Skip to content

fix: prevent race condition when span count approaches the 1000-span limit #5227

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
jamescrosswell merged 2 commits into from
May 13, 2026
+23 −8
Merged

fix: prevent race condition when span count approaches the 1000-span limit #5227

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
41fe826
fix: prevent race condition when span count approaches the 1000-span …
jamescrosswell May 13, 2026
54fb9fa
Merge origin/maui-trace-ui-5116 into fix/issue-5173-spanlimit-race
jamescrosswell May 13, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
16 changes: 8 additions & 8 deletions src/Sentry/TransactionTracer.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -324,16 +324,16 @@ internal ISpan StartChild(SpanId? spanId, SpanId parentSpanId, string operation,

private void AddChildSpan(SpanTracer span)
{
var isOutOfLimit = _spans.Count >= SpanLimit;
span.IsSampled = isOutOfLimit ? false : IsSampled;
if (isOutOfLimit)
{
_options?.LogDebug("Discarding child span '{0}' due to {1} span limit", SpanId, SpanLimit);
return;
}

lock (_finishLock)
{
var isOutOfLimit = _spans.Count >= SpanLimit;
span.IsSampled = isOutOfLimit ? false : IsSampled;
if (isOutOfLimit)
{
_options?.LogDebug("Discarding child span '{0}' due to {1} span limit", SpanId, SpanLimit);
return;
}

if (_hasFinished)
{
_options?.LogDebug("Discarding child span '{0}' as the trace has already finished", SpanId);
Expand Down
15 changes: 15 additions & 0 deletions test/Sentry.Tests/Protocol/SentryTransactionTests.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -350,6 +350,21 @@ public void StartChild_Limit_Maintained()
spans.Count(s => s.IsSampled == true).Should().Be(1000);
}

[Fact]
public void StartChild_Limit_Maintained_Concurrently()
{
// Arrange
var transaction = new TransactionTracer(DisabledHub.Instance, "my name", "my op");
var spans = new ConcurrentBag<ISpan>();

// Act
Parallel.For(0, 5000, i => spans.Add(transaction.StartChild("span " + i)));

// Assert
transaction.Spans.Should().HaveCount(1000);
spans.Count(s => s.IsSampled == true).Should().Be(1000);
}

[Fact]
public void StartChild_SamplingInherited_True()
{
Expand Down
Loading