16.6 Logging Error Information for Oracle Net Services

All errors encountered by Oracle Net Services are appended to a log file for evaluation by a network or database administrator. The log file provides additional information for an administrator about on-screen error messages. The error stack in the log file shows the state of the software at various layers.

To ensure that all errors are recorded, logging cannot be disabled on clients or name servers. Furthermore, only an administrator may replace or erase log files. The log file for the listener includes audit trail information about every client connection request, and most listener control commands.

• Oracle Net Error Stacks
  Log files provide information contained in an error stack. An error stack refers to the information that is produced by each layer in an Oracle communications stack as the result of a network error.
• Understanding Error Stack Messages
  Although the application displays only a one-line error message, an error stack that is much more informative is recorded in the log file by the network layer.
• Oracle Net Services Log File Names
  Each Oracle Net Services component produces its own log file. When using ADR, the default, the log file names are log.xml in the appropriate alert directory.
• Oracle Network Log File Segmentation
  The maximum size and number of text log files can be configured for Oracle Network components such as Oracle Net Listener, Oracle Connection Manager, and Global Service Manager.
• About the Logging Parameters
  Parameters that control logging, including the type and amount of information logged, and the location where the files are stored, are set in the configuration file of each network component.
• Setting Logging Parameters in Configuration Files
  You configure logging parameters for the sqlnet.ora file with Oracle Net Manager and for the listener.ora file with either Oracle Enterprise Manager Cloud Control or Oracle Net Manager.
• Setting Logging During Control Utilities Runtime
  You can set logging during control utility runtime. Setting logging with a control utility does not set parameters in the *.ora files, and the setting is only valid for the control utility session.
• Using Log Files
  This procedure describes how to use a log file to diagnose a network error.
• Analyzing Listener Logs
  The listener log file records information about audit trails, service registration-related events, direct hand-off events, subscriptions for Oracle Notification Service (ONS) node-down events, and Oracle Clusterware notifications.
• Analyzing Oracle Connection Manager Logs
  Oracle Connection Manager (CMAN) generates the cman_alias.log file in the specified log directory. This log file records messages related to the CMAN listener, gateway, CMADMIN processes, and alerts.