Ein DB2 Client mit einer Version kleiner als DB2 for LUW V9.7 FP4 meldet SQLCODE4700 (-4700) beim Verbindungsaufbau zu einem DB2 10 for z/os Server? Dann liegt’s an der alten DB2 Client Version!

IBM fordert ihre Kunden dazu auf einen Upgrade der Clients auf DB2 for LUW V9.7 FP4 oder höher vorzunehmen. Aber was tun, wenn der Upgrade nicht oder nicht so schnell durchgeführt werden kann? Mit einem DB2 z/OS PFT werden neue DSN6FAC DDF Compatibility Einstellungen angeboten, die Kunden mit alten DB2 Clients helfen sollen, dass Verhalten ihrer Clients zu kompensieren:

Users have observed unexpected behavior in remote client application environments where remote client environment related changes are necessary in order to tolerate or correct the situation.
The following situations are considered:

• Idle Thread Time-Out serviceability:
  When a DDF Idle Thread Time-Out event occurs, DB2 (DDF) will terminate the network connection and abort the work related to the idle transaction. DB2 also returns companion serviceability information, in the form of a DRDA AGNPRMRM (AGeNt PeRManent error Reply Message) reply, to assist the remote client application environment in identifying the source, or cause, of the failed connection.
  Some remote client application environments are not prepared to tolerate the change in behavior that they may see as a result of this serviceability related reply.
  For example, remote client application environments may not be prepared to tolerate an ERROR CODE -1224 or SQL1224N that
  is returned instead of an ERROR CODE -4499 or SQL30081N that they may have been accustomed to.
• Prior version dependency:
  Some remote client application environments may not be prepared to tolerate a new version of DB2, even when the DB2 (server) version is still operating in Conversion Mode.
  For example, this may lead to erroneous SQLCODE -4700 conditions due to an incorrect attempt, by the remote client application environment, to utilize DB2 New Function that is not yet available.

Remote client application environment changes are necessary to tolerate or correct the condition but these changes may take time to implement and/or deploy. As a result, DB2 for z/OS changes are required to allow users to compensate for the condition and hence allow remote client application environments to continue operating until the necessary client environment related changes can be deployed.

To help users bridge the gap until the remote client application environment adjustments can be made, DB2 will provide two new DSNZPARM DSN6FAC DDF_COMPATIBILITY keyword specifications:

• Disable Idle Thread Time-Out serviceability:
  The DDF_COMPATIBILITY DISABLE_ITTO_EXCPTN specification can be used, perhaps in conjunction with other DDF_COMPATIBILITY
  specifications, to cause DB2 to sacrifice the Idle Thread Time-Out serviceability information that is normally returned to remote client application environments.
  This specification can be changed on-line.
  When this specification is provided, Idle Thread Time-Out events will cause the connection to be terminated only, and DB2 will not return companion serviceability information that identifies the source of the connection termination.
• Prior version dependency:
  The DDF_COMPATIBILITY IDNTFY_Vnn_PRIOR_VER specification can be used, perhaps in conjunction with other DDF_COMPATIBILITY
  specifications, to cause DB2 to identify itself, and its DRDA functionality, relative to the prior version that DB2 was migrated from.
  This specification applies only to CM, ENFM, CM*, or ENFM* migration environments. It does not apply once DB2 is
  migrated to NFM.
  This specification can be changed on-line.
  This specification allows remote client application environments to believe that they are still operating with the prior version of DB2 where the applications are known to behave correctly.
  Users should understand that these specifications are only intended to be a temporary measure until the remote client application environment can be modified to tolerate the condition.

Hier gibts Informationen dazu:

• IBM DB2 PTF PI07515
• I14619: DB2 V10.1 DDF MIGRATION INFOAPAR
• Literatur im IBM DB2 Knowlege Center