SET @base_seq = (SELECT CAST(variable_value AS UNSIGNED) FROM performance_schema.global_status WHERE variable_name = 'Lizard_commit_gcn');
create table t1 (a int , primary key (a));
# innodb_snapshot_update_gcn = true
set global innodb_snapshot_update_gcn = true;
# global query with normal trx, xa trx
xa begin 'x10000';
insert into t1 values (10000);
xa end 'x10000';
xa prepare 'x10000';
set innodb_commit_seq = @base_seq +10000;
xa commit 'x10000';
xa begin 'x12000';
set innodb_snapshot_seq = @base_seq +12000;
select * from t1;
a
10000
insert into t1 values (12001);
xa begin 'x12002';
insert into t1 values (12002);
xa end 'x12002';
xa commit 'x12002' one phase;
xa begin 'x13000';
insert into t1 values (13000);
xa end 'x13000';
xa prepare 'x13000';
set innodb_commit_seq = @base_seq +13000;
xa commit 'x13000';
select * from t1;
a
10000
xa end 'x12000';
xa commit 'x12000' one phase;
xa begin 'x14000';
set innodb_snapshot_seq = @base_seq +14000;
select * from t1;
a
10000
12001
12002
13000
xa end 'x14000';
xa commit 'x14000' one phase;
insert into t1 values (14001);
# restart && global query
# restart: --innodb_snapshot_update_gcn=true
xa begin 'x12000';
set innodb_snapshot_seq = @base_seq +12000;
select * from t1;
a
10000
xa end 'x12000';
xa commit 'x12000' one phase;
delete from t1;
# crash && global query 
xa begin 'x15000';
insert into t1 values (15000);
xa end 'x15000';
xa prepare 'x15000';
set innodb_commit_seq = @base_seq +15000;
xa commit 'x15000';
xa begin 'x15001';
set innodb_snapshot_seq = @base_seq +15001;
select * from t1 where a >= 13000;
a
15000
xa end 'x15001';
xa commit 'x15001' one phase;
set debug ='d,ib_trx_crash_during_commit';
insert into t1 values (15001);
ERROR HY000: Lost connection to MySQL server during query
xa begin 'x15001';
set innodb_snapshot_seq = @base_seq +15001;
select * from t1 where a >= 13000;
a
15000
xa end 'x15001';
xa commit 'x15001' one phase;
truncate table t1;
# innodb_snapshot_update_gcn = false
set global innodb_snapshot_update_gcn = false;
# global query with normal trx, xa trx
xa begin 'x20000';
insert into t1 values (20000);
xa end 'x20000';
xa prepare 'x20000';
set innodb_commit_seq = @base_seq +20000;
xa commit 'x20000';
xa begin 'x22000';
set innodb_snapshot_seq = @base_seq +22000;
select * from t1;
a
20000
insert into t1 values (22001);
xa begin 'x22002';
insert into t1 values (22002);
xa end 'x22002';
xa commit 'x22002' one phase;
xa begin 'x23000';
insert into t1 values (23000);
xa end 'x23000';
xa prepare 'x23000';
set innodb_commit_seq = @base_seq +23000;
xa commit 'x23000';
select * from t1;
a
20000
22001
22002
xa end 'x22000';
xa commit 'x22000' one phase;
xa begin 'x24000';
set innodb_snapshot_seq = @base_seq +24000;
select * from t1;
a
20000
22001
22002
23000
xa end 'x24000';
xa commit 'x24000' one phase;
insert into t1 values (24001);
# restart && global query
# restart: --innodb_snapshot_update_gcn=false
xa begin 'x22000';
set innodb_snapshot_seq = @base_seq +22000;
select * from t1;
a
20000
22001
22002
xa end 'x22000';
xa commit 'x22000' one phase;
delete from t1;
# crash && global query 
xa begin 'x25000';
insert into t1 values (25000);
xa end 'x25000';
xa prepare 'x25000';
set innodb_commit_seq = @base_seq +25000;
xa commit 'x25000';
xa begin 'x25001';
set innodb_snapshot_seq = @base_seq +25001;
select * from t1 where a >= 23000;
a
25000
xa end 'x25001';
xa commit 'x25001' one phase;
set debug ='d,ib_trx_crash_during_commit';
insert into t1 values (25001);
ERROR HY000: Lost connection to MySQL server during query
xa begin 'x25001';
set innodb_snapshot_seq = @base_seq +25001;
select * from t1 where a >= 23000;
a
25000
25001
xa end 'x25001';
xa commit 'x25001' one phase;
drop table t1;
set global innodb_snapshot_update_gcn = default;