[ReplicatedLoglet] Implement remote sequencer find tail #2017
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Summary: Implements a remote loglet append calls to leader sequencer
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Thanks for creating this PR @muhamadazmy. What happens if we lose the GetSequencerInfo or its response?
| .call( | ||
| &self.networking, | ||
| self.params.sequencer, | ||
| GetSequencerInfo { | ||
| header: CommonRequestHeader { | ||
| log_id: self.log_id, | ||
| loglet_id: self.params.loglet_id, | ||
| segment_index: self.segment_index, | ||
| }, | ||
| }, | ||
| ) | ||
| .await |
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What happens if the request or response get lost? Would sync_sequencer_tail get stuck?
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Yeah, that's definitely something that need to be handled. I have paused working on this draft PR in favour of #2019 and wasn't sure if I should continue on this one.
| ); | ||
| } | ||
| _ => { | ||
| unreachable!() |
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Maybe state why this case is unreachable. Maybe also don't use the wildcard. That way we'll see the places where a newly SequencerStatus variant needs to be handled.
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Good point. Thank you :)
| async fn sync_log_servers_tail(&self) -> Result<(), OperationError> { | ||
| todo!() | ||
| } |
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That's where #2019 comes into play, right?
| if self.sync_sequencer_tail().await.is_ok() { | ||
| return Ok(*self.known_global_tail.get()); | ||
| } | ||
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| // otherwise we need to try to fetch this from the log servers. | ||
| self.sync_log_servers_tail().await?; | ||
| Ok(*self.known_global_tail.get()) |
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Is there value in racing these two variants?
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I am not sure I get your question here.
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Whether we should run both variants for obtaining the known global tail in parallel/concurrently?
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Thank you for clarification. Yeah, that's definitely a good idea.
[ReplicatedLoglet] Implement remote sequencer find tail
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