Calling Acp Neeku Rac Interview Pedutunna..tondaraga Raa!

[PMREDDY19]

[quote name='k2s' timestamp='1324406511' post='1301171164']

malli inko doubt ....... maaku telusa..... memu ikada edo corner lo kusoni... nerchukuntam kada.....
[/quote]



Single Client Access Name (SCAN) is s a new Oracle Real Application Clusters (RAC) 11g Release 2 feature that provides
a single name for clients to access Oracle Databases running in a cluster. The benefit is that the client’s connect
information does not need to change if you add or remove nodes in the cluster. Having a single name to access the
cluster allows clients to use the EZConnect client and the simple JDBC thin URL to access any database running in
the cluster, independently of which server(s) in the cluster the database is active. SCAN provides load balancing and
failover for client connections to the database. The SCAN works as a cluster alias for databases in the cluster.

[PMREDDY19]

[quote name='PMR aka OM' timestamp='1324406567' post='1301171168']
SCAN in the Oracle RAC<<<

Why ?? what ? How???


ikkada undi>>>


[url="http://www.oracle.com/technetwork/database/clustering/overview/scan-129069.pdf"]http://www.oracle.co...scan-129069.pdf[/url]




USING OPTION 1 - DEFINE THE SCAN IN YOUR CORPORATE DNS
If you choose Option 1, you must ask your network administrator to create a single name that resolves to 3 IP
addresses using a round-robin algorithm. Three IP addresses are recommended considering load balancing and high
availability requirements regardless of the number of servers in the cluster. The IP addresses must be on the same
subnet as your public network in the cluster. The name must be 15 characters or less in length, not including the
domain, and must be resolvable without the domain suffix (for example: “sales1-scan’ must be resolvable as opposed
to “scan1-scan.example.com”). The IPs must not be assigned to a network interface (on the cluster), since Oracle
Clusterware will take care of it.
Figure 2: Sample DNS entry for SCAN
You can check the SCAN configuration in DNS using “nslookup”. If your DNS is set up to provide round-robin
access to the IPs resolved by the SCAN entry, then run the “nslookup” command at least twice to see the round-robin
algorithm work. The result should be that each time, the “nslookup” would return a set of 3 IPs in a different order.
EZconnet sqlplus system/manager@sales1-scan:1521/oltp
JDBC connect jdbc:oracle:thin:@sales1-scan:1521/oltp
sales1-scan.example.com IN A 133.22.67.194
IN A 133.22.67.193
IN A 133.22.67.192
[/quote]

Inka good night mari , e ratriki idhi sadivesi inka padukondi malla...

inkosari inko Architecture meedapadi subject telsukundaaam..

[k2s]

[quote name='PMR aka OM' timestamp='1324406567' post='1301171168']
SCAN in the Oracle RAC<<<

Why ?? what ? How???


ikkada undi>>>


[url="http://www.oracle.com/technetwork/database/clustering/overview/scan-129069.pdf"]http://www.oracle.co...scan-129069.pdf[/url]




USING OPTION 1 - DEFINE THE SCAN IN YOUR CORPORATE DNS
If you choose Option 1, you must ask your network administrator to create a single name that resolves to 3 IP
addresses using a round-robin algorithm. Three IP addresses are recommended considering load balancing and high
availability requirements regardless of the number of servers in the cluster. The IP addresses must be on the same
subnet as your public network in the cluster. The name must be 15 characters or less in length, not including the
domain, and must be resolvable without the domain suffix (for example: “sales1-scan’ must be resolvable as opposed
to “scan1-scan.example.com”). The IPs must not be assigned to a network interface (on the cluster), since Oracle
Clusterware will take care of it.
Figure 2: Sample DNS entry for SCAN
You can check the SCAN configuration in DNS using “nslookup”. If your DNS is set up to provide round-robin
access to the IPs resolved by the SCAN entry, then run the “nslookup” command at least twice to see the round-robin
algorithm work. The result should be that each time, the “nslookup” would return a set of 3 IPs in a different order.
EZconnet sqlplus system/manager@sales1-scan:1521/oltp
JDBC connect jdbc:oracle:thin:@sales1-scan:1521/oltp
sales1-scan.example.com IN A 133.22.67.194
IN A 133.22.67.193
IN A 133.22.67.192
[/quote]
seppindhi antha ok..... kani emi ardam kaledu....

aa 6 pages doc sadivi ostha... nuvvu ikkadey undu... deggariki raaku

[k2s]

[quote name='PMR aka OM' timestamp='1324406666' post='1301171172']



Single Client Access Name (SCAN) is s a new Oracle Real Application Clusters (RAC) 11g Release 2 feature that provides
a single name for clients to access Oracle Databases running in a cluster. The benefit is that the client’s connect
information does not need to change if you add or remove nodes in the cluster. Having a single name to access the
cluster allows clients to use the EZConnect client and the simple JDBC thin URL to access any database running in
the cluster, independently of which server(s) in the cluster the database is active. SCAN provides load balancing and
failover for client connections to the database. The SCAN works as a cluster alias for databases in the cluster.
[/quote]

idi edo baaney ardam ayindhi....

[PMREDDY19]

Kuditithey repu naa macines lo edho oka RAC chesina server ki undey
ips ni modiify chesi ikkada post lo vestaanu....apppudu chudamu asalu a ip endhuku anedhi...

[PMREDDY19]

[quote name='k2s' timestamp='1324406856' post='1301171178']

idi edo baaney ardam ayindhi....
[/quote]
in simple words,,



nenu 3 -node RAC cluster kosam Racking & Stacking chesey time loney, naaku motham e 3 -node RAC ki innni IPs kaavaali ani adugutaamu ba.. vaalu assign chestaaru,
apppudey manam node 1 meeda extragaa oka 3 ip address teesukuntaamu,

All those 3 ip addresses resolve to a singe machine inthe RAC kind of.. using these IP address you can add any number of servers into a RAC cluster.. and you can simply integrate them annatugaa edho cheptunandu ,

repu maa Server vallani adigi kuditithey reu edho time lo DB lo post vestaanu , office lo asalu DB lo posts chudataannikikuda time undatley e madya full busy ayyoipyaa e madya e panulu anni chestu..

[Maximus]

[img]http://i908.photobucket.com/albums/ac281/abi4u/fao18m.gif[/img]

[CheGuevara]

[quote name='k2s' timestamp='1324406292' post='1301171159']
silence....
eey evvadraa akkada.... veedu edo edo sepi....naaku ochina 2 mukka ni..... confuse sethunnadu ...kotha doubts tho .....
[/quote]

mama first physical IP use chesi connect DB ki connect ayyevallam but that has a disadvantage of TCP/IP error timeout...so VIP concept introduce chesaru which in case fails will shift to another node using its VIP in no time without waiting for the TCP/IP error, so started using VIP in the connection string.....but every node has only single physical IP and single VIP...then what will be the case if all the VIP's fail....

so ala anni VIP's fail aite then we cannot connect to DB , e case ni mind lo pettukoni they introduced SCAN IP's which have 3 IP's and we can use 2 IP's in a round robin fashion to connect to the DB............so the perentage the failing to onnect to the DB because of network IP failure is decreased...........endukante SCAN IP's lo all IP's fail ayye chance chala rare.......

so basically SCAN IP's s to decrease the percentage of failures of connectivity to the Database.....alage eppudite VIP's use chesaro tns entry lo then they have to manually change those entries if there is any network issue on VIP's ....ade scan IP's use cheste tns entry lo , all the time there will be atleast one IP working to connect to the database and there will be less requirement to change the tns entry .....


ade mana time balekunte unna aa 3 IP's work cheyyakunte, inka evvadu em cheyyaledu but the chances are rare...........

[PMREDDY19]

[quote name='CheGuevara' timestamp='1324407249' post='1301171187']

mama first physical IP use chesi connect DB ki connect ayyevallam but that has a disadvantage of TCP/IP error timeout...so VIP concept introduce chesaru which in case fails will shift to another node using its VIP in no time without waiting for the TCP/IP error, so started using VIP in the connection string.....but every node has only single physical IP and single VIP...then what will be the case if all the VIP's fail....

so ala anni VIP's fail aite then we cannot connect to DB , e case ni mind lo pettukoni they introduced SCAN IP's which have 3 IP's and we can use 2 IP's in a round robin fashion to connect to the DB............so the perentage the failing to onnect to the DB because of network IP failure is decreased...........endukante SCAN IP's lo all IP's fail ayye chance chala rare.......

so basically SCAN IP's s to decrease the percentage of failures of connectivity to the Database.....alage eppudite VIP's use chesaro tns entry lo then they have to manually change those entries if there is any network issue on VIP's ....ade scan IP's use cheste tns entry lo , all the time there will be atleast one IP working to connect to the database and there will be less requirement to change the tns entry .....


[color=#ff0000][size=8][b]ade mana time balekunte unna aa 3 IP's work cheyyakunte, inka evvadu em cheyyaledu but the chances are rare........[/b][/size][/color]...
[/quote]


Appudey mee DBA laa value company ki telustundhi mee jobs ki safety kuda untundhi..

[PMREDDY19]

[quote name='Maximus' timestamp='1324407142' post='1301171185']
[img]http://i908.photobucket.com/albums/ac281/abi4u/fao18m.gif[/img]
[/quote]

Ante antey mari aaa aaa maari,, antey anteymm hmm

ala ala plowlo edho antey

[k2s]

[quote name='PMR aka OM' timestamp='1324407085' post='1301171184']
in simple words,,



nenu 3 -node RAC cluster kosam Racking & Stacking chesey time loney, naaku motham e 3 -node RAC ki innni IPs kaavaali ani adugutaamu ba.. vaalu assign chestaaru,
apppudey manam node 1 meeda extragaa oka 3 ip address teesukuntaamu,

All those 3 ip addresses resolve to a singe machine inthe RAC kind of.. using these IP address you can add any number of servers into a RAC cluster.. and you can simply integrate them annatugaa edho cheptunandu ,

repu maa Server vallani adigi kuditithey reu edho time lo DB lo post vestaanu , office lo asalu DB lo posts chudataannikikuda time undatley e madya full busy ayyoipyaa e madya e panulu anni chestu..
[/quote]

samaj ayindhi ...samaj ayindhi.....

aa doc lo 2nd page configuration ardam ayithaledu

[Maximus]

[quote name='PMR aka OM' timestamp='1324407419' post='1301171191']

Ante antey mari aaa aaa maari,, antey anteymm hmm

ala ala plowlo edho antey
[/quote]

[img]http://lh5.ggpht.com/-YcLdudIi6Qw/TmVJiIgXeaI/AAAAAAAAEAo/V3jT4PdOYe4/PK-7.gif[/img]alagalageyyyy

[k2s]

[quote name='CheGuevara' timestamp='1324407249' post='1301171187']

mama first physical IP use chesi connect DB ki connect ayyevallam but that has a disadvantage of TCP/IP error timeout...so VIP concept introduce chesaru which in case fails will shift to another node using its VIP in no time without waiting for the TCP/IP error, so started using VIP in the connection string.....but every node has only single physical IP and single VIP...then what will be the case if all the VIP's fail....

so ala anni VIP's fail aite then we cannot connect to DB , e case ni mind lo pettukoni they introduced SCAN IP's which have 3 IP's and we can use 2 IP's in a round robin fashion to connect to the DB............so the perentage the failing to onnect to the DB because of network IP failure is decreased...........endukante SCAN IP's lo all IP's fail ayye chance chala rare.......

so basically SCAN IP's s to decrease the percentage of failures of connectivity to the Database.....alage eppudite VIP's use chesaro tns entry lo then they have to manually change those entries if there is any network issue on VIP's ....ade scan IP's use cheste tns entry lo , all the time there will be atleast one IP working to connect to the database and there will be less requirement to change the tns entry .....


ade mana time balekunte unna aa 3 IP's work cheyyakunte, inka evvadu em cheyyaledu but the chances are rare...........
[/quote]

gippudu full to ardam ayindhi
kani from network point of view... IPs pani cheyyaka povatam enti ?

[CheGuevara]

[quote name='k2s' timestamp='1324407609' post='1301171196']

gippudu full to ardam ayindhi
kani from network point of view... IPs pani cheyyaka povatam enti ?
[/quote]


sometimes the hostnames cannot resolve to IP's, sometimes there may have firewall issues and some times there might be NIC card issue on the servers............etc etc

[Gachibowli_Diwakar]

[quote name='CheGuevara' timestamp='1324407249' post='1301171187']

mama first physical IP use chesi connect DB ki connect ayyevallam but that has a disadvantage of TCP/IP error timeout...so VIP concept introduce chesaru which in case fails will shift to another node using its VIP in no time without waiting for the TCP/IP error, so started using VIP in the connection string.....but every node has only single physical IP and single VIP...then what will be the case if all the VIP's fail....

so ala anni VIP's fail aite then we cannot connect to DB , e case ni mind lo pettukoni they introduced SCAN IP's which have 3 IP's and we can use 2 IP's in a round robin fashion to connect to the DB............so the perentage the failing to onnect to the DB because of network IP failure is decreased...........endukante SCAN IP's lo all IP's fail ayye chance chala rare.......

so basically SCAN IP's s to decrease the percentage of failures of connectivity to the Database.....alage eppudite VIP's use chesaro tns entry lo then they have to manually change those entries if there is any network issue on VIP's ....ade scan IP's use cheste tns entry lo , all the time there will be atleast one IP working to connect to the database and there will be less requirement to change the tns entry .....


ade mana time balekunte unna aa 3 IP's work cheyyakunte, inka evvadu em cheyyaledu but the chances are rare...........
[/quote]asalu VIP pani cheyyakunda unde scenarios untaaaya ba ?? if so when ??