Running MySQL InnoDB Cluster / Group Replication, there is a transaction size limit (https://dev.mysql.com/doc/refman/8.0/en/group-replication-options.html#sysvar_group_replication_transaction_size_limit)
The default value of "group_replication_transaction_size_limit" is about 143 MB (150000000 bytes)
How can we determine the size of a batch job (single transaction) in MySQL?
Setting a small value with variable group_replication_transaction_size_limit and running the transaction produces the error message in error log.
For example :
Assuming there is primary node on port 3310
mysql -uroot -p -h127.0.0.1 -P3310 -e " set global group_replication_transaction_size_limit=1024;"
mysql -uroot -p -h127.0.0.1 -P3310 << EOL
create database if not exists demox;
create table demox.mytable (f1 int not null auto_increment primary key, f2 varchar(1024));
insert into demox.mytable (f2) values (repeat('a',1024));
EOL
Checking the error log file, we may see the message like
2023-03-21T06:40:40.997931Z 1133317 [ERROR] [MY-011608] [Repl] Plugin group_replication reported: 'Error on session 1133317. Transaction of size 1833 exceeds specified limit 1024. To increase the limit please adjust group_replication_transaction_size_limit option.'
2023-03-21T06:40:40.997991Z 1133317 [ERROR] [MY-010207] [Repl] Run function 'before_commit' in plugin 'group_replication' failed
By adjusting the transaction size limit, the size is logged in the error log file.
Note: This is not a good practice for production usage. Adjusting the global variable 'group_replication_transaction_size_limit' affects all transactions.