17.00 - Parallel Processing Return Codes - Parallel Transporter

Teradata® Parallel Transporter Application Programming Interface Programmer Guide

prodname
Parallel Transporter
vrm_release
17.00
created_date
June 2020
category
Programming Reference
featnum
B035-2516-220K

Teradata PT supplies the following return codes for two types of synchronization:

  • TD_SYNC_TELINFO - Synchronize the TELINFO communication area from the master to the slave instances, and do not proceed until all instances reach this barrier.
  • TD_SYNC_Barrier - Do not proceed until all instances reach this barrier.

The Teradata PT parallel synchronization is master driven. All slave instances will receive the same synchronization return code in the same phase. The master, however, may receive a different synchronization return code. In these cases, the action taken should follow the synchronization code returned by the master. The following table lists possible synchronization return code combinations and the proper action to take.

Synchronization Return Code Combinations and Suggested Actions 
Received by Master Received by Slave Suggested Action
TD_SYNC_Barrier TD_SYNC_Barrier Call the method again which returned the barrier code after all instances reach this barrier.
TD_SYNC_Barrier TD_END_Method Master calls the method again which returned the barrier code. Slave(s) wait to call the next method until Master receives TD_END_Method.
TD_SYNC_TELINFO TD_SYNC_Barrier Master calls the GetTELINFO function to get the TELINFO area and passes a copy of the TELINFO area to each of the slaves. Slave(s) call the PutTELINFO function to process the master’s TELINFO area. Master and slave(s) call the method again which returned the barrier code after all instances reach this barrier and after TELINFO area has been synchronized.
TD_SYNC_TELINFO TD_SYNC_TELINFO Master calls the GetTELINFO function to get the TELINFO area and passes a copy of the TELINFO area to each of the slaves. Slave(s) call the PutTELINFO function to process the master’s TELINFO area. Master and slave(s) call the method again which returned the barrier code after all instances reach this barrier and after TELINFO area has been synchronized.
TD_END_Method TD_END_Method Proceed to next method after all instances receive TD_END_Method.

Usage Notes

  • The master instance job must be started before starting the slave instance jobs
  • The CLIv2 environment variable THREADONOFF must be set to one for running the Teradata PT multi-threaded application. See Teradata Call-Level Interface Version 2 Reference for Workstation-Attached Systems (B035-2418) for details about this variable.