Ko te ariā CAP te tūāpapa o te ariā pūnaha tohatoha. Heoi anō, he tautohenga tonu: kāore ōna whakamāramatanga i te tino tika, ā, kāore he taunakitanga pakari. Heoi anō, i runga i te whakaaro noa™, ka mārama tātou he pono te ariā.
Ko te mea anake kāore i te mārama ko te tikanga o te reta "P." Ina wehe te rōpū, ka whakatau ia mēnā ka noho puku kia tae rā anō ki te kōruma, ka whakahokia rānei ngā raraunga kei a ia. I runga i te putanga o tēnei whakatau, ka whakarōpūtia te pūnaha hei CP, hei AP rānei. Hei tauira, ka taea e Cassandra te whanonga i ngā taha e rua, ehara i te mea i runga i ngā tautuhinga rōpū engari i runga i ngā tawhā o ia patai motuhake. Engari ki te kore te pūnaha he "P" ā, ka wehe, kāti me pēhea?
Kāore i te tino kitea te whakautu ki tēnei pātai: kāore e taea e te tautau CA te wehe.
He aha tēnei rōpū e kore e taea te wehe?
Ko tētahi āhuatanga nui o tētahi rōpū pēnei ko tētahi pūnaha rokiroki raraunga tiritahi. I te nuinga o te wā, ko te tikanga o tēnei he hononga mā te SAN, e whakawhāiti ana i te whakamahinga o ngā otinga CA ki ngā umanga nunui e kaha ana ki te pupuri i tētahi hanganga SAN. Kia maha ai ngā tūmau Hei mahi me ngā raraunga ōrite, me whai pūnaha kōnae taupū. Kei roto i ngā kohinga kōnae a HPE (CFS), Veritas (VxCFS), me IBM (GPFS) ēnei pūnaha kōnae.
Oracle RAC
I puta tuatahi mai te kōwhiringa Real Application Cluster i te tau 2001 me te tukunga o Oracle 9i. I roto i tētahi rōpū pēnei, he maha ngā tauira tūmau mahi tahi me te pātengi raraunga kotahi.
Ka taea e Oracle te mahi me tētahi pūnaha kōnae taupū me tana ake otinga – ASM, Whakahaere Rokiroki Aunoa.
Ka pupuri ia tauira i tana ake rangitaki. Ka whakahaerehia, ka tukuna hoki he tauwhitinga e te tauira kotahi. Ki te rahua tetahi tauira, ka pānuihia e tetahi o ngā pūnga tautau (ngā tauira) e ora tonu ana tana rangitaki, ā, ka whakahokia mai ngā raraunga ngaro, kia wātea ai.
Ka pupurihia e ngā tauira katoa ā rātou ake keteroki, ā, ka taea e ngā whārangi kotahi (poraka) te noho i roto i ngā keteroki o ngā tauira maha i te wā kotahi. Hei tāpiri, ki te hiahia tētahi tauira ki tētahi whārangi kei roto i te keteroki o tētahi atu tauira, ka taea e ia te tiki mai i tōna hoa tata mā te whakamahi i te whakakotahitanga keteroki hei utu mō te pānui mai i te kōpae.
Engari, he aha te mea ka tupu mēnā me huri te raraunga i tētahi o ngā tauira?
Ko te āhuatanga ahurei o Oracle ko te korenga o tētahi ratonga raka motuhake: ki te hiahia tētahi tūmau ki te raka i tētahi rarangi, ka tuhia tika te tāurunga raka ki te whārangi mahara kei reira te rarangi hei raka. Mā tēnei huarahi ka waiho a Oracle hei toa mahi i roto i ngā pātengi raraunga kotahi: kāore te ratonga raka e waiho hei aukati. Heoi, i roto i tētahi whirihoranga rōpū, ka taea e tēnei hoahoa te arahi ki te nui o te haere o te whatunga me ngā arai.
Kia maukatihia tētahi tuhinga, ka whakamōhiotia e tētahi tauira ngā tauira katoa kua maukatihia anake te whārangi kei roto taua tuhinga. Mena me whakarerekē e tētahi atu tauira tētahi tuhinga i runga i taua whārangi anō, me tatari kia oti rā anō ngā huringa ki te whārangi, arā, kia tuhia rā anō ngā mōhiohio huringa ki te rangitaki kōpae (i te mea ka taea tonu te haere tonu o te tauwhitinga). Tērā pea ka whakarerekēhia tētahi whārangi i runga i te raupapatanga e ngā tauira maha, i roto i tēnei take, ina tuhia te whārangi ki te kōpae, me whakatau ko tēhea tauira kei a ia te putanga o nāianei o te whārangi.
Mā te whakahōu matapōkere i ngā whārangi kotahi puta noa i ngā pona RAC rerekē ka tino heke te mahi a te pātengi raraunga, tae noa ki te wāhi ka iti iho pea te mahi a ngā rōpū i tērā o tētahi tauira kotahi.
Ko te whakamahinga tika o Oracle RAC ko te wehewehe ā-tinana i ngā raraunga (hei tauira, mā te whakamahi i tētahi tikanga ripanga wehewehe) me te uru atu ki ia huinga wehewehe mā tētahi pona motuhake. Ko te kaupapa matua o te RAC ehara i te tauine whakapae, engari ko te manawanui hapa.
Ki te mutu te urupare a te pūnga ki te pao o te ngakau, ka tīmata te pōti kōpae a te pūnga i kite tuatahi i tēnei. Ki te kore tonu te pūnga ngaro e urupare, ka riro i tētahi o ngā pūnga te kawenga mō te whakaora raraunga:
- "whakatio" i ngā whārangi katoa i roto i te keteroki o te pūnga ngaro;
- ka pānui i ngā rangitaki mahi anō o te pūnga ngaro, ka whakamahi anō i ngā huringa kua tuhia ki roto i ēnei rangitaki, me te tirotiro anō mēnā he putanga hou ake o ngā whārangi e whakarerekētia ana e ētahi atu pūnga;
- ka huri whakamuri i ngā whakawhitiwhitinga kāore anō kia oti.
Hei whakangawari i te rahunga i waenga i ngā pūnga, ka whakaurua e Oracle te ariā o tētahi ratonga—he tauira mariko. Ka taea e tētahi tauira te tautoko i ngā ratonga maha, ā, ka taea e tētahi ratonga te heke i waenga i ngā pūnga. Ka mahi tētahi tauira tono e tautoko ana i tētahi wāhanga motuhake o te pātengi raraunga (hei tauira, he rōpū kiritaki) me tētahi ratonga, ko te ratonga e kawenga ana mō taua wāhanga o te pātengi raraunga ka heke ki tētahi atu pūnga mēnā ka rahua tētahi pūnga.
Ngā Pūnaha Raraunga Pure a IBM mō ngā Whakawhitiwhitinga
I puta mai tētahi otinga rōpū mō te DBMS i roto i te putea a Big Blue i te tau 2009. I runga i te whakaaro, koinei te uri o te rōpū Parallel Sysplex, i hangaia i runga i ngā taputapu "noa". I te tau 2009, i tukuna a DB2 pureScale, he huinga pūmanawa, ā, i te tau 2012, i tukuna e IBM tētahi taputapu taputapu me te pūmanawa e kiia nei ko Pure Data Systems for Transactions. Kaua tēnei e pohehe ki a Pure Data Systems for Analytics, he mea whakarerekē noa iho i te ingoa Netezza.
I te tirohanga tuatahi, he rite te hoahoanga pureScale ki te Oracle RAC: he maha ngā pona e hono ana ki tētahi pūnaha rokiroki tiritahi, ā, ka whakahaerehia e ia pona tana ake tauira DBMS me ōna ake wāhi mahara me ngā rangitaki tauwhitinga. Heoi, he rerekē ki a Oracle, he ratonga raka motuhake tā DB2, e tohuhia ana e tētahi huinga o ngā tukanga db2LLM*. I roto i tētahi whirihoranga taupū, ka tukuna tēnei ratonga ki tētahi pona motuhake, e kiia nei ko te whare honohono (CF) i roto i te Parallel Sysplex me te PowerHA i roto i te Pure Data.
Ka whakaratohia e PowerHA ngā ratonga e whai ake nei:
- kaiwhakahaere poraka;
- keteroki pūrua ā-ao;
- te wāhanga o ngā whakawhitiwhitinga whakawhitiwhitinga.
Ka whakamahia te urunga mahara mamao hei whakawhiti raraunga mai i PowerHA ki ngā pūnga raraunga me te hoki whakamuri, nō reira me tautoko te hononga tautau i te kawa RDMA. Ka taea e PureScale te whakamahi i a Infiniband me te RDMA mā runga i te Ethernet.
Mena ka hiahiatia he whārangi e te pūnga, ā, kāore i roto i te keteroki, ka tonohia te whārangi mai i te keteroki ā-ao, ā, ki te kore i reira ka pānuihia mai i te kōpae. Kāore i rite ki a Oracle, ka tukuna noa te tono ki a PowerHA, kāore ki ngā pūnga tata.
Ina whakarerekētia e tētahi tauira tētahi rarangi, ka rakahia ki te aratau motuhake, ā, ko te whārangi kei roto te rarangi i te aratau tiritahi. Ka rēhitatia ngā raka katoa ki te kaiwhakahaere raka ā-ao. Ina oti te tauwhitinga, ka tukuna e te pūnga he karere ki te kaiwhakahaere raka, ka tāruatia te whārangi kua whakarerekētia ki te keteroki ā-ao, ka tukuna ngā raka, ā, ka whakakorengia te whārangi kua whakarerekētia i roto i ngā keteroki o ētahi atu pūnga.
Mena kua raka kē te whārangi kei roto te rarangi e whakarerekētia ana, ka pānuihia e te kaiwhakahaere raka te whārangi kua whakarerekētia mai i te mahara o te pūnga i hanga i te whakarerekētanga, ka tukuna te raka, ka whakakore i te whārangi kua whakarerekētia i roto i ngā keteroki o ētahi atu pūnga, ka whakahokia te raka whārangi ki te pūnga i tono ai.
"Paruparu", arā, kua whakarerekētia, ka taea te tuhi i ngā whārangi ki te kōpae mai i tētahi pūnga noa me tētahi PowerHA (castout).
Ki te rahua tētahi pūnga pureScale, ka herea te whakaoranga ki ngā tauwhitinga kāore anō kia oti i te wā o te rahua: ko ngā whārangi i whakarerekētia e tēnei pūnga i roto i ngā tauwhitinga kua oti ka rongoa ki te keteroki ā-ao i runga i te PowerHA. Ka tīmata anō te pūnga i roto i tētahi whirihoranga kua tangohia i runga i tētahi o ngā tūmau taupū, ka hurihia ngā tauwhitinga kāore anō kia oti, ka tukuna ngā raka.
E rua ngā tūmau e rere ana a PowerHA, ā, ka tāruatia ngātahitia e te pūnga matua tōna āhua. Mēnā ka rahua te pūnga matua, ka haere tonu te mahi a te tautau PowerHA i runga i te pūnga tārua.
He pono, mā te uru atu ki tētahi huinga raraunga mā tētahi pūnga kotahi ka pai ake te mahi whānui o te rōpū. Ka taea e PureScale te kite kei te tukatukahia tētahi wāhi raraunga e tētahi pūnga kotahi, kātahi ka tukatukahia ngā raka katoa e pā ana ki taua wāhi e taua pūnga ā-rohe, me te kore e kōrero ki a PowerHA. Heoi, ina ngana te tono ki te uru atu ki aua raraunga mā tētahi atu pūnga, ka tīmata anō te tukatuka raka pokapū.
Ko ngā whakamātautau ā-roto a IBM, i whakahaerehia me te kawenga mahi o te 90% pānui me te 10% tuhi, he rite tonu ki ngā kawenga mahi whakaputa o te ao tūturu, e whakaatu ana i te tauine tata-rārangi tae atu ki te 128 pona. Engari, kāore i whakaaturia ngā tikanga whakamātautau.
HPE Kore-Mutu SQL
Kei a Hewlett-Packard Enterprise tana ake tūāpapa wātea-nui. Ko te tūāpapa NonStop, i whakarewaina i te tau 1976 e Tandem Computers. I te tau 1997, i hokona te kamupene e Compaq, ā, i hanumi rātou ki a Hewlett-Packard i te tau 2002.
Ka whakamahia a NonStop hei hanga i ngā tono tino hira, pērā i te HLR, i te tukatuka kāri peeke rānei. Ka tukuna te tūāpapa hei taputapu pūmārō me te pūmanawa, tae atu ki ngā pūnga rorohiko, he pūnaha rokiroki raraunga, me ngā taputapu whakawhitiwhiti kōrero. Ko te whatunga ServerNet (Infiniband i roto i ngā pūnaha hou) e mahi ana mō te whakawhitiwhiti kōrero i waenga i ngā pūnga me te urunga atu ki te pūnaha rokiroki raraunga.
I whakamahia e ngā putanga tōmua o te pūnaha ngā tukatuka motuhake i tukutahitia tetahi ki tetahi: i mahia ngā mahi katoa i runga i te tukutahitanga e ngā tukatuka maha, ā, ki te rahua tetahi tukatuka, ka kati, ko tetahi atu ka haere tonu te mahi. I muri mai, ka neke te pūnaha ki ngā tukatuka tikanga (MIPS tuatahi, kātahi ko Itanium, ā, i te mutunga ko x86), ā, i whakamahia ētahi atu tikanga mō te tukutahitanga:
- Karere: He māhanga "atarangi" tō ia tukanga pūnaha, ā, ka tukuna atu e te tukanga hohe ngā karere mō tōna tūnga i ia wā; ki te kore e angitu te tukanga matua, ka tīmata te tukanga atarangi mai i te wā i whakatauhia e te karere whakamutunga;
- Pōti: He wāhanga taputapu motuhake tō te pūnaha rokiroki e whakaae ana ki ngā tono ōrite maha, ā, ka whakahaerehia mēnā ka ōrite ngā tono; kaua e tukutahi ā-tinana, ka mahi kore tukutahi ngā tukatuka, ā, ka whakaritea ngā hua o tā rātou mahi i ngā pūwāhi I/O anake.
Mai i te tau 1987, kua whakahaerehia e te tūāpapa NonStop tētahi Pūnaha Raraunga Whakawhanaungatanga – ko SQL/MP te tuatahi, ā, muri iho ko SQL/MX.
Kua wehea te pātengi raraunga katoa kia maha ngā wāhanga, ā, ko ia wāhanga e whakahaerehia ana e tana ake tukanga Kaiwhakahaere Uru Raraunga (DAM). Ka whakahaerehia te tuhi raraunga, te pupuri raraunga, me te raka. Ka whakahaerehia te tukatuka raraunga e ngā Tukanga Tūmau Kaiwhakahaere e rere ana i runga i ngā pona kotahi me ngā kaiwhakahaere raraunga e rite ana. Ka wehea e te kaiwhakarite SQL/MX ngā mahi i waenga i ngā kaiwhakahaere, ā, ka whakakotahi i ngā hua. Ina hiahiatia he huringa ōrite, ka whakamahia te kawa tuku rua-wāhanga e whakaratohia ana e te whare pukapuka TMF (Transaction Management Facility).
Ka taea e NonStop SQL te whakarite i ngā tukanga kia kore ai ngā uiui tātari roa e whakararuraru i te whakahaerenga o ngā tauwhitinga. Heoi, ko tana kaupapa he tukatuka i ngā tauwhitinga poto, ehara i te tātari. Ka oati te kaiwhakawhanake i te wātea o te tautau NonStop i ngā "iwa" e rima, ko te tikanga he rima meneti noa iho te wā whakatā i ia tau.
SAP-HANA
I te marama o Noema 2010 i puta ai te tukunga pumau tuatahi o te HANA DBMS (1.0), ā, i te marama o Mei 2013 i huri te mōkihi SAP ERP ki te HANA. E hangai ana te tūāpapa ki ngā hangarau kua riro mai: TREX Search Engine (rapu i roto i te rokiroki pou), P*TIME DBMS me MAX DB.
Ko te kupu "HANA" he kupu whakarāpopoto mō te High Performance Analytical Appliance. Ka tukuna tēnei DBMS hei waehere ka taea te whakahaere i runga i tētahi tūmau x86, engari ka whakaaetia ngā tāutanga whakaputa i runga i ngā taputapu kua whakamanahia anake. Kei te wātea ngā otinga mai i HP, Lenovo, Cisco, Dell, Fujitsu, Hitachi, me NEC. Ka taea e ētahi whirihoranga Lenovo te whakahaere me te kore he SAN, me te taupū GPFS i runga i ngā puku ā-rohe e mahi ana hei rokiroki tiritahi.
He rerekē te HANA i ngā tūāpapa kua whakarārangihia i runga ake nei, he DBMS kei roto i te mahara, arā, ko te ahua raraunga tuatahi ka rongoatia ki roto i te RAM, ā, ko ngā rangitaki me ngā whakaahua poto anake ka tuhia ki te kōpae hei whakaora i ngā āhuatanga kino.
Ko ia pūnga tautau HANA te kawenga mō tōna ake wāhanga o ngā raraunga, ā, kei roto i tētahi wāhanga motuhake te mahere raraunga—te Tūmau Ingoa—kei runga i te pūnga kaiwhakarite. Kāore ngā raraunga e tāruatia i waenga i ngā pūnga. Kei runga hoki i ia pūnga ngā mōhiohio raka, engari he taputapu tirotiro raka ā-ao kei te pūnaha.
Ina hono atu ki tētahi taupū HANA, ka tikiakehia e te kiritaki tana āhuarangi, ā, ka taea te uru tika ki tētahi pūnga i runga i ngā raraunga e hiahiatia ana. Mena ka pāngia ngā raraunga i runga i tētahi pūnga kotahi e tētahi tauwhitinga, ka taea te whakahaere ā-rohe e taua pūnga. Heoi, ki te whakarerekētia ngā raraunga i runga i ngā pūnga maha, ka whakapā atu te pūnga tīmata ki te pūnga kaiwhakarite, e whakatuwhera ana, e whakarite ana hoki i te tauwhitinga tohatoha, e tuku ana mā te whakamahi i tētahi kawa tuku rua-wāhanga kua arotauhia.
Kua tāruatia te pūnga kaiwhakahaere, nō reira, ki te kore e angitu te kaiwhakahaere, ka tangohia tonutia e te pūnga tārua. Heoi, ki te kore e angitu tētahi pūnga raraunga, ko te huarahi anake hei uru atu ki ana raraunga ko te tīmata anō i te pūnga. I te nuinga o te wā, ka pupuri ngā tautau HANA i tētahi tūmau tāpiri hei tīmata anō i te pūnga ngaro i te wā tere rawa atu.
Source: will.com
