Bug #88717 MySQL Group Replication Large Transactions Limit
Submitted: 30 Nov 2017 14:10 Modified: 15 Feb 2019 15:08
Reporter: Hugo Dubois Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server: Documentation Severity:S3 (Non-critical)
Version:5.7.19 OS:Any
Assigned to: CPU Architecture:Any

[30 Nov 2017 14:10] Hugo Dubois 
Description:
Hello,

I don't know if it's a documentation bug or not but in this page: https://dev.mysql.com/doc/refman/5.7/en/group-replication-limitations.html we can find : "Individual transactions that result in GTID contents which are large enough that it cannot be copied between group members over the network within a 5 second window can cause failures in the group communication."

Does this limitation exist with these bugs fix?
https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-19.html#mysqld-5-7-19-bug
"Replication: Transmission of large GCS messages could take so long the sender appeared to have died. (Bug #22671846)"

and 

https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-19.html
"Replication: The group_replication_transaction_size_limit variable was added to enable you to protect a group against large transactions causing a failure. (Bug #84785, Bug #25510757)"

How to repeat:
Compare 

https://dev.mysql.com/doc/refman/5.7/en/group-replication-limitations.html we can find : "Individual transactions that result in GTID contents which are large enough that it cannot be copied between group members over the network within a 5 second window can cause failures in the group communication."

with:

https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-19.html#mysqld-5-7-19-bug
"Replication: Transmission of large GCS messages could take so long the sender appeared to have died. (Bug #22671846)"

https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-19.html
"Replication: The group_replication_transaction_size_limit variable was added to enable you to protect a group against large transactions causing a failure. (Bug #84785, Bug #25510757)"

Suggested fix:
Update documentation ?
[1 Dec 2017 6:47] MySQL Verification Team 
Hello Hugo Dubois,

Thank you for the report and feedback!

Thanks,
Umesh
[15 Feb 2019 15:08] Margaret Fisher 
Posted by developer:
 
Thanks for pointing this out! The documentation has been updated in:

https://dev.mysql.com/doc/refman/5.7/en/group-replication-limitations.html
https://dev.mysql.com/doc/refman/8.0/en/group-replication-limitations.html
https://dev.mysql.com/doc/refman/5.7/en/group-replication-options.html#sysvar_group_replic...
https://dev.mysql.com/doc/refman/8.0/en/group-replication-options.html#sysvar_group_replic...

Sorry you didn't get a response earlier, and thanks for helping us improve the documentation.