NAME | FEATURE SUMMARY | API | ATTRIBUTES
The HOT_RESTART feature provides support for rapidly reloading and reinitializing failed ChorusOS actors. Actors which benefit from this support are known as restartable actors. HOT_RESTART also provides all actors (not just restartable actors) with a means of storing persistent data.
The HOT_RESTART feature relies on the use of persistent memory, i.e., memory which can persist beyond a run-time instance of an actor. When HOT_RESTART is active, the initial text and data segments for restartable actors are stored in persistent memory. When the restartable actor fails, it is reloaded from this persistent memory, without accessing stable storage. Such an operation is known as restarting the actor, and is generally faster than reloading the actor from stable storage.
HOT_RESTART exports the following services:
An actor restart mechanism which detects crashes in restartable actors and automatically restarts them from persistent memory, at the same addresses, with their code and data segments reset to their initial state.
Named persistent memory allocation. Actors can allocate persistent memory as named blocks. These blocks can be used to store additional data which will persist beyond the lifetime of the run-time instance of the actor. Named persistent memory can be used by both restartable actors and non-restartable actors.
A site restart mechanism to restart the kernel, boot actors and all restartable actors on a system without accessing stable storage.
The HOT_RESTART feature requires the ACTOR_EXTENDED_MNGT, LAPSAFE and ADMIN_SHUTDOWN features. For more information about hot restart, see the ChorusOS Hot Restart Programmer's Guide.
The HOT_RESTART feature API is summarized in the following tables. All functions are grouped in the 2RESTART ChorusOS man page section.
Comment
Spawn and load a hot restartable actor. This call can only be made from a hot restartable actor.
Get the identifier of a given restartable actor's restart group.
Kill (and do not restart) a group of restartable actors. This call is restricted to supervisor and trusted user actors.
The sysShutdown(2K) function, and the C_INIT commands arun(1M), akill(1M), aps(1M), shutdown(1M) and restart(1M) also provide support for restartable actors. For more information, see the corresponding manual pages.
See attributes(5) for descriptions of the following attributes:
ATTRIBUTE TYPE | ATTRIBUTE VALUE |
---|---|
Interface Stability | Evolving |
NAME | FEATURE SUMMARY | API | ATTRIBUTES