Получить мастер СР из ЗК:
/usr/lib/zookeeper/bin/zkCli.sh
[zk: localhost:2181(CONNECTED) 1] get /schema_registry/schema_registry_master
{"host":"host name of current master schema registry","port":8081,"master_eligibility":true,"scheme":"http","version":1}
cZxid = ...
ctime = ...
mZxid = ...
mtime = ...
pZxid = ...
cversion = ...
dataVersion = ...
aclVersion = ...
ephemeralOwner = ...
dataLength = ...
numChildren = ...