You can upgrade WebSphere® eXtreme Scale to a new version, either by applying maintenance or installing a new version, without interrupting service.
To support enterprise data grid configurations,
you must upgrade your transport mechanism from Object Request Broker
(ORB) to IBM eXtremeIO (XIO). If you are not already using XIO, all
of your servers and clients must be migrated to version 8.6 before
you can switch to using the XIO transport. Your servers and clients
can use the ORB transport while you are upgrading. When the upgrade
is complete, you can move to XIO.