Intermediate commit.
Update some existing test cases to work with the new handling of
mysql.gtid_slave_pos* tables:
- The tables are now checked during START SLAVE, which causes some
errors or error injections to trigger differently.
- Some test cases that play games with renaming or altering the
mysql.gtid_slave_pos table need adjustments.
Fix a race in the test case. When we do start_slave.inc immediately
followed by stop_slave.inc, it is possible to kill the IO thread while
it is still running inside get_master_version_and_clock(), and this
gives warnings in the error log that cause the test to fail.
When @@GLOBAL.gtid_strict_mode=1, then certain operations result
in error that would otherwise result in out-of-order binlog files
between servers.
GTID sequence numbers are now allocated independently per domain;
this results in less/no holes in GTID sequences, increasing the
likelyhood that diverging binlogs will be caught by the slave when
GTID strict mode is enabled.
Change of user interface to be more logical and more in line with expectations
to work similar to old-style replication.
User can now explicitly choose in CHANGE MASTER whether binlog position is
taken into account (master_gtid_pos=current_pos) or not (master_gtid_pos=
slave_pos) when slave connects to master.
@@gtid_pos is replaced by three separate variables @@gtid_slave_pos (can
be set by user, replicated GTIDs only), @@gtid_binlog_pos (read only), and
@@gtid_current_pos (a combination of the two, most recent GTID within each
domain). mysql.rpl_slave_state is renamed to mysql.gtid_slave_pos to match.
This fixes MDEV-4474.
Implement START SLAVE UNTIL master_gtid_pos = "<GTID position>".
Add test cases, including a test showing how to use this to promote
a new master among a set of slaves.
