3 nodes (includes one master node), 8Gb memory, 4Gb Heap size.
Worked fine after 5.6.8 but then after upgrading to 6.3.1 we get a java heap error on the master as it gets to 90% (5hrs later) and then the elasticsearch service crashes.
I wonder if there could be an issue with the index, I saw an error in the index migration.
I am unsure on how to troubleshoot this. Anyone seen anything like that?