15.10 - Common Warning and Error Messages - Teradata Database

Teradata Database Application Programming Reference

Teradata Database
Programming Reference

Most of the monitor requests covered in this chapter depend on periodic collection of data. When this collection process is disturbed, the returned data can temporarily become confusing or inaccurate.

If this happens, the user receives a warning message indicating that the data returned may not give a true picture of system or user activity.

The following are some common situations in which a warning message is provided:

  • The data returned may have been affected by a system restart or a single processor recovery. Resource/session usage values may not be realistic until requests on the Teradata Database re-attain their normal level of activity.
  • Data may also be incomplete in cases where:
  • A full data collection period has not transpired since the Teradata Database has gone through a recovery.
  • A full data collection period has not transpired since the related monitoring rate was changed.
  • For more detailed information on warning and error messages, see Messages.

    Errors Resulting from PMPC Subsystem Failures

    All MONITOR requests get their information from the PMPC subsystem. In the event of a PMPC internal software failure, the system will generate one of several possible errors. Each of these errors causes the PMPC subsystem to discontinue the current session to prevent the error from crashing the entire system.

    If the system encounters such an error, it takes a snapshot dump and does one of the following:

  • If the internal software error occurs during the initial parsing of the System PMPC request, the session and the interface that caused the error will be discontinued. The user can log on again and submit other System PMPC requests, however, sometimes the internal software error will persist. On the third instance that a PE sees the internal software error, the PE will be shutdown for further logons. Even if this happens the PMPC subsystem may still be available through other PEs.
  • If an internal software error occurs during a subsequent request processing task, the system will take a snapshot dump both of the problem task and parsing task. Then it will shut down the entire PMPC subsystem from further logons.
  • Even though the PMPC subsystem may be partially or fully shut down due to an internal software error, the shut down avoids a crash and allows the system to process other types (non-PMPC) of requests. Although the system resources are cleaned up as much as possible after such an internal software error, there may be leftover resources or tasks that stay hung waiting on a response from the task that originally caused the error.

    After encountering a PMPC subsystem internal failure, especially if a subsequent MONITOR request results in an error, the administrator should do a manual DBS restart as soon as possible (taking care not to unnecessarily disrupt users) to rid the system of task and resource fragments. The administrator should also report the snapshot dump and any related errors in the event log to the Teradata Support Center.