JMX queue move/remove/copyTo/retry ops behave badly when a queue is memory constrained. The operations loop over pageIn() but don't check for cursor being full and nothing further being paged into memory. In addition, they allow concurrent operation which thwarts the linear search.
this can lead to excessive looping (high CPU), hanging and NPE depending on the particular JMX op.
The loops need to short-circuit if pageIn blocks as is the norm when the cursor is memory constrained.