15.10 - Application Behavior - Preprocessor2 for Embedded SQL

Teradata Preprocessor2 for Embedded SQL Programmer Guide

prodname
Preprocessor2 for Embedded SQL
vrm_release
15.10
category
Programming Reference
featnum
B035-2446-035K

The behavior of Teradata Database‑generated applications in the event of a node resetting depends on the:

  • Crash notification setting
  • Type of node on which PP2 is running
  • Application Behavior on a Resetting Node

    If a PP2‑generated application is running on a resetting node, PP2 aborts. Restart the application after the node resets.

    This is equivalent to the situation where a utility or application is initiated on an external client that fails.

    Setting Crash Notification

    Specify crash notification behavior with the SET CRASH statement, which sets the following wait_across_crash (WAC) and tell_about_crash (TAC) options:

     

    Specified Option

    WAC Setting

    TAC Setting

    WAIT_NOTELL

    ‘Y’

    ‘N’

    NOWAIT_TELL

    ‘N’

    ‘Y’

    The default settings for these options are:

  • wait_across_crash (WAC) = ‘Y’
  • tell_about_crash (TAC) = ‘N’
  • For information on GET CRASH and SET CRASH, see SQL Stored Procedures and Embedded SQL (B035‑1148).

    Application Response When WAC is Set to Y and TAC is Set to N

    The following table describes the behavior of PP2‑generated applications when a node resets and WAC = ‘Y’ and TAC = ‘N’.

     

    Type of Node or Client PP2‑Generated Application Runs On

    Action Taken

  • Non‑Resetting node
  • LAN‑attached client
  • Mainframe‑attached client
  • PP2 reconnects its session and returns one of the following error codes from the server. The PP2‑generated application takes action appropriate to the error condition:

     

     

    Code Number

    Description

     

     

    Error 2825

    No record of the last request was found after the Teradata Database restart.

     

     

    Error 2826

    Request completed but all output was lost due to Teradata Database restart.

     

     

    Error 2828

    Request was rolled back during system recovery.

     

     

    Error 3120

    The request is aborted because of a Teradata Database recovery.

     

     

    Application Response When WAC is Set to N and TAC is Set to Y

    The following table describes the behavior of PP2‑generated applications when a node resets and WAC = 'N' and TAC = 'Y'.

     

    Type of Node or Client PP2‑Generated Application Runs On

    Action Taken

  • Non‑Resetting node
  • LAN‑attached client
  • Mainframe‑attached client
  • PP2 immediately disconnects the session. The application receives one of the following CLI error codes:

     

    Code Number

    Description

     

     

    Error 219(EM_DBC_CRASH_B)

    Server connection lost (network or server problem).

     

     

    Error 220(EM_DBC_CRASH_A)

    Server connection lost (network or server problem).