Oracle 11g RAC Interview Question and Answers

8/19/2019 Oracle 11g RAC Interview Question and Answers

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Oracle 11g RAC Interview question and answers1. What is the major diference between 10g and 11g RAC?

Well, there is not much diference between 10g and 11gR (1) RAC.

But there is a signicant diference in 11gR.

Prior to 11gR1(10g) RAC, the oowing were managed b! "race CR#

o !atabases

o "nstances

o A##lications

o $ode %onitoring

o &'ent er'ices

o igh A'ailabilit*

$rom 11gR%(onwards) its com&eted 'A stac managing and &roiding theoowing reso*rces as ie the other c*ster sotware ie +C# etc.

• !atabases

• "nstances

• A##lications

•

Cluster %anagement

• $ode %anagement

• &'ent er'ices

• igh A'ailabilit*

• $etwor+ %anagement (#ro'ides !$-$%!$! ser'ices on behal o othertraditional ser'ices) and CA$ / ingle Access Client $aming method, A"

• torage %anagement (with hel# o A% and other new AC les*stem)

• 2ime s*nchroni3ation (rather de#ending u#on traditional $2)

• Remo'ed 4 de#endent hang chec+er etc, manages with own additional monitor#rocess

%. What are "race C*ster Com&onents?

Cluster "nterconnect (A")


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hared torage (4CR5oting !is+)

Clusterware sotware

. What are "race RAC Com&onents?

5", $ode a##s etc.

-. What are "race erne Com&onents (nothing b*t how does "race RACdatabase difers than /orma singe instance database in terms o inaries and&rocess)

Basicall* 4racle +ernel need to switched on with RAC 4n o#tion when *ou con'ert to RAC,that is the diference as it acilitates ew RAC bg #rocess li+e 6%4$,6C7,6%!,6% etc.

o t*rn on RAC8 lin+ the oracle libraries9 cd 94RAC6&:4%&rdbmslib9 ma+e ; ins:rdbms.m+ rac:on8 rebuild oracle9 cd 94RAC6&:4%&bin

9 relin+ oracle4racle RAC is com#osed o two or more database instances. 2he* are com#osed o %emor*structures and bac+ground #rocesses same as the single instance database.4racle RACinstances use two #rocesses -&(-lobal &nAtomic Controlle to %emor* er'ice (AC%)-2?0;@>-lobal 2ransaction rocess6%4$>-lobal &n-lobal Cache er'ice rocess6C70>"nstance &n4racle RAC %anagement rocesses (R%n)

R%$>Remote la'e %onitor2. What is C*sterware?

otware that #ro'ides 'arious interaces and ser'ices or a cluster. 2*#icall*, this includesca#abilities that=

• Allow the cluster to be managed as a whole

• rotect the integrit* o the cluster

• %aintain a registr* o resources across the cluster

• !eal with changes to the cluster

• ro'ide a common 'iew o resources

3. What are the bacgro*nd &rocess that e4ists in 11gr% and *nctionait!?


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rocess$ame

unctionalit*

crsd

2he CR daemon (crsd) manages cluster resources based on congurationinormation that is stored in 4racle Cluster Registr* (4CR) or each resource.

2his includes start, sto#, monitor, and ailo'er o#erations. 2he crsd #rocessgenerates e'ents when the status o a resource changes.

cssd

Cluster *nchroni3ation er'ice (C)= %anages the cluster congurationb* controlling which nodes are members o the cluster and b* noti*ingmembers when a node @oins or lea'es the cluster. " *ou are using certiedthird;#art* clusterware, then C #rocesses interaces with *our clusterwareto manage node membershi# inormation. C has three se#arate#rocesses= the C daemon (ocssd), the C Agent (cssdagent), and theC %onitor (cssdmonitor). 2he cssdagent #rocess monitors the cluster and#ro'ides in#utout#ut encing. 2his ser'ice ormerl* was #ro'ided b* 4raclerocess %onitor daemon (o#rocd), also +nown as 4raenceer'ice on

Windows. A cssdagent ailure results in 4racle Clusterware restarting thenode.

dis+mon

!is+ %onitor daemon (dis+mon)= %onitors and #erorms in#utout#utencing or 4racle &adata torage er'er. As &adata storage can be addedto an* 4racle RAC node at an* #oint in time, the dis+mon daemon is alwa*sstarted when ocssd is started.

e'md&'ent %anager (&5%)= "s a bac+ground #rocess that #ublishes 4racleClusterware e'ents

mdnsd%ulticast domain name ser'ice (m!$)= Allows !$ re


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-rid 'irtual " address

ocls+dCluster +ill daemon (ocls+d)= andles instancenode e'ictions re


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7. As !o* said +oting 8 "CR 9is resides in A#: 9isgro*&s, b*t as &er start*&se;*ence "C##9 starts


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H. !atabase 6isteners listen the re


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!ata les !B "6&!ata -uardconguration

2em#orar* data

les

R%A$ bac+u#

sets

Changetrac+ingbitma#s

4nline redologs

R%A$ data leco#ies

4CR les

Archi'e logs 2rans#ort datales

A% "6&

1-. >ist e! bene


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acti'ities such as dro# or oKine andad'ancing the A% dis+ grou# com#atibilit*

:AR %ar+s A% allocation units as stale whenneeded

"nnn4ne or more A% sla'e #rocesses orming a#ool o connections to the A% instance orechanging messages

P@7n4ne or more #arallel sla'e #rocesses usedin etching data on clustered A%installation rom -59 'iews

1. What is node istener?

"n 11gr the listeners will run rom -rid "nrastructure sotware home

• 2he node listener is a #rocess that hel#s establish networ+ connections rom A%clients to the A% instance.

• Runs b* deault rom the -rid 94RAC6&:4%&bin director*

• 6istens on #ort 1I1 b* deault

• "s the same as a database instance listener

• "s ca#able o listening or all database instances on the same machine in addition to

the A% instance

• Can run concurrentl* with se#arate database listeners or be re#laced b* a se#aratedatabase listener

• "s named tnslsnr on the 6inu #latorm

12. What is #CA/ istener?

A scan listener is something that additional to node listener which listens the incoming dbconnection re


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• Registering cluster resources

sr'ctl manages 4racle resource/related o#erations=

• tarting and sto##ing database instances and ser'ices

• Also rom 11gR manages the cluster resources li+e networ+,'i#,dis+s etc

15. 'ow to contro "race C*sterware?

2o start or sto# 4racle Clusterware on a s#ecic node=

8 crsctl sto# crs

8 crsctl start crs

2o enable or disable 4racle Clusterware on a s#ecic node=

8 crsctl enable crs

8 crsctl disable crs17. 'ow to chec the c*ster (a nodes) stat*s?

2o chec+ the 'iabilit* o Cluster *nchroni3ation er'ices (C) across nodes=

9 crsctl chec+ cluster

CR;HIGL= Cluster Read* er'ices is online

CR;HIM= Cluster *nchroni3ation er'ices is online

CR;HIGG= &'ent %anager is online

%0. 'ow to chec the c*ster (one node) stat*s?

9 crsctl chec+ crs

CR;HJGN= 4racle igh A'ailabilit* er'ices is online

CR;HIGL= Cluster Read* er'ices is online

CR;HIM= Cluster *nchroni3ation er'ices is online

CR;HIGG= &'ent %anager is online

%1. 'ow to


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6ocated G 'oting dis+(s).

%%. 'ow to ocation o "CR?

• cat etcoracleocr.loc

ocrcong:locQ!A2Alocal:onl*QA6&

• 84CRC&C7 (also about 4CR integrit*)

%. >ist some bacgro*nd &rocess that *sed in A#: nstances?

Process

9escri&tion

RA>4#ens all de'ice les as #art o disco'er*and coordinates the rebalance acti'it*

ARn4ne or more sla'e #rocesses that do therebalance acti'it*

=:"/Res#onsible or managing the dis+;le'elacti'ities such as dro# or oKine andad'ancing the A% dis+ grou# com#atibilit*

:AR %ar+s A% allocation units as stale when

needed

"nnn4ne or more A% sla'e #rocesses orming a#ool o connections to the A% instance orechanging messages

P@7n4ne or more #arallel sla'e #rocesses usedin etching data on clustered A%installation rom -59 'iews

H. What are t*#es o A% %irroringE

9is =ro*&!&e

#*&&orted:irroring>ees

9ea*t:irroring >ee

&ternalredundanc*

n#rotected($one)

n#rotected($one)


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$ormalredundanc*

2wo;wa*2hree;wa*n#rotected($one)

2wo;wa*

ighredundanc* 2hree;wa* 2hree;wa*

%2. What is A#: #tri&ing?

A% can use 'ariable si3e data etents to su##ort larger les, reduce memor* re


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. $ormal redundanc* maimum le si3e is H B.

G. igh redundanc* maimum le si3e is 1I B.

%5. 'ow to


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2o add a CA$ listener resource=

9 sr'ctl add scan:listener

9 sr'ctl add scan:listener ;# 1I1

2o remo'e Clusterware resources rom all CA$ listeners=

9 sr'ctl remo'e scan:listener O;P

1. 'ow to chec the node connectiit! in "race =rid nrastr*ct*re?

9 clu'* com# nodecon ;n all /'erbose

%. Can sto& a nodes in one command? :eaning that sto&&ing whoe c*ster ?

"n 10g its not #ossible, where in 11g it is #ossible

OrootT#ic1P8 crsctl start cluster ;allOrootT#icP8 crsctl sto# cluster /all

. What is ">R? Which o the oowing statements regarding the "race >ocaRegistr! (">R) is tr*e?

1.&ach cluster node has a local registr* or node;s#ecic resources.

.2he 46R should be manuall* created ater installing -rid "nrastructure on each node inthe cluster.

G.4ne o its unctions is to acilitate Clusterware startu# in situations where the A% storesthe 4CR and 'oting dis+s.

H.Fou can chec+ the status o the 46R using ocrchec+.

-. What is r*n


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crsctl sto# cluster (#ossible onl* rom 11gr), #lease note crsctl commands becomesglobal now, i *ou do not s#eci* node s#ecicall* the command eecuted globall* oream#le

crsctl sto# crs (sto#s in all crs resource in all nodes)

crsctl sto# crs /n Undeoname) (sto#s onl* in s#ecied node)

3. CR# is not starting a*tomatica! ater a node reboot, what !o* do to mae itha&&en?

crsctl enable crs (as root)

to disable

crsctl disable crs (as root)

-1. What is the diference between A$ and $A/ 8 $C$? at what conditions !o**se them?

1) A$ with tnsnamesa feature of Oracle Net Services for OCI8 clients. TAF is transparent application failover

which will move a session to a bacup connection if the session fails. !ith Oracle "#g$elease 2% &ou can 'e(ne the TAF polic& on the service using 'bms)service pacage. It willonl& wor with OCI clients. It will onl& move the session an' if the parameter is set% it willfailover the select statement. For insert% up'ate or 'elete transactions% the application mustbe TAF aware an' roll bac the transaction. *+S% &ou shoul' enable FCF on &our OCI clientwhen &ou use TAF% it will mae the failover faster.Note, TAF will not wor with -/C thin.%) $A/ with tnsnames with a; noti


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Reationshi& between $A/H$C$H"/#

4$ /V A$ /V CONS 79 sen'1receive messages on local an' remote no'es.FAN 79 uses ONS to notif& other processes about changes in con(guration of service levelFCF 79 uses FAN information woring with conection pools -A6A an' others.

-%. Can !o* add oting dis onine? 9o !o* need oting dis bac*&?

Fes, as #er documentation, i *ou ha'e multi#le 'oting dis+ *ou can add online, but i *ouha'e onl* one 'oting dis+ , b* that cluster will be down as its lost *ou @ust need to start crsin eclusi'e mode and add the 'otedis+ using

crsctl add 'otedis+ U#athV

-. Jo* hae ost "CR dis, what is !o*r ne4t ste&?

2he cluster stac+ will be down due to the act that cssd is unable to maintain the integrit*,this is true in 10g, rom 11gR onwards, the crsd stac+ will be down, the hasd still u# andrunning. Fou can add the ocr bac+ b* restoring the automatic bac+u# or im#ort the manualbac+u#,

Read com#lete ste#s here

--. What ha&&ens when ocssd ais, what is node eiction? how does nodeeiction ha&&ens? $or a answer wi be same.

HI. What is 'irtual " and how does it wor+sE

HJ. !escribe some rac wait e'ents *ou e#eriencedE

4racle RAC Wait e'ents

and this table,


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HL. Can *ou modi* 5" address ater *our cluster installationE

Fes

HN. ow do *ou inter#ret AWR re#ort in RAC instances, what sections in awr re#ort or racinstances are most im#ortantE

Read here.

#date 1;%a*;01G, ome #ractical


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G. 5eri*ing Cluster "nterconnect

Clster interconnects can be veri'ie# by

i. oi'c'! !eti'

ii. ro* +,R Report.

iii. show para*eter clster_interconnect

iv. srvctl con'i! networ$

H. !oes scan " re


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7) Ta$e a control 'ile bac$p in 'or*at ;new#is$!rop

:) ht#own the #b& startp no*ont the #atabase

bac$p #atabase as copy 'or*at 4;new#is$!rop na*e4 ?

7) RM+> witch #atabase to copy.

:) "eri'y #ba_#ata_'ilesba_te*p_'iles& v9lo! that all 'iles are pointin! to

new #is$!rop na*e.

c. Case 7 Mi!ratin! #is$ !rop to new stora!e bt no a##itional #is$!rop !iven

5) Ta$e the RM+ bac$p as copy o' all the #atabases with new 'or*at an#

place it in the #is$.

6) Prepare rena*e co**an#s 'ro* v9lo! &v9#ata'ile etc (#yna*ic %eries)

7) Ta$e a bac$p o' p'ile an# *o#i'y the 'ollowin! re'errin! to new #is$!rop

na*e

.control_'iles

.#b_create_'ile_#est

.#b_create_online_lo!_#est_5

.#b_create_online_lo!_#est_6

.#b_recovery_'ile_#es

:) stop the #atabase


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L. !atabase rename in RAC, what could be the chec+list or *ouE

a. Ta$e the otpts o' all the services that are rnnin! on the #atabases.

b. set clster_#atabase8+E1

c. Drop all the services associate# with the #atabase.

#. top the #atabase e. tartp *ont

'. Use ni# to chan!e the DB a*e.

Feneric %estion& /' sin! +M the sal location 'or the #ata'ile wol# be

;D+T+2#ata'ile2OEDDB+M12syste*5.#b'4

Does /D chan!es this path tooG to re'lect the new #b na*eG

Hes it will& by sin! proper #irectory strctre it will create a lin$s to

ori!inal #irectory strctre. ;D+T+2#ata'ile21,DB+M12syste*5.#b'4

this has to be teste#& ,e #ont have test be#& bt than$s to +n3i who con'ir*e# it

will

!. Chan!e the para*eters accor#in! to the new #atabase na*e

h. Chan!e the passwor# 'ile.

i. top the #atabase.

3. Mont the #atabase

$. Open #atabase with Reset lo!s

l. Create sp'ile 'ro* p'ile.

*. +## #atabase to the clster.

n. Create the services that are #roppe# in prior to rena*e.

o. Bonce the #atabase.

N.ow to nd the database in which #articular ser'ice is attached to when *ou ha'e a largenumber o databases running in the ser'er, *ou cannot chec+ one b* one manuall*

Write a shell scri#t to read the database name rom oratab and iterate the loo# ta+ing in#tas !B name in sr'ctl to get the result.8bin+sh4RAC6&:4%&QA2Q94RAC6&:4%&bin=9A26!:6"BRARF:A2Q9XA5&:66Y=9X4RAC6&:4%&Ylibe#ort 2$:A!%"$ 4RAC6&:4%& A2 6!:6"BRARF:A2or "$2A$C& in Zcat etcoratab[gre# ;' \]8\[cut ;1 ;d= ;sZdoe#ort 4RAC6&:"!Q9"$2A$C&echo Zsr'ctl status ser'ice ;d 9"$2A$C& ;s 91[ gre# ;i \is running\Zdone

M. !iference between 4A and CR4A is com#lete cluster stac+ which includes some +ernel le'el tas+s li+e managingnetwor+,time s*nchroni3ation, dis+s etc, where the CR has the abilit* to manage theresources li+e database,listeners,a##lications, etc With both o this 4racle #ro'ides the higha'ailabilit* clustering ser'ices rather onl* a^nit* to databases.


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ORACLE CAREER

Top 30 RAC Interview Questions ThatHelped Me. Are You Prepared?Getting ready for a RAC interview? Make sure to refresh your knowledge by reviewing this list of RAC Interview Questions.

What is ahe !usion?In a RAC environment, it is the ombining of data bloks, whih are shi!!ed aross the interonnet from remote database ahes "#GA$ tothe loal node, in order to fulfill the re%uirements for a transation "&M', Query of &ata &itionary$.

What is split "rain?(hen database nodes in a luster are unable to ommuniate with eah other, they may ontinue to !roess and modify the data bloks

inde!endently. If the

same blok is modified by more than one instane, synhroni)ation*loking of the data bloks does not take !lae and bloks may beoverwritten by others in the luster. +his state is alled s!lit brain.

What is the di!!erene "etween Crash reover# and Instane reover#?(hen an instane rashes in a single node database on startu! a rash reovery takes !lae. In a RAC enviornment the same reovery foran instane is !erformed by the surviving nodes alled Instane reovery.

What is the interonnet used !or?It is a !rivate network whih is used to shi! data bloks from one instane to another for ahe fusion. +he !hysial data bloks as well asdata ditionary bloks are shared aross this interonnet.

How do #ou deter$ine what protool is "ein% used !or Interonnet tra!!i?ne of the ways is to look at the database alert log for the time !eriod when the database was started u!.

What $ethods are availa"le to &eep the ti$e s#nhroni'ed on all nodes in the luster?-ither the etwork +ime /rotool"+/$ an be onfigured or in 00gr1, Cluster +ime #ynhroni)ation #ervie "C+##$ an be used.

What !iles o$ponents in RAC $ust reside on shared stora%e?#!files, Control2iles, &atafiles and Redolog files should be reated on shared storage.

Where does the Clusterware write when there is a networ& or (tora%e $issed heart"eat?+he network !ing failure is written in 3CR#45M-*log

How do #ou !ind out what )CR "a&ups are availa"le?+he oronfig 6showbaku! an be run to find out the automati and manually run baku!s.

I! #our )CR is orrupted what options do have to resolve this?7ou an use either the logial or the !hysial CR baku! o!y to restore the Re!ository.

How do #ou !ind out what o"*et has its "lo&s "ein% shipped aross the instane the $ost?7ou an use the dba4hist4seg4stats.


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What is a +IP in RAC use !or?+he 8I/ is an alternate 8irtual I/ address assigned to eah node in a luster. &uring a node failure the 8I/ of the failed node moves to thesurviving node and relays to the a!!liation that the node has gone down. (ithout 8I/, the a!!liation will wait for +C/ timeout and then find

out that the session is no longer live due to the failure.

How do we &now whih data"ase instanes are part o! a RAC luster?7ou an %uery the 83AC+I8-4I#+AC-# view to determine the member instanes of the RAC luster.

What is )C,-M) used !or in a luster environ$ent?+he Cluster 5ealth Monitor "C5M$ stores o!erating system metris in the C5M re!ository for all nodes in a RAC luster. It stores informationon C/9, memory, !roess, network and other # data, +his information an later be retrieved and used to troubleshoot and identify any

luster related issues. It is a default om!onent of the 00gr1 grid install. +he data is stored in the master re!ository and re!liated to astandby re!ository on a different node.

What would "e the possi"le per!or$ane i$pat in a luster i! a less power!ul node /e.%.

slower CP-s1 is added to the luster? All !roessing will show down to the C/9 s!eed of the slowest server.

What is the purpose o! ),R?rale 'oal re!ository ontains information that allows the luster !roesses to be started u! with the CR being in the A#M storage

ssytem. #ine the A#M file system is unavailable until the Grid !roesses are started u! a loal o!y of the ontents of the CR is re%uiredwhih is stored in the 'R.

What is the de!ault $e$or# alloation !or A(M?In 0:g the default #GA si)e is 0G in 00g it is set to 1;

• C'9#+-R4&A+AA#-


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• C'9#+-R4&A+AA#-4I#+AC-

• I#+AC-4+7/- "R&M# or A#M$

• AC+I8-4I#+AC-4C9+

• 9&4MAAG-M-+

What is the !uture o! the )rale 4rid?+he Grid software is beoming more and more a!able of not @ust su!!orting 5A for rale &atabases but also other a!!liations inluding

rales a!!liations. (ith 01 there are more features and funtionality built6in and it is easier to de!loy these !re6built solutions, availablefor ommon rale a!!liations.

What o$ponents o! the 4rid should I "a& up?+he baku!s should inlude 'R, CR and A#M Metadata.

Is there an eas# wa# to veri!# the inventor# !or all re$ote nodes7ou an run the o!ath lsinventory 6all4nodes ommand from a single node to look at the inventory details for all nodes in the luster.

ADDITIONAL RESOURCES

)rale Interview Questions+o !re!are for your rale &A interview here are some additional rale %uestions fousing on other database areas.

• Goldengate Interview Questions

• -Badata Interview Questions

Related )rale Artiles

• rale 01 RAC Installation on rale 'inuB < using 8irtualoB

• RAC log

RAC/AS/!OTIN" DIS# Interview $uestions % Answer

K What is #CA/?

ingle Client Access $ame (CA$) is s a new 4racle Real A##lication Clusters (RAC) 11gRelease eature that #ro'ides a single name or clients to access an 4racle !atabaserunning in a cluster. 2he benet is clients using CA$ do not need to change i *ou add or

remo'e nodes in the cluster.

K what is d!namic remastering ? When wi the d!namic remastering ha&&ens?

d*namic remastering is abilit* to mo'e the ownershi# o resource rom one instance toanother instance in RAC. d*namic resource remastering is used to im#lement or resource

http://www.vitalsofttech.com/recovering-the-local-oracle-registry-in-rac-11gr2/http://www.vitalsofttech.com/recovering-the-local-oracle-registry-in-rac-11gr2/http://www.vitalsofttech.com/recovering-the-local-oracle-registry-in-rac-11gr2/http://www.vitalsofttech.com/restore-ocr-and-voting-disk/http://www.vitalsofttech.com/restore-ocr-and-voting-disk/http://www.vitalsofttech.com/relink-oracle-binaries/http://www.vitalsofttech.com/relink-oracle-binaries/http://www.vitalsofttech.com/relink-oracle-binaries/http://www.vitalsofttech.com/goldengate-interview-questions/http://www.vitalsofttech.com/exadata-interview-questions/http://www.vitalsofttech.com/oracle-12c-rac-installation-on-oracle-linux-6-using-virtualboxhttp://www.vitalsofttech.com/articles/rac/http://www.vitalsofttech.com/recovering-the-local-oracle-registry-in-rac-11gr2/http://www.vitalsofttech.com/restore-ocr-and-voting-disk/http://www.vitalsofttech.com/relink-oracle-binaries/http://www.vitalsofttech.com/goldengate-interview-questions/http://www.vitalsofttech.com/exadata-interview-questions/http://www.vitalsofttech.com/oracle-12c-rac-installation-on-oracle-linux-6-using-virtualboxhttp://www.vitalsofttech.com/articles/rac/


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a^nit* or increased #erormance. resource a^nit* o#timi3ed the s*stem in situation whereu#date transactions are being eecuted in one instance. when acti'it* shit to anotherinstance the resource a^nit* corres#ondingl* mo'e to another instance. " acti'it* is notlocali3ed then resource ownershi# is hashed to the instance.

"n 10g d*namic remastering ha##ens in leob@ect le'el.the #rocess o remastering is 'er*

stringent. or one instance should touch more than I0 times than the other instance in#articular #eriod(sa* 10 mints). this touch ratio and time can be tuned b* gc:a^nit*:limitand :gc:a^nit*:time #arameter.

K wh! we re;*ired to maintain odd n*mber o oting diss?

4dd number o dis+ are to a'oid s#lit brain, When $odes in cluster can_t tal+ to each otherthe* run to loc+ the 5oting dis+ and whoe'er loc+ the more dis+ will sur'i'e, i dis+ numberare e'en there are chances that node might loc+ I0` o dis+ ( out o H) then how to decidewhich node to e'ict.whereas when number is odd, one will be higher than other and each or cluster to e'ict thenode with less number

K 'ow !o* chec the heath o Jo*r RAC 9atabase? LcrsctL command rom root or oracle user can be used to chec+ the clusterware health Butor starting or sto##ing we ha'e to use root user or an* #ri'ilege user.

OoracleT2&2:$4!&1 P9 crsct chec crsC a##ears health*

CR a##ears health*&5% a##ears health*

K 'ow !o* chec the serices in RAC /ode?

We can chec+ the ser'ice or start the ser'ices with _sr'ctl_ command.load balanced2Aser'ice named RAC online.

OoracleT2&2:$4!&1 P9 sr'ctl start ser'ice ;d orcl ;s RACOoracleT2&2:$4!&1 P9 crsstat

K there is some iss*e with irt*a P how wi !o* tro*beshoot it?'ow wi !o*change irt*a i&?

2o change the 5" ('irtual ") on a RAC node, use the command


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OoracleTtestnode oracleP9 srct modi! nodea##s ;A new:address

K 'ow !o* wi bac*& !o*r RAC 9atabase?

Bac+u# strateg* o RAC !atabase=An RAC !atabase consists o 1)"CR%)+oting dis 8

)9atabase


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sr'ctl sto# database ;d name O;o sto#:o#tionsP

sr'ctl start database ;d orcl ;o mount

K :ention the "race RAC sotware com&onents ?

4racle RAC is com#osed o two or more database instances. 2he* are com#osed o %emor*structures and bac+ground #rocesses same as the single instance database.4racle RACinstances use two #rocesses -&(-lobal &nAtomic Controlle to %emor* er'ice (AC%)-2?0;@>-lobal 2ransaction rocess6%4$>-lobal &n-lobal Cache er'ice rocess

6C70>"nstance &n4racle RAC %anagement rocesses (R%n)R%$>Remote la'e %onitor

K What is =R9?

-R! stands or -lobal Resource !irector*. 2he -& and -C maintains records o thestatuses o each datale and each cahed bloc+ using global resource director*.2his #rocessis reerred to as cache usion and hel#s in data integrit*.

K What are the diferent networ com&onents are in 10g RAC?

#ublic, #ri'ate, and 'i# com#onentsri'ate interaces is or intra node communication. 5" is all about a'ailabilit* o a##lication.When a node ails then the 5" com#onent ail o'er to some other node, this is the reasonthat all a##lications should based on 'i# com#onents means tns entries should ha'e 'i#entr* in the host list

K =ie 9etais on AC:#G

AC% stands or Atomic Controlle %emor* er'ice."n an 4racle RAC en'ironment AC% isan agent that ensures a distributed -A memor* u#date(ie)-A u#dates are globall*committed on success or globall* aborted in e'ent o a ailure.


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K What are the major RAC wait eents?

"n a RAC en'ironment the bufer cache is global across all instances in the cluster and hence

the #rocessing difers.2he most common wait e'ents related to this are gc cr re


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2his #rocess is called as -lobal Cache ser'ice #rocess.2his #rocess maintains statuses odatales and each cahed bloc+ b* recording inormation in a -lobal Resource!ector*(-R!).2his #rocess also controls the ow o messages to remote instances andmanages global data bloc+ access and transmits bloc+ images between the bufer caches o diferent instances.2his #rocessing is a #art o cache usion eature.

K =ie detais on >C0

2his #rocess is called as "nstance en


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8 -enerate "nstance resource

sr'ctl status database ;d 9!B$A%& [ aw+ ;' dbnameQ\9!B$A%&\

_9Hrunning X #rint \`s `s `s `s `s `sn\, \sr'ctl add instance ;d \,dbname, \ ;i \, 9 ,\

;n \, 9L Y

9Irunning X #rint \`s `s `s `s `s `s n\, \sr'ctl add instance ;d \,dbname, \ ;i \, 9 ,\

;n \, 9N Y_

8 %odi* instance or 10- ; A% de#endenc*

i O 9(echo 94RAC6&:4%& [ gre# \100\ [ wc ;l ) ;e< 1 P

then

sr'ctl status database ;d 9!B$A%& [ aw+ ;' dbnameQ\9!B$A%&\

_919 X #rint \`s `s `s `s `s n\, \sr'ctl modi* instance ;d \,dbname, \ ;i \, 9 ,\ ;s

A%1\ Y99 X #rint \`s `s `s `s `s n\, \sr'ctl modi* instance ;d \,dbname, \ ;i \, 9 ,\ ;s

A%\ Y

9G9 X #rint \`s `s `s `s `s n\, \sr'ctl modi* instance ;d \,dbname, \ ;i \, 9 ,\ ;s

A%G\ Y

9H9 X #rint \`s `s `s `s `s n\, \sr'ctl modi* instance ;d \,dbname, \ ;i \, 9 ,\ ;s

A%H\ Y_

echo \sr'ctl start database ;d 9!B$A%&\

8 -enerate er'ice resource

snamelistQ9(sr'ctl status ser'ice ;d 9!B$A%& [ aw+ _X#rint 9Y_)

or sname in 9snamelist

do

sr'ctl cong ser'ice ;d 9!B$A%& ;s 9sname[ aw+ ;' dbnameQ\9!B$A%&\ ;'

snameQ9sname

_B&-"$ X Q\=\Y

91reerred instances X#re Q \;r\ 9Y91R& X#re Q \;r\ 9 sub(A5A"6, \\, #re) Y

91A'ailable instances Xa'ail Q \;a\ 9Y

9A5A"6 Xa'ail Q \;a\ 9GY

91ailo'er t*#e Xt Q \;e\ 9Y

91ailo'er method Xm Q \;m\ 9Y

91Runtime 6oad Balancing -oal Xg Q \;B\ 9Y


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&$! X i (a'ail QQ \;a \) Xa'ail Q \\Y #rint \`s `s `s `s `s `s `s `s `s `sn\, \sr'ctl

add ser'ice ;d \,dbname, \;s \, sname, #re, a'ail ,t, m,g, \; BA"C\Y_

echo \sr'ctl start ser'ice ;d 9!B$A%& ;s 9sname\

done

done

8 6istener at 11- ome. 10- listener can_t ba added with sr'ctl.

sr'ctl cong listener [ aw+

_B&-"$ X Q\=\ state Q 0 Y

91$ame Xlname Q \;l\ 9 stateQ1Y

91ome DD state QQ 1 Xohome Q \;o\ 9 stateQY

91&nd #oints DD state QQ Xl#ort Q \;# \ 9G stateQGY

state QQ G Xi (ohome Q \;o \) X#rint \`s `s `s `sn\, \sr'ctl add listener \, lname,ohome, l#ortY stateQ0Y_

K =ie detais on R#:/

2his #rocess is called as Remote la'e %onitor.2his #rocess manages bac+ground sla'e#rocess creation andd communication on remote instances. 2his is a bac+ground sla'e#rocess.2his #rocess #erorms tas+s on behal o a co;ordinating #rocess running in anotherinstance.

K What com&onents in RAC m*st reside in shared storage?

All datales, controlles, "les, redo log les must reside on cluster;aware shred storage.

K What is the signi


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K =ie ew e4am&es or so*tions that s*&&ort c*ster storage

A%(automatic storage management),raw dis+ de'ices,networ+ le s*stem($), 4Cand 4C(4racle Cluster ie s*stems).

K What is an interconnect networ?

An interconnect networ+ is a #ri'ate networ+ that connects all o the ser'ers in a cluster. 2he interconnect networ+ uses a switchmulti#le switches that onl* the nodes in the clustercan access.

K 'ow can we con


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K What is the *se o a serice in "race RAC enironment?

A##lications should use the ser'ices eature to connect to the 4racle database.er'icesenable us to dene rules and characteristics to control how users and a##lications connectto database instances.

K What are the characteristics controed b! "race serices eat*re?

2he charateristics include a uni


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K What is the signi


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a##lications can recei'e A$ e'ents and react immediatel*.2his #re'ents a##lications rom#olling database and detecting a #roblem ater such a state change.

K Wh! sho*d we hae se&erate homes or A#m instance?

"t is a good #ractice to ha'e A% home se#erate rom the databasehom(4RAC6&:4%&).2his hel#s in u#grading and #atching A% and the 4racle databasesotware inde#endent o each other.Also,we can deinstall the 4racle database sotwareinde#endent o the A% instance.

K What is the adantage o *sing A#:?

a'ing A% is the 4racle recommended storage o#tion or RAC databases as the A%maimi3es #erormance b* managing the storage conguration across the dis+s.A% doesthis b* distributing the database le across all o the a'ailable storage within our clusterdatabase en'ironment.

K What is roing *&grade?

"t is a new A% eature rom !atabase 11g.A% instances in 4racle database 11grelease(rom 11.1) can be u#graded or #atched using rolling u#grade eature. 2his enablesus to #atch or u#grade A% nodes in a clustered en'ironment without afecting databasea'ailabilit*.!uring a rolling u#grade we can maintain a unctional cluster while one or moreo the nodes in the cluster are running in diferent sotware 'ersions.

K Can roing *&grade be *sed to *&grade rom 10g to 11g database?

$o,it can be used onl* or 4racle database 11g releases(rom 11.1).

K #tate the initiaiNation &arameters that m*st hae same a*e or eer!instance in an "race RAC database

ome initiali3ation #arameters are critical at the database creation time and must ha'e


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same 'alues.2heir 'alue must be s#ecied in "6& or "6& or e'er* instance.2he list o#arameters that must be identical on e'er* instance are gi'en below=AC2"5&:"$2A$C&:C4$2ARC"5&:6A-:2AR-&2C4%A2"B6&C62&R:!A2ABA&

C62&R:!A2ABA&:"$2A$C&C4$2R46:"6&!B:B64C7:"&!B:!4%A"$!B:"6&!B:$A%&!B:R&C45&RF:"6&:!&2!B:R&C45&RF:"6&:!&2:"&!B:$"&:$A%&"$2A$C&:2F& (R!B% or A%)ARA66&6:%A?:&R5&RR&%42&:64-"$:#assW4R!:"6&

$!4:%A$A-&%&$2

K What is "RAD0030G "RAC>O serer session terminated b! ata error or "RAD

%750%G error occ*rred in C*ster =ro*& #erice o&eration?

RAC node name was listed in the loo#bac+ address...

K Can the 9:>F>"C# and RO#6>FCAC'OF:AMF#@O be identica on a instances?

2hese #arameters can be identical on all instances onl* i these #arameter 'alues are set to3ero.What two #arameters must be set at the time o starting u# an A% instance in a RACen'ironmentE2he #arameters C62&R:!A2ABA& and "$2A$C&:2F& must be set.

K :ention the com&onents o "race c*sterware4racle clusterware is made u# o com#onents li+e 'oting dis+ and 4racle ClusterRegistr*(4CR).

K What is a CR# reso*rce?


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4racle clusterware is used to manage high;a'ailabilit* o#erations in a cluster.An*thing that4racle Clusterware manages is +nown as a CR resource.ome eam#les o CR resourcesare database,an instance,a ser'ice,a listener,a 5" address,an a##lication #rocess etc.

K What is the *se o "CR?

4racle clusterware manages CR resources based on the conguration inormation o CRresources stored in 4CR(4racle Cluster Registr*).

K 'ow does a "race C*sterware manage CR# reso*rces?

4racle clusterware manages CR resources based on the conguration inormation o CRresources stored in 4CR(4racle Cluster Registr*).

K /ame some "race c*sterware toos and their *ses?

4"C- ; allocating and deallocating networ+ interaces4CRC4$"- ; Command;line tool or managing 4racle Cluster Registr*4CR!% ; "denti* the interconnect being usedC5 ; Cluster 'erication utilit* to get status o CR resources

K What are the modes o deeting instances rom "Race Rea A&&ication c*ster9atabases?

We can delete instances using silent mode or interacti'e mode using !BCA(!atabaseConguration Assistant).

K 'ow do we remoe A#: rom a "race RAC enironment?

We need to sto# and delete the instance in the node rst in interacti'e or silent mode.Aterthat asm can be remo'ed using sr'ctl tool as ollows=sr'ctl sto# asm ;n node:namesr'ctl remo'e asm ;n node:name


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We can 'eri* i A% has been remo'ed b* issuing the ollowing command=sr'ctl cong asm ;n node:name

K 'ow do we eri! that an instance has been remoed rom "CR ater deetingan instance?

"ssue the ollowing sr'ctl command=sr'ctl cong database ;d database:namecd CR:4%&bin.crs:stat

K 'ow do we eri! an e4isting c*rrent bac*& o "CR?

We can 'eri* the current bac+u# o 4CR using the ollowing command = ocrcong;showbac+u#What are the #erormance 'iews in an 4racle RAC en'ironmentEWe ha'e '9 'iews that are instance s#ecic. "n addition we ha'e -59 'iews called as global'iews that has an "$2:"! column o numeric data t*#e.-59 'iews obtain inormation romindi'idual 59 'iews.What are the t*#es o connection load;balancingE

2here are two t*#es o connection load;balancing=ser'er;side load balancing and client;sideload balancing.

K What is the diference between sererDside and cientDside connection oadbaancing?

Client;side balancing ha##ens at client side where load balancing is done using listener."ncase o ser'er;side load balancing listener uses a load;balancing ad'isor* to redirectconnections to the instance #ro'iding best ser'ice.

K What are the three greatest bene


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lot o mone* in the earl* stages o a #ro@ect.

"n a RAC en'ironment, i a node in the cluster ails, the a##lication continues to run on thesur'i'ing nodes contained in the cluster. " *our a##lication is congured correctl*, mostusers won_t e'en +now that the node the* were running on became una'ailable.

K What are the major RAC wait eents?

"n a RAC en'ironment the bufer cache is global across all instances in the cluster and hencethe #rocessing difers.2he most common wait e'ents related to this are gc cr re;*est andgc bufer bus*

=C CR re;*est= the time it ta+es to retrie'e the data rom the remote cache

Reason= RAC 2ra^c sing low Connection or "ne^cient


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Also since the C_s are diferent R4! can ha'e more number o ma number o#rocesses as com#ared to the rest o them.

But as " said this is @ust conguration, this is not tuning. uestion is not clear.

K Write a sam&e scri&t or R:A/ or the recoer! i a the instance are down.($irst e4&ain the &roced*re how !o* wi restore)

Bring all nodes down.tart one $odeRestore all datales and archi'e logs.Reco'er 1 $ode.4#en the database.bring other nodes u#.

Conrm that all nodes are o#erational.

K. Cients are &erorming some o&eration and s*dden! one o the data


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4CR le. se the ollowing command to generate an e#ort o the online 4CR le=

"n 10.

8 ocrcon(g :e;port 7s online

"n 11g

8 ocrcon(g 7manualbacup

2he new 4CR dis+ must be owned b* root, must be in the oinstall grou#, and must ha'e

#ermissions set to JH0. ro'ide at least 100 %B dis+ s#ace or the 4CR.

4n one node as root run=

< ocrcon(g 7replace ocr

< ocrcon(g 7replace ocrmirror

$ow run ocrchec+ to 'eri* i the 4CR is #ointing to the new le

:oing +oting 9is

$ote= crsctl 'otedis+ commands must be run as root

hutdown the 4racle Clusterware (crsctl sto# crs as root) on all nodes beore ma+ing an*

modication to the 'oting dis+. !etermine the current 'oting dis+ location using=

crsctl =uer& css vote'is

2a+e a bac+u# o all 'oting dis+=

'' if>voting)'is)name of>bacup)(le)name

2o mo'e a 5oting !is+, #ro'ide the ull #ath including le name=

crsctl 'elete css vote'is :force

crsctl a'' css vote'is :force

Ater modi*ing the 'oting dis+, start the 4racle Clusterware stac+ on all nodes


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< crsctl start crs

5eri* the 'oting dis+ location using

crsctl =uer& css vote'is

K What is r*n


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. Ater the ummar* screen, 4" will start co#*ing under the 9CR:4%& (this is the94RAC6&:4%& or 4racle Clusterware) in the local node the libraries and eecutables.; here we will ha'e the daemons and scri#ts init. created and congured #ro#erl*.

Oracle Clusterware is forme' of several 'aemons% each one of which have a special function

insi'e the stac. aemons are e;ecute' via the init.? scripts 0init.css'% init.crs' an'

init.evm'.

; note that or CR onl* some client libraries are recreated, but not all the eecutables (asor the R!B%).

-. 6ater the sotware is #ro#agated to the rest o the nodes in the cluster and theora"n'entor* is u#dated.

2. 2he installer will as+ to eecute root.sh on each node. ntil this ste# the sotware or4racle Clusterware is inside the 9CR:4%&.

Running root.sh will create se'eral com#onents outside the 9CR:4%&=

; 4CR and 5! will be ormated.

; control les (or C6:RC les ) will be created with the correct contents to start 4racleClusterware.

These (les are use' to control some aspects of Oracle Clusterware lie,7 enable1'isable processes from the CSS famil& 0+g. oproc'% oslsvmon

7 stop the 'aemons 0ocss'.bin% crs'.bin% etc.7 prevent Oracle Clusterware from being starte' when the machine boots.

7 etc.

; etcinittab will be u#dated and the init #rocess is notied.

In or'er to start the Oracle Clusterware 'aemons% the init.? scripts (rst nee' to be run.These scripts are e;ecute' b& the 'aemon init. To accomplish this some entries must be

create' in the (le 1etc1inittab.

; the diferent #rocesses init. (init.cssd, init.crsd, etc) will start the daemons (ocssd.bin,crsd.bin, etc). When all the daemons are running then we can sa* that the installation wassuccessul

; 4n 10. and later, running root.sh on the last node in the cluster also will create thenodea##s (5", -! and 4$). 4n 10.1, 5"CA is eecuted as #art o the RAC installation.

3. Ater running root.sh on each node, we need to continue with the 4" session. Ater#ressing the _47_ button 4" will include the inormation or the #ublic andcluster:interconnect interaces. Also C5 (Cluster 5erication tilit*) will be eecuted.


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K What are "race C*sterware &rocesses or 10g on 6ni4 and >in*4

Cluster S&nchroni@ation Services 0ocss' %anages cluster node membershi# and runs asthe oracle user ailure o this #rocess results in cluster restart.

Cluster $ea'& Services 0crs' > 2he crs #rocess manages cluster resources (which could be

a database, an instance, a ser'ice, a 6istener, a 'irtual " (5") address, an a##lication#rocess, and so on) based on the resource_s conguration inormation that is stored in the4CR. 2his includes start, sto#, monitor and ailo'er o#erations. 2his #rocess runs as the rootuser

+vent manager 'aemon 0evm' A bac+ground #rocess that #ublishes e'ents that crscreates.

4rocess Bonitor aemon 0O4$OC 2his #rocess monitor the cluster and #ro'ide "4encing. 4R4C! #erorms its chec+, sto#s running, and i the wa+e u# is be*ond thee#ected time, then 4R4C! resets the #rocessor and reboots the node. An 4R4C! ailureresults in 4racle Clusterware restarting the node. 4R4C! uses the hangchec+ timer on

6inu #latorms.

$AC 0racgmain% racgimon >&tends clusterware to su##ort 4racle;s#ecic re


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Oracle Cluster $egistr& 0OC$ > %aintains cluster conguration inormation as well asconguration inormation about an* cluster database within the cluster. 2he 4CR mustreside on shared dis+ that is accessible b* all o the nodes in *our cluster

K 'ow do !o* tro*beshoot node reboot

lease chec+ metalin+ ...

$ote JILJM.1 2roubleshooting CR Reboots$ote.IIMGJI.1 sing !iagwait as a diagnostic to get more inormation or diagnosing 4racleClusterware $ode e'ictions.

K 'ow do !o* bac*& the "CR

2here is an automatic bac+u# mechanism or 4CR. 2he deault location is =94RA:CR:4%&cdata\clustername\

2o dis#la* bac+u#s =8ocrcong ;showbac+u#

2o restore a bac+u# =8ocrcong ;restore

With 4racle RAC 10g Release or later, *ou can also use the e#ort command=

8ocrcong ;e#ort ;s online, and use ;im#ort o#tion to restore the contents bac+.With 4racle RAC 11g Release 1, *ou can do a manaual bac+u# o the 4CR with thecommand=8 ocrcong ;manualbac+u#

K 'ow do !o* bac*& oting dis

8dd iQ'oting:dis+:name oQbac+u#:le:name

K 'ow do identi! the oting dis ocation

8crsctl


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K 'ow do identi! the "CR


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K What do !o* do i !o* see =C CR >"C >"# in to& 2 imed Oents in AWRRe&ort?

2his is most li+el* due to a ault in interconnect networ+.

Chec+ netstat ;si *ou see \ragments dro##ed\ or \#ac+et reassemblies ailed\ , Wor+ with *our s*stemadministrator nd the ault with networ+.

K 'ow man! nodes are s*&&orted in a RAC 9atabase?

10g Release , su##ort 100 nodes in a cluster using 4racle Clusterware, and 100 instancesin a RAC database.

K #rct cannot start instance, get the oowing error PRPD1001 CR#D0%12,

howeer s;&*s can start it on both nodes? 'ow do !o* identi! the &robem?

et the en'ironmental 'ariable R5%:2RAC& to true.. And start the instance with sr'ctl. $ow*ou will get detailed error stac+.

K what is the &*r&ose o the "/# daemon?

2he 4racle $otication er'ice (4$) daemon is an daemon started b* the CR clusterwareas #art o the nodea##s. 2here is one ons daemon started #er clustered node.

2he 4racle $otication er'ice daemon recei'e a subset o #ublished clusterware e'ents 'iathe local e'md and racgimon clusterware daemons and orward those e'ents to a##licationsubscribers and to the local listeners.

2his in order to acilitate=

a. the A$ or ast A##lication $otication eature or allowing a##lications to res#ond todatabase state changes.b. the 10gR 6oad Balancing Ad'isor*, the eature that #ermit load balancing accrossdiferent rac nodes de#endent o the load on the diferent nodes. 2he rdbms %%4$ iscreating an ad'isor* or distribution o wor+ e'er* G0seconds and orward it 'ia racgimonand 4$ to listeners and a##lications.


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K 'ow do *sers connect to database in an "race RAC enironment?

sers can access a RAC database using a clientser'er conguration or through one or moremiddle tiers, with or without connection #ooling. sers can use oracle ser'ices eature toconnect to database.

K What is the *se o a serice in "race RAC enironment?

A##lications should use the ser'ices eature to connect to the 4racle database. er'icesenable us to dene rules and characteristics to control how users and a##lications connectto database instances.

K What are the characteristics controed b! "race serices eat*re?

2he characteristics include a uni


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ater we com#lete an* node addition or deletion #rocedures.

) irst, as root user, sto# 4racle Clusterware (with the crsctl sto# crs command) on allnodes. 2hen, determine the current 'oting dis+ b* issuing the ollowing command=

crsctl


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K 'ow can we add and remoe m*ti&e oting diss?

" we ha'e multi#le 'oting dis+s, then we can remo'e the 'oting dis+s and add them bac+into our en'ironment using the ollowing commands, where #ath is the com#lete #ath o thelocation where the 'oting dis+ resides=

crsctl delete css votedisk path

crsctl add css votedisk path

K 'ow do we sto& "race C*sterware?When do we sto& it?

Beore ma+ing an* modication to the 'oting dis+, as root user, sto# 4racle Clusterwareusing the crsctl sto# crs command on all nodes.

K 'ow do we add oting dis?

2o add a 'oting dis+, issue the ollowing command as the root user, re#lacing the #ath'ariable with the ull*


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K What sho*d we do ater modi!ing oting diss?

Ater modi*ing the 'oting dis+, restart 4racle Clusterware using the crsctl start crscommand on all nodes, and 'eri* the 'oting dis+ location using the ollowing command=

crsctl


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1LM2—3lobal $ache 2ervice Process

1LM)—3lobal nueue 2ervice )aemon

1LM#0—3lobal nueue 2ervice Monitor

1L$45—Instance nueue Process

To ensure that each #racle %&$ database instance obtains the bloc' that itneeds to satisf* a uer* or transaction, #racle %&$ instances use two

processes, the 3lobal $ache 2ervice (3$2! and the 3lobal nueue 2ervice(32!. The 3$2 and 32 maintain records of the statuses of each data fileand each cached bloc' using a 3lobal %esource )irector* (3%)!. The 3%)

contents are distributed across all of the active instances.

What are Oracle Clusterware Co"ponents

"oting Dis# — #racle %&$ uses the voting dis' to manage clustermembership b* wa* of a health chec' and arbitrates cluster ownership

among the instances in case of networ' failures. The voting dis' must resideon shared dis'.

Oracle Cluster Registry (OCR) — Maintains cluster configuration informationas well as configuration information about an* cluster database within thecluster. The #$% must reside on shared dis' that is accessible b* all of the

nodes in *our cluster

#ow do $ou trouleshoot node reoot

Please chec' metalin' ...

0ote 67897:. Troubleshooting $%2 %eboots0ote.88:Docrconfig -showbac'upTo restore a bac'up >Docrconfig -restore


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Eith #racle %&$ 5g %elease 6 or later, *ou can also use the e+portcommand>

Docrconfig -e+port -s online, and use -import option to restore the contentsbac'.

Eith #racle %&$ g %elease , *ou can do a manaual bac'up of the #$%with the command>

D ocrconfig -manualbac'up

#ow do $ou ac!up voting dis!

Ddd ifFvoting@dis'@name ofFbac'up@file@name

#ow do I identif$ the voting dis! location

Dcrsctl uer* css votedis'

#ow do I identif$ the OCR file location

chec' varoptoracleocr.loc or etcocr.loc ( depends upon platform!or

Docrchec'

Is ssh required for nor"al Oracle RAC operation %

CsshC are not reuired for normal #racle %&$ operation. Aowever CsshC

should be enabled for #racle %&$ and patchset installation.

What is &CA'%

2ingle $lient &ccess 0ame (2$&0! is s a new #racle %eal &pplication$lusters (%&$! g %elease 6 feature that provides a single name for clients

to access an #racle )atabase running in a cluster. The benefit is clientsusing 2$&0 do not need to change if *ou add or remove nodes in the

cluster.

$lic' here for more details from #racle

What is the purpose of (rivate Interconnect %

$lusterware uses the private interconnect for cluster s*nchroniGation(networ' heartbeat! and daemon communication between the the clustered

nodes. This communication is based on the T$P protocol.%&$ uses the interconnect for cache fusion (=)P! and inter-process

http://www.oracle.com/technology/products/database/clustering/pdf/scan.pdfhttp://www.oracle.com/technology/products/database/clustering/pdf/scan.pdf


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communication (T$P!. $ache /usion is the remote memor* mapping of #racle buffers, shared between the caches of participating nodes in the

cluster.

Wh$ do we have a )irtual I( *)I(+ in Oracle RAC%

Eithout using IPs or /&0, clients connected to a node that died will oftenwait for a T$P timeout period (which can be up to 5 min! before getting an

error. &s a result, *ou don"t reall* have a good A& solution without usingIPs.

Ehen a node fails, the IP associated with it is automaticall* failed over tosome other node and new node re-arps the world indicating a new M&$

address for the IP. 2ubseuent pac'ets sent to the IP go to the new node,which will send error %2T pac'ets bac' to the clients. This results in the

clients getting errors immediatel*.

What do $ou do if $ou see ,C CR -LOC. LO&/ in top /i"ed vents

in AWR Report%

This is most li'el* due to a fault in interconnect networ'.$hec' netstat -s

if *ou see Cfragments droppedC or Cpac'et reassemblies failedC , Eor' with*our s*stem administrator find the fault with networ'.

#ow "an$ nodes are supported in a RAC 2ataase%

5g %elease 6, support 55 nodes in a cluster using #racle $lusterware, and55 instances in a %&$ database.

&rvctl cannot start instance3 I get the following error (R.(41001

CR&40513 however sqlplus can start it on oth nodes% #ow do $ouidentif$ the prole"%

2et the environmental variable 2%M@T%&$ to true.. &nd start the instancewith srvctl. 0ow *ou will get detailed error stac'.

what is the purpose of the O'& dae"on%

The #racle 0otification 2ervice (#02! daemon is an daemon started b* the$%2 clusterware as part of the nodeapps. There is one ons daemon started

per clustered node.The #racle 0otification 2ervice daemon receive a subset of published

clusterware events via the local evmd and racgimon clusterware daemonsand forward those events to application subscribers and to the local


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listeners.

This in order to facilitate>

a. the /&0 or /ast &pplication 0otification feature or allowing applications to

respond to database state changes.b. the 5g%6 Load Halancing &dvisor*, the feature that permit load

balancing accross different rac nodes dependent of the load on the differentnodes. The rdbms MM#0 is creating an advisor* for distribution of wor'ever* #racle %&$ Interview uestions htt#=dbaanswers.blogs#ot.com00L0Jsroracle;dba;racdatagaurd;inter'iew.html
http://dbaregistry.blogspot.com/search/label/Oracle%20RAC%20Interview%20questionshttp://dbaregistry.blogspot.com/search/label/Oracle%20RAC%20Interview%20questions

Oracle 11g RAC Interview Question and Answers

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