innodb_fast_shutdown
    - Description: The shutdown mode.
        
            - 0- InnoDB performs a slow shutdown, including full purge (before MariaDB 10.3.6, not always, due to MDEV-13603) and change buffer merge. Can be
                very slow, even taking hours in extreme cases.
- 1- the default, InnoDB performs a fast shutdown, not
                performing a full purge or an insert buffer merge.
- 2, the InnoDB redo log is flushed and a cold
                shutdown takes place, similar to a crash. The resulting startup then performs crash recovery. Extremely
                fast, in cases of emergency, but risks corruption. Not suitable for upgrades between major versions!
- 3(from MariaDB 10.3.6) - active
                transactions will not be rolled back, but all changed pages will be written to data files. The active
                transactions will be rolled back by a background thread on a subsequent startup. The fastest option that
                will not involve InnoDB redo log apply on subsequent
                startup. See MDEV-15832.
 
- Commandline: --innodb-fast-shutdown[=#]
- Scope: Global
    
- Dynamic: Yes
    
- Data Type: numeric
- Default Value: 1
- Range:  0to3(>= MariaDB 10.3.6),0to2(<= MariaDB 10.3.5)