This is a command-line option for the
mariabackup commands (arg: Required).
This option specifies time in seconds that innobackupex should wait for queries that would block FTWRL before running it. If there are still such queries when the timeout expires, innobackupex terminates with an error. Default is 0, in which case innobackupex does not wait for queries to complete and starts FTWRL immediately.