Skip to content
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

[ETW Exporter] - Add Trace flags in SpanContext #1618

Merged
merged 8 commits into from
Sep 19, 2022
Merged

[ETW Exporter] - Add Trace flags in SpanContext #1618

Show file tree
Hide file tree
Changes from 6 commits
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
95d47a5
fix
lalitb Sep 15, 2022
97f521a
Merge branch 'main' into etw-sampler-fix
lalitb Sep 15, 2022
eab88dd
fix
lalitb Sep 15, 2022
609a9cd
Merge branch 'etw-sampler-fix' of github.com:lalitb/opentelemetry-cpp…
lalitb Sep 15, 2022
8ed4dfe
fix
lalitb Sep 15, 2022
f4e0033
Fix
lalitb Sep 16, 2022
8c00f47
Merge branch 'main' into etw-sampler-fix
lalitb Sep 19, 2022
5fb17a0
fix review comments
lalitb Sep 19, 2022
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
83 changes: 44 additions & 39 deletions exporters/etw/include/opentelemetry/exporters/etw/etw_tracer.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -64,9 +64,10 @@ class Span;
template <class SpanType, class TracerType>
SpanType *new_span(TracerType *objPtr,
nostd::string_view name,
const opentelemetry::trace::StartSpanOptions &options)
const opentelemetry::trace::StartSpanOptions &options,
std::unique_ptr<opentelemetry::trace::SpanContext> span_context)
{
return new (std::nothrow) SpanType{*objPtr, name, options};
return new (std::nothrow) SpanType{*objPtr, name, options, std::move(span_context)};
}

/**
Expand Down Expand Up @@ -374,30 +375,6 @@ class Tracer : public opentelemetry::trace::Tracer,
const opentelemetry::trace::SpanContextKeyValueIterable &links,
const opentelemetry::trace::StartSpanOptions &options = {}) noexcept override
{
const auto &cfg = GetConfiguration(tracerProvider_);

// Parent Context:
// - either use current span
// - or attach to parent SpanContext specified in options
opentelemetry::trace::SpanContext parentContext = GetCurrentSpan()->GetContext();
if (nostd::holds_alternative<opentelemetry::trace::SpanContext>(options.parent))
{
auto span_context = nostd::get<opentelemetry::trace::SpanContext>(options.parent);
if (span_context.IsValid())
{
parentContext = span_context;
}
}
auto sampling_result =
GetSampler(tracerProvider_)
.ShouldSample(parentContext, traceId_, name, options.kind, attributes, links);
if (sampling_result.decision == sdk::trace::Decision::DROP)
{
static nostd::shared_ptr<trace::Span> noop_span(
new trace::NoopSpan{this->shared_from_this()});
return noop_span;
}

#ifdef OPENTELEMETRY_RTTI_ENABLED
common::KeyValueIterable &attribs = const_cast<common::KeyValueIterable &>(attributes);
Properties *evt = dynamic_cast<Properties *>(&attribs);
Expand Down Expand Up @@ -433,12 +410,42 @@ class Tracer : public opentelemetry::trace::Tracer,
opentelemetry::trace::SpanContext parentContext = GetCurrentSpan()->GetContext();
if (nostd::holds_alternative<opentelemetry::trace::SpanContext>(options.parent))
{
auto span_context = nostd::get<opentelemetry::trace::SpanContext>(options.parent);
if (span_context.IsValid())
auto spanContext = nostd::get<opentelemetry::trace::SpanContext>(options.parent);
if (spanContext.IsValid())
{
parentContext = span_context;
parentContext = spanContext;
}
}
auto traceId = parentContext.IsValid() ? parentContext.trace_id() : traceId_;

// Sampling based on attributes is not supported for now, so passing empty below.
std::map<std::string, int> empty_attributes = {{}};
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

cosmetic: It seems this file has mixed camel case and snake case.
It would be good if you could unify at least the parts you are changing.

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks good comment. I gave it a thought, and using snake-case now, to make it consistent with the existing ETW exporter naming style. We will eventually move this component out of the core library.

opentelemetry::sdk::trace::SamplingResult sampling_result =
GetSampler(tracerProvider_)
.ShouldSample(parentContext, traceId, name, options.kind,
opentelemetry::common::KeyValueIterableView<std::map<std::string, int>>(
empty_attributes),
links);

opentelemetry::trace::TraceFlags trace_flags =
sampling_result.decision == opentelemetry::sdk::trace::Decision::DROP
? opentelemetry::trace::TraceFlags{}
: opentelemetry::trace::TraceFlags{opentelemetry::trace::TraceFlags::kIsSampled};

auto spanContext =
std::unique_ptr<opentelemetry::trace::SpanContext>(new opentelemetry::trace::SpanContext(
traceId, GetIdGenerator(tracerProvider_).GenerateSpanId(), trace_flags, false,
sampling_result.trace_state
? sampling_result.trace_state
: parentContext.IsValid() ? parentContext.trace_state()
: opentelemetry::trace::TraceState::GetDefault()));

if (sampling_result.decision == sdk::trace::Decision::DROP)
{
auto noop_span = nostd::shared_ptr<trace::Span>{
new (std::nothrow) trace::NoopSpan(this->shared_from_this(), std::move(spanContext))};
return noop_span;
}

// Populate Etw.RelatedActivityId at envelope level if enabled
GUID RelatedActivityId;
Expand All @@ -456,11 +463,9 @@ class Tracer : public opentelemetry::trace::Tracer,

// This template pattern allows us to forward-declare the etw::Span,
// create an instance of it, then assign it to tracer::Span result.
auto currentSpan = new_span<Span, Tracer>(this, name, options);
auto currentSpan = new_span<Span, Tracer>(this, name, options, std::move(spanContext));
nostd::shared_ptr<opentelemetry::trace::Span> result = to_span_ptr<Span>(currentSpan);

auto spanContext = result->GetContext();

// Decorate with additional standard fields
std::string eventName = name.data();

Expand All @@ -475,13 +480,13 @@ class Tracer : public opentelemetry::trace::Tracer,
{
evt[ETW_FIELD_SPAN_PARENTID] = ToLowerBase16(parentContext.span_id());
}
evt[ETW_FIELD_SPAN_ID] = ToLowerBase16(spanContext.span_id());
evt[ETW_FIELD_SPAN_ID] = ToLowerBase16(result.get()->GetContext().span_id());
}

// Populate Etw.Payload["TraceId"] attribute
if (cfg.enableTraceId)
{
evt[ETW_FIELD_TRACE_ID] = ToLowerBase16(spanContext.trace_id());
evt[ETW_FIELD_TRACE_ID] = ToLowerBase16(result.get()->GetContext().trace_id());
}

// Populate Etw.ActivityId at envelope level if enabled
Expand Down Expand Up @@ -705,7 +710,7 @@ class Span : public opentelemetry::trace::Span
*/
Span *GetParent() const { return parent_; }

opentelemetry::trace::SpanContext context_;
std::unique_ptr<opentelemetry::trace::SpanContext> context_;

public:
/**
Expand Down Expand Up @@ -759,13 +764,13 @@ class Span : public opentelemetry::trace::Span
Span(Tracer &owner,
nostd::string_view name,
const opentelemetry::trace::StartSpanOptions &options,
std::unique_ptr<opentelemetry::trace::SpanContext> span_context,
Span *parent = nullptr) noexcept
: opentelemetry::trace::Span(),
start_time_(std::chrono::system_clock::now()),
owner_(owner),
parent_(parent),
context_{owner.traceId_, GetIdGenerator(owner.tracerProvider_).GenerateSpanId(),
opentelemetry::trace::TraceFlags{0}, false}
context_(std::move(span_context)),
parent_(parent)
{
name_ = name;
UNREFERENCED_PARAMETER(options);
Expand Down Expand Up @@ -883,7 +888,7 @@ class Span : public opentelemetry::trace::Span
* @brief Obtain SpanContext
* @return
*/
opentelemetry::trace::SpanContext GetContext() const noexcept override { return context_; }
opentelemetry::trace::SpanContext GetContext() const noexcept override { return *context_.get(); }

/**
* @brief Check if Span is recording data.
Expand Down
70 changes: 69 additions & 1 deletion exporters/etw/test/etw_tracer_test.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,13 +7,15 @@
# include <map>
# include <string>

# include "opentelemetry//sdk/trace/sampler.h"
# include "opentelemetry/exporters/etw/etw_tracer_exporter.h"
# include "opentelemetry/sdk/trace/samplers/always_off.h"
# include "opentelemetry/sdk/trace/simple_processor.h"

using namespace OPENTELEMETRY_NAMESPACE;

using namespace opentelemetry::exporter::etw;
using namespace opentelemetry::sdk::trace;

const char *kGlobalProviderName = "OpenTelemetry-ETW-TLD";

Expand All @@ -40,6 +42,42 @@ class MockIdGenerator : public sdk::trace::IdGenerator
uint8_t buf_trace[16] = {1, 2, 3, 4, 5, 6, 7, 8, 8, 7, 6, 5, 4, 3, 2, 1};
};

/* A Custom Sampler, implementing parent based sampler*/
class MockSampler : public sdk::trace::Sampler
{
public:
MockSampler(std::shared_ptr<Sampler> delegate_sampler) noexcept
: delegate_sampler_(delegate_sampler)
{}
sdk::trace::SamplingResult ShouldSample(
const trace_api::SpanContext &parent_context,
trace_api::TraceId trace_id,
nostd::string_view name,
trace_api::SpanKind span_kind,
const opentelemetry::common::KeyValueIterable &attributes,
const trace_api::SpanContextKeyValueIterable &links) noexcept
{
if (!parent_context.IsValid())
{
// If no parent (root span) exists returns the result of the delegateSampler
return delegate_sampler_->ShouldSample(parent_context, trace_id, name, span_kind, attributes,
links);
}

// If parent exists:
if (parent_context.IsSampled())
{
return {Decision::RECORD_AND_SAMPLE, nullptr, parent_context.trace_state()};
}
return {Decision::DROP, nullptr, parent_context.trace_state()};
}

nostd::string_view GetDescription() const noexcept { return "Custom Sampler"; }

private:
std::shared_ptr<Sampler> delegate_sampler_;
};

/* clang-format off */
TEST(ETWTracer, TracerCheck)
{
Expand Down Expand Up @@ -417,7 +455,8 @@ TEST(ETWTracer, AlwayOffSampler)
std::move(always_off));
auto tracer = tp.GetTracer(providerName);
auto span = tracer->StartSpan("span_off");
EXPECT_EQ(span->GetContext().IsValid(), false);
EXPECT_EQ(span->GetContext().IsValid(), true);
EXPECT_EQ(span->GetContext().IsSampled(), false);
}

TEST(ETWTracer, CustomIdGenerator)
Expand All @@ -440,6 +479,35 @@ TEST(ETWTracer, CustomIdGenerator)
EXPECT_EQ(span->GetContext().trace_id(), id_generator->GenerateTraceId());
}

TEST(ETWTracer, CustomSampler)
{
std::string providerName = kGlobalProviderName; // supply unique instrumentation name here
auto parent_off = std::unique_ptr<Sampler>(new MockSampler(std::make_shared<AlwaysOnSampler>()));
exporter::etw::TracerProvider tp
({
{"enableTraceId", true},
{"enableSpanId", true},
{"enableActivityId", true},
{"enableRelatedActivityId", true},
{"enableAutoParent", true}
},
std::move(parent_off));
auto tracer = tp.GetTracer(providerName);
{
auto span = tracer->StartSpan("span_off");
EXPECT_EQ(span->GetContext().IsValid(), true);
EXPECT_EQ(span->GetContext().IsSampled(), true);
auto scope = tracer->WithActiveSpan(span);
auto trace_id = span->GetContext().trace_id();
{
auto child_span = tracer->StartSpan("span on");
EXPECT_EQ(child_span->GetContext().IsValid(), true);
EXPECT_EQ(child_span->GetContext().IsSampled(), true);
EXPECT_EQ(child_span->GetContext().trace_id(), trace_id);
}
}
}

/* clang-format on */

#endif