SQL Server Overview

Gii thiu chung cch Qun tr CSDL trong SQL Server 2000

Ngi vit: Nguyn Vn Dng

Ni dung trnh byI. II.1. 2. 3.

III.1. 2.

Gii thiu chung Lm vic vi Database To mi Database Sao lu Database Phc hi Database Thit lp c ch bo mt trong SQL Server Kin trc bo mt Cc mc bo mt

Ni dung trnh byS u quyn v xc nhn quyn hp l ca ti khon 5. Hierarchical Security 6. Thm windows user hoc group 7. Mt s system role v database role c nh ca SQL Server Gii thiu Data Transformation Services 1. Cc thnh phn ca DTS4.

I.

Ni dung trnh byIV. 1. 2. 3. 4. 5.

Tng quan v ReplicationKhi nim v Replication Cc loi Replication Tc dng ca Replecation S dng Replecation khi no? L do s dng.

Ni dung trnh byCch thc thc hin nhn bn 4. Nhn bn d liu qua Internet. 5. Nhn bn d liu qua FTP Qun tr CSDL khi gp s c 1. Gii thiu 2. Failover Cluster 3. S dng Failover Cluster 4. Log shiping3.

VI.

I. Gii thiu chungL mt h qun tr CSDL theo m hnh Client/Server

SQL Server c y cc chc nng v vic xy dng qun tr cc CSDL. iu hnh c s d liu ton x nghip, qun tr kho lu tr d liu, qun tr cc ti khon ngi dng, qun tr cc quyn truy nhp h thng, x l thng bo cnh gic ca h phc v v ln lch thc hin cc cng vic theo k hoch t ra, sao lp, kt ni mng Ngoi ra, SQL cn h tr xy dng cc kho d liu (Data Warehouse), truy vn d liu bng ngn ng t nhin (English Query), kt xut d liu ln web.

II.Lm vic vi Database1.

To mi Database S dng tin ch Attatch file y l qu trnh sao chp d liu t file CSDL c sn vo kho d liu. S dng Backup/Restore Database y l qu trnh sao chp lu tr file CSDL theo mt ng dn ch nh(Backup) hoc nhn li file CSDL c sn t mt ng dn ch nh thng qua vic Restore d liu.

II.Lm vic vi Database(Tip)

S dng tin ch copy sql server object trn DTS y l cng c ha v cc i tng c th lp trnh cho php trch dn, chuyn i, copy cc i tng d liu theo cc ngun d liu khc nhau n mt hay nhiu ngun tu theo yu cu s dng.

II.Lm vic vi Database(Tip)M hnh cho php xy dng cc package cha cc workflow phc tp thng qua DTS

Cc loi kt ni

Cc tc v

II.Lm vic vi Database(Tip)2.

Sao lu Database

Thit lp chin lc sao lu d liu d phng

i vi mi loi d liu khc nhau cn c mt chin lc thc hin sao lu khc nhau m bo vic thc hin phc hi d liu lun thnh cng v p ng cc yu cu cn c. thc hin k hoch sao lu d liu thnh cng cn:

Phn tch cc yu cu v phc hi d liu t k hoch thc hin phc hi d liu Chn ch phc hi d liu thch hp

II.Lm vic vi Database(Tip)

Cc thao tc thc hin sao lu d phng

Database BackupsMt database backup thc cht l mt bn sao d liu ca csdl c thc hin backup. y l mt thao tc n gin c thc hin nh k theo lch c xc nh sn. Database backup s dng nhiu khng gian nh hn transaction log v differential backups.

II.Lm vic vi Database(Tip)Differential BackupsDifferential backup ch ghi nhn cc thay i sau ln thc hin database backup cui cng. C th thc hin differential backup thng xuyn lm nhm gim ri ro mt d liu khi c s c, do differential backups chim khng gian nh nh hn v thc hin nhanh hn do vi database backup.

II.Lm vic vi Database(Tip)Transaction Log Backup Transaction log l mt chui cc s kin c ghi nhn khi cc transaction c thc hin trn csdl bt u t transaction trong transaction log c thc hin sao lu ln cui cng. Vi transaction log backup ta c th phc hi d liu ti ng thi im xc nh hay ti thi im d liu gp s c.

II.Lm vic vi Database3.

Phc hi Database Cc ch phc hi d liu

Ch phc hi d liu n ginVi ch ny CSDL c th c phc hi ti thi im ca ln backup cui cng. Tuy nhin khng th phc hi d liu ti thi im xy ra s c hoc ti mt thi im xc nh. Mun nh vy nn chn ch Full Recovery hoc Bulk-Logged Recovery.

II.Lm vic vi Database(Tip)Ch phc hi d liu ton vn (Full Recovery) Ch ny s dng cc backup ca CSDL v backup ca transaction log phc hi li ton b d liu. Full Recovery h tr kh nng phc hi CSDL ti thi im xy ra s c hoc ti mt thi im xc nh no . m bo ton b d liu u c phc hi nh ch ny, tt c cc thao tc bao gm SELECT INTO, CREATE INDEX u phi c ghi nhn vo file log.

II.Lm vic vi Database(Tip)Phc hi d liu theo khi c lu(BulkLogged Recovery) Trong ch Bulk-Logged Recovery, khi lng d liu cn phc hi ln hn rt nhiu so vi ch Full Recovery. Ngoi ra ch ny ch cho php phc hi d liu n ln commit cui cng ca transaction log backup ch khng phc hi d liu ti mt thi im xc nh no .

III.Thit lp c ch bo mt trong SQL Server1.

Kin trc bo mtKin trc ca mt h thng bo mt ph thuc vo cc users v cc users groups. M hnh sau m t cch cc users v cc global groups, local groups trong Windows 2000 nh x vo security accounts trong SQL Server. SQL Server iu khin cc security accounts c lp vi cc account trong Windows 2000, Windows NT.

III.Thit lp c ch bo mt trong SQL Server(Tip)

M hnh nh x cc user t Windows NT, 2000 sang SQL Server.


2.

Cc mc bo mtSQL Server 2000 cho php nh qun tr tu chn chy my phc v trong hai ch bo mt:

Windows Authentication:

Cho php ngi s dng kt ni vi SQL Server thng qua ti khon ngi s dng ca Windows NT hay Windows 2000(Windows only).

Mixed Mode.

Cho php ngi s dng kt ni vo my phc v SQL Server thng qua ch

III.Thit lp c ch bo mt trong SQL Server(Tip)M hnh bo mt ca SQL Server


3.

S u quyn v xc nhn quyn hp l ca ti khon

S u quyn security account l kh nng kt ni n nhiu servers, v vi mi server thay i, n gi li kh nng chng thc ca client u tin. Sau khi mt user c xc nhn v cho php ng nhp vo mt instance ca SQL Server. Mi user trong mi database c quyn thao tc trn cc i tng (Table,View, Stored Produce Trigger) trn database .


User account ny c th c nh x t cc ti khon ngi s dng ca Windows NT /2000, cc nhm Windows NT /2000 m trong user l mt thnh vin, hay cc ti khon ng nhp (login accounts) ca SQL Server.


4.

Hierarchical Security (S phn cp bo mt) n gin ho vic qun tr nhiu users, SQL Server s dng cc group v cc role Group l n v qun tr trong Windows NT / 2000 cha cc users ca Windows NT/2000 hay cc groups khc. Role l n v qun tr trong SQL Server cha cc SQL Server logins, Windows NT 4.0/2000 logins, groups, hay cc roles khc.


Vic t cc users vo cc groups v roles gip bn d dng phn cp hoc hu quyn cho php n nhiu users cng mt ln. Vic thit lp security nh ngha cho mt group l p dng ton b cho tt c cc thnh vin (member) ca group . Khi mt group l member ca mt group cp cao hn, th tt c cc member ca group s k tha vic thit lp bo mt t group cp cao hn .

III.Thit lp c ch bo mt trong SQL Server(Tip)5.

Thm Windows user hoc group Thm Users: y l qu trnh s dng cc li users c sn ca windows. Cc user ny do windows to ra. SQL Server s s dng cc user ny dng kt ni vo mt instance ca SQL Server. Thm Group: Vic to Group l do Windows thc hin. Mc ch ca n l nhm cc user theo cc nhm phc v cho mc ch khc nhau mi Group c qun l bi mt Domain tng ng.


6.

Mt s Server role v database role c nh ca SQL Server

Server role: y l tp lut dng lm vic vi h thng qun tr SQL Server. System admintrator: C th thc hin tt c

cc hot ng ca SQL Server Server admintrator: C th thit lp cc tu chn cu hnh server. Setup admintrator: C th qun l cc linked servers v khi ng cc procedure.


Security admintrator: C th qun l cc login v cc quyn Create Database, cng c th c c cc li v thay i password. Process admintrator: C th qun l cc tin trnh ang chy trong SQL Server. Database creator: C th to, sa i v xa cc CSDL Disk admintrator: C th qun l cc file trn a. Bulk admintrator: C th thc thi cc cu lnh Bulk Insert

III.Thit lp c ch bo mt trong SQL Server(Tip) Database

Database.

role: Cc tp lut dng lm vic vi

db_owner: Thc thi tt c cc hot ng cng nh

duy tr cc thit lp cu hnh trong CSDL. Cc quyn ca role ny m rng cho tt c cc database role c nh khc. db_accessadmin: B sung hay loi b cc group hay user ca Windows NT 4.0/2000 v cc user ca SQL Server trong CSDL. db_datareader: C th xem c tt c d liu trong tt c cc bng ca user trong CSDL db_datawriter: C th b sung, thay i hay xa d liu ca tt c cc bng ca user trong CSDL.


db_ddladmin: C th b sung, thay i hay xa cci tng trong CSDL (thc hin c tt c cc DLL) db_securityadmin: Qun l cc role v cc member ca database role trong SQL Server 2000 v qun l cc quyn thc thi cu lnh v i tng trong CSDL. db_backupoperator:C quyn backup CSDL db_denydatareader: Khng c php c d liu trong CSDL. db_denydatawriter: Khng c php thay i d liu trong CSDL.

IV.Gii thiu Data Transformation Servicesy l tin ch ca SQL Server dng trch dn chuyn i CSDL t nhiu ngun d liu khc nhau n mt hoc nhiu ngun d liu.1.

Cc thnh phn ca DTSDTS Packages: DTS package l mt tp hp c sp

xp cc kt ni, cc DTS tasks, DTS transformation v cc rng buc thc hin theo tin trnh c t hp cng vi DTS tool v c lu tr di dng SQL Server, SQL Server 2000 Meta Data Services

IV.Gii thiu Data Transformation Services(Tip)

DTS Task:

Mt DTS task l mt chc nng ring bit c thc hin nh mt bc n trong package. C th s dng cc task ny mt cch d dng thng qua cc icon c h tr trong DTS Designer hoc thng qua lp trnh.

DTS Tranformations:

Mt DTS transformation l mt hoc nhiu chc nng hay thao tc c s dng trn cc mnh d liu trc khi d liu c chuyn n ch.


DTS Package Workflow:

Workflow thc cht l s iu khin th t thc hin cc bc v iu kin thc hin cc bc trong mt package.

Connetivity: DTS da trn kin trc OLE DB kt ni n cc ngun d liu khc nhau.


DTS Tools:

DTS cung cp mt s cng c n gin to lp thc hin v qun l package.

IV.Gii thiu Data Transformation Services(Tip)2.

To lp v qun l cc DTS package

Cc task chuyn i d liu: Data Transformation Services (DTS) s dng cu trc thnh phn gi l DTS data pump chuyn i d liu. Transform Data Task: cho php sao chp v chuyn d liu gia cc ngun d liu OLEDB. Data Driven Query task: cho php thc hin linh hot cc cu lnh Transact-SQL (cc SP_th tc c lu, cc cu lnh INSERT, UPDATE hoc DELETE) ParallelDataPump Task Object: cho php copy v chuyn i d liu phn cp OLE BD.


Cc task sao chp v qun l d liu: Bulk Insert task: H tr cch thc copy d liu c khi lng ln t cc file text n cc bng hoc view trong SQL Server mt cch nhanh nht. Excute SQL Server task: Thc thi cc cu lnh SQL trong qu trnh thc hin v lu tr d liu kt qu ca truy vn. Copy SQL Server Objects task: Sao chp hoc to lp cc i tng SQL Server nh l bng, view, cc indext instance SQL Server ny sang instance SQL Server khc.

IV.Gii thiu Data Transformation Services(Tip)Ngoi ra cn c cc tc v ton b csdl, cc job, cc thng bo li, cc login cc th tc c lu trong csdl master. Transfer Database Task: Cho php copy hay di chuyn mt csdl SQL Server t instance ca SQL Server 7.0 sang instance ca SQL Server 2000 hoc gia cc instance ca SQL Server 2000. Transfer Error Messages Task: Dng copy cc thng bo li do ngi s dng to ra bng th tc sp_addmessage. Transfer Logins Task: Cho php copy cc login t instance ca SQL Server 7.0 hoc 2000 sang instance SQL Server 2000.


Transfer Jobs Task: Cho php copy cc job t instance ca SQL Server 7.0 hoc 2000 sang instance SQL Server 2000. Transfer Master Stored Procedures Task: Cho php copy cc th tc c lu (sp) t csdl master ca instance SQL Server 7.0 hoc 2000 sang instance SQL Server 2000.

V.Tng quan v Replication1.

Khi nim v Replication

Replication: L qu trnh sao chp d liu gia cc csdl trn cng mt server hoc trn nhiu server khc nhau c kt ni vi nhau thng qua mng LAN, WAN v Internet. Publisher: L server hoc csdl gi d liu n server hoc csdl khc. Publisher cha cc publication. Subscriber: L server hoc csdl nhn d liu t server hoc csdl khc.

V.Tng quan v Replication(Tip)Distributor: L server gim st v qun l dng d liu i qua h thng sao chp (Replication system). Server ny cha csdl phn tn (distribution database). Publication: L tp hp cc articles c gi n subscriber server hoc subscriber database. Article l n v c bn ca qu trnh sao chp (replication), n c th l mt bng, mt tp con ca bng hoc mt i tng ca csdl. Subscription l nhm d liu m mt server hoc mt csdl s nhn. C hai loi subcription: push v pull subcription.

V.Tng quan v Replication(Tip)

Push subscription: L subscription m publishing server y qua subcriber theo nh k. Pull subscription: L subscription m subscribing server kt ni n csdl phn tn (distribution database) ko d liu v. Distribution database: L csdl h thng c lu trn Distributor; n c dng lu cc cng vic sao chp (snapshot jobs) v cc transactions ang trng thi ch c phn phi n Subscribers. Csdl ny khng cha bt k mt bng no do ngi s dng to ra.

V.Tng quan v Replication(Tip)2.

Cc loi Replication

C 3 loi Replication:Snapshot replication:

L loi n gin nht, khi thc hin snapshot replication th ton b d liu cn nhn bn (replication) s c sao chp nguyn bn t csdl ca Publisher sang Subscriber. Mi ln thc hin ng b ha ton b d liu t Publisher c ln Subscriber. Loi ny c li khi cn thc hin replicate thng xuyn v kch thc d liu khng qu ln. Snapshot replication thng c dng khi cn duyt d liu tnh chng hn nh danh sch gi c, mc lc trc tuyn hoc h tr ra quyt nh.


Transactional replication: Vi loi ny SQL Server qun l v lu gi tt c cc thay i din ra trn article vo distribution database. Sau cc thay i ny c p dng trn Subscriber theo th t nh khi c lu vo Distribution database. Khi vic thay i d liu phi c thc hin trn Publisher m bo tnh ng nht d liu.

V.Tng quan v Replication(Tip)Cui cng tt c cc Subcriber u c cng d liu ging nh Publisher. C th lp lch ng b ho d liu trn Subcriber v Publisher theo nh k. Nn s dng loi ny khi d liu dng replicate thng xuyn thay i hoc khi kch thc d liu ln v khng cn h tr tnh c lp d liu replicate trn Publisher v Subscriber hay khi cn c cc thuc tnh ACID ca mt transaction


Merge replication: y l loi phc tp nht, n c h tr tnh c lp d liu replicate trn Publisher v Subscriber. Trong trng hp ny SQL Server s qun l tt c cc thay i d liu trn c csdl ngun v ch sau tho g cc mu thun d liu da trn cc qui tc (rule) c thit lp trn d liu hoc da trn mt b tng thch d liu no do ngi s dng to ra. C th ng b ho d liu trn Publisher v Subscriber ngay khi c s thay i din ra hoc theo nh k hay theo yu cu.

V.Tng quan v Replication(Tip)Khi ng b ha, d liu thay i c th t Subscriber chuyn n Publisher v ngc li. Do nn ch n vic xung t d liu khi c nhiu ngi dng cng cp nht mt bn ghi. Nn s dng merge replication khi cn h tr tnh c lp thay i d liu trn Publisher v Subscriber.


Tc dng ca Replecation: Tc dng in hnh nht ca replication l lm cho d liu kh dng ngay bt c lc no chng c cn n. Cho php nhiu site sao chp cng mt d liu. C ch khi nhiu site cn c cng d liu hay phn loi server cho cc ng dng bo co.

V.Tng quan v Replication(Tip) Phn

loi cc ng dng OLTP t cc ng dng ch c nh l csdl OLAP, data marts, hay data warehouses. Cho tnh c lp cao. Ngi s dng c th lm vic, hiu chnh cc bn sao d liu khi khng kt ni n ngun d liu v c th cp nht cc thay i n ngun d liu khi c kt ni.

V.Tng quan v Replication(Tip)C th duyt qua d liu bng nhiu cch, chng hn nh duyt d liu bng cc ng dng Webbased Lm gim thiu cc xung t khi c nhiu ngi thay i d liu v truy vn v d liu c th c phn phi qua mng. Cng c th phn chia d liu da vo cc nhu cu ca cc n v kinh doanh hay ngi s dng khc.


S dng Replecation khi no?i vi cc t chc chuyn h tr cc ng dng khc nhau v phn cng v phn mm trong mi trng phn tn, replication tr nn cn thit lu tr cc d liu d tha. Ngoi ra n cng cn thit cho cc ng dng cn tnh c lp v d liu thng nht.


Replication l gii php cho mi trng phn phi d liu khi cn:

Sao chp v phn phi d liu n mt hay nhiu site. Phn phi cc bn sao d liu theo nh k. Phn phi cc d liu thay i n cc server khc. Cho php nhiu ngi s dng hay nhiu site thc hin cc thay i sau trn cc d liu c thay i li vi nhau, nhn bit v gii quyt cc xung t.


Xy dng cc ng dng s dng d liu trong cc mi trng trc tuyn v phi tuyn. Xy dng cc ng dng m ngi s dng cn duyt mt khi lng ln d liu Tu chn cc thay i ti cc site thu bao d iu khin giao dch ca cc nh xut bn.


L do s dng Chia x khi lng cng vic cho nhiu server khc nhau nhm gim ti cng vic. SQL Server c th qun l hn 15000 ngi dng trn mt processor v 10TB d liu. Ci thin kh nng d liu sn c: h iu hnh ngy cng pht trin i hi cc ng dng phi tng thch vi cc h khc nhau, khi cn phi c nhiu bn sao d liu trn nhiu my khc nhau c th lm vic hiu qu v thch nghi.

V.Tng quan v Replication(Tip)Cn chia x d liu t mt server trung tm n cc csdl khc. V d mt cng ty bo him cn gi cc giy t chng nhn bn quyn kinh doanh n cc doanh nghip th vi Replication qu trnh ny tr thnh t ng sao chp cc thng tin lin quan t csdl bn quyn n csdl giao dch. Gim lng giao thng trn mng.


Cch thc thc hin nhn bn

Lp cu hnh nhn bn d liu

Trc ht khi trin khai nhn bn l thit lp Publisher v Distributor. Distributor c th l mt server khc vi Publisher hoc c th l cng mt server. Distributor l thnh phn chnh trong Snapshot Replication v transactional replication; tuy nhin, vai tr ca Distributor b gii hn trong merge replication.

V.Tng quan v Replication(Tip)Distributor ch c s dng cho cc agent vi cc mc ch bo co v gim st. Trong merge replication, Publisher v Distributor thng cng mt server, gi l local Distributor. Sau khi Publisher v Distributor c thit lp, c th to cc xut bn phm da vo nhu cu d liu.

V.Tng quan v Replication(Tip) Khi

to v thc hin Initial Snapshot

Cho d loi replication no c chn nhn bn d liu th SQL Server 2000 cng khi to mt snapshot ban u cho lc v d liu sau lu vo th mc snapshot folder c chn khi to xut bn phm. Tuy nhin lc ng trong merge replication v cc n phm (csdl nhn d liu xut bn) cho mi snapshot s c to th cng. Snapshot Agent chun b cc file snapshot cha schema, d liu v cc i tng csdl lu vo snapshot folder, ghi nhn cc cng vic ng b trong c s d liu phn phi trn Distributor i vi snapshot replication hay transactional replication.


Hiu chnh d liu c nhn bn Tu thuc vo kiu nhn bn v cc ty chn c thit lp khi to xut bn phm, Subscriber c th hiu chnh d liu ri chuyn sang Publisher, sau phn tn n cc Subscriber khc. Cc loi replication v thit lp ty chn cho php Subscriber chuyn d liu thay i sang Publisher: Merge replication Snapshot replication hay transactional replication cp nht tc thi Snapshot replication hoc transactional replication cp nht hng i Bt k loi replication no m d liu c lc v th cc phn d liu c th c thay i ti cc site c nhn mt cch c lp m khng c xung t din ra gia cc site.

V.Tng quan v Replication(Tip) ng

b v phn tn d liu thay i

ng b d liu l qu trnh chuyn d liu gia Publisher v cc Subscriber sau khi initial Snapshot c to ra ti Subscriber. ng b d liu l qu trnh chuyn d liu gia Publisher v cc Subscriber. i vi snapshot replication, ng b ngha l to li snapshot Subscriber to mi lc v d liu ti csdl nhn d liu xut bn (Subscription) nht qun vi csdl xut bn (publication).


i vi transactional replication, ng b d liu ngha l d liu INSERTs, UPDATEs, DELETE v cc thay i khc c phn phi gia Publisher v Subscriber. i vi merge replication, ng b ngha l cc thay i d liu c thc hin trn nhiu site c trn vi nhau, cc xung t (nu c) c d tm v gii quyt. Cui cng tt c cc site u c d liu thng nht.

V.Tng quan v Replication(Tip)M hnh Snapshot replication

V.Tng quan v Replication(Tip)M hnh Merge replication

V.Tng quan v Replication(Tip)M hnh Transactional replication


Nhn bn d liu qua Internet C th dng Internet nh mt phng tin trung gian nhn bn d liu gia hai server cng kt ni vo Internet. Cch thc nhn bn d liu ph thuc vo hai yu t chnh: Ch bo mt cn thit cho mng cc b Tc kt ni vt l v tn sut kt ni ca mng cc b. Nu mng cc b kt ni Internet khng lin tc (dial_up) th cn phi thit lp nhn bn d liu qua giao thc FTP di chuyn cc file snapshot t ni ny n ni khc.


Nhn bn d liu qua FTP

C th thit lp kt ni ODBC qua TCP/IP gia Publisher/Distributor v Subscriber v dng mt site FTP chung chuyn i cc file snapshot khi thc hin nhn bn d liu qua Internet.

V.Tng quan v Replication(Tip) Cc

bc thit lp cu hnh nhn bn d liu bao gm:Thit lp giao thc TCP/IP cho Publisher hoc Distributor. To xut bn phm cho php Subscriber truy xut cc file snapshot qua FTP. To subscription truy xut snapshot qua FTP. To subscription agent dng TCP/IP.

VI. Qun tr CSDL khi gp s c1.

Gii thiu Microsoft a ra mt gii php khc phc cc hu qu do cc s c hng hc c th xy ra khi vn hnh my tnh mt cch nhanh chng, ng tin cy v t ng gi l Cluster nhm lm tng kh nng chu li ca h thng. Cluster c ngha l dng nhiu my tnh khc nhau thc hin mt chc nng no . Khi c s c trn my ny th my kia pht hin ra v m nhim cng vic thay cho my gp s c nhm phc phi cc s c mt cch nhanh nht. Qu trnh x l nh vy c gi l hot standby.

VI. Qun tr CSDL khi gp s c(Tip)C th xem Cluster nh l mt hp en. Khi ngi s dng kt ni n Cluster th h thy n nh ang hot ng trn mt h my tnh hay trn mt c s d liu nhng thc cht bn di l s dng 2 hay nhiu hn 2 h my tnh khc nhau phc v cho vic kt ni . K thut Cluster c tip cn theo hai hng: Failover cluster: h tr tin cy cao v kh nng phc hi nhanh khi gp s c cho cc my tnh lm server. Performance cluster: h tr cho cc thao tc thc hin khc nhau.

VI. Qun tr CSDL khi gp s c(Tip)

Microsoft gii thiu 02 dch v: Microsoft Cluster Service (MSCS): i km vi cc h iu hnh Win 2K/NT, cho php mt standby server m nhim cc chc nng ca server chnh khi gp s c hng hc. Network Load Balancing cluster (Federated server cluster): c h tr trong SQL Server, nhm gim ti server khi cn thc hin cc thao tc truy xut c s d liu c kch thc qu ln. y d liu c chia nh v t trn nhiu server khc nhau, mi server s cha mt phn d liu.

VI. Qun tr CSDL khi gp s c( Tip)2.

Failover ClusterTrong SQL server, Cluster c phn loi theo cch thit lp cu hnh nh sau: Active/Active: 2 instance SQL c ci t trn my tnh hot ng mt cch c lp v ngi s dng nhn thy c hai server SQL khc nhau. Nu mt SQL Server gp li, SQL Server cn li s m nhim thay cho server b li . Nh vy trong trng hp ny hai instance ca SQL server cng chy trn mt my tnh. Yu cu phn cng cao hn Active/passive.


Active/Passive: 2 instance SQL Server cng chy trn hai my tnh c lp Server active s m nhim vic thc hin cc thao tc truy xut d liu. Server passive khng lm g c, ch cho n khi server active gp s c th n s m nhim cng vic ca server active. Nh vy, nu c kinh ph th nn thit lp cluster theo cu hnh ny d ci t, d qun tr, tng kh nng thc hin.

VI. Qun tr CSDL khi gp s c(Tip)3.

Log shiping i vi cc ng dng khng qu quan trng ngi ta t s dng Cluster, thay vo ngi ta s dng Replication nhn bn ton b d liu t my tnh trung tm sang cc my con. Tuy nhin, Replication khng th ng vai tr Standby m nhim thay cho my tnh trung tm khi my tnh ny gp s c. lm tng kh nng chu li ca h thng m khng s dng Cluster v Replication ngi ta a ra mt phng thc Log Shipping.

VI. Qun tr CSDL khi gp s c(Tip)Log Shipping c gi l Warm standby, do Log Shipping c thc hin theo chu k thi gian nn d liu khng l thng tin cp nht ti thi im s c xy ra trn my tnh trung tm m l d liu c commit bi transaction cui cng trc khi s c xy ra. Mt s hn ch khi s dng Log Shipping: Khng t ng khi gp s c: Ngi qun tr c s d liu phi c mt gii quyt khi c s c xy ra.


Ngi s dng phi ch mt khong thi gian khc phc s c: khong thi gian ch i ny di hay ngn ph thuc vo cu hnh mng, vo cu hnh thc hin log shipping, vo ng dng b li D liu c th b thiu, lng d liu mt mt t hay nhiu ph thuc vo chu k thc hin ca log shipping di hay ngn v ph thuc vo transaction log. i khi cn phi thit lp li mt vi thng s th ng dng mi hot ng bnh thng tr li.

Xin cm n mi ngi lng nghe!

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