Waiting for ndbcluster global lock

Hi there,

I’ve started the mysql_upgrade job on my cluster (7.1.4b, 3 Nodegroups, 6 Data Nodes, 6 API Nodes)

This Job completely blocks any request to the cluster.
I can not get into the mysql client because of ‘too many connections’.

is ist harmfull, to interrupt the upgrade ?
It hangs at
server2:/usr/local/mysqlCluster/mysql/bin # ./mysql_upgrade -p
Enter password:
Looking for ‘mysql’ as: ./mysql
Looking for ‘mysqlcheck’ as: ./mysqlcheck
Running 'mysqlcheck with default connection arguments

If I try to start a mysql client from an other node, it hangs while requesting the NDB DB Layout.
It comes up quickly, if I start ‘mysql -A’, regardless, which database I*m using, show tables hangs

Who is doing the global lock?
How may I interrupt it?
I’m unable to log into the mysal client on the machine, running mysql_update, because of too many connections…

What can I do?

Regards, Stefan