Txheej txheem cej luam: Apache Cassandra yog ib tus tseem nrov thiab scalable qhib tau qhov twg los NoSQL database. Cassandra yog ib qho zoo tagnrho database rau tswj loj loj ntim ntawm unstructured, xyaum ib thiab xyaum cov nyob chaw zov me nyuam ntau yam ntaub ntawv thiab rau ntawm tej huab. Cassandra yuav muab kev pab scalability siab thiab txaus nyob hauv ntau servers tsis muaj compromising kev ua tau zoo. Nrog rau cov qauv no yog tsis muaj ib txoj uas tsis ua hauj lwm, thiab nws muab ib cov qauv ntaub ntawv haib yooj siab tshaj plaws thiab lub sij hawm yoo teb. Scalability tawm thiab tus txhaum tiv thaiv Radon los yog ib tug huab infrastructure thaum lawv tseem zoo meej rau tej ntaub ntawv tseem ceeb heev ua rau.
Taw qhia: Yeej paub databases zoo heev hauv dlaws tau tej yam teeb meem cia ntaub ntawv. Tab sis, raws li qhov kom pom tseeb yog txawv rau RDBMS, nws ua ib qho teeb meem thaum scaling rau loj loj ntim ntawm cov ntaub ntawv. Li ntawd, peb yuav tsum nrhiav ib txoj kev los rhuav tshem ntawm cov joins. Qhov no yuav ua tau rau de-normalizing cov ntaub ntawv. Qhov no yuav ua rau tus neeg tuav cov ntaub ntawv no ntau daim ntawv thiab kuj ua tau ib puas loj loj rau tus tsim, ob lub database thiab nyob rau hauv daim ntawv thov. Hauv no mob ntsiab los ntawm NoSQL rau nkawd yuav tsawg radical thiab scary tsawg tshaj peb yuav tau xav. Lub hom phiaj tsim ntawm NoSQL database tau kom koj to taub meej ua ntej kev siv rau ib daim ntawv thov.
Tsim cov hom phiaj ntawm cov Cassandra NoSQL database: Tus tsim NoSQL database yog txawv kiag li los paub database. Li ntawd, cov kev xaiv uas siv NoSQL DB los yog RDBMS tseem nyob li cas daim ntawv thov thiab nws yuav tsum tau. Raws li peb paub tias ACID tham thiab muab ib cov qauv muaj zog li qub tas li txhua lub web ntawv tsim thiab tsim feeb ntau. Tab sis thaum peb xav txog scalability, nws los them tus nqi thiab cov kev cai raws li nyob rau hauv RDMBS tsim tej conflicts. Yog li kev qhia nyob rau pem li qub tas li yog ib yam tseem ceeb tsim rau NoSQL databases. Uas tsim lub hom phaj raws kev Cassandra yog teev nram qab no.
- Kev kawm siab
- Kab rov tav scalability
- Simplicity
- Schema yooj
Cassandra architecture uas tswj ntaub ntawv loj ntim: Raws li peb yeej paub tias NoSQL databases yuav faib rau tus nab npawb rau hauv cov ntshav. Cassandra no los faib rau ib tug xov tooj ntawm cov ntshav thiab yuav ua raws ' masterless’ architecture. ' Masterless’ txhais tau tias architecture, yog tib cov ntshav thiab yuav tsis muaj ib qho ntawm uas controls lwm o. Cassandra tau distributes tej ntaub ntawv nyob tag nrho rau hauv ntshav ntaub ntawv twg yog cov uas cov ' ntiv nplhaib’ peb paub los lawm raws li pawg database. Raws li cov ntaub ntawv no thiab tau transparently partitioned rau cov pawg, developers tsis tau ua dab tsi programmatically. Feature ntawm Cassandra architecture tseem ceeb yog txhawb cov los ua-ua tau thiab customizable replication. Cov ntaub ntawv redundant muab nyob rau ntau cov ntshav nyob hauv Cassandra ntiv nplhaib. Thiaj li yog tias qhov twg tsis ua hauj lwm hauv tej ntawm, cov qub ntaub ntawv yog retrieved los ntawm lwm cov ntshav uas muaj ntaub ntawv replicated. Tus replication yuav tau configured nyob rau yam nram qab no.
- Nyob rau ib cov ntaub ntawv chaw
- Nyob rau tej ntaub ntawv ntau hom rau me nyuam
- Nyob rau ntau yam huab infrastructure
Lwm architectural feature yog tej kev pab txhawb rau cov scalability tawm. Nws txhais tau hais tias lub peev xwm los yog scalability yuav muab ntau zog los ntawm kev ntxiv ntshav tshiab xwb. Piv txwv, Yog hais tias 2 o yuav lis 1000 muas/sec, ces 4 o yuav txhawb 2000 muas/sec thiab hais txog. Daim duab hauv qab no qhia tau hais tias cov scalability tawm ntawm ib lub nplhaib Cassandra.
Ntiv nplhaib Cassandra
Tus txheejtxheem loj ntim ntawm cov ntaub ntawv: Thawj qhov uas yuav los txog rau hauv siab yog cov nyob rau ntawm hom kev qiv thaum sau cov ntaub ntawv database uas tau tsav. Cov khoom uas tsis RDBMS tus muaj qiv yog ncaj nraim rau pem hauv ntej. Piv txwv, JDBC yog tus txheem database saib API rau daim ntaub ntawv raws li Java. Feem ntau yog ib zaug xwb JDBC tsav vendor rau ib qho yam khoom database. Rau lwm cov tes, Cassandra muaj kwv yees li cuaj txawv neeg tau rau txoj kev loj hlob thov Java. Thiab qhov tseem ceeb tshaj plaws uas yog, cov neeg tau muab flavors sib txawv rau cov tswj tau cov ntaub ntawv. Ib txhia yog muab tej kwv kuas paub APIs, ib txhia Self CQL raws kev pab txhawb thiab muaj ntau ntxiv yog. Vim li ntawd cov yooj rau tus txheejtxheem qhov NoSQL DB yog lwm cov loj kom zoo dua rau daim ntawv thov kev loj hlob. Tus developers muaj cai xaiv hom ntaub ntawv raws li lawv yuav tsum tau.
Loj ntim ntawm cov ntaub ntawv nyob rau hauv Cassandra yuav tsum accessed thiab tswj los APIs uas ua raws cov RPC style. Tib lub sijhawm, Cassandra tseem muab tej lus nug lus kev them nyiaj yug hu ua CQL uas zoo xws li cov SQL rau tej tus twg. Tab sis, tus tsim tawm daim ntawv thov yuav tsum muaj kev paub txog cov kua cav thiab nws cov functionality suab.
Txuj siv ua plaub rau Cassandra NoSQL DB: Raws li peb tau qhia txog kev uas cov neeg txheem siv rau Cassandra yog txawv ntawm RDBMS kev siv tshuaj. Nram qab no yog tej rooj plaub ntug txheem siv.
- Daim ntaub ntawv tuav ntaub ntawv loj ntim
- Kev siv scalability siab thiab ua raws li daim phiaj
- Daim ntaub ntawv uas yuav tsum tau muaj kev cia siab rau rau cov ntaub ntawv cia
- Qauv dynamic cov ntaub ntawv uas yuav tsum hloov nws thaum lub sij hawm
- Tis dua datacenters sib txawv
Daus thiab txhim kho Cassandra: Tam sim no peb tham txog lub ces thiab plahaum ib feem ntawm Cassandra NoSQL DB. Cov ces thiab cov plahaum yuav siv cov sij hawm ib co.
Apache Cassandra yuav tsum downloaded ntawm http://cassandra.apache.org . Lub binary tis npe li apache-cassandra -<VERSION>-bin.tar.gz. Txoj kev uas yooj yim rau nruab Cassandra yog hais rau cov nram qab no cov kauj ruam hauv qab no –
- Download tau lub binary tis ntawm lub website saum toj no
- Unzip no uas siv ib co txwm ZIP company
- Ib zaug unzipped, koj yuav tsum tau cov Wage hauv qab no –
- rau hauv – qhov no muaj cov executables khiav Cassandra thiab cov nyob hauv kev pab hais kom ua kab interface.
- conf – qhov no muaj cov ntaub ntawv siv los configure Cassandra
- interface – interface txhais siv cov Thrift syntax thiab muab ib txoj kev yooj yim los ua kom muaj neeg. Yog hais tias koj xav saib tag nrho cov haujlwm uas tuav Cassandra, qhib cov ntaub ntawv no yog siv ib tug txwm ntawv editor. Cov ntaub ntawv no yuav muaj tag nrho Cassandra txhawb neeg rau Java, C , PHP, Ruby, thiab nab hab sej, Perl, thiab C # ntawm no interface.
- lib – qhov no muaj cov sab nraud uas yuav tsum tau coj Cassandra.
- javadoc – qhov no muaj cov ntaub ntawv nyob rau hauv hom html rau Cassandra.
Pib lub neeg rau zaub mov Cassandra NoSQL: Thov koj ua raws li qhia hauv qab no kom tau tus neeg rau zaub mov Cassandra.
Los pib lub Cassandra neeg rau zaub mov ntawm tej OS zoo ib yam li linux los sis qhov rais, ua ntej koj yuav tsum mus qhib ib tug txhob hais kom ua los yog cov davhlau ya nyob twg qhov rai. Tam sim no mus rau lub <cassandra-directory>/rau hauv qhov twg koj unpacked Cassandra, thiab khiav rau nram qab no hais kom ua los pib lub Cassandra neeg rau zaub mov. Yog tus plahaum huv, peb yuav pom tej cav lus zoo li no:
Qhia 1: pib Cassandra neeg rau zaub mov
utpalb@Cassandraserver$ rau hauv/cassandra - f
PAB NTXIV YOG 13:23:22,367 DiskAccessMode ' nws pib’ yeej mus yuav txheem, indexAccessMode yuav txheem
PAB NTXIV YOG 13:23:22,475 Tsis tau ntes tej schema txhais cov ntsiab lus nyob hauv lub zos cia.
PAB NTXIV YOG 13:23:22,476 Nrhiav tau cov ntaub ntawv cov lus nyob rau hauv cov ntaub ntawv Wage. Zoo xav txog JMX hu rau org.apache.cassandra.service.StorageService.loadSchemaFromYaml().
PAB NTXIV YOG 13:23:22,497 Cassandra version: 0.7.0-beta1
PAB NTXIV YOG 13:23:22,497 Thrift API version: 10.0.0
PAB NTXIV YOG 13:23:22,498 Rua Token nrhiav tsis tau. Siv qFABQw5XJMvs47lg
PAB NTXIV YOG 13:23:22,498 Rua ClusterName nrhiav tsis tau. Siv kuaj sawv
PAB NTXIV YOG 13:23:22,502 Npaj cov tshiab commitlog ya /var/lib/cassandra/commitlog/CommitLog-1282508602502.log
PAB NTXIV YOG 13:23:22,507 switching nyob rau hauv ib cov Memtable rau LocationInfo nyob CommitLogContext(
File='/Var/lib/cassandra/commitlog/CommitLog-1282508602502.log', txoj hauj lwm = 276)
PAB NTXIV YOG 13:23:22,510 Enqueuing yaug cov Memtable-LocationInfo@29857804(178 bytes, 4 haujlwm)
PAB NTXIV YOG 13:23:22,511 Sau ntawv ua Memtable-LocationInfo@29857804(178 bytes, 4 haujlwm)
PAB NTXIV YOG 13:23:22,691 Tiav kais /var/lib/cassandra/data/system/LocationInfo-e-1-Data.db
PAB NTXIV YOG 13:23:22,701 Pib los lus xaiv neeg rau zaub mov
PAB NTXIV YOG 13:23:22,750 Binding qhov thrift los localhost/127.0.0.1:9160
PAB NTXIV YOG 13:23:22,752 Siv cov TFramedTransport uas muaj ib tug ncej max luaj li cas 15728640 bytes.
PAB NTXIV YOG 13:23:22,753 Mloog rau neeg thrift…
PAB NTXIV YOG 13:23:22,792 ntse mx4j loaded HttpAdaptor version 3.0.2 pib ntawm chaw nres nkoj 8081
Cov kev xaiv -f ntawm no siv los qhia Cassandra nyob hauv lub foreground tsis txhob khiav raws ib tug txheej txheem keeb kwm yav dhau. Qhov no yuav pab peb, tag nrho cov neeg rau zaub mov cav yuav luam tawm txheem thiab koj yuav pom tau koj qhov rai davhlau ya nyob twg, Nws yog ib qho pab tau thaum uas soj ntsuam.
Txoj kev:
Peb cia xaus peb sib tham nyob rau hauv daim ntawv uas cia nyias qhov hauv qab no –
- Apache Cassandra yog ib NoSQL nyob scalable database
- Nws yuav muab downloaded thiab ntsia ntawm lub qhov website Apache
- Cassandra yog ib tug zoo tagnrho database rau tswj ntau xyaum, xyaum ib, thiab ntaub ntawv unstructured hla cov ntaub ntawv ntau hom rau me nyuam thiab tus huab.
- Cassandra kev txhawb zog tawm scalability thiab kev kawm ntawv siab thoob ntau hauv servers uas tsis muaj ib txoj uas tsis ua hauj lwm, thiab muaj ib tug qauv rua yooj siab tshaj plaws thiab lub sij hawm yoo teb haib dynamic ntaub ntawv.
