IiLayers ezintathu zeCache phakathi kokuKhetha kunye neDiski

Xa isicelo sakho sitshisa ingxelo KHETHA, loo mbuzo uphantse ungachukumisi idisk ejikelezayo okanye ugcino lwe-flash eluhlaza — idlula kwi-cache layers ezintathu ezicacileyo ezibonisa ngokuthe cwaka ukuba impendulo yakho ifika kwi-microseconds okanye i-milliseconds. Ukuqonda ezi maleko ngumahluko phakathi kweqonga leshishini elenza isikali ngokungasebenziyo kunye nelibophayo phantsi komthwalo wehlabathi lokwenyani.

Kwenzeka Ntoni Umzuzu Wombuzo OKHETHAYO Ushiya Isicelo Sakho?

Ngomzuzu isicelo sakho sithumela KHETHA umbuzo, ingena kumbhobho uninzi lwabaphuhlisi abasoze bawuhlole. I-injini yedatha iyasithintela isicelo phambi kokuba nayiphi na i-I / O yenzeke, ichaza i-SQL kwisicwangciso sophumezo lwangaphakathi kwaye ngokukhawuleza ibonise umgca wayo wokuqala wokukhusela: i-cache yesiphumo sombuzo. Ukuba umbuzo ofanayo oneparameters ezifanayo uye wasetyenziswa kutshanje, injini ingabuyisela iziphumo ezigciniweyo ngaphandle kokuchukumisa iphepha elinye ledatha. Ngamanye amaxesha oku kubizwa ngokubai-cache yombuzookanye i-cache yesiphumo, kunye ne-high-read, i-low-write workloads - njenge-analytics dashboards kunye neemodyuli zokunika ingxelo - inokuphelisa ubuninzi beediski ezifundwayo ngokupheleleyo.

Ukuqonda okubalulekileyo apha kukuba i-cache yombuzo inovakalelo kakhulu kutshintsho lwedatha. Nayiphi na FAKA, UPDATE, okanye CIMA ngokuchasene netheyibhile engaphantsi ayisebenzi iziphumo ezigciniweyo ezifanelekileyo. Yiyo loo nto iisistim zetransekshini ezibhala-nzima zihlala zivala i-cache yombuzo ngokupheleleyo kwaye zixhomekeke kumaleko anzulu endaweni yoko.

Yintoni i-Buffer Pool kwaye Kutheni ibalulekile ngaphezu kokuba Ucinga?

I-cache layer yesibini - kwaye ngokuqinisekileyo ibaluleke kakhulu kwiinkqubo zokuvelisa - yii-buffer pool (ebizwa ngokuba yi-buffer ekwabelwana ngayo kwi-PostgreSQL, i-InnoDB buffer pool kwi-MySQL). Lo ngummandla we-RAM i-injini yedatha esetyenziswayo ukubamba amaphepha edatha asandul’ ukufikelela. Xa umbuzo ungenakho ukubonelelwa kuvimba wesiphumo, i-injini ijonga ukuba ingaba amaphepha edatha afunekayo sele ehlala kwidama le-buffer phambi kokukhupha nayiphi na idiski efundiweyo.

Idama le-buffer lisebenza ngokomgaqo wendawo kunye nendawo yendawo: idatha ekufikelelwe kuyo kutshanje kusenokwenzeka ukuba ifikelelwe kwakhona, kwaye idatha egcinwe kufutshane nedatha ekufikelelwe kuyo kusenokwenzeka ukuba ifumaneke kwakamsinya. Abalawuli besiseko sedatha balungisa ubungakanani bedama lebuffer njengenye yezona zigqibo zoqwalaselo oluphezulu abazenzayo. Idama le-buffer elincinane kakhulu libangela ukukhutshwa kwephepha rhoqo, kuvelisa into ebizwa ngokuba yithrashing, apho inkqubo ichitha ixesha elininzi ilawula i-cache elahlekileyo kunokuqhuba imibuzo.

Ukuqonda okuPhambili: Kuninzi lwe-OLTP yomthwalo, i-buffer pool enkulu ithetha ukuba i-95-99% yazo zonke iinkcukacha ezifundwayo zinikezelwa kwi-RAM. Iseti esebenzayo - iseti esezantsi yedatha yakho ebuzwa rhoqo-ihlala incinci kakhulu kunobungakanani bedatha epheleleyo. Ukulinganisa iqula lakho lebuffer ukuze lilingane neseti yakho yokusebenza, hayi isethi yakho yedatha iyonke, lelona nyathelo liphezulu lokubuyisela onokuthi ulithathe.

I-Cache yeNkqubo yokuSebenza igcwalisa njani uMsantsa phakathi kwe-RAM kunye neDiski?

Naxa i-database yebuffer pool iphosakele, umbuzo awukamiselwa ukuba ifundwe yidiski yokwenyani. Inkqubo yokusebenza igcina icache yephepha (ekwabizwa ngokuba yinkqubo yefayile cache), ummandla we-RAM elawulwa yikernel efundeka kwaye ibhale ukubhloka izixhobo. Xa i-injini yedatha icela iphepha elingekhoyo kwi-buffer pool yayo, i-OS kernel ijonga i-cache yephepha layo phambi kokuba ikhuphe umyalelo we-I/O obonakalayo kumlawuli wogcino.

Lo maleko wesithathu awubonakali kakhulu kubaphuhlisi besicelo kodwa kubaluleke kakhulu kwiinkqubo apho iphuli yedatha yedatha ibonelelwa ngaphantsi. I-cache yekhasi le-OS kwabelwana ngayo kuzo zonke iinkqubo, ngoko ikhuphisana neseva yesicelo sakho, iseva yewebhu, kunye nayo nayiphi na enye isoftware esebenza kumamkeli omnye. Kwiiseva ezinikezelweyo zedatha, olu khuphiswano luncinci, kwaye i-cache ye-OS ibonelela ngesithintelo sethuba lesibini elinentsingiselo. Kwiinginginya ekwabelwana ngazo okanye izikhongozeli ezinemida yenkumbulo engqongqo, i-cache ye-OS ihlala incinci kakhulu ukuba inganceda.

Yeyiphi iCache Layer enoxanduva lolona Sebenzi luPhumelelayo kwiPractice?

Kwiinkqubo zemveliso yehlabathi lokwenyani, ipool ye-buffer ilawula iziphumo zokusebenza ngomda obanzi. Nasi isizathu sokuba umaleko ngamnye unegalelo ngokwahlukileyo kuzo zonke iimeko zokusetyenziswa:

• I-Cache yeziphumo zombuzo: Eyona nzuzo iphezulu kwi-read-heavy, ikakhulu i-datasets engatshintshiyo — imibuzo yokunika ingxelo, i-cached dashboards, isiphelo somxholo woluntu. Ayinamsebenzi kwiitafile zokubhala ezinzima.
• I-Database buffer pool: Ihashe lomsebenzi jikelele. Yonke iseva yedatha yemveliso kufuneka ilungiswe apha kuqala. Uzibamba zombini iipateni zofikelelo olungakhethiyo nolulandelelanayo ngokufanelekileyo.
• I-cache yekhasi le-OS: Ibonelela ngomnatha wokhuseleko xa i-buffer pool iphantsi. Ikwanceda kakhulu ngexesha lokuskena okulandelelanayo kweetheyibhile ezinkulu ezinokuthi ngenye indlela zikhuphe amaphepha ashushu kwidama le-buffer.
• I-cache yokulawula isitoreji (i-hardware layer): Isesine, isoloko ihoywa umaleko - ii-NVMe SSDs kunye nabalawuli be-RAID bagcina ii-cache zokubhala kwi-board kunye nebhetri okanye i-capacitor backup. Oku kukhusela ukuhlala ixesha elide ngaphandle kokuncama ukubhala ngeendleko ze-fsync latency.
• I-Application-layer cache (Redis, Memcached): Ihlala ngaphezulu kwesiseko sedatha ngokupheleleyo, igcina i-caching serialized query results or computed objects ukuphepha ukubetha i-database konke konke — ilungele amaqonga e-SaaS abaqashiweyo abaninzi abakhonza amawakawaka abasebenzisi abasebenzisana nabo.

Njani ukuba iiPlatifomu zeShishini zanamhlanje ziFakamisa iCache yoLwakhiwo lokuThembeka kwisikali?

Kumashishini asebenza kwiimodyuli ezininzi ezisebenzayo - i-CRM, ulawulo lweprojekthi, i-e-commerce, i-analytics - i-cache architecture inquma ngokuthe ngqo ukuphendula kweqonga njengoko amaqela akhula. Iiplatform ezakhelwe kwisicwangciso se-cache esakhiwe kakuhle zinokusebenza amashumi amawaka abasebenzisi abasebenzisanayo ngaphandle kweendleko ezilinganayo zeziseko zophuhliso. Undoqo kukuyila iipatheni zofikelelo lwedatha ezihlonipha imida ye-cache: ukugcina idatha eshushu incinci kunye nokufikelela iipateni ezinokuqikelelwa, usebenzisa i-read replicas ukusabalalisa umthwalo we-buffer pool, kunye nokubeka indawo ye-cache ye-application-layer efana ne-Redis phambi kwesiseko sedatha yeendawo zokuphela ezinikezela idatha efanayo kubasebenzisi abaninzi ngaxeshanye.

I-Mewayz yakhiwe inale filosofi engqondweni. Ngeemodyuli zeshishini ezihlanganisiweyo ezingama-207 ezinika amandla kubasebenzisi abangama-138,000, umaleko wedatha weqonga uyilwe ngendlela yokuba uninzi lokufundwayo lunikezelwe kwi-cache - ukugcina amaxesha okuphendula ngokukhawuleza kunye neendleko zeziseko ezingundoqo ezinokuqikelelwa nokuba uqhuba isicwangciso sokuqala se-$19/ngenyanga okanye inqanaba lobuchwephesha le-$49/ngenyanga.

Imibuzo Ebuzwa Rhoqo

Ngaba ukuvala i-cache yombuzo kusoloko kuphucula ukusebenza kwesiseko sedata?

Ayisoloko, kodwa ukubhala-umthwalo onzima wemisebenzi iqhele ukwenza. I-cache yombuzo ifuna i-global mutex ukugcina ukungaguquguquki, okuba ngumqobo phantsi kwe-concurrency ephezulu. I-MySQL 8.0 isuse i-cache yombuzo ngokupheleleyo ngenxa yesi sizathu. I-PostgreSQL ayizange iphumeze i-cache yombuzo eyakhelwe-ngaphakathi, endaweni yoko ixhomekeke kwi-buffer pool kunye ne-caching-layer caching. Ukuba umlinganiselo wakho wokufunda-ukubhala uphezulu kwaye imibuzo yakho iphindaphindwa kakhulu, i-cache yombuzo inokuzisa iinzuzo zokwenyani - kungenjalo, tyala loo nzame yokulungisa kwi-buffer pool.

Ndazi njani ukuba isithinteli sam silingana ngokufanelekileyo?

Jonga isithinteli sakho sokubetha umlinganiselo: ipesenti yezicelo zephepha ezinikezelweyo kwiqula elichasene nezo zifuna idisk efundwe. Umlinganiselo wokubethelwa ngaphantsi kwe-95% kumsebenzi we-OLTP ngumqondiso wokwandisa ubungakanani bedama. Kwi-MySQL, umbuzo BONISA INDLELA YOKUBONISA INNODB STATUS kwaye ujonge i-buffer pool hit rate. Kwi-PostgreSQL, i-pg_statio_user_tables imboniselo ibonisa iibhloko zemfumba ezifundwe kwidisk xa kuthelekiswa neenkonzo ezivela kwi-buffer pool. Injongo yokugcina yonke iseti yakho yokusebenza — hayi iseti yakho yedatha epheleleyo — ehlala kwi-RAM.

Yintoni ubudlelwane phakathi kwe-cache layers kunye nokuthembeka kwe-SaaS yabaqashi abaninzi?

Kwi-SaaS enabaqashi abaninzi, iileya ze-cache zithintela iingxaki "zommelwane ongxolayo" apho umbuzo onzima womqeshi wehlisa ukusebenza kwabo bonke abanye abaqashi. Ugcino lwesicelo esinolwazi lomqeshi kunye nokunganyaniseki okusekwe kwi-TTL kugcina idatha eshushu yomqeshi ngamnye kwiRedis, inciphisa kakhulu uxinzelelo lwe-buffer pool kwiiakhawunti ezinkulu. Ukudityaniswa koqhagamshelo lwenqanaba lesiseko sedatha kudityaniswe nephuli eshushu yesithinteli kuqinisekisa ukuba umsebenzi ogqabhukileyo kuyo nayiphi na i-akhawunti enye ayigungxuli amaphepha okwabelwana ngawo kwi-cache kwaye ibangele ukujikeleza kwexesha elide kwiqonga.

I-Cache layers ayiyo-trivia yedatha - zisisiseko soyilo esahlula amaqonga ahlala ngokukhawuleza kwisikali ukusuka kwezo zifuna ukucinywa komlilo rhoqo kweziseko zophuhliso. Ukuba wakha okanye uqhuba ishishini elifuna iqonga esele lilungiselelwe ezi nyani, jonga iMewayz kuapp.mewayz.com — Iimodyuli ezingama-207, iqonga elinye elibambeneyo, elakhelwe ukusebenza ngokuthembekileyo ukusuka kumsebenzisi wakho wokuqala ukuya kwikhulu lamawaka.