11.2 client and DNS

  • From: Wolfson Larry - lwolfs <lawrence.wolfson@xxxxxxxxxx>
  • To: ORACLE-L <oracle-l@xxxxxxxxxxxxx>
  • Date: Wed, 23 May 2012 20:28:51 +0000

of the 3 DNS servers for this client databases.
This caused very long wait times where some people thought the listener was 
hung and or the databases were down.
Listener and databases  never were down.
They said they were using 3 servers in a round-robin fashion.

They replaced the server and things were fine again.
Someone asked what "oracle" did when there was an issue with DNS and all I 
found so far was this RAC pdf
It stated:
Note: If your DNS server does not return a set of 3 IPs as shown in figure 3 or 
does not round-robin, ask your
network administrator to enable such a setup. DNS using a round-robin algorithm 
on its own does not ensure failover
of connections. However, the Oracle Client typically handles this. It is 
therefore recommended that the minimum
version of the client used is the Oracle Database 11g Release 2 client.

It seems to me this should work the same way RAC or not. But some other DBAs 
said it only works that way for RAC.

Can someone clarify this and can anyone point me to a better document?

Did I miss this in
Oracle(r) Database
Net Services Administrator's Guide
11g Release 2 (11.2)

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