Kuchepetsa kuchuluka kwa zopempha nthawi imodzi kuchokera kwa kasitomala yemweyo
Ntchito zilizonse zomwe zimapezeka pagulu, kuphatikiza ma API athu, zitha kukhala zopempha zambiri. Zifukwa za iwo zitha kukhala zosiyana kotheratu, kuchokera ku zolakwika za ogwiritsa ntchito mpaka kuukira kolunjika. Timakhala nthawi ndi nthawi DDoSed ndi ma adilesi a IP. Makasitomala nthawi zambiri amalakwitsa m'malemba awo ndikutipatsa ma mini-DDoSs.
Mwanjira ina, chitetezo chowonjezera chiyenera kuperekedwa. Yankho lodziwikiratu ndikuchepetsa kuchuluka kwa zopempha za API osati kuwononga nthawi ya CPU pokonza zopempha zoyipa.
Kuti tigwiritse ntchito zoletsa zotere, timagwiritsa ntchito malire amitengo, okonzedwa pamaziko a HAProxy, pogwiritsa ntchito matebulo a ndodo omwewo. Kukhazikitsa malire ndikosavuta ndipo kumakupatsani mwayi wochepetsera wogwiritsa ntchito kuchuluka kwa zopempha ku API. Algorithm imakumbukira magwero a IP komwe zopempha zimapangidwira ndikuchepetsa kuchuluka kwa zopempha nthawi imodzi kuchokera kwa wogwiritsa ntchito m'modzi. Zachidziwikire, tidawerengera kuchuluka kwambiri kwa API pautumiki uliwonse ndikuyika malire a ≈ 10 nthawi zamtengo uwu. Timapitiriza kuyang'anitsitsa zochitikazo ndikusunga chala chathu pamphuno.
Kodi izi zikuwoneka bwanji muzochita? Tili ndi makasitomala omwe amagwiritsa ntchito autoscaling APIs nthawi zonse. Amapanga makina pafupifupi mazana awiri kapena atatu m'mawa ndikuchotsa madzulo. Kwa OpenStack, kupanga makina enieni, komanso ndi ntchito za PaaS, zimafuna zosachepera zopempha za 1000 API, popeza kuyanjana pakati pa mautumiki kumapezekanso kudzera mu API.
Kusamutsa ntchito zotere kumabweretsa katundu wambiri. Tidaunika katunduyu, kusonkhanitsa nsonga zatsiku ndi tsiku, kuchulukitsa kakhumi, ndipo izi zidakhala malire athu. Timasunga chala chathu pamtima. Nthawi zambiri timawona bots ndi scanner omwe akuyesera kutiyang'ana kuti awone ngati tili ndi zolemba za CGA zomwe zingathe kuyendetsedwa, tikuzidula mwachangu.
Momwe mungasinthire codebase yanu osazindikira ogwiritsa ntchito
Timakhazikitsanso kulekerera zolakwika pamlingo wa njira zotumizira ma code. Pakhoza kukhala glitches panthawi yotulutsidwa, koma zotsatira zake pa kupezeka kwa ntchito zikhoza kuchepetsedwa.
Timasintha ntchito zathu nthawi zonse ndipo tiyenera kuwonetsetsa kuti codebase ikusinthidwa popanda kukhudza ogwiritsa ntchito. Tinatha kuthetsa vutoli pogwiritsa ntchito luso la kasamalidwe la HAProxy ndi kukhazikitsidwa kwa Graceful Shutdown mu ntchito zathu.
Kuti athetse vutoli, kunali koyenera kuonetsetsa kuwongolera kwa balancer ndi kutseka "kolondola" kwa ntchito:
- Pankhani ya HAProxy, kuwongolera kumachitika kudzera mu fayilo ya ziwerengero, yomwe kwenikweni imakhala socket ndipo imatanthauzidwa mu HAProxy config. Mutha kutumiza malamulo kwa izo kudzera pa stdio. Koma chida chathu chachikulu chowongolera kasinthidwe ndichotheka, chifukwa chake chimakhala ndi gawo lokhazikika loyang'anira HAProxy. Zomwe timagwiritsa ntchito mwachangu.
- Zambiri mwazinthu zathu za API ndi Engine zimathandizira matekinoloje otsekera mwachisomo: akatseka, amadikirira kuti ntchito yomwe ilipoyo ithe, kaya ndi pempho la http kapena ntchito ina yautumiki. Zomwezo zimachitikanso ndi wogwira ntchito. Imadziwa ntchito zonse zomwe ikuchita ndipo imatha ikamaliza zonse.
Chifukwa cha mfundo ziwirizi, ma algorithm otetezeka pakutumizidwa kwathu akuwoneka motere.
- Wopanga mapulogalamu amasonkhanitsa phukusi latsopano la code (kwa ife iyi ndi RPM), amayesa mu chikhalidwe cha dev, amayesa pa siteji, ndikuyisiya pamalo osungiramo siteji.
- Wopanga mapulogalamuwa amakhazikitsa ntchito kuti atumizidwe ndi kufotokozera mwatsatanetsatane za "zojambula": ndondomeko ya phukusi latsopano, kufotokozera za ntchito zatsopano ndi zina zokhudzana ndi kutumizidwa ngati kuli kofunikira.
- Woyang'anira dongosolo akuyamba kusintha. Ikuyambitsa buku lamasewera la Ansible, lomwe limachita izi:
- Imatengera phukusi kuchokera kumalo osungiramo siteji ndikuigwiritsa ntchito kuti isinthe mtundu wa phukusi muzosungiramo zinthu.
- Imalemba mndandanda wazotsatira zantchito zomwe zasinthidwa.
- Imayimitsa ntchito yoyamba kuti isinthidwe mu HAProxy ndikudikirira kuti njira zake zimalize. Chifukwa cha kuyimitsidwa kwabwino, tili ndi chidaliro kuti zopempha zonse zamakasitomala zidzatha bwino.
- Pambuyo pa API ndi antchito ayimitsidwa kwathunthu, ndipo HAProxy yazimitsidwa, code imasinthidwa.
- Ansible amayendetsa ntchito.
- Pa ntchito iliyonse, "zogwirizira" zina zimakoka, zomwe zimayesa mayunitsi pamayeso angapo omwe afotokozedwa kale. Kufufuza kofunikira kwa code yatsopano kumachitika.
- Ngati palibe zolakwika zomwe zapezeka mu sitepe yapitayi, backend imatsegulidwa.
- Tiyeni tipite ku backend yotsatira.
- Pambuyo pa ma backends onse asinthidwa, kuyesa kogwira ntchito kumayambika. Ngati akusowa, ndiye kuti wopanga amayang'ana magwiridwe antchito aliwonse omwe adapanga.
Izi zimamaliza kutumiza.
Kuzungulira kwantchito
Chiwembuchi sichikanagwira ntchito ngati tinalibe lamulo limodzi. Timathandizira onse akale ndi atsopano Mabaibulo nkhondo. Pasadakhale, pa siteji ya chitukuko cha mapulogalamu, zimayikidwa kuti ngakhale kusintha kwa database yautumiki, sikudzaphwanya code yapitayi. Zotsatira zake, maziko a code amasinthidwa pang'onopang'ono.
Pomaliza
Kugawana malingaliro anga okhudzana ndi kamangidwe ka WEB kolekerera zolakwika, ndikufuna kuwonanso mfundo zake zazikulu:
- kulekerera zolakwa zakuthupi;
- kulekerera zolakwika pamaneti (ma balancers, BGP);
- kulekerera zolakwika kwa mapulogalamu omwe amagwiritsidwa ntchito ndikupangidwa.
Nthawi yokhazikika aliyense!
Source: www.habr.com
