Bug #101179 The variable group_replication_force_members is better to be case insensitive
Submitted: 15 Oct 2020 6:55 Modified: 20 Oct 2020 7:53
Reporter: Richard Hao Email Updates:
Status: Duplicate Impact on me:
None 
Category:MySQL Server: Group Replication Severity:S4 (Feature request)
Version:8.0.21 OS:CentOS (7.5.1804)
Assigned to: CPU Architecture:x86 (Intel(R) Core(TM) i5-8300H CPU @ 2.30GHz)

[15 Oct 2020 6:55] Richard Hao
Description:
A member is specified by the hostname and the port in our GR group, and that is very easy for DBAs to use different case for group_replication_group_seeds,group_replication_group_seeds。such as in our my.cnf file

group_replication_local_address = 'centos7-cerver6:33061'
group_replication_group_seeds ='CentOS7-Server6:33061,Centos7-Server7:33061,CentOS7-Server8:33061'

Sometimes when we encounter a GR error which the Primary node is not able to reach a majority of members in the group,we need to force a new group membership, we do follow steps:
1. use sql "select * from performance_schema.replication_group_members;" to get member's info: member_host, member_port and form the active member list 

2. then force a new group membership by setting group_replication_force_members = active member list getting in step 1.

then we will get error:
ERROR 1231 (42000): Variable 'group_replication_force_members' can't be set to the value of 'XXXXXXXX'

We spend a lot of time to find the cause. 

How to repeat:
1. group_replication_local_address in lower case 
2. group_replication_group_seeds in upper case
3. GR group has five members, kill 3 secondary members at the same time
4. Primary node will block all dml and ddl,
5. use sql "select * from performance_schema.replication_group_members;" to get member's info: member_host, member_port and form the active member list 
6.setting group_replication_force_members = active member list getting in step 5.

then you will get the error
[19 Oct 2020 12:27] MySQL Verification Team
Hi,

Your bug report is a duplicate of the bug #101178.
[20 Oct 2020 7:53] Richard Hao
>Your bug report is a duplicate of the bug #101178.

Hi, Yes, I clicked "Send bug report" two times in a very short time. please ignore  bug 101179