{"id":71858,"date":"2020-02-28T21:00:08","date_gmt":"2020-02-28T18:00:08","guid":{"rendered":"https:\/\/prohoster.info\/blog\/patterny-hraneniya-dannyh-v-kubernetes"},"modified":"2020-03-03T16:14:09","modified_gmt":"2020-03-03T13:14:09","slug":"patterny-hraneniya-dannyh-v-kubernetes","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sq\/blog\/administrirovanie\/patterny-hraneniya-dannyh-v-kubernetes","title":{"rendered":"Modelet e ruajtjes s\u00eb t\u00eb dh\u00ebnave n\u00eb Kubernetes","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

\"Modelet<\/a><\/noindex>
\nP\u00ebrsh\u00ebndetje, Habr!<\/p>\n

Ju kujtojm\u00eb se kemi publikuar nj\u00eb tjet\u00ebr artikull tep\u00ebr interesant dhe t\u00eb dobish\u00ebm lib\u00ebr<\/a><\/noindex> p\u00ebr modelet Kubernetes. E gjith\u00e7ka filloi me \"Modelet<\/a><\/noindex>\" Brendan Burns, dhe, megjithat\u00eb, puna n\u00eb k\u00ebt\u00eb segment p\u00ebr ne n\u00eb zhvillim<\/a><\/noindex>. Sot, ne ju ofrojm\u00eb t\u00eb lexoni nj\u00eb artikull nga blogu MinIO, i cili paraqet shkurtimisht tendencat dhe specifikat e modeleve t\u00eb ruajtjes s\u00eb t\u00eb dh\u00ebnave n\u00eb Kubernetes.
\n<\/a><\/noindex><\/p>\n

Kubernetes ka ndryshuar n\u00eb m\u00ebnyr\u00eb themelore modelet tradicionale t\u00eb zhvillimit dhe implementimit t\u00eb aplikacioneve. Tani ekipi mund t\u00eb shpenzoj\u00eb vet\u00ebm disa dit\u00eb p\u00ebr t\u00eb zhvilluar, testuar dhe implementuar nj\u00eb aplikacion \u2013 n\u00eb mjedise t\u00eb ndryshme, dhe gjith\u00e7ka brenda klastereve Kubernetes. Puna me teknologjit\u00eb e brezave t\u00eb kaluar zakonisht merrte jav\u00eb t\u00eb t\u00ebra, n\u00ebse jo muaj.<\/p>\n

Ky p\u00ebrshpejtim \u00ebsht\u00eb b\u00ebr\u00eb i mundur fal\u00eb abstraksionit q\u00eb ofron Kubernetes \u2014 dmth, fal\u00eb faktit se Kubernetes nd\u00ebrvepron me detalet e ul\u00ebta t\u00eb pajisjeve fizike ose virtuale, duke lejuar p\u00ebrdoruesit t\u00eb shpallin, p\u00ebrve\u00e7 parametrave t\u00eb tjer\u00eb, procesorin e nevojsh\u00ebm, sasin\u00eb e kujtes\u00ebs, numrin e instancave t\u00eb kontejner\u00ebve. Duke qen\u00eb se nj\u00eb komunitet i madh \u00ebsht\u00eb i angazhuar n\u00eb mb\u00ebshtetje t\u00eb Kubernetes dhe shkalla e p\u00ebrdorimit t\u00eb Kubernetes vazhdon t\u00eb zgjerohet, ai \u00ebsht\u00eb n\u00eb m\u00ebnyr\u00eb t\u00eb dukshme lider n\u00eb mesin e t\u00eb gjitha platformave t\u00eb orkestrimit t\u00eb kontejner\u00ebve.<\/p>\n

Me rritjen e p\u00ebrdorimit t\u00eb Kubernetes, rritet edhe konfuzioni n\u00eb lidhje me modelet e ruajtjes s\u00eb t\u00eb dh\u00ebnave t\u00eb aplikuara atje.<\/b><\/i>.<\/p>\n

Me gjith\u00eb konkurrenc\u00ebn p\u00ebr nj\u00eb cop\u00eb t\u00eb tort\u00ebs Kubernetes (dmth, p\u00ebr ruajtjen e t\u00eb dh\u00ebnave), kur b\u00ebhet fjal\u00eb p\u00ebr ruajtjen e t\u00eb dh\u00ebnave, sinjali k\u00ebtu humbet n\u00eb nj\u00eb zhurm\u00eb t\u00eb madhe.
\nKubernetes p\u00ebrmbush modelin modern t\u00eb zhvillimit dhe implementimit t\u00eb aplikacioneve, si dhe menaxhimin e tyre. Ky model modern ndan ruajtjen e t\u00eb dh\u00ebnave nga llogaritjet. P\u00ebr t\u00eb kuptuar plot\u00ebsisht k\u00ebt\u00eb ndarje n\u00eb kontekstin e Kubernetes, \u00ebsht\u00eb e nevojshme gjithashtu t\u00eb kuptohet se \u00e7far\u00eb p\u00ebrfaq\u00ebsojn\u00eb aplikacionet me ruajtje gjendjeje dhe pa ruajtje gjendjeje, si dhe se si lidhen kjo me ruajtjen e t\u00eb dh\u00ebnave. K\u00ebtu \u00ebsht\u00eb vendi ku qasja REST API e aplikuar nga S3 ka avantazhe t\u00eb qarta krahasuar me qasjen POSIX\/CSI, tipike p\u00ebr zgjidhjet e tjera.<\/p>\n

N\u00eb k\u00ebt\u00eb artikull do t\u00eb flasim p\u00ebr modelet e ruajtjes s\u00eb t\u00eb dh\u00ebnave n\u00eb Kubernetes dhe do t\u00eb trajtojm\u00eb ve\u00e7mas debatin n\u00eb lidhje me aplikacionet q\u00eb punojn\u00eb me gjendje dhe pa gjendje, p\u00ebr t\u00eb kuptuar sakt\u00ebsisht se \u00e7far\u00eb p\u00ebrb\u00ebn dallimin mes tyre dhe pse \u00ebsht\u00eb i r\u00ebnd\u00ebsish\u00ebm. M\u00eb tej, do t\u00eb shqyrtohen aplikacionet dhe modelet e ruajtjes s\u00eb t\u00eb dh\u00ebnave q\u00eb p\u00ebrdoren n\u00eb to n\u00eb drit\u00ebn e praktikave m\u00eb t\u00eb mira t\u00eb pun\u00ebs me kontejner\u00ebt dhe Kubernetes.<\/p>\n

Kontejner\u00eb pa gjendje<\/h4>\n

\nKontejner\u00ebt natyrsh\u00ebm jan\u00eb t\u00eb leht\u00eb dhe efemer. Ata mund t\u00eb ndalen, hiqen ose vendosen pa mundim n\u00eb nj\u00eb nod tjet\u00ebr - t\u00eb gjitha k\u00ebto k\u00ebrkojn\u00eb vet\u00ebm disa sekonda. N\u00eb nj\u00eb sistem t\u00eb madh orkestrimi t\u00eb kontejner\u00ebve, k\u00ebto operacione ndodhin vazhdimisht dhe p\u00ebrdoruesit nuk e v\u00ebrejn\u00eb asnj\u00ebher\u00eb k\u00ebto ndryshime. Megjithat\u00eb, l\u00ebvizjet jan\u00eb t\u00eb mundshme vet\u00ebm n\u00ebse kontenieri nuk ka asnj\u00eb var\u00ebsi nga nodi n\u00eb t\u00eb cilin ndodhet. P\u00ebr k\u00ebta kontejner\u00eb thuhet se ata punojn\u00eb pa gjendje<\/i>.<\/p>\n

Kontejner\u00eb me gjendje<\/h4>\n

\nN\u00ebse nj\u00eb kontenier ruan t\u00eb dh\u00ebna n\u00eb pajisje t\u00eb lidhura lokalisht (ose n\u00eb nj\u00eb pajisje bllok), at\u00ebher\u00eb ruajtja e t\u00eb dh\u00ebnave, n\u00eb t\u00eb cil\u00ebn ndodhet, do t\u00eb duhet t\u00eb l\u00ebvizi n\u00eb nj\u00eb nod t\u00eb ri s\u00eb bashku me vet\u00eb kontenierin - n\u00eb rast se ndodh nj\u00eb d\u00ebshtim. Kjo \u00ebsht\u00eb e r\u00ebnd\u00ebsishme, sepse n\u00eb t\u00eb kund\u00ebrt aplikacioni q\u00eb ekzekutohet n\u00eb kontenier nuk do t\u00eb funksionoj\u00eb si\u00e7 duhet, pasi i nevojitet t\u00eb aksesoj\u00eb t\u00eb dh\u00ebnat e ruajtura n\u00eb m\u00e9dhjet lokale. P\u00ebr k\u00ebta kontejner\u00eb thuhet se ata punojn\u00eb me gjendje<\/i>.<\/p>\n

Nga nj\u00eb k\u00ebndv\u00ebshtrim t\u00ebr\u00ebsor teknik, kontejner\u00ebt me gjendje gjithashtu mund t\u00eb l\u00ebvizin n\u00eb nod t\u00eb tjer\u00eb. Kjo zakonisht sigurohet p\u00ebrmes sistemeve t\u00eb shp\u00ebrndara t\u00eb skedar\u00ebve ose ruajtjeve t\u00eb dh\u00ebnash t\u00eb lidhura me rrjet t\u00eb bllokut, t\u00eb cilat jan\u00eb t\u00eb lidhura me t\u00eb gjith\u00eb nodet ku punojn\u00eb kontejner\u00ebt. K\u00ebshtu, kontejner\u00ebt aksesojn\u00eb volumin p\u00ebr ruajtjen e q\u00ebndrueshme t\u00eb t\u00eb dh\u00ebnave, dhe informacioni ruhet n\u00eb disqe q\u00eb ndodhen n\u00eb t\u00eb gjith\u00eb rrjetin. Ky metod\u00eb un\u00eb do ta quaj \"p\u00ebrqasje konteinerike me gjendje<\/i>\", dhe n\u00eb pjes\u00ebn tjet\u00ebr t\u00eb artikullit do ta quaj ashtu p\u00ebr shkak t\u00eb uniformitetit.<\/p>\n

\"Modelet
\n
\nMe qasja tipike me kontejner\u00eb q\u00eb ruajn\u00eb gjendjen, t\u00eb gjitha pods e aplikacioneve lidhen me nj\u00eb sistem t\u00eb shp\u00ebrndar\u00eb skedar\u00ebsh - duke krijuar nj\u00eb lloj ruajtjeje t\u00eb p\u00ebrbashk\u00ebt, ku gjenden t\u00eb dh\u00ebnat e t\u00eb gjitha aplikacioneve. Megjith\u00ebse mund t\u00eb ket\u00eb disa variacione, ky \u00ebsht\u00eb nj\u00eb qasje me nivel t\u00eb lart\u00eb.<\/p>\n

Tani le t\u00eb shqyrtojm\u00eb se pse qasja me kontejner\u00eb q\u00eb ruajn\u00eb gjendjen n\u00eb bot\u00ebn e orientuar drejt cloud-it \u00ebsht\u00eb nj\u00eb antipattern.<\/p>\n

Projektimi i aplikacioneve t\u00eb orientuara drejt cloud-it<\/h4>\n

\nTradicionalisht, aplikacionet p\u00ebrdornin bazat e t\u00eb dh\u00ebnave p\u00ebr ruajtjen e strukturuar t\u00eb informacionit dhe disqet lokale ose sistemet e shp\u00ebrndara t\u00eb skedar\u00ebve, ku mblidheshin t\u00eb gjitha t\u00eb dh\u00ebnat e pa-strukturuara ose madje gjysm\u00eb-strukturuara. Nd\u00ebrsa volumi i t\u00eb dh\u00ebnave t\u00eb pa-strukturuara rritej, zhvilluesit kuptuan se POSIX ishte tep\u00ebr \"i z\u00ebsh\u00ebm\", p\u00ebrfshir\u00eb kosto t\u00eb konsiderueshme dhe, p\u00ebrfundimisht, pengonte funksionimin e aplikacionit kur kalonte n\u00eb nivele t\u00eb v\u00ebrteta t\u00eb m\u00ebdha.<\/p>\n

Kjo kryesisht ndihmoi n\u00eb shfaqjen e nj\u00eb standardi t\u00eb ri p\u00ebr ruajtjen e t\u00eb dh\u00ebnave, q\u00eb do t\u00eb thot\u00eb, ruajtje t\u00eb orientuar drejt cloud-it, q\u00eb funksionon kryesisht mbi REST API dhe \u00e7liron aplikacionin nga mbikqyrja e ngarkuar e ruajtjes lokale t\u00eb t\u00eb dh\u00ebnave. N\u00eb k\u00ebt\u00eb rast, aplikacioni n\u00eb fakt kalon n\u00eb nj\u00eb mod t\u00eb pun\u00ebs q\u00eb nuk ruan gjendjen (pasi gjendja \u00ebsht\u00eb n\u00eb ruajtjen e larg\u00ebt). Aplikacionet moderne nd\u00ebrtohen me k\u00ebt\u00eb faktor n\u00eb mendje. Si rregull, \u00e7do aplikacion modern q\u00eb proceson t\u00eb dh\u00ebna t\u00eb ndonj\u00eb lloji (logs, metadata, blobs, etj.) \u00ebsht\u00eb nd\u00ebrtuar mbi paradigmen e orientuar drejt cloud-it, ku gjendja transferohet n\u00eb nj\u00eb sistem softuerik t\u00eb ve\u00e7ant\u00eb p\u00ebr ruajtjen e saj. <\/p>\n

Qasja me kontejner\u00eb q\u00eb ruajn\u00eb gjendjen e kthen t\u00ebr\u00eb k\u00ebt\u00eb paradig\u00ebm sakt\u00ebsisht atje ku filloi! <\/b><\/i><\/p>\n

Duke p\u00ebrdorimi t\u00eb nd\u00ebrfaqeve POSIX p\u00ebr ruajtjen e t\u00eb dh\u00ebnave, aplikacionet punojn\u00eb ashtu si\u00e7 do t\u00eb b\u00ebjn\u00eb n\u00ebse do t\u00eb ruanin gjendjen, dhe p\u00ebr k\u00ebt\u00eb arsye, ata largohen nga postulatat m\u00eb t\u00eb r\u00ebnd\u00ebsishme t\u00eb projektimit t\u00eb orientuar ndaj cloud, pra, nga mund\u00ebsia p\u00ebr t\u00eb variuar p\u00ebrmasat e rrjedhave t\u00eb pun\u00ebs t\u00eb aplikacionit n\u00eb var\u00ebsi t\u00eb ngarkes\u00ebs s\u00eb hyrjes, t\u00eb kalojn\u00eb n\u00eb nj\u00eb nyje t\u00eb re sapo nyja aktuale t\u00eb d\u00ebshtoj\u00eb, e k\u00ebshtu me radh\u00eb.<\/p>\n

Duke e shqyrtuar k\u00ebt\u00eb situat\u00eb m\u00eb af\u00ebr, zbulojm\u00eb se kur zgjedhim ruajtjen e t\u00eb dh\u00ebnave, p\u00ebrs\u00ebri dhe p\u00ebrs\u00ebri hasim n\u00eb dilemm\u00ebn \"POSIX kund\u00ebr REST API\", POR me nj\u00eb komplikim shtes\u00eb t\u00eb problemeve POSIX t\u00eb shkaktuara nga natyra e shp\u00ebrndar\u00eb e mjediseve Kubernetes. N\u00eb ve\u00e7anti,<\/p>\n