public ReplicationPeerConfig refreshPeerConfig(String peerId) throws ReplicationException {
    ReplicationPeerImpl peer = peerCache.get(peerId);
    peer.setPeerConfig(peerStorage.getPeerConfig(peerId));
    return peer.getPeerConfig();
  }
Returns the set of peerIds of the clusters that have been connected and have an underlying
ReplicationPeer.
@return a Set of Strings for peerIds
hbase-replication/src/main/java/org/apache/hadoop/hbase/replication/ReplicationPeers.java