Retry failed writes

Overview

If a write fails when autocommit is enabled and no transactions are open, it is safe to attempt a retry of the query if a replacement master server is available.

Task Details

This task is mainly about refactoring the retrying code to handle multiple types of queries and targets. The rough outline of this task is:

• Store target type of the active query
• Abstract retrying by trying to find a server of the same target type
• Take the new code into use for both reads and writes