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Title
Connect to Dataguard-connection failed when trying to connect to Oracle database with Spotlight o -
Description
When I try to connect to a Database wich is handled as Oracle Dataguard, the following Message occurs:
'Spotlight cannot connect
The TNS entry associated with this Spotlight on Oracle connection has load balancing set to on. ....
Spotlight on Oracle RAC (if available) should be used to connect to this database instead.' -
Cause
Spotlight on Oracle checks the selected TNS entry, and if it sees any of the parameters "LOAD_BALANCE", "FAILOVER" or "FAILOVER_MODE" set to a value equivalent to "ON", it disallows the connection.
The reason Spotlight disallows the connection is that if Spotlight's session is moved to another instance (via a failover) mid-session, its collected data will be invalidated and it is at risk of raising incorrect alarms or the like, via its rate and delta calculations. We also disallow such connections because it means that Spotlight cannot control which instance its session will run on, and this would seem to invalidate the entire diagnostic process.
Essentially it's required that Spotlight connects to a pre-determined Oracle instance, and that it cannot be moved mid-session to another instance.This constraint was initially imposed to cope with RAC environments, but the FAILOVER parameter also applies to Dataguard, in that situation, the error message should be improved.In the just released version 7.6, we permit connection to READ-ONLY databases, which would include Logical Standby databases, but once again the Spotlight connection must explicitly define the database being connected to (i.e. no FAILOVER or LOAD_BALANCE in the TNS entry). In a future release, (due mid 2011) we will include more diagnostics covering Dataguard environments, and the issue of failover will be considered for that.
So in summary:
- Spotlight will not allow you to connect to TNS entries that specify FAILOVER or LOAD_BALANCE
- To connect to such databases, you need to add a TNS entry that does not have these parameters
- There will be new functionality in future releases of Spotlight to provide enhanced overall diagnostics of Dataguard environments. -
Resolution
Plese remove the entry for Failover or Load_balance from the connection entry in your local tnsnames.ora file where you are running Spotlight on Oracle.
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Additional Information
If an old format QSAuth key is in use, Spotlight v8 is unable to connect to Data Guard.
Please ask Licensing (license@quest.com) to update the key to a newer format 'Quest Key', and this should also fix the issue.