4.x: Document that evs.version = 1

[philip-galera]

In particular, autoeviction.html should be changed accordingly.

[kirjaamo]

@byte Can I change the evs.version default value to 1?

[byte]

Hi @kirjaamo -- this is a problem when we keep Galera Cluster 3 and Galera Cluster 4 documentation in the same place.

Because, please read this as well: https://galeracluster.com/library/documentation/auto-eviction.html#upgrade-evs

"Releases of Galera Cluster prior to version 3.8 use EVS Protocol version 0, which is not directly compatible with version 1. As such, when you upgrade Galera Cluster for a node, the node continues to use EVS Protocol version 0."

How do you propose to change evs.version=1 when there are older installations of Galera Cluster around as well?

[kirjaamo]

Can we replace sentence "The default value is version 0, for backwards compatibility." with:
If you use Galera Cluster version 3.9 or older, the default value is 0.
If you use Galera Cluster version 4.0 or newer, the default value is 1.

[byte]

Can we replace sentence "The default value is version 0, for backwards compatibility." with:
If you use Galera Cluster version 3.9 or older, the default value is 0.
If you use Galera Cluster version 4.0 or newer, the default value is 1.

Yes, this is OK.

But can you also ensure that in the documentation you find a way to let people know what version of Galera Cluster they are using? We do not have a mapping of released versions and cluster versions I suspect

[kirjaamo]

Who would know more about finding the version one uses?

[byte]

Who would know more about finding the version one uses?

@temeo can you help here?

[temeo]

This version information is quite scattered for historical reasons. Versions related to gcomm can be found from Galera parameters:

https://galeracluster.com/library/documentation/galera-parameters.html#evs-version
https://galeracluster.com/library/documentation/galera-parameters.html#gmcast-version
https://galeracluster.com/library/documentation/galera-parameters.html#pc-version
https://galeracluster.com/library/documentation/galera-parameters.html#protonet-version

These should be visible in wsrep_provider_options. Though the provider options string has grown so much over time that depending on MariaDB/MySQL server version it may get truncated and all information might not be available.

evs.version seems to be 0 by default in Galera 3 series, 1 in Galera 4. Others are still 0 by default.

Galera version is shown in wsrep_provider_version: https://galeracluster.com/library/documentation/galera-status-variables.html#wsrep-provider-version

[kirjaamo]

The wsrep_profvider_version example vale is 25.3.5-wheezy(rXXXX). Does this mean that Galera version is 3.5?

[byte]

@kirjaamo this should be some inspiration for a new doc https://mariadb.com/kb/en/meta/galera-versions/

Remember that we have to do this for... MySQL provided by Codership, and I think for added value, have the above meta information, and maybe also include Percona XtraDB Cluster (PXC). So we become the canonical source of all information relation to Galera Cluster

[byte]

The wsrep_profvider_version example vale is 25.3.5-wheezy(rXXXX). Does this mean that Galera version is 3.5?

and the answer to this is yes!

[kirjaamo]

Do you mean that we add the tables from https://mariadb.com/kb/en/meta/galera-versions/ to our documentation, and create similar tables for MySQL and PXC?

[byte]

Do you mean that we add the tables from https://mariadb.com/kb/en/meta/galera-versions/ to our documentation, and create similar tables for MySQL and PXC?

I think this is a good idea. People need to have such information available to them, and it should come from our documentation.

[kirjaamo]

Who could collect the versions to a table?

[byte]

Who could collect the versions to a table?

Besides MariaDB, I haven't found something similar, so I presume this is something you will have to do

[byte]

e.g. we are going to release "Codership is pleased to announce the release of Galera Replication library 4.8,
implementing wsrep API version 26." -- but... there is no real reference to 4.8 / wsrep version / etc. in any docs at the moment

[kirjaamo]

I understand. Can you propose a solution that I am able to do? The table that we started turned out to be too complicated, as I cannot find the necessary information.

[kirjaamo]

@byte Now that we have the release versions page and have explained evs.version being 1 as of Galera 4 and 0 in older versions, can we close this issue?

[kirjaamo]

@byte You mentioned that we should "become the canonical source of all information relation to Galera Cluster". I took a look at MariaDB and PXC versioning info. If I were to update our versions table, would the example below be correct?

Galera Cluster version	MariaDB version	PXC version
4.3	10.5.0, 10.4.9	8.0.19-10
3.37	10.3.36	None

[kirjaamo]

I think I got them right. Next, I'll add links. By the way, do you know if there is a reason why we keep tables in documentation so narrow? Maybe tablet use?