Move record-progress processing to separate thread #618
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This is intended to let us prioritize work on other requests over work on record-progress, thereby avoiding some of the timeouts and "database is locked" errors we would otherwise see when the record-progress requests happen to take priority. This separate thread is designed to only run when the server has no requests in-flight (other than a short, bounded, queue of record-progress requests). If that queue fills up, we will tell workers to slow down, causing them to retry requests -- currently at fixed intervals and per worker thread, but a future commit might clean that up a little to have a more intentional delay. In general this should, hopefully, decrease the error rate as particularly human-initiated requests should never have to wait for more than one record-progress event to complete before having largely uncontended access to the database. (Other requests still happen concurrently, but requests are typically very rare in comparison to record-progress which are multiple times a second, effectively constantly processing).
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@bors r+ |
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📌 Commit 229283e has been approved by |
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This is intended to let us prioritize work on other requests over work on
record-progress, thereby avoiding some of the timeouts and "database is locked"
errors we would otherwise see when the record-progress requests happen to take
priority.
This separate thread is designed to only run when the server has no requests
in-flight (other than a short, bounded, queue of record-progress requests). If
that queue fills up, we will tell workers to slow down, causing them to retry
requests -- currently at fixed intervals and per worker thread, but a future
commit might clean that up a little to have a more intentional delay.
In general this should, hopefully, decrease the error rate as particularly
human-initiated requests should never have to wait for more than one
record-progress event to complete before having largely uncontended access to the
database. (Other requests still happen concurrently, but requests are typically
very rare in comparison to record-progress which are multiple times a second,
effectively constantly processing).
Errors like rust-lang/rust#94775 (comment) are the primary motivation here, which I hope this is enough to largely clear up.