This commit changes backup execution (namely the block ddl phase),
so that node is not paused from cluster. Instead, the following
backup execution is declared as vulnerable for possible cluster
level conflicts, especially with DDL statement applying.
With this, the mariabackup execution may be aborted, if DDL
statements happen during backup execution. This abortable
backup execution is optional feature and may be
enabled/disabled by wsrep_mode: BF_ABORT_MARIABACKUP.
Note that old style node desync and pause, despite of
WSREP_MODE_BF_MARIABACKUP is needed if node is operating as
SST donor.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>
Added a new wsrep_mode feature DISALLOW_LOCAL_GTID for this.
Nodes can have GTIDs for local transactions in the following scenarios:
A DDL statement is executed with wsrep_OSU_method=RSU set.
A DML statement writes to a non-InnoDB table.
A DML statement writes to an InnoDB table with wsrep_on=OFF set.
If user has set wsrep_mode=DISALLOW_LOCAL_GTID these operations
produce a error ERROR HY000: Galera replication not supported
