PPS maintains its objects in memory while it's running. It will, as
required:
- save its objects to persistent storage, either on demand while it's running, or at
shutdown
- restore its objects on startup, either immediately, or on first access (deferred
loading)
Note:
- PPS may be used to create objects that are rarely (or never) published or
subscribed to, but that require persistence.
- Shutdown means the orderly exit of the PPS server process. An orderly
exit can be triggered by SIGTERM, SIGINT, or SIGQUIT.
Since other signals (such as SIGKILL, SIGSEGV, and SIGABRT)
don't result in an orderly exit, they don't constitute a
shutdown for the purposes of persistence.