Platform and/or application software on all online, machine/servers in a
cluster is updated without manually taking each machine/server offline.
Initially, platform and/or application software for updating is stored in
respective directories in an APPLY phase. Next, the new platform and/or
application software is activated with or without a trial/test phase in
an ACTIVATE phase. Where the new platform and/or application software is
activated with a trial/test phase, a ROLLBACK phase is either
automatically or manually invoked by the application in the event of a
failure of the new software for backing out the new platform and/or
application software and reactivating the previous platform and/or
application software. An OFFICLAL phase then transitions the new platform
and/or application software to the official state followed by a
REACTIVATE phase for reactivating the backup copy of the previous/old
platform and/or application software after the new software has been made
official.