Coordinated Shutdown

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Shutdown sequence

1. Stops background services (eviction, passivation, scheduler)
2. Runs coordinated shutdown hooks (if registered)
3. Stops datacenter services (if enabled)
4. Snapshots cluster state (if clustered)
5. Shuts down user actors depth-first (children before parents)
6. Deactivates all grains, each after the messages already in its mailbox
7. Shuts down system actors
8. Leaves cluster and stops remoting

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Shutdown hooks

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The ShutdownHook interface

package actor

type ShutdownHook interface {
    Execute(ctx context.Context, actorSystem ActorSystem) error
    Recovery() *ShutdownHookRecovery
}

• Execute: Run cleanup logic. Use the actor system for final operations.
• Recovery: Return retry and recovery configuration for failures.

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Recovery strategies

• ShouldFail: Stop shutdown on hook failure.
• ShouldRetryAndFail: Retry, then stop if still failing.
• ShouldSkip: Skip failed hook, continue.
• ShouldRetryAndSkip: Retry, then skip and continue if still failing.

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Configuring recovery

recovery := actor.NewShutdownHookRecovery(
    actor.WithShutdownHookRetry(2, time.Second),
    actor.WithShutdownHookRecoveryStrategy(actor.ShouldRetryAndSkip),
)

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Shutdown timeout