Re: Data Node/Mgmt Node in NDBCluster disconnect make error code 157 returned in Java Persistence application

[Mikael Ronström]

Transaction failure at node failure is normal.
Simply retry transaction again and it should work.

Node failures introduce a lot of problematic situations that
are hard to solve without aborting transaction. So transaction
failures at node crashes is normal and application should be
designed to handle it with normal retries. There is a number
of other situations also in databases that can lead to temporary
errors such as deadlocks, various timeouts. So it is always a
good idea to handle temporary errors from transactions.