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MDEV-11675 Lag Free Alter On Slave

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This commit implements two phase binloggable ALTER.
When a new

      @@session.binlog_alter_two_phase = YES

ALTER query gets logged in two parts, the START ALTER and the COMMIT
or ROLLBACK ALTER. START Alter is written in binlog as soon as
necessary locks have been acquired for the table. The timing is
such that any concurrent DML:s that update the same table are either
committed, thus logged into binary log having done work on the old
version of the table, or will be queued for execution on its new
version.

The "COMPLETE" COMMIT or ROLLBACK ALTER are written at the very point
of a normal "single-piece" ALTER that is after the most of
the query work is done. When its result is positive COMMIT ALTER is
written, otherwise ROLLBACK ALTER is written with specific error
happened after START ALTER phase.
Replication of two-phase binloggable ALTER is
cross-version safe. Specifically the OLD slave merely does not
recognized the start alter part, still being able to process and
memorize its gtid.

Two phase logged ALTER is read from binlog by mysqlbinlog to produce
BINLOG 'string', where 'string' contains base64 encoded
Query_log_event containing either the start part of ALTER, or a
completion part. The Query details can be displayed with `-v` flag,
similarly to ROW format events.  Notice, mysqlbinlog output containing
parts of two-phase binloggable ALTER is processable correctly only by
binlog_alter_two_phase server.

@@log_warnings > 2 can reveal details of binlogging and slave side
processing of the ALTER parts.

The current commit also carries fixes to the following list of
reported bugs:
MDEV-27511, MDEV-27471, MDEV-27349, MDEV-27628, MDEV-27528.

Thanks to all people involved into early discussion of the feature
including Kristian Nielsen, those who helped to design, implement and
test: Sergei Golubchik, Andrei Elkin who took the burden of the
implemenation completion, Sujatha Sivakumar, Brandon
Nesterenko, Alice Sherepa, Ramesh Sivaraman, Jan Lindstrom.
This commit is contained in:
Sachin
2021-01-29 11:59:14 +00:00
committed by Andrei
parent c64e507fad
commit 0c5d1342ae
87 changed files with 8448 additions and 147 deletions
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83
mysql-test/suite/rpl/r/rpl_start_alter_chain_basic.result Normal file
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include/rpl_init.inc [topology=1->2->3->4]
connection server_3;
set global gtid_strict_mode=1;
include/stop_slave.inc
SET GLOBAL slave_parallel_threads=10;
set global slave_parallel_mode=optimistic;
change master to master_use_gtid=slave_pos;
include/start_slave.inc
connection server_1;
set global binlog_alter_two_phase=YES;
set binlog_alter_two_phase=YES;
connect master_node,127.0.0.1,root,,$db_name, $SERVER_MYPORT_1;
connect slave_node,127.0.0.1,root,,test, $SERVER_MYPORT_2;
# innodb
connection master_node;
create table t1(a int, b int) engine=innodb;;
insert into t1 values(1,1);
insert into t1 values(2,2);
# Normal Alter
alter table t1 add column c int;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(11) DEFAULT NULL,
`b` int(11) DEFAULT NULL,
`c` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1
# Failed Alter
insert into t1 values(1,1, NULL);
alter table t1 change a a int unique;
ERROR 23000: Duplicate entry '1' for key 'a'
set @@session.binlog_alter_two_phase = 0;
alter table t1 change a a int;
set @@session.binlog_alter_two_phase = 1;
alter table t1 change a a int;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(11) DEFAULT NULL,
`b` int(11) DEFAULT NULL,
`c` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1
include/save_master_gtid.inc
connection slave_node;
include/sync_with_master_gtid.inc
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(11) DEFAULT NULL,
`b` int(11) DEFAULT NULL,
`c` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1
connection master_node;
drop table t1;
include/save_master_gtid.inc
connection slave_node;
include/sync_with_master_gtid.inc
disconnect master_node;
disconnect slave_node;
connection server_1;
set global binlog_alter_two_phase=No;;
include/rpl_sync.inc
connection server_2;
select domain_id, seq_no from mysql.gtid_slave_pos order by seq_no desc limit 1;
domain_id seq_no
0 12
connection server_3;
select domain_id, seq_no from mysql.gtid_slave_pos order by seq_no desc limit 1;
domain_id seq_no
0 12
include/stop_slave.inc
set global slave_parallel_threads = 0;;
set global slave_parallel_mode = optimistic;;
set global gtid_strict_mode = 0;;
include/start_slave.inc
select @@slave_parallel_threads;
@@slave_parallel_threads
0
connection server_4;
select domain_id, seq_no from mysql.gtid_slave_pos order by seq_no desc limit 1;
domain_id seq_no
0 12
include/rpl_end.inc