Video: DataNode thiab NameNode hauv Hadoop yog dab tsi?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
DataNodes yog cov qhev nodes hauv HDFS . Tsis zoo li Lub npeNode , DataNode yog cov khoom siv kho vajtse, uas yog, cov khoom siv tsis kim uas tsis yog cov khoom zoo lossis cov khoom siv siab. Cov DataNode yog ib lub server thaiv uas khaws cov ntaub ntawv hauv zos cov ntaub ntawv ext3 lossis ext4.
Ib qho ntxiv, NameNode ua haujlwm li cas hauv Hadoop?
Lub npeNode tsuas khaws cov metadata ntawm HDFS - cov ntoo directory ntawm tag nrho cov ntaub ntawv nyob rau hauv cov ntaub ntawv system, thiab taug qab cov ntaub ntawv nyob rau hauv pawg. NameNode tsis khaws cov ntaub ntawv tiag tiag lossis dataset. Cov ntaub ntawv nws tus kheej tau khaws cia hauv DataNodes. NameNode yog ib lub ntsiab lus ntawm kev ua tsis tiav hauv Hadoop pawg.
Ib tug kuj yuav nug, NameNode RPC yog dab tsi? Hauv Hadoop, lub Lub npeNode yog ib lub tshuab uas tswj hwm HDFS cov haujlwm hauv nws lub npe. Cov haujlwm no suav nrog tau txais qhov chaw thaiv, sau npe, thiab tsim cov ntaub ntawv. Cov NameNode tau txais kev ua haujlwm HDFS raws li RPC hu thiab muab tso rau hauv FIFO hu queue rau kev ua tiav los ntawm kev nyeem xov.
Hais txog qhov no, cov nodes hauv Hadoop yog dab tsi?
A node hauv hadoop tsuas yog txhais tau tias lub computer uas siv tau rau kev ua thiab khaws cia. Muaj ob hom nodes hauv hadoop Lub npe node thiab Data node . Nws yog hu ua a node raws li tag nrho cov computers no yog interconnected. NameNode tseem hu ua tus Xib Hwb node.
Qhov thib ob NameNode hauv Hadoop yog dab tsi?
Secondary NameNode hauv hadoop yog ib qho tshwj xeeb ntawm node nyob rau hauv HDFS pawg uas nws lub luag haujlwm tseem ceeb yog los saib xyuas cov ntaub ntawv kaw lus metadata tam sim no npe . Nws tsis yog thaub qab npe . Nws tsuas yog checkpoints cov npe file system namespace.
Pom zoo:
Qhov thib ob Namenode hauv Apache Hadoop yog dab tsi?
Secondary NameNode nyob rau hauv hadoop yog ib qho tshwj xeeb ntawm node nyob rau hauv HDFS pawg uas nws lub luag haujlwm tseem ceeb yog los saib xyuas cov ntaub ntawv kaw lus metadata tam sim no ntawm namenode. Nws tsis yog ib tug backup namenode. Nws tsuas yog checkpoints namenode cov ntaub ntawv system namespace
Dab tsi yog txoj hauv kev virtual thiab txoj hauv lub cev hauv asp net?
Ua ntej tshaj, cia peb tau txais cov ntsiab lus ntawm ob qho tib si. Txoj kev lub cev - Qhov no yog txoj hauv kev tiag tiag cov ntaub ntawv nyob ntawm IIS. Txoj kev Virtual - Qhov no yog txoj hauv kev kom nkag mus rau cov ntaub ntawv uas tau taw qhia los ntawm sab nraud ntawm IIS daim ntawv thov folder
Dab tsi yog qhov sib txawv ntawm lub thawv thiab lub thawv ntawv thiab lub thawv ntawv yog dab tsi?
Ib lub thawv thiab cov ntawv nplawm (qee zaum hu ua boxplot) yog ib daim duab uas nthuav tawm cov ntaub ntawv los ntawm tsib lub ntsiab lus. Nyob rau hauv ib lub thawv thiab whisker zajlus: qhov kawg ntawm lub thawv yog lub sab sauv thiab sab quartiles, yog li lub thawv spans lub interquartile ntau yam. qhov nruab nrab yog cim los ntawm ib txoj kab ntsug hauv lub thawv
Dab tsi yog qhov zoo sib xws thiab qhov txawv ntawm relays thiab PLC yog dab tsi?
Relays yog electro-mechanical keyboards uas muaj coil thiab ob hom kev sib cuag uas tsis yog NO & NC. Tab sis Programmable Logic Controller, PLC yog lub khoos phis tawj me uas tuaj yeem txiav txim siab raws li qhov kev zov me nyuam thiab nws cov tswv yim & tso tawm
Dab tsi yog mapper thiab reducer hauv Hadoop?
Qhov zoo dua ntawm MapReduce yog tias nws yooj yim los ntsuas cov ntaub ntawv ua ntau dua cov lej suav. Raws li tus qauv MapReduce, cov ntaub ntawv ua haujlwm tseem ceeb yog hu ua mappers thiab reducers. Decomposing cov ntaub ntawv ua daim ntawv thov rau hauv mappers thiab reducers yog qee zaum tsis tseem ceeb