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https://issues.apache.org/jira/browse/FLINK-12887?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16867023#comment-16867023
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Till Rohrmann commented on FLINK-12887:
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I think the current contract is that you cannot schedule an unfenced message.
That's why there is only {{runAsyncWithoutFencing}} and
{{callAsyncWithoutFencing}} and no {{scheduleRunAsyncWithoutFencing}}. If there
is no delay for the {{RunAsync}} or {{CallAsync}}, they would be directly
executed. Only if delay is {{> 0}} you would run into this case. Thus, I think
it is not a real problem at the moment.
Have you experienced a problem with that or is this more of a theoretical
consideration if we would add a {{scheduleRunAsyncWithoutFencing}} method
[~Tison]?
> Schedule UnfencedMessage would lost envelope info
> --------------------------------------------------
>
> Key: FLINK-12887
> URL: https://issues.apache.org/jira/browse/FLINK-12887
> Project: Flink
> Issue Type: Bug
> Components: Runtime / Coordination
> Affects Versions: 1.9.0
> Reporter: TisonKun
> Priority: Major
>
> We provide {{runAsync}}, {{callAsync}} and {{scheduleRunAsync}} for
> {{MainThreadExecutable}}, while providing {{runAsyncWithoutFencing}} and
> {{callAsyncWithoutFencing}} additionally for {{FencedMainThreadExecutable}}.
> Let's think about a case when we want to schedule a unfenced runnable or any
> other unfenced message(currently, we don't have such code path but it's
> semantically valid.).
> 1. {{FencedAkkaRpcActor}} received an unfenced runnable with delay
> 2. It extracted the runnable from unfenced message and call
> {{super.handleRpcMessage}}.
> 3. {{AkkaRpcActor}} enveloped the message and schedule it by
> {{AkkaRpcActor#L410}}.
> However, {{FencedAkkaRpcActor#envelopeSelfMessage}} was called for envelope.
> Thus the unfenced message now become a fenced message.
> We can anyway implement {{scheduleRunAsyncWithoutFencing}} to schedule
> unfenced message directly by {{actorsystem.scheduler.scheduleOnce(...,
> dispatcher)}}, but with current codebase I notice that {{RunAsync}} has a
> wried {{atTimeNanos}}(i.e., delay) property. Ideally how to schedule a
> message is shown on what params ScheduleExecutorService called with, at least
> we cannot extract an unfenced message and envelop it into a fence message and
> then schedule it, which goes into wrong semantic.
> cc [~till.rohrmann]
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