Clustering compatibility between ejabebrd versions?

Is there a some page listing which version of ejabberd are safe to cluster together?

Primarily we want to be able to upgrade between versions without bringing down all nodes.

In ejabberd, clustering is

In ejabberd, clustering is done at the mnesia level: nodes share some tables' content. So, it depends on which mnesia tables you configured to be replicated in the nodes (only you know this), and whether such tables have changed their schema between versions (there isn't any document for this, you can compare the source code, specifically the table definitions).

In practice, the most basic tables haven't changed their schema in many months or years (roster, offline, muc_room...)

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