Unreleased Release Notes

17.4.0

New Features

• Added support for detecting and handling MariaDB error 1020 “Record has changed since last read” which occurs under REPEATABLE-READ isolation level when MariaDB detects that a row has changed since it was last read in the current transaction. This error is now wrapped in a new DBConsistencyError exception class that inherits from DBDeadlock, ensuring that existing retry decorators and error handling code will automatically handle this transient concurrency condition.

Bug Fixes

• Fixed handling of MariaDB error 1020 that was previously not properly categorized by oslo.db’s exception filtering system. This error, which can occur in OpenStack services like Nova and Keystone when using MariaDB with REPEATABLE-READ isolation level, is now properly wrapped in a DBConsistencyError exception (a subclass of DBDeadlock) instead of being passed through as a generic OperationalError. This ensures that existing retry mechanisms that handle deadlock-like conditions will automatically work with this MariaDB-specific consistency error.

  For more details, see bug 2116186.