Oracle7 Server Distributed Systems Volume I: Distributed Data
Testing your Configuration
After configuring the network using Network Manager and distributing the configuration files to the destination machines, each component can be started and tested.
The preferred sequence for testing the network is to:
- start and test each Listener
- start and test each MultiProtocol Interchange
In addition, if Oracle Names is running on your network, test Oracle Names. For further information on how to do so, see the Oracle Names Administrator's Guide.
Start the Listener
From each listener's node, use the Listener Control Utility, LSNRCTL, to start each listener. In command line mode, the command is:
LSNRCTL START listener_name
LSNRCTL should display a status message indicating that it has started the listener process successfully. Check that all expected SIDs for that listener are listed in the services summary in the status message.
Test the Listener
To test the listener, initiate a connection from a client in the same community as the listener to any active database controlled by
that listener.
The simplest test uses SQL*Plus as follows:
SQLPLUS user/password@service_name
The service_name is found in the TNSNAMES.ORA file before each entry. For more information about testing from a client, see ![[*]](jump.gif)
.
If there are no clients in the same community as the listener, you must start an Interchange before testing the listener.
Repeat these steps for each listener in the network.
Start the MultiProtocol Interchanges
Use the Interchange Control Utility, INTCTL, on the Interchange node to start an Interchange. For example, in command line mode the command is:
INTCTL START INTERCHANGE
or
INTCTL START INT
INTCTL should display a status message indicating that it has started the interchange successfully. For more information on the
Interchange Control Utility, see the Oracle MultiProtocol Interchange Administrator's Guide.
Test the Interchanges
To test the Interchange, initiate a connection through the Interchange from a client in one community to a database in another. On the client machine type:
SQLPLUS user/password@service_name
The service_name for the database in the other community is found in the TNSNAMES.ORA file. To ensure that the connection went through the Interchange, type:
INTCTL STATUS INTERCHANGE
The Connection Manager should indicate that there is one active connection through the Interchange. The STATUS command can be run on the Interchange machine, or, if the Interchange is listed in the TNSNAMES.ORA file, from any other node.
Test Each Client Type to Make Sure you can Connect to Servers
Make sure that each client type is tested. It is not enough to test that the Interchange works. If there are several different client types in your network, initiate a connection to a server from each of them.
If a connection is unsuccessful, use logging and tracing, the diagnostic utilities, to find the cause of the problem. An error stack in the error log may point to the problem. If not, turn on tracing and repeat the operation. You can find information about error logging and tracing in the Oracle Network Products Troubleshooting Guide.
Common Errors During Testing
If you are unsuccessful in bringing up a listener or Interchange, or fail to make a connection to a database, one of the following common errors may be the cause.
- The listener name in the LSNRCTL START command is invalid. Check for typos. Check the LISTENER.ORA file to ensure that the listener name you are using is valid.
- Files are in the wrong place. Both the listener and the Interchange will indicate that they cannot start because configuration files could not be found.
Additional Information: See your operating system-specific documentation to see that the LISTENER.ORA file has been placed correctly for the listener, and the INTCHG.ORA, TNSNAV.ORA, and TNSNET.ORA files are placed correctly on the Interchange. Be sure that the TNSNAMES.ORA file you access is the one created by Network Manager.
- A specified address is already in use. Another process may already be using the address listed in LISTENER.ORA. On some protocols such as TCP/IP, DECnet, and OSI, each network service on a node must use a unique port or socket. On other network protocols such as SPX/IPX or NetBIOS, each network service name must be unique for the entire network. Another network service may be using the same configuration. Contact your network administrator to evaluate whether the network address is available.
- When trying to connect to a database, you may get the message ORA-12203: "TNS: Unable to connect to destination." Use the LSNRCTL utility to start the listener on the server machine. See Understanding SQL*Net for further information.
- When trying to make a connection from a client, you may get the message ORA-12154:"TNS:Could not resolve service name." The service name you requested is not listed in the TNSNAMES.ORA file, or the TNSNAMES.ORA file has been placed incorrectly. See Understanding SQL*Net for
more information.
- When trying to connect to a database, you may get the message ORA-1034: "Oracle Not Available". The database is not running on the server machine. A listener alone does not provide a database connection, the database instance must also be started.
Other common errors are listed in Understanding SQL*Net. All the error messages generated by SQL*Net, the MultiProtocol Interchange, Oracle Names, and Network Manager (and their underlying layers) can be found in the Oracle Network Products Troubleshooting Guide. This book also contains information about how to interpret log files and how to use the trace facility for trouble-shooting purposes.