Overview of Unplanned Application Lossless and Transparent

Unplanned application lossless and transparent (ALT) means that recoverable faults can be shielded from applications when failover occurs in centralized deployment. The driver transparently switches to the new primary node, restores the session status, and re-executes the interrupted transaction. In this way, the application does not detect I/O exceptions or data inconsistency during transaction processing. Only a short pause occurs, which is similar to a slow SQL statement.

This section describes the functions supported by ALT in M-compatible mode.