Cov thev naus laus zis los txhim kho kev ua tau zoo raws li kev siv SSDs thiab siv dav hauv cov tshuab khaws cia tau ntev tau tsim. Ua ntej tshaj plaws, nws yog kev siv SSD ua qhov chaw cia, uas yog 100% zoo, tab sis kim. Yog li ntawd, kev siv thev naus laus zis thiab kev siv caching, qhov twg SSDs tsuas yog siv rau cov ntaub ntawv nrov tshaj plaws ("kub"). Tiering yog qhov zoo rau cov xwm txheej ntawm lub sijhawm ntev (hnub-lub lim tiam) siv cov ntaub ntawv "kub". Caching, ntawm qhov tsis sib xws, yog siv sijhawm luv luv (feeb-teev) siv. Ob qho kev xaiv no yog siv rau hauv qhov system cia . Hauv tsab xov xwm no peb yuav saib qhov kev siv ntawm qhov thib ob algorithm - .
Lub ntsiab lus ntawm SSD caching thev naus laus zis yog kev siv SSDs ua qhov nruab nrab cache ntawm hard drives thiab tus maub los lub RAM. Qhov kev ua tau zoo ntawm SSD yog, ntawm chav kawm, qis dua qhov ua tau zoo ntawm tus tswj hwm tus kheej cache, tab sis qhov ntim yog qhov kev txiav txim siab dua. Yog li ntawd, peb tau txais ib qho kev sib haum xeeb ntawm kev ceev thiab ntim.
Cov lus qhia rau kev siv SSD cache rau kev nyeem ntawv:
- Qhov tseem ceeb ntawm kev nyeem ntawv tshaj li kev sau ntawv ua haujlwm (feem ntau yog rau databases thiab web applications);
- Lub xub ntiag ntawm lub fwj hauv daim ntawv ntawm kev ua haujlwm ntawm lub hard drive array;
- Tus nqi ntawm cov ntaub ntawv xav tau tsawg dua qhov loj ntawm SSD cache.
Cov lus qhia rau kev siv nyeem ntawv + sau SSD cache yog tib yam, tshwj tsis yog rau qhov xwm txheej ntawm kev ua haujlwm - hom sib xyaw (piv txwv li, cov ntaub ntawv server).
Feem ntau cov neeg muag khoom cia siv nyeem nkaus xwb SSD cache hauv lawv cov khoom. Qhov tseem ceeb sib txawv Lawv muab lub peev xwm los siv lub cache rau kev sau ntawv thiab. Txhawm rau qhib SSD caching kev ua haujlwm hauv QSAN khaws cia, koj yuav tsum yuav daim ntawv tso cai cais (muab hluav taws xob).
SSD cache nyob rau hauv XCubeSAN yog siv lub cev nyob rau hauv daim ntawv ntawm cais SSD cache pas dej ua ke. Nws tuaj yeem muaj txog li plaub ntawm lawv hauv qhov system. Txhua lub pas dej, tau kawg, siv nws cov txheej txheem ntawm SSDs. Thiab twb nyob rau hauv cov khoom ntawm lub virtual disk peb txiav txim seb nws puas yuav siv lub cache pas dej ua ke thiab qhov twg. Ua kom siv tau thiab tsis siv lub cache rau ntim tuaj yeem ua tiav hauv online yam tsis muaj I / O. Koj tuaj yeem kub ntxiv SSDs rau hauv pas dej thiab tshem tawm ntawm qhov ntawd. Thaum tsim SSD pas dej ua ke cache, koj yuav tsum xaiv hom twg nws yuav ua haujlwm hauv: nyeem nkaus xwb lossis nyeem + sau. Nws lub cev lub koom haum nyob ntawm qhov no. Txij li thaum muaj peev xwm muaj ntau lub pas dej cache, lawv txoj haujlwm tuaj yeem sib txawv (uas yog, lub kaw lus tuaj yeem muaj ob qho tib si nyeem thiab nyeem + sau cache pas dej ua ke tib lub sijhawm).
Yog tias siv cov ntawv nyeem nkaus xwb, nws tuaj yeem muaj 1-8 SSDs. Disks tsis tas yuav yog tib lub peev xwm thiab tib tus neeg muag khoom, vim lawv tau muab tso ua ke rau hauv NRAID + qauv. Tag nrho SSDs hauv pas dej tau sib koom. Lub kaw lus ntawm nws tus kheej sim ua kom sib piv cov lus thov tuaj ntawm txhua qhov SSDs kom ua tiav qhov ua tau zoo tshaj plaws. Yog tias ib qho ntawm SSDs ua tsis tiav, tsis muaj dab tsi phem yuav tshwm sim: tom qab tag nrho, lub cache tsuas muaj ib daim ntawv luam ntawm cov ntaub ntawv khaws cia rau ntawm qhov chaw ntawm lub hard drive. Nws tsuas yog tias cov nyiaj muaj SSD cache yuav txo qis (lossis dhau los ua xoom yog siv tus thawj SSD cache los ntawm ib lub tsav).
Yog tias lub cache siv rau kev nyeem ntawv + sau cov haujlwm, ces tus naj npawb ntawm SSDs hauv pas dej ua ke yuav tsum yog ntau yam ntawm ob, vim tias cov ntsiab lus tau tsom rau ntawm ob lub drives (NRAID 1+ qauv siv). Duplicating lub cache yog qhov tsim nyog vim nws yuav muaj cov ntaub ntawv uas tseem tsis tau sau rau hauv lub hard drive. Thiab nyob rau hauv cov ntaub ntawv no, tsis ua hauj lwm ntawm SSD los ntawm lub cache pas dej ua ke yuav ua rau poob cov ntaub ntawv. Nyob rau hauv rooj plaub ntawm NRAID 1+, qhov ua tsis tiav ntawm SSD tsuas yog ua rau lub cache raug xa mus rau lub xeev nyeem nkaus xwb, nrog cov ntaub ntawv tsis sau tau muab pov tseg rau hauv hard drive array. Tom qab hloov qhov yuam kev SSD, lub cache yuav rov qab mus rau nws qhov kev ua haujlwm qub. Los ntawm txoj kev, kom muaj kev ruaj ntseg ntau dua, koj tuaj yeem muab cov khoom kub tshwj xeeb rau kev nyeem + sau cache.
Thaum siv SSD caching muaj nuj nqi hauv XCubeSAN, muaj ntau qhov yuav tsum tau ua rau tus nqi ntawm lub cim xeeb ntawm cov tswj chaw cia: ntau lub cim xeeb, qhov loj dua lub pas dej cache yuav muaj.
Tsis zoo li feem ntau cov chaw tsim khoom lag luam, uas tsuas yog muaj kev xaiv qhib / tawm SSD cache, QSAN muab ntau txoj kev xaiv. Hauv particular, koj tuaj yeem xaiv lub cache kev khiav hauj lwm hom nyob ntawm seb qhov xwm txheej ntawm lub load. Muaj peb qhov preset templates uas ze tshaj plaws hauv lawv txoj haujlwm rau cov kev pabcuam sib raug: database, file system, web service. Tsis tas li ntawd, tus thawj tswj hwm tuaj yeem tsim nws tus kheej profile los ntawm kev teeb tsa qhov tseem ceeb parameter:
- Block loj (Cache Block Size) β 1/2/4 MB
- Tus naj npawb ntawm kev thov kom nyeem ib qho thaiv kom nws tau theej rau hauv cache (Populate-on-Read Threshold) - 1..4
- Tus naj npawb ntawm kev thov kom sau ib qho thaiv kom nws tau theej rau hauv lub cache (Populate-on-Write Threshold) - 0..4
Profiles tuaj yeem hloov pauv sai, tab sis, ntawm chav kawm, nrog cov ntsiab lus ntawm lub cache rov pib dua thiab nws qhov tshiab "ua kom sov".
Xav txog lub hauv paus ntsiab lus ntawm kev ua haujlwm ntawm SSD cache, peb tuaj yeem hais txog cov haujlwm tseem ceeb thaum ua haujlwm nrog nws:
Nyeem cov ntaub ntawv thaum nws tsis nyob hauv lub cache
- Kev thov los ntawm tus tswv tsev tuaj txog ntawm tus tswj hwm;
- Txij li cov neeg thov tsis nyob hauv SSD cache, lawv tau nyeem los ntawm lub hard drive;
- Cov ntaub ntawv nyeem yog xa mus rau tus tswv tsev. Nyob rau tib lub sijhawm, kev kuaj xyuas kom pom tias cov blocks no yog "kub";
- Yog tias muaj, ces lawv tau theej rau SSD cache rau kev siv ntxiv.
Nyeem cov ntaub ntawv thaum nws nyob hauv lub cache
- Kev thov los ntawm tus tswv tsev tuaj txog ntawm tus tswj hwm;
- Txij li thaum cov ntaub ntawv thov nyob hauv SSD cache, nws tau nyeem los ntawm qhov ntawd;
- Cov ntaub ntawv nyeem yog xa mus rau tus tswv tsev.
Sau cov ntaub ntawv thaum siv nyeem cache
- Ib daim ntawv thov los ntawm tus tswv tsev tuaj txog ntawm tus tswj;
- Cov ntaub ntawv yog sau rau hard drives;
- Cov lus teb uas qhia tau hais tias ua tiav cov ntaub ntawv raug xa rov qab mus rau tus tswv tsev;
- Nyob rau tib lub sijhawm, nws raug kuaj xyuas seb qhov thaiv puas yog "kub" (qhov Populate-on-Sau Threshold parameter piv). Yog tias muaj, ces nws tau theej rau SSD cache rau kev siv tom qab.
Sau cov ntaub ntawv thaum siv cov ntawv nyeem + sau cache
- Ib daim ntawv thov los ntawm tus tswv tsev tuaj txog ntawm tus tswj;
- Cov ntaub ntawv raug sau rau SSD cache;
- Cov lus teb uas qhia tau hais tias ua tiav cov ntaub ntawv raug xa rov qab mus rau tus tswv tsev;
- Cov ntaub ntawv los ntawm SSD cache yog sau rau hard drives hauv keeb kwm yav dhau;
Tshawb xyuas hauv kev nqis tes ua
Test sawv
2 servers (CPU: 2 x Xeon E5-2620v3 2.4Hz / RAM: 32GB) txuas nrog ob lub chaw nres nkoj ntawm Fiber Channel 16G ncaj qha mus rau XCubeSAN XS5224D cia qhov system (16GB RAM / maub los).
Peb siv 16 x Seagate Constellation ES, ST500NM0001, 500GB, SAS 6Gb/s, ua ke hauv RAID5 (15+1), rau cov ntaub ntawv array thiab 8 x HGST Ultrastar SSD800MH.B, HUSMH8010BSS200, AS100 as12.
2 ntim tau tsim: ib qho rau txhua tus neeg rau zaub mov.
Kuaj 1. Nyeem-tsuas SSD cache los ntawm 1-8 SSDs
SSD Cache
- I/O Hom: Customization
- Cache Block Loj: 4MB
- Populate-on-read Threshold: 1
- Populate-on-write Threshold: 0
I/O Pattern
- Cov cuab yeej: IOmeter V1.1.0
- Cov neeg ua haujlwm: 1
- Tshaj Tawm (Queue Depth): 128
- Access Specifications: 4KB, 100% Nyeem, 100% Random
Hauv kev xav, ntau SSDs hauv lub pas dej cache, qhov ua tau zoo dua. Hauv kev xyaum, qhov no tau lees paub. Qhov tsuas yog qhov tseem ceeb ntawm cov SSDs nrog cov ntim me me tsis ua rau muaj kev cuam tshuam tawg.
Kuaj 2. SSD cache hauv hom nyeem + sau nrog 2-8 SSDs
SSD Cache
- I/O Hom: Customization
- Cache Block Loj: 4MB
- Populate-on-read Threshold: 1
- Populate-on-write Threshold: 1
I/O Pattern
- Cov cuab yeej: IOmeter V1.1.0
- Cov neeg ua haujlwm: 1
- Tshaj Tawm (Queue Depth): 128
- Access Specifications: 4KB, 100% Sau, 100% Random
Qhov tshwm sim zoo ib yam: kev ua tau zoo ntawm kev loj hlob thiab kev loj hlob raws li tus naj npawb ntawm SSDs nce.
Hauv ob qhov kev sim, tus nqi ntawm cov ntaub ntawv ua haujlwm tsawg dua li tag nrho cov cache loj. Yog li ntawd, dhau sij hawm, tag nrho cov blocks tau theej rau lub cache. Thiab txoj haujlwm, qhov tseeb, twb tau ua nrog SSDs, xyaum tsis cuam tshuam rau hard drives. Lub hom phiaj ntawm cov kev ntsuam xyuas no yog ua kom pom tseeb qhov ua tau zoo ntawm kev ua kom sov lub cache thiab ntsuas nws qhov kev ua tau zoo nyob ntawm seb muaj pes tsawg tus SSDs.
Tam sim no cia peb rov qab los rau hauv lub ntiaj teb thiab tshawb xyuas qhov xwm txheej muaj tseeb dua, thaum cov ntaub ntawv ntau dua li qhov cache loj. Txhawm rau kom qhov kev xeem dhau los ntawm lub sijhawm tsim nyog (lub sij hawm cache "sov-up" nce ntau vim qhov ntim loj ntxiv), peb yuav txwv qhov ntim loj rau 120GB.
Test 3. Database emulation
SSD Cache
- Hom I/O: Database
- Cache Block Loj: 1MB
- Populate-on-read Threshold: 2
- Populate-on-write Threshold: 1
I/O Pattern
- Cov cuab yeej: IOmeter V1.1.0
- Cov neeg ua haujlwm: 1
- Tshaj Tawm (Queue Depth): 128
- Access Specifications: 8KB, 67% Nyeem, 100% Random
Txiav txim
Qhov tseeb qhov xaus, tau kawg, yog qhov ua tau zoo ntawm kev siv SSD cache los txhim kho kev ua haujlwm ntawm txhua qhov chaw cia. Siv rau Cov nqe lus no siv tau tag nrho: SSD caching muaj nuj nqi tau ua tiav zoo. Qhov kev txhawj xeeb no txhawb kev nyeem ntawv thiab nyeem + sau hom, hloov tau yooj yim rau txhua qhov kev siv scenario, nrog rau kev ua tau zoo ntawm lub kaw lus tag nrho. Yog li ntawd, rau tus nqi tsim nyog heev (tus nqi ntawv tso cai yog piv rau tus nqi ntawm 1-2 SSDs), koj tuaj yeem ua kom muaj kev ua tau zoo tag nrho.
Tau qhov twg los: www.hab.com