postgresql-12-slony1-2 binary package in Ubuntu Focal s390x

 Slony-I is an asynchronous master-to-multiple-slaves replication system
 for PostgreSQL with cascading and slave promotion.
 .
 This package contains the support functions that are loaded into the
 PostgreSQL database server. It needs to be installed on the hosts where
 the database server nodes are running. This package works with version
 12 of the PostgreSQL server; you need the package that corresponds to
 the version of your database server.
 .
 The actual replication daemon and the administration tools are in the
 package slony1-2-bin. This package is useless without slony1-2-bin installed
 somewhere in the network.

Source package