16.10 - Nonparticipant AMPs - Parallel Transporter

Teradata Parallel Transporter Reference

Product
Parallel Transporter
Release Number
16.10
Published
July 2017
Content Type
Programming Reference
Publication ID
B035-2436-077K
Language
English (United States)

An AMP can become nonparticipant for an Update operator task one of the following ways:

  • When any AMP is down at the end of the acquisition phase/beginning of the application phase, the associated AMP becomes a nonparticipant if the AmpCheck 'None' option is specified. Because the Update operator does not run after the acquisition phase if an AMP is down and the target table is nonfallback, an AMP can become a nonparticipant only if the target table is defined as having fallback protection. The AmpCheck 'Apply' and 'All' options prevent the occurrence of nonparticipant AMPs in this situation.
  • When I/O errors occur in certain Update operator tables during the application phase, the associated AMP becomes a nonparticipant if the I/O recovery operation stops the Update operator task.
  • When a head/disk assembly (HDA) fails during the application phase, the associated AMP becomes a nonparticipant but it returns after the disk is replaced and the Disk Copy and Table Rebuild utilities are run.

In effect, the Update operator treats a nonparticipant AMP as if it were a down AMP. Thus, the Update operator does not run if a cluster has any combination of more than one AMP that is:

  • Down
  • Offline
  • Nonparticipant

And, if more than one AMP in a cluster becomes a nonparticipant during the application phase, the Update operator tasks cannot continue. The target tables are considered unusable, and must be recovered from archives.