If GERRIT_REPLICATION_MODE is set slave, this token specifies external system ID of the 'master' Git integration server.
Alphanumeric string (exsy<number>) of a master Git integration server
This token is mandatory if GERRIT_REPLICATION_MODE is set to slave, without which the runtime creation shall fail. On the contrary, the runtime recreation will also fail if GERRIT_REPLICATION_MODE is set to master and this token is present in the site-options.conf file.