Bug #84631 Group Replication Installation Documentation
Submitted: 24 Jan 2017 1:38 Modified: 3 Jan 11:45
Reporter: Kenny Gryp Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server: Documentation Severity:S3 (Non-critical)
Version:5.7 OS:Any
Assigned to: CPU Architecture:Any
Tags: documentation, gr, group replication

[24 Jan 2017 1:38] Kenny Gryp
Description:

The documentation of Group Replication mentions in 19.2.1 to configure my.cnf with:

loose-group_replication_group_name="aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa"
loose-group_replication_start_on_boot=off
loose-group_replication_local_address= "127.0.0.1:24902"
loose-group_replication_group_seeds= "127.0.0.1:24901,127.0.0.1:24902,127.0.0.1:24903"
loose-group_replication_bootstrap_group= off

Then it says to start mysql. As these are loose- variables and group replication plugin is not loaded yet, the variables are not loaded.

So the START GROUP REPLICATION command will therefore fail as the variables in /etc/my.cnf will not be loaded in the first place.

How to repeat:
follow the documentation instructions on a clean install: 

https://dev.mysql.com/doc/refman/5.7/en/group-replication-deploying-in-single-primary-mode...

Suggested fix:
both with the bootstrapped node and the other nodes we should do:

- start mysql
- load the plugin
- add the variables to my.cnf
- restart mysql
- start group replication
[24 Jan 2017 1:38] Kenny Gryp
Also reported in Also reported in http://bugs.mysql.com/bug.php?id=84281
[24 Jan 2017 14:34] Bogdan Kecman
Hi,

Yes, https://dev.mysql.com/doc/refman/5.7/en/group-replication-configuring-instances.html should mention also you need to load the plugin

thanks
Bogdan
[2 Feb 2017 0:48] Kenny Gryp
Additionally, I would avoid using `loose-` at all as this is IMO a bad practice: this means when GR plugin cannot be loaded mysql will just start as an individual node
[3 Jan 11:45] Erlend Dahl
Posted by developer (David Moss): 

Thanks for your feedback, the loose- prefix has been removed from the
mentioned docs.