Avoid emitting probe metrics after context cancellation #793
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test passing, should be ready now |
manugarg
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Jul 12, 2024
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| // exit without exporting stats if the probe run was interrupted. | ||
| select { | ||
| case <-ctx.Done(): | ||
| return | ||
| default: | ||
| } | ||
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Since runProbe is not impacted by context, this is pretty much inconsequential, right? I'd drop ping.go from this change.
| @@ -422,7 +430,7 @@ func (p *Probe) runProbe(startCtx context.Context) { | |||
| if p.mode == "server" { | |||
| p.runServerProbe(probeCtx, startCtx) | |||
| } else { | |||
| p.runOnceProbe(probeCtx) | |||
| p.runOnceProbe(probeCtx, startCtx) | |||
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probeCtx is already tied to startCtx, so you can just use probeCtx.
| // exit without saving metrics if the probe was interrupted by context closure | ||
| // while running the command | ||
| select { | ||
| case <-startCtx.Done(): |
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As commented below, you can probably just use ctx here and skip passing startCtx to this method.
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@AdamEAnderson Thanks for this PR. I think it makes sense. I added a few comments. |
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Hi @AdamEAnderson, just wanted to check if you want to follow up on this PR. |
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When a probe is stopped, i.e. via the probe removal process, sometimes the cancellation of the probe context happens while a probe run is in progress. This can cause that probe run to be interrupted mid-execution and return with a failure, which then gets reported through the metrics channel and out to the surfacer as a failed probe, even though the failure was due to probe cancellation rather than an external cause.
This PR adds a check to make sure the context is still live after the probe run is completed but before metrics are emitted. If the context is done, the probe stops without emitting the metrics.
Probe types and their susceptibilities for this issue:
schedutility to run probes, which is susceptible to this failure.schedhas been updated in the same way ashttp