IOM Helm Charts v.1.2.1 or newer are required to operate IOM 3.3. Only this version or newer versions of Helm Charts are able to upgrade IOM without downtime if there are backward compatible database changes. For changes that are not backward compatible, the upgrade process still requires downtime.
In older versions of IOM, heap dumps were written to stdout in order to get caught by the monitoring system. They are now stored in the sub-directory dumps of IOM's shared file-system. The naming conventions of dump files are: java-<pod name>-<time stamp (start time)>.hprof.
Using these naming conventions, heap dumps are never overwritten, they can be assigned to pods (and therefore aligned to error messages) and they can be sorted over time.