Mysql version: Server version: 5.7.16 - NDB - 7.5.4 - cluster - the GPL mysql cluster Community Server (GPL)

The lock table information: Waiting for ndbcluster global schema lock

Now with the client database, even those who involved in the operation of the query schema table will be stuck, with show the processlist command query process qurey state all the kill or not
How to unlock this table?