periodic checkpoint: Don't checkpoint at startup #1883
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Currently there's no way to disable checkpoint but one can emulate it by enabling periodic checkpoint with really long interval between checkpoints. Unfortunately, current implementation runs checkpoint first before waiting for the interval to pass. This change makes the periodic checkpoint to first wait and only after that checkpoint. Signed-off-by: Piotr Jastrzebski <[email protected]>
athoscouto
approved these changes
Dec 16, 2024
penberg
reviewed
Dec 16, 2024
| @@ -368,6 +368,8 @@ where | |||
| tracing::info!("setting checkpoint interval to {:?}", period); | |||
| let mut interval = interval(period); | |||
| interval.set_missed_tick_behavior(MissedTickBehavior::Delay); | |||
| // Make sure that we don't checkpoint immediately after startup | |||
| interval.tick().await; | |||
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I am not sure I understand the patch, unfortunately. If you set interval to be really long, why is it checkpointing immediately?
The loop looks as follows:
if let Some(retry) = retry.take() {
if retry.is_zero() {
tracing::warn!("database was not set in WAL journal mode");
return Ok(());
}
sleep(retry).await;
} else {
interval.tick().await;
}
When you call run_periodic_checkpoint() you should always end up calling interval.tick().await, which should be identical to what your patch is doing. (Except that in your patch you wait two times the interval.)
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Never, mind Tokio's documentation explains this -- arguably confusing -- behavior:
The first tick completes immediately.
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I think we should document this in the code too with the same link
penberg
approved these changes
Dec 16, 2024
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Currently there's no way to disable checkpoint but one can emulate it by enabling periodic checkpoint with really long interval between checkpoints.
Unfortunately, current implementation runs checkpoint first before waiting for the interval to pass.
This change makes the periodic checkpoint to first wait and only after that checkpoint.