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which instance [message #265765]

Fri, 07 September 2007 05:33

maoro
Messages: 312
Registered: May 2005

Senior Member

hello
when connecting to RAC instances that runs on 2 nodes named "A" and "B" lets say
from a client machine supposing that the instance is "orclA" on node A and "orclB" on node B,
how do i connect from a client machine when using net services:
which hostname of which node do i provide ?
which service name " orclA" or "orclB" ?
and which port number
i know its a newbie question
i have read the documentation
but it talks about RAC installation and administration only

thanks

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Re: which instance [message #265843 is a reply to message #265765]

Fri, 07 September 2007 10:11

DreamzZ
Messages: 1666
Registered: May 2007
Location: Dreamzland

Senior Member

You dont need to Provide the Instance Name you will give the main db name it will automatically connect to the instance wheres load will be low.

eg

let you have 2 instances ORCLa & ORCLb
you will connect like this

Code: [Select all] [Show/ hide]

sqlplus user/pass@ORCL

It will automatically throw you to the instance where load will low.

In this case your TNSNAMES looks like

Code: [Select all] [Show/ hide]

UCHOOSE =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = udb01vip)(PORT = 1521))
    (ADDRESS = (PROTOCOL = TCP)(HOST = udb02vip)(PORT = 1521))
    (LOAD_BALANCE = yes)
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = UCHOOSE)
    )
  )

LISTENERS_UCHOOSE =
  (ADDRESS_LIST =
    (ADDRESS = (PROTOCOL = TCP)(HOST = udb01vip)(PORT = 1521))
    (ADDRESS = (PROTOCOL = TCP)(HOST = udb02vip)(PORT = 1521))
  )

UCHOOSE2 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = udb02vip)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = UCHOOSE)
      (INSTANCE_NAME = UCHOOSE2)
    )
  )

UCHOOSE1 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = udb01vip)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = UCHOOSE)
      (INSTANCE_NAME = UCHOOSE1)
    )
  )

EXTPROC_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
    )
    (CONNECT_DATA =
      (SID = PLSExtProc)
      (PRESENTATION = RO)
    )
  )

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