{"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 arkitektonike 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 coronavirusit, nj\u00eb s\u00ebr\u00eb sh\u00ebrbimesh interneti ka filluar t\u00eb p\u00ebrjetoj\u00eb nj\u00eb ngarkes\u00eb t\u00eb rritur. P\u00ebr shembull, nj\u00eb nga rrjetet tregtare n\u00eb Mbret\u00ebrin\u00eb e Bashkuar sapo ndali faqen e saj me porosi online<\/a><\/noindex>, pasi nuk kishte kapacitete t\u00eb mjaftueshme. Dhe nuk \u00ebsht\u00eb gjithmon\u00eb e mundur t\u00eb p\u00ebrshpejtohet serveri thjesht duke shtuar pajisje m\u00eb t\u00eb fuqishme, por duhen trajtuar k\u00ebrkesat e klient\u00ebve (ndryshe ata do t\u00eb kalojn\u00eb te konkurrent\u00ebt).<\/p>\n

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N\u00eb k\u00ebt\u00eb artikull, do t\u00eb flas 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 besuesh\u00ebm. Megjithat\u00eb, nga skemat e mundshme t\u00eb zhvillimit, kam zgjedhur vet\u00ebm ato q\u00eb tani jan\u00eb leht\u00ebsisht t\u00eb p\u00ebrdorshme<\/strong>. P\u00ebr secil\u00ebn pik\u00eb, ju ose keni biblioteka t\u00eb gatshme, ose keni mund\u00ebsin\u00eb t\u00eb zgjidhni detyr\u00ebn p\u00ebrmes nj\u00eb platforme cloud.<\/p>\n

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

Zgjerimi horizontal<\/h1>\n

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Pika m\u00eb e thjesht\u00eb dhe m\u00eb e njohur. N\u00eb m\u00ebnyr\u00eb t\u00eb p\u00ebrgjithshme, dy skema m\u00eb t\u00eb zakonshme t\u00eb shp\u00ebrndarjes s\u00eb ngarkes\u00ebs jan\u00eb: horizontal dhe vertikal. N\u00eb rastin e par\u00eb<\/a><\/noindex> ju lejoni sh\u00ebrbimet t\u00eb funksionojn\u00eb paralelisht, duke shp\u00ebrndar\u00eb ngarkes\u00ebn midis tyre. N\u00eb t\u00eb dytin<\/a><\/noindex> ju porosisni server\u00eb 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 paqart\u00eb cloud, pra nj\u00eb disa analogji t\u00eb OwnCloud, OneDrive dhe k\u00ebshtu me radh\u00eb.<\/p>\n

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Pamja standarde e nj\u00eb skeme t\u00eb till\u00eb \u00ebsht\u00eb m\u00eb posht\u00eb, megjithat\u00eb ajo thjesht demonstruar kompleksitetin e sistemit. Sepse na nevojitet 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 pastaj do ta shikoj\u00eb at\u00eb nga telefoni?<\/p>\n

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\"Modelet
\nDallimi midis qasjeve: n\u00eb shkall\u00ebzimin vertikal jemi t\u00eb gatsh\u00ebm t\u00eb rrisim kapacitetet e nyjeve, nd\u00ebrsa n\u00eb at\u00eb horizontal \u2014 shtojm\u00eb nyje t\u00eb reja p\u00ebr t\u00eb shp\u00ebrndar\u00eb ngarkes\u00ebn.<\/p>\n

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CQRS<\/h1>\n

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Segregimi i P\u00ebrgjegj\u00ebsive t\u00eb K\u00ebrkes\u00eb dhe K\u00ebrkes\u00ebs<\/a><\/noindex> \u00ebsht\u00eb nj\u00eb model quite i r\u00ebnd\u00ebsish\u00ebm, pasi i lejon klient\u00ebve t\u00eb ndrysh\u00ebm jo vet\u00ebm t\u00eb lidhen me sh\u00ebrbime t\u00eb ndryshme, por edhe t\u00eb marrin rrjedha ngjarjesh identike. Benefitet 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 e r\u00ebnd\u00ebsishme (dhe e thjesht\u00eb) p\u00ebr nj\u00eb sh\u00ebrbim t\u00eb ngarkuar. Thelbi i tij: rrjedhat e dh\u00ebnave hyr\u00ebse dhe dal\u00ebse nuk duhet t\u00eb kalojn\u00eb. K\u00ebshtu, nuk mund t\u00eb d\u00ebrgoni nj\u00eb k\u00ebrkes\u00eb dhe t\u00eb prisni nj\u00eb p\u00ebrgjigje, p\u00ebrkundrazi d\u00ebrgoni nj\u00eb k\u00ebrkes\u00eb n\u00eb sh\u00ebrbimin A, megjithat\u00eb merrni p\u00ebrgjigjen n\u00eb sh\u00ebrbimin B.<\/p>\n

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Benefiti i par\u00eb i k\u00ebsaj qasje \u00ebsht\u00eb mund\u00ebsia e nd\u00ebrprerjes s\u00eb lidhjes (n\u00eb kuptimin e gjer\u00eb t\u00eb fjal\u00ebs) gjat\u00eb kryerjes s\u00eb nj\u00eb k\u00ebrkese t\u00eb gjat\u00eb. P\u00ebr shembull, le t\u00eb marrim nj\u00eb renditje m\u00eb se standarde:<\/p>\n

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    \n
  1. Klienti d\u00ebrgoi nj\u00eb k\u00ebrkes\u00eb n\u00eb server.<\/li>\n
  2. Serveri nisi nj\u00eb p\u00ebrpunim t\u00eb 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 rikonektua, ose p\u00ebrdoruesi kaloi n\u00eb nj\u00eb tjet\u00ebr faqe, duke shk\u00ebputur lidhjen). N\u00eb k\u00ebt\u00eb rast serverit do t'i ishte e v\u00ebshtir\u00eb t\u00eb d\u00ebrgonte p\u00ebrgjigjen te p\u00ebrdoruesi me informacionin se \u00e7far\u00eb u p\u00ebrpunua. Duke aplikuar CQRS, renditja do t\u00eb ishte paksa ndryshe:<\/p>\n

    <\/p>\n

      \n
    1. Klienti u abonua 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 e pranuar\".<\/li>\n
    4. Serveri iu p\u00ebrgjigj rezultatit p\u00ebrmes kanalit nga \"1\".<\/li>\n<\/ol>\n

      <\/p>\n

      \"Modelet<\/p>\n

      <\/p>\n

      Si\u00e7 tregohet, skema \u00ebsht\u00eb paksa m\u00eb e komplikuar. M\u00eb shum\u00eb se kaq, qasja intuitiv\u00eb e k\u00ebrkes\u00ebs dhe p\u00ebrgjigjes k\u00ebtu mungon. Megjithat\u00eb si\u00e7 duket, nd\u00ebrprerja e lidhjes gjat\u00eb p\u00ebrpunimit t\u00eb k\u00ebrkes\u00ebs nuk do t\u00eb sjell\u00eb gabim. M\u00eb tep\u00ebr, n\u00ebse p\u00ebrdoruesi n\u00eb t\u00eb v\u00ebrtet\u00eb \u00ebsht\u00eb i lidhur me sh\u00ebrbimin nga disa pajisje (p\u00ebr shembull, nga telefoni celular dhe nga tableti), \u00ebsht\u00eb e mundur q\u00eb p\u00ebrgjigja t\u00eb vij\u00eb n\u00eb t\u00eb dy pajisjet.<\/p>\n

      <\/p>\n

      Ajo q\u00eb \u00ebsht\u00eb interesante \u00ebsht\u00eb se kodi i p\u00ebrpunimit t\u00eb mesazheve hyr\u00ebse b\u00ebhet i nj\u00ebjt\u00eb (jo 100%) si p\u00ebr ngjarjet q\u00eb ndikuan vet\u00eb klientin, ashtu edhe p\u00ebr ngjarjet e tjera, duke p\u00ebrfshir\u00eb ato nga klient\u00eb t\u00eb tjer\u00eb.<\/p>\n

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      Megjithat\u00eb n\u00eb realitet ne marrim p\u00ebrfitime t\u00eb tjera fal\u00eb faktit se rrjedha nj\u00ebkah\u00ebshe mund t\u00eb p\u00ebrpunohet n\u00eb stilin funksional (duke p\u00ebrdorur RX dhe analog\u00eb). Dhe kjo \u00ebsht\u00eb nj\u00eb p\u00ebrfitim i r\u00ebnd\u00ebsish\u00ebm, sepse n\u00eb fakt aplikacioni mund t\u00eb b\u00ebhet krejt\u00ebsisht reaktiv, madje edhe me p\u00ebrdorimin e qasjeve funksionale. P\u00ebr aplikacione t\u00eb dhjamosura, kjo mund t\u00eb ndihmoj\u00eb ndjesh\u00ebm n\u00eb kursimin e burimeve n\u00eb zhvillim dhe mb\u00ebshtetje.<\/p>\n

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      N\u00ebse e kombinosh k\u00ebt\u00eb qasje me shkall\u00ebzimin horizontal, at\u00ebher\u00eb si bonus ne fitojm\u00eb mund\u00ebsin\u00eb p\u00ebr t\u00eb d\u00ebrguar k\u00ebrkesa n\u00eb nj\u00eb server dhe p\u00ebr t\u00eb marr\u00eb p\u00ebrgjigje nga nj\u00eb tjet\u00ebr. N\u00eb k\u00ebt\u00eb m\u00ebnyr\u00eb, klienti mund t\u00eb zgjedh\u00eb sh\u00ebrbimin q\u00eb i p\u00ebrshtatet m\u00eb mir\u00eb, nd\u00ebrsa sistemi brenda mund t\u00eb trajtoj\u00eb ngjarjet n\u00eb m\u00ebnyr\u00eb t\u00eb sakt\u00eb.<\/p>\n

      <\/p>\n

      Event Sourcing<\/h1>\n

      <\/p>\n

      Si e dini, nj\u00eb nga tiparet 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 realizoni sinkronizimin (n\u00eb t\u00eb nj\u00ebjtat mutex), brenda t\u00eb cilit jeni t\u00eb sigurt se askush tjet\u00ebr nuk po e 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, sepse do t\u00eb k\u00ebrkonte shpenzime t\u00eb larta, si dhe do t\u00eb shkat\u00ebrronte gjith\u00eb bukurin\u00eb e shkall\u00ebzimit - megjithat\u00eb t\u00eb gjith\u00eb komponent\u00ebt do t\u00eb prisnin nj\u00ebri-tjetrin.<\/p>\n

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      Nga kjo nxjerrim 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 at\u00ebher\u00eb ne do t\u00eb reduktojm\u00eb performanc\u00ebn. N\u00eb an\u00ebn tjet\u00ebr, shpesh na nevojitet nj\u00eb koherenc\u00eb e caktuar e komponent\u00ebve. Dhe p\u00ebr k\u00ebt\u00eb mund t\u00eb p\u00ebrdorim qasjen me konsistenc\u00eb t\u00eb p\u00ebrhershme<\/a><\/noindex>, ku garanton se n\u00eb munges\u00eb t\u00eb ndryshimeve t\u00eb t\u00eb dh\u00ebnave pas nj\u00eb periudhe t\u00eb caktuar kohe pas azhurnimit t\u00eb fundit (\"fundit\") t\u00eb gjitha k\u00ebrkesat do t\u00eb kthjellin vler\u00ebn e fundit t\u00eb azhurnuar.<\/p>\n

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      \u00cbsht\u00eb e r\u00ebnd\u00ebsishme t\u00eb kuptohet se p\u00ebr bazat e t\u00eb dh\u00ebnave klasike shpesh aplikohet koherenca strikte<\/a><\/noindex>, ku \u00e7do nyje ka 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 mbetet i nj\u00ebjt\u00eb - mund t\u00eb jetoni n\u00eb nj\u00eb bot\u00eb t\u00eb plot\u00eb t\u00eb koherenc\u00ebs.<\/p>\n

      <\/p>\n

      Megjithat\u00eb, le t\u00eb kthehemi te detyra e fillimit. N\u00ebse nj\u00eb pjes\u00eb e sistemit mund t\u00eb nd\u00ebrtohet me konsistenc\u00eb t\u00eb p\u00ebrhershme<\/a><\/noindex>, at\u00ebher\u00eb mund t\u00eb nd\u00ebrtohet skema e m\u00ebposhtme.<\/p>\n

      <\/p>\n

      \"Modelet<\/p>\n

      <\/p>\n

      Ve\u00e7orit\u00eb e r\u00ebnd\u00ebsishme t\u00eb k\u00ebsaj qasje jan\u00eb:<\/p>\n

      <\/p>\n