Connecting to a RAC (Real Application Cluster) using SQL*Net

Discussion of open issues, suggestions and bugs regarding usage of dbExpress drivers for Oracle in Delphi and C++Builder
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fabnavigator
Posts: 6
Joined: Tue 24 May 2011 12:22

Connecting to a RAC (Real Application Cluster) using SQL*Net

Post by fabnavigator » Tue 24 May 2011 17:04

Hello,

Our IT department is migrating a number of our servers to a RAC configuration. After they do this, I am no longer able to connect to them using SQL*Net. I can still connect to the cluster with OCI using the TNS name.

Is there any way to connect to the cluster with SQL*Net?

Best regards,

Bill

AlexP
Devart Team
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Joined: Tue 10 Aug 2010 11:35

Post by AlexP » Thu 26 May 2011 08:59

Hello,

I cannot reproduce the problem.
dbExpress driver for Oracle connects to Oracle RAC servers in the Direct mode successfully.
Please specify the exact version of your dbExpress driver for Oracle and send us your tnsnames.ora file and the Database value you are using.

fabnavigator
Posts: 6
Joined: Tue 24 May 2011 12:22

Post by fabnavigator » Thu 26 May 2011 11:43

Hi,

Thank you for looking into this. I'm glad to hear that it works for you. Note: I replaced our domain name with "xxxxxxxxxxx".

I've tried both of these database strings:

DataBase=srd01v.xxxxxxxxxxx.com:1523:SN=vqaprod
DataBase=srd02v.xxxxxxxxxxx.com:1523:SN=vqaprod

I get: "Database Server Error: NET: Invalid Service Name"

Driver version: 4.90.0.25

Section of tnsnames.ora file:

VQA_PROD.WORLD =
(DESCRIPTION =
(FAILOVER = ON)
(LOAD_BALANCE = OFF)
(ADDRESS = (PROTOCOL = tcp)(HOST = srd02v.xxxxxxxxxxx.com)(PORT = 1523))
(ADDRESS = (PROTOCOL = tcp)(HOST = srd01v.xxxxxxxxxxx.com)(PORT = 1523))
(CONNECT_DATA =
(SERVICE_NAME = VQAPROD.xxxxxxxxxxx.COM)
)
)

AlexP
Devart Team
Posts: 5530
Joined: Tue 10 Aug 2010 11:35

Post by AlexP » Fri 27 May 2011 06:21

Hello,

To connect using Service Name, you should set the DataBase property in the following way:

Code: Select all

DataBase=srd02v.xxxxxxxxxxx.com:1523:SN=VQAPROD.xxxxxxxxxxx.COM
DataBase=srd01v.xxxxxxxxxxx.com:1523:SN=VQAPROD.xxxxxxxxxxx.COM

fabnavigator
Posts: 6
Joined: Tue 24 May 2011 12:22

Post by fabnavigator » Sat 28 May 2011 12:22

Hi again,

I had tried that, and after a log wait, I get back "Database Server Error: ORA-12571".

AlexP
Devart Team
Posts: 5530
Joined: Tue 10 Aug 2010 11:35

Post by AlexP » Mon 30 May 2011 09:01

Hello,

Please try to connect to one of your Oracle servers using SID instead of Service Name. If the same error occurs in this case, please check records in the trace file (you should enable tracing).
Also please try to connect after disabling your antivirus program and firewall.

fabnavigator
Posts: 6
Joined: Tue 24 May 2011 12:22

Post by fabnavigator » Tue 31 May 2011 19:20

Hi,

When I use the SID to connect to one of the two servers it works.

AlexP
Devart Team
Posts: 5530
Joined: Tue 10 Aug 2010 11:35

Post by AlexP » Wed 01 Jun 2011 08:27

Hello,

We cannot reproduce the problem on our RAC servers.
Try to connect using servers IP address instead of its name. If your server is accessible from the Internet, please tell us its exact address (we don't need login and password), and we will try to check this problem on your servers.

fabnavigator
Posts: 6
Joined: Tue 24 May 2011 12:22

Post by fabnavigator » Wed 01 Jun 2011 11:51

Hi,

Sorry. These servers are not accessible from the Internet.

I have a question. Why do I need to include the server when connecting by Service Name? The server specified may not even be one that is up.

Also, I can connect by the Service Name from the "Oracle SQL Developer" application.

AlexP
Devart Team
Posts: 5530
Joined: Tue 10 Aug 2010 11:35

Post by AlexP » Wed 01 Jun 2011 12:42

Hello,

For the time being ODAC cannot switch between servers automatically in the Direct mode, that's why you have to specify the server to which you want to connect.
Please send your trace and log files to alexp*devart*com.

fabnavigator
Posts: 6
Joined: Tue 24 May 2011 12:22

Post by fabnavigator » Wed 01 Jun 2011 12:51

Oh. If ODAC cannot switch between servers automatically in Direct mode, I don't need to be able to connect by Service Name.

The whole reason to use the Service Name was to get the automatic switching. If I'm on my own to know which server to connect to, I can just use the SID.

When, do you expect to have automatic switching available?

AlexP
Devart Team
Posts: 5530
Joined: Tue 10 Aug 2010 11:35

Post by AlexP » Wed 01 Jun 2011 13:31

Hello,

We are working on the implementation of this feature now. We plan to add it in one of the next versions.

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