ccl/sqlproxyccl: fix possible NPE within the connector #96161
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complete! 0 of 0 LGTMs obtained (waiting on @jeffswenson)
pkg/ccl/sqlproxyccl/connector.go line 266 at r1 (raw file):
reportFailureErrs = 0 } err = errors.Wrap(err, reportErr.Error())
Not using errors.CombineErrors is deliberate. Using that requires callers to manually extract the second error. In our case here, a simple Wrap is sufficient.
pkg/ccl/sqlproxyccl/connector_test.go line 373 at r1 (raw file):
}) t.Run("context canceled after dial fails", func(t *testing.T) {
This test fails without the fix, which confirms the root cause analysis.
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Previously, an invariant is violated where it was possible to return err=nil when the infinite retry dial loop exits. When that happens, callers would attempt to read from the net.Conn object, which is nil, leading to a panic. The invariant is violated whenever the context that was passed down to `dialTenantCluster` gets cancelled or expires. In particular, this can happen in two cases: 1. when the main stopper stops 2. when a connection migration process hits a timeout (of 15 seconds) The first case is rare since this has to happen in concert with a transient failure to dial the SQL server. Here's one example for the second case: 1. we block while dialing the SQL server 2. while we're waiting for (1), transfer hits a timeout, so context gets cancelled 3. (1) gets unblocked due to a timeout 4. err from (1) gets replaced with the error from ReportFailure 5. retry loop checks for context cancellation, and exits 6. we end up returning `nil, errors.Mark(nil, ctx.Err())` = `nil, nil` The root cause of this issue is that the error from ReportFailure replaced the original error, and usually ReportFailure suceeds. This commit fixes that issue by not reusing the same error variable for ReportFailure. Epic: none Release note: None
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TFTR! bors r=JeffSwenson |
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bors r=JeffSwenson |
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Related: https://github.com/cockroachlabs/support/issues/2040
Previously, an invariant is violated where it was possible to return err=nil when the infinite retry dial loop exits. When that happens, callers would attempt to read from the net.Conn object, which is nil, leading to a panic.
The invariant is violated whenever the context that was passed down to
dialTenantClustergets cancelled or expires. In particular, this can happen in two cases:The first case is rare since this has to happen in concert with a transient failure to dial the SQL server.
Here's one example for the second case:
nil, errors.Mark(nil, ctx.Err())=nil, nilThe root cause of this issue is that the error from ReportFailure replaced the original error, and usually ReportFailure suceeds. This commit fixes that issue by not reusing the same error variable for ReportFailure.
Epic: none
Release note: None