Changing client connectivity information

To use the connectivity information to redirect clients, you must change the connectivity information for the clients and change other connectivity files, if necessary.

To change the connectivity information about the client computer:

  1. In the sqlhosts file or registry, comment out the entry for the failed database server.
  2. Add an entry that specifies the dbservername of the failed database server in the servername field and information for the database server to which you are redirecting clients in the nettype, hostname, and servicename fields.
  3. Use the following options in the sqlhosts file or registry to redirect applications to another database server if a failure occurs:
    1. Connection-redirection option
    2. End-of-group option
    3. Group option
  4. Edit the /etc/hosts file on UNIX or hosts file on Windows to add an entry, if necessary, for the hostname of the computer that is running the database server to which you are redirecting clients.
  5. Edit the /etc/services file on UNIX or services file on Windows to add an entry, if necessary, for the servicename of the database server to which you are redirecting clients.

The following figure shows how connectivity values might be modified to redirect clients.

You are not required to change entries in the connectivity information on either of the computers that is running the database servers.
Figure 1. Connectivity values before and after a failure of the cliff_ol database server
This figure shows connectivity values before and after a failure of a sample database server named cliff_ol. The connectivity values were changed during the failure. The paragraphs before this figure explain how to change connectivity information on the client computer. The paragraphs after this figure explain how to change other connectivity files.

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