RUST-856 Fix race between server selection and server monitoring #460
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patrickfreed
commented
Sep 10, 2021
| if self.check_server(&topology, &server).await { | ||
| topology.notify_topology_changed(); | ||
| } | ||
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| let mut topology_check_requests_subscriber = |
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My theory is that the following sequence happens:
- check completes
- monitor notifies that topology changed
- operation sleeping in server selection gets notification and quickly fails server selection, requesting another check
- monitor starts subscribing to request checks, missing the previous one
- monitor sleeps until heartbeatFrequencyMS is hit
This fixes that by ensuring any requests that come in after the check will be recorded too, hopefully fixing this case.
abr-egn
approved these changes
Sep 13, 2021
isabelatkinson
approved these changes
Sep 13, 2021
awitten1
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Sep 21, 2021
patrickfreed
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patrickfreed
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RUST-856
This PR fixes a race between server selection requesting an update to the topology and a monitor subscribing to those requests, which occasionally would result in the
min_heartbeat_frequencytest failing.