ethstats: avoid creating subscriptions on background goroutine #22587
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holiman
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Mar 26, 2021
fjl
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Mar 26, 2021
ethstats/ethstats.go
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| if headSub == nil { | ||
| log.Info("Stats daemon stopped due to nil head subscription") | ||
| return | ||
| } |
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It's easy to avoid this error by subscribing earlier. If you create the subscriptions in New (or Start) they can never be nil.
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If they're created in Start, then the deferred Unsubscribe will become "decoupled" from the Subscribe, which is not great either...
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The Unsubscribe would need to move into Service.Stop then.
holiman
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Mar 30, 2021
Co-authored-by: Martin Holst Swende <[email protected]>
fjl
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atif-konasl
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Oct 15, 2021
…eum#22587) This fixes an issue where the ethstats service could crash if geth was started and then immediately stopped due to an internal error. The cause of the crash was a nil subscription being returned by the backend, because the background goroutine creating them was scheduled after the backend had already shut down. Moving the creation of subscriptions into the Start method, which runs synchronously during startup of the node, means the returned subscriptions can never be 'nil'. Co-authored-by: Felix Lange <[email protected]> Co-authored-by: Martin Holst Swende <[email protected]>
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This was referenced Sep 23, 2022
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