I would also recommend to take a look at EntryProcessor [1]. It allows to do co-located atomic updates, so it doesn't require transaction and reduces the amount of data transferred across network, so it should give best performance results.
[1] https://apacheignite.readme.io/docs/jcache#entryprocessor -Val -- Sent from: http://apache-ignite-users.70518.x6.nabble.com/
