---
features:
  - |
    Add a new parameter named ``synchronous_reader`` for sqlalchemy backend so
    an operator can choose from configuration file if reader context should
    be synchronous or not.
    When ``synchronous_reader`` is set to ``True`` (the default), a database
    reader context will guarantee it can read data from a writer context by
    reusing the same ``connection`` parameter, thus ignoring the
    ``slave_connection`` parameter.
    When ``synchronous_reader`` is set to ``False``, a database reader context
    works the same as an async_reader and will select the ``slave_connection``
    parameter to connect to the database if present.
    When setting this parameter to ``False``, make sure your cluster lag is
    not a problem or set ``mysql_wsrep_sync_wait`` accordingly.
