Purpose - Teradata Director Program

Teradata® Director Program Reference

Product
Teradata Director Program
Release Number
17.10
Published
October 2021
Language
English (United States)
Last Update
2021-11-02
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B035-2416
Product Category
Teradata Tools and Utilities

Displays the status of channel processors (CPs) that are assigned to this TDP.

Because this command displays information about the status of a CP, the processing by a CP is briefly described as an aid to understanding. An optional ATTACH and a START command is issued for each CP. The START command specifies the even device address of an even/odd pair of device addresses. Both devices are allocated to TDP. A process between TDP and the database initializes the communication protocol. This protocol aggregates requests and responses to maximize throughput. Finally, TDP synchronizes its status of any existing sessions and requests with the database's status. Then normal channel transfers begin between TDP and the database. Requests are associated with a CP from the time they are sent until their responses are received. Should a communication problem occur, the communication protocol is interrupted and must be re-established. Until this is done, the CP is idle. The goal is to resume communication with the database. If at any time an unrecoverable error occurs, use of the CP is halted. The STOP and DETACH commands may be used to discontinue use of a CP. The processing is the reverse of starting the CP: normal channel transmissions are quiesced, when they end the communication protocol is terminated, and TDP's use of the CP's device addresses ends.

The communication protocol and synchronization between TDP and the database are the same for network and channel communication.