Unable to access any database on NDB cluster node after "lock wait timeout exceeded" error

[Douglas Tan]

I have an application that uses a NDB cluster as the database server and I've
been seeing this error occur for a particular table: "ERROR 1205 (HY000): Lock
wait timeout exceeded;"

So I'm trying to find the cause of this problem by testing on another NDB
database. I managed to get the error on the same table on the testing database
and I took the following steps to try and make the error go away:

1. Drop a TEXT column (as the error message only appears when I include it in
the SELECT clause). The database server doesn't allow the operation and returns
"ERROR 1205 (HY000): Lock wait timeout exceeded;"
2. Next, I attempted to drop the table (which contained about 20 rows). I waited
for a while and the command didn't return. So I aborted the query with Ctrl-C.

This is when I could connect to a node but could not access any database with
"use database-name;". The command would just not return from the console. 

I checked the node logs and there wasn't anything related to failure that was
logged. 

How should I go about restoring access to the databases? Did I do something
irreparably damaging to the databases?