Video: Dab tsi yog chav kawm mapper?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Cov Mapper chav kawm yog hom generic, nrog plaub yam tsis raug cai uas qhia meej cov tswv yim tseem ceeb, tus nqi tawm tswv yim, tso tawm qhov tseem ceeb thiab cov nqi tso tawm hom ntawm daim ntawv qhia muaj nuj nqi.
Kuj nug, dab tsi yog chav kawm mapper hauv Java?
Java Object rau Object Daim ntawv qhia . Orika: Orika yog ib Java Bean mapping moj khaum uas recursively luam (ntawm lwm lub peev xwm) cov ntaub ntawv los ntawm ib yam khoom mus rau lwm tus. Nws tuaj yeem muaj txiaj ntsig zoo thaum tsim cov ntawv thov ntau txheej.
Tsis tas li ntawd, mapper thiab reducer yog dab tsi? MapReduce muaj ob lub luag haujlwm tseem ceeb: Mapper thiab Reducer . Daim ntawv qhia yog ib txoj haujlwm uas ua cov ntaub ntawv nkag. Cov daim ntawv qhia ua cov ntaub ntawv thiab tsim ntau yam me me ntawm cov ntaub ntawv.
Raws li, Mapper chav kawm hauv Hadoop yog dab tsi?
Daim ntawv qhia yog lub hauv paus chav kawm uas yog siv los siv daim ntawv qhia kev ua haujlwm hauv Hadoop MapReduce . Maps yog cov haujlwm ntawm tus kheej uas khiav ua ntej reducers thiab hloov cov khoom nkag mus rau hauv cov khoom tsim tawm. Cov txiaj ntsig tso tawm no yog cov txiaj ntsig nruab nrab uas ua raws li cov tswv yim rau Kev Txo cov haujlwm.
MapReduce piv txwv yog dab tsi?
Ib piv txwv ntawm MapRub Lub nroog yog tus yuam sij, thiab qhov kub thiab txias yog tus nqi. Siv cov MapQhia lub moj khaum, koj tuaj yeem rhuav tshem qhov no ua tsib daim ntawv qhia ua haujlwm, qhov twg txhua tus mapper ua haujlwm ntawm ib qho ntawm tsib cov ntaub ntawv. Txoj haujlwm mapper mus dhau cov ntaub ntawv thiab rov qab qhov kub siab tshaj plaws rau txhua lub nroog.
Pom zoo:
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