{"id":80035,"date":"2020-05-02T13:42:54","date_gmt":"2020-05-02T11:42:54","guid":{"rendered":"https:\/\/prohoster.info\/blog\/administrirovanie\/udobnye-arhitekturnye-patterny"},"modified":"2020-05-02T13:42:54","modified_gmt":"2020-05-02T11:42:54","slug":"udobnye-arhitekturnye-patterny","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sq\/blog\/administrirovanie\/udobnye-arhitekturnye-patterny","title":{"rendered":"Modelet arkitekturore t\u00eb p\u00ebrshtatshme","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

P\u00ebrsh\u00ebndetje, Habr!<\/p>\n

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N\u00eb drit\u00ebn e ngjarjeve aktuale p\u00ebr shkak t\u00eb koronavirusit, disa sh\u00ebrbime n\u00eb internet kan\u00eb filluar t\u00eb p\u00ebrballen me ngarkesa t\u00eb shtuar. P\u00ebr shembull, nj\u00eb nga rrjetet tregtare n\u00eb Britanin\u00eb e Madhe thjesht e ndali faqen me porosit\u00eb online<\/a><\/noindex>, sepse nuk kishte mjaft kapacitete. Dhe jo gjithmon\u00eb \u00ebsht\u00eb e mundur t\u00eb shpejtohet serveri thjesht duke shtuar pajisje m\u00eb t\u00eb fuqishme, megjithat\u00eb k\u00ebrkesat e klient\u00ebve duhet t\u00eb p\u00ebrpunohen (ose ata do t\u00eb ikin tek konkurrencat).<\/p>\n

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N\u00eb k\u00ebt\u00eb artikull do t'ju tregoj shkurtimisht p\u00ebr praktikat e njohura q\u00eb do t\u00eb lejojn\u00eb krijimin e nj\u00eb sh\u00ebrbimi t\u00eb shpejt\u00eb dhe t\u00eb q\u00ebndruesh\u00ebm. Megjithat\u00eb, nga format e mundshme t\u00eb zhvillimit kam p\u00ebrzgjedhur vet\u00ebm ato me t\u00eb cilat \u00ebsht\u00eb leht\u00eb t\u00eb p\u00ebrdoren<\/strong>. P\u00ebr \u00e7do pik\u00eb, ju tashm\u00eb keni biblioteka t\u00eb gatshme ose keni mund\u00ebsin\u00eb t\u00eb zgjidhni problemin p\u00ebrmes nj\u00eb platforme n\u00eb re.<\/p>\n

<\/a><\/noindex><\/p>\n

Shkall\u00ebzim horizontal<\/h1>\n

<\/p>\n

Nj\u00eb nga pikat m\u00eb t\u00eb thjeshta dhe t\u00eb njohura. N\u00eb m\u00ebnyr\u00eb kategorizuese, zakonisht ndodhin dy skema t\u00eb shp\u00ebrndarjes s\u00eb ngarkes\u00ebs\u2014shkall\u00ebzimi horizontal dhe vertikal. N\u00eb rastin e par\u00eb<\/a><\/noindex> ju lejoni sh\u00ebrbimet t\u00eb punojn\u00eb paralelisht, duke shp\u00ebrndar\u00eb k\u00ebshtu ngarkes\u00ebn midis tyre. N\u00eb t\u00eb dytin<\/a><\/noindex> ju porositni servera m\u00eb t\u00eb fuqish\u00ebm ose optimizoni kodin.<\/p>\n

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P\u00ebr shembull, do t\u00eb marr nj\u00eb ruajtje t\u00eb till\u00eb abstrakte t\u00eb skedar\u00ebve n\u00eb re, pra nj\u00eb analog t\u00eb OwnCloud, OneDrive dhe k\u00ebshtu me radh\u00eb.<\/p>\n

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Imazhi standard i nj\u00eb skeme t\u00eb till\u00eb \u00ebsht\u00eb m\u00eb posht\u00eb, megjithat\u00eb ajo tregon vet\u00ebm kompleksitetin e sistemit. Sepse duhet t\u00eb sinkronizojm\u00eb ndonj\u00ebher\u00eb sh\u00ebrbimet. \u00c7far\u00eb do t\u00eb ndodh\u00eb n\u00ebse nj\u00eb p\u00ebrdorues ruan nj\u00eb skedar nga tableti dhe m\u00eb pas d\u00ebshiron ta shikoj\u00eb at\u00eb nga telefoni?<\/p>\n

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\"Modelet
\nDallimi midis qasjeve: n\u00eb shkall\u00ebzimin vertikal ne jemi t\u00eb gatsh\u00ebm t\u00eb rrisim fuqin\u00eb e nyjeve, nd\u00ebrsa n\u00eb at\u00eb horizontal\u2014t\u00eb shtojm\u00eb nyje t\u00eb reja p\u00ebr t\u00eb shp\u00ebrndar\u00eb ngarkes\u00ebn.<\/p>\n

<\/p>\n

CQRS<\/h1>\n

<\/p>\n

Command Query Responsibility Segregation<\/a><\/noindex> \u00ebsht\u00eb nj\u00eb model mjaft i r\u00ebnd\u00ebsish\u00ebm, pasi ndihmon klient\u00ebt e ndrysh\u00ebm t\u00eb lidhen me sh\u00ebrbime t\u00eb ndryshme dhe gjithashtu t\u00eb marrin t\u00eb nj\u00ebjtat rrjedha ngjarjesh. Avantazhet e tij nuk jan\u00eb aq t\u00eb dukshme p\u00ebr nj\u00eb aplikacion t\u00eb thjesht\u00eb, megjithat\u00eb ai \u00ebsht\u00eb jasht\u00ebzakonisht i r\u00ebnd\u00ebsish\u00ebm (dhe i thjesht\u00eb) p\u00ebr nj\u00eb sh\u00ebrbim t\u00eb ngarkuar. Pika e tij thelb\u00ebsore: rrjedhat hyr\u00ebse dhe dal\u00ebse t\u00eb t\u00eb dh\u00ebnave nuk duhet t\u00eb nd\u00ebrthuren. K\u00ebshtu q\u00eb nuk mund t\u00eb d\u00ebrgoni nj\u00eb k\u00ebrkes\u00eb dhe t\u00eb prisni nj\u00eb p\u00ebrgjigje, p\u00ebrkundrazi, ju d\u00ebrgoni nj\u00eb k\u00ebrkes\u00eb n\u00eb sh\u00ebrbimin A, por merrni p\u00ebrgjigjen n\u00eb sh\u00ebrbimin B.<\/p>\n

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Bonusi i par\u00eb i k\u00ebtij qasje \u00ebsht\u00eb mund\u00ebsia e nd\u00ebrprerjes s\u00eb lidhjes (n\u00eb kuptimin e gjer\u00eb t\u00eb k\u00ebsaj fjale) gjat\u00eb realizimit t\u00eb nj\u00eb k\u00ebrkese t\u00eb gjat\u00eb. Si nj\u00eb shembull, le t\u00eb marrim nj\u00eb sekuenc\u00eb m\u00eb shum\u00eb-m\u00eb pak standarde:<\/p>\n

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    \n
  1. Klienti d\u00ebrgoi nj\u00eb k\u00ebrkes\u00eb n\u00eb server.<\/li>\n
  2. Serveri filloi p\u00ebrpunimin e gjat\u00eb.<\/li>\n
  3. Serveri iu p\u00ebrgjigj klientit me rezultatin.<\/li>\n<\/ol>\n

    <\/p>\n

    Imagjinoni se n\u00eb pik\u00ebn 2 ndodhi nj\u00eb nd\u00ebrprerje e lidhjes (ose rrjeti u rivendos, ose p\u00ebrdoruesi kaloi n\u00eb nj\u00eb faqe tjet\u00ebr, duke nd\u00ebrprer\u00eb lidhjen). N\u00eb k\u00ebt\u00eb rast, serverit do t\u2019i jet\u00eb e v\u00ebshtir\u00eb t\u00eb d\u00ebrgoj\u00eb nj\u00eb p\u00ebrgjigje p\u00ebrdoruesit me informacionin se \u00e7far\u00eb u procesua. Duke aplikuar CQRS, sekuenca do t\u00eb jet\u00eb pak m\u00eb ndryshe:<\/p>\n

    <\/p>\n

      \n
    1. Klienti u regjistrua p\u00ebr p\u00ebrdit\u00ebsime.<\/li>\n
    2. Klienti d\u00ebrgoi nj\u00eb k\u00ebrkes\u00eb n\u00eb server.<\/li>\n
    3. Serveri iu p\u00ebrgjigj: \"k\u00ebrkesa u pranua\".<\/li>\n
    4. Serveri iu p\u00ebrgjigj me rezultatin n\u00ebp\u00ebrmjet kanalit t\u00eb pik\u00ebs \"1\".<\/li>\n<\/ol>\n

      <\/p>\n

      \"Modelet<\/p>\n

      <\/p>\n

      Si\u00e7 shihet, skema \u00ebsht\u00eb pak m\u00eb e komplikuar. M\u00eb shum\u00eb se kaq, qasja intuitive k\u00ebrkes\u00eb-p\u00ebrgjigje k\u00ebtu mungon. Megjithat\u00eb, si\u00e7 shihet, nd\u00ebrprerja e lidhjes gjat\u00eb p\u00ebrpunimit t\u00eb k\u00ebrkes\u00ebs nuk do t\u00eb shkaktoj\u00eb nj\u00eb gabim. P\u00ebr m\u00eb tep\u00ebr, n\u00ebse p\u00ebrdoruesi \u00ebsht\u00eb n\u00eb t\u00eb v\u00ebrtet\u00eb i lidhur me sh\u00ebrbimin nga disa pajisje (p\u00ebr shembull, nga telefoni celular dhe nga tableta), \u00ebsht\u00eb e mundur t\u00eb b\u00ebhet q\u00eb p\u00ebrgjigja t\u00eb vij\u00eb n\u00eb t\u00eb dy pajisjet.<\/p>\n

      <\/p>\n

      E ve\u00e7anta \u00ebsht\u00eb se kodi p\u00ebr p\u00ebrpunimin e mesazheve t\u00eb ardhshme b\u00ebhet i nj\u00ebjt\u00eb (jo 100%) si p\u00ebr ngjarjet q\u00eb ndikon vet\u00eb klienti, ashtu edhe p\u00ebr ngjarjet e tjera, duke p\u00ebrfshir\u00eb ato nga klient\u00eb t\u00eb tjer\u00eb.<\/p>\n

      <\/p>\n

      Megjithat\u00eb, n\u00eb realitet, ne marrim bonuset e tjera q\u00eb lidhen me faktin se rrjedha nj\u00ebkah\u00ebshe mund t\u00eb p\u00ebrpunohet n\u00eb stilin funksional (duke p\u00ebrdorur RX dhe analoge). Dhe kjo \u00ebsht\u00eb nj\u00eb p\u00ebrfitim serioz, sepse n\u00eb thelb aplikacioni mund t\u00eb b\u00ebhet plot\u00ebsisht reaktiv, madje duke p\u00ebrdorur qasjen funksionale. P\u00ebr programet e m\u00ebdha, kjo mund t\u00eb kursej\u00eb ndjesh\u00ebm burimet p\u00ebr zhvillim dhe mb\u00ebshtetje.<\/p>\n

      <\/p>\n

      N\u00ebse e bashkojm\u00eb k\u00ebt\u00eb qasje me shkall\u00ebzimin horizontal, at\u00ebher\u00eb kemi mund\u00ebsin\u00eb p\u00ebr t\u00eb d\u00ebrguar k\u00ebrkesa n\u00eb nj\u00eb server, nd\u00ebrsa t\u00eb marrim p\u00ebrgjigje nga nj\u00eb tjet\u00ebr. K\u00ebshtu, klienti mund t\u00eb zgjedh\u00eb sh\u00ebrbimin q\u00eb i p\u00ebrshtatet m\u00eb mir\u00eb, nd\u00ebrsa sistemi brenda do t\u00eb jet\u00eb ende n\u00eb gjendje t\u00eb procesoj\u00eb ngjarjet n\u00eb m\u00ebnyr\u00eb korrekte.<\/p>\n

      <\/p>\n

      Event Sourcing<\/h1>\n

      <\/p>\n

      Si keni, nj\u00eb nga karakteristikat kryesore t\u00eb nj\u00eb sistemi t\u00eb shp\u00ebrndar\u00eb \u00ebsht\u00eb mungesa e nj\u00eb kohe t\u00eb p\u00ebrbashk\u00ebt, nj\u00eb seksioni kritik t\u00eb p\u00ebrbashk\u00ebt. P\u00ebr nj\u00eb proces, mund t\u00eb b\u00ebni sinkronizimin (n\u00eb t\u00eb nj\u00ebjtat mutex), brenda t\u00eb cilit jeni t\u00eb sigurt se askush tjet\u00ebr nuk po ekzekuton k\u00ebt\u00eb kod. Megjithat\u00eb, p\u00ebr nj\u00eb sistem t\u00eb shp\u00ebrndar\u00eb, di\u00e7ka e till\u00eb \u00ebsht\u00eb e rrezikshme, pasi do t\u00eb k\u00ebrkohen kostot shtes\u00eb, dhe gjithashtu do t\u00eb d\u00ebmtohet e gjith\u00eb bukuria e shkall\u00ebzimit - gjithsesi t\u00eb gjith\u00eb komponent\u00ebt do t\u00eb pretendojn\u00eb nj\u00eb gj\u00eb.<\/p>\n

      <\/p>\n

      Nga k\u00ebtu marrim nj\u00eb fakt t\u00eb r\u00ebnd\u00ebsish\u00ebm - nj\u00eb sistem t\u00eb shp\u00ebrndar\u00eb t\u00eb shpejt\u00eb nuk mund t\u00eb sinkronizohet, sepse ndryshe do t\u00eb zvog\u00eblojm\u00eb performanc\u00ebn. Nga ana tjet\u00ebr, shpesh na nevojitet nj\u00eb konsistenc\u00eb e caktuar e komponent\u00ebve. Dhe p\u00ebr k\u00ebt\u00eb mund t\u00eb p\u00ebrdorim qasjen me konsistenc\u00eb eventuale<\/a><\/noindex>, ku garanton se n\u00eb munges\u00eb t\u00eb ndryshimeve t\u00eb t\u00eb dh\u00ebnave p\u00ebrmes nj\u00eb periudhe t\u00eb caktuar kohe pas p\u00ebrdit\u00ebsimit t\u00eb fundit (\u201cn\u00eb fund t\u00eb fundit\u201d) t\u00eb gjith\u00eb k\u00ebrkesat do t\u00eb kthejn\u00eb vler\u00ebn e fundit t\u00eb p\u00ebrdit\u00ebsuar.<\/p>\n

      <\/p>\n

      \u00cbsht\u00eb e r\u00ebnd\u00ebsishme t\u00eb kuptohet se p\u00ebr bazat e t\u00eb dh\u00ebnave klasike aplikohet mjaft shpesh konsistenca e rrept\u00eb<\/a><\/noindex>, ku \u00e7do nyje zot\u00ebron t\u00eb nj\u00ebjtat informacione (kjo shpesh arrihet kur nj\u00eb transaksion konsiderohet i vendosur vet\u00ebm pas p\u00ebrgjigjes nga serveri i dyt\u00eb). K\u00ebtu ka disa leht\u00ebsira p\u00ebr shkak t\u00eb niveleve t\u00eb izolimit, megjithat\u00eb thelbi i p\u00ebrgjithsh\u00ebm mbetet i nj\u00ebjt\u00eb - mund t\u00eb jetoni n\u00eb nj\u00eb bot\u00eb plot\u00ebsisht t\u00eb konsoliduar.<\/p>\n

      <\/p>\n

      Megjithat\u00eb, le t\u00eb kthehemi n\u00eb detyr\u00ebn fillestare. N\u00ebse nj\u00eb pjes\u00eb e sistemit mund t\u00eb nd\u00ebrtohet me konsistenc\u00eb eventuale<\/a><\/noindex>, at\u00ebher\u00eb mund t\u00eb nd\u00ebrtojm\u00eb skem\u00ebn e m\u00ebposhtme.<\/p>\n

      <\/p>\n

      \"Modelet<\/p>\n

      <\/p>\n

      Karakteristikat e r\u00ebnd\u00ebsishme t\u00eb k\u00ebtij Qasjeje:<\/p>\n

      <\/p>\n