Ndb is pretty stable if your workload is stable. Most HLRs at network operators around the world run NDB 24x7, so it is the go-to HA OLTP real-time DB. If, however, you start overloading it, it can be temperamental. So, don't treat it like innodb and do full table scans while expecting millisecond PK lookups. I can't really comment on running Aerospike in production, because i haven't done it - just run experiments with it.