Debian 10.7
MySQL 8 Group Replication

I just realized later that I had installed a wrong DEB version (4.0.4) from another repo, THAT file didn't contain the schema.sql.gz
After correcting the repository to use official Zabbix repo, he added the file properly.
But the schema.sql.gz file sent, still does not contain the creation of the table with a primary key, so same problem persists.

After loading the zabbix proxy properly it seems is a no go so far... I will try to evaluate what workarounds I can do tomorrow.

  1027:20210130:181907.982 Zabbix supports only "utf8_bin" collation. Database "zabbix_proxy" has default collation "utf8_general_ci"
  1027:20210130:181907.997 character set name or collation name that is not supported by Zabbix found in 442 column(s) of database "zabbix_proxy"
  1027:20210130:181907.997 only character set "utf8" and collation "utf8_bin" should be used in database

And also:

1040:20210130:181908.132 [Z3005] query failed: [3098] The table does not comply with the requirements by an external plugin. [delete from trigger_queue]

Humm, looks like I'm not the sharpest tool on the shed today :/

"utf8_general_ci"
was changed to:
"utf8_bin"
MySQL8 messages persist, but Zabbix support message is gone.

Added patch file, fixing all the tables which had no Primary Key... like that is working, so far... tomorrow more tests.

Another development here.

When trying to add the create.sql file for the server, I ran into the same problem:

ERROR 3098 (HY000) at line xxxx: The table does not comply with the requirements by an external plugin.

Then I went through the whole SQL file and fixed all the tables without PRIMARY KEY. When trying again, the same error, but from a different line, which made the mystery a bit deeper.

The line in question is:

INSERT INTO `users` (`userid`,`alias`,`name`,`surname`,`passwd`,`url`,`autologin`,`autologout`,`refresh`,`rows_per_page`,`roleid`) values ('1','Admin','Zabbix'
,'Administrator','$2y$10$92nDno4n0Zm7Ej7Jfsz8WukBfgSS/U0QkIuu8WkJPihXBb2A1UrEK','','1','0','30s','50','3');

Reading about some possible reasons, it looks like there is a relationship with this: https://dev.mysql.com/doc/refman/5.7/en/group-replication-options.html#sysvar_group_replication_enforce_update_everywhere_checks

But I could not successfully test yet.

Note this created an impossibility to run zabbix server on MySQL8 Group Replication, I wonder if there are other people doing it and how.

To make it clear, I am trying with MySQL 8.0.23

hummm it seems not ready.

Or I am missing some configuration which I am unable to figure out at this moment.

I see this on Zabbix Proxy log:

 19894:20210201:122820.523 [Z3005] query failed: [3098] The table does not comply with the requirements by an external plugin. [delete from task where status
 in (3,4) and clock<=1612096100]

And this on MySQL Error log:

2021-02-01T12:28:20.523822Z 192887 [ERROR] [MY-011543] [Repl] Plugin group_replication reported: 'Table task has a foreign key with 'CASCADE', 'SET NULL' or 
'SET DEFAULT' clause. This is not compatible with Group Replication.'

Looks like it is not compatible at this moment after all. At least with these versions combined.

Hello,

Sorry for a long waited reply. Indeed it's not directly compatible, but primary index can be added manually. If you need it - please for history* tables use alter table command like this:
alter table history add primary key (itemid, clock,ns);
use ns in key too, not just itemid and clock - otherwise, you may receive errors during high-frequency monitoring.
Also, you should understand that adding indexes to large tables will take time and cause degradation of the monitoring service. Plan resources first.
But overall this is not a bug. Are there any other issues I could assist you with?

Best Regards,
Aleksandrs

Aleksandrs,

yeah, I realize the complication with MySQL8 Group Replication thing...

I did a number of tests and I got the server / proxy working, but only when there is no multiple R/W servers, it only works when there is one R/W and multiple R/O.
In the end, I did created a new field in some of the tables and added a primary key on it. That worked fine.
Your suggestion on primary key with all the fields maybe another option for people going on this direction as well.
Maybe that should be also explicit in the documentation about the lack of support for MySQL 8 Group Replication when in multi master operation, while it runs in single master mode. Just need to fix some table's primary keys.
Because everything is new here, I also stumbled on the fact that PHP 8.0 will also breaks the interface, so, ... slowly but surely we'll get there.

Related to https://support.zabbix.com/browse/ZBX-18043. I was going to file a feature request if I had not seen this and the other tickets. Zabbix HA would be a lot better if it would support MySQL Router and therefore, InnoDB Cluster both in single R/W node and multiple R/W nodes.

Yes - it's true that because InnoDB uses a clustered index and that index is partitioned by either primary or unique key. From a performance standpoint, it's best to have a non-contextual primary key such as an auto_increment column. This keeps the lookups of rows faster because the size of the primary key is kept as small as reasonably possible.