fix: Save traceID and spanID as hex string into search config (#31071)

Issue: #30961

Signed-off-by: Yudong Cai <yudong.cai@zilliz.com>

internal/core/src/common/Tracer.cpp

@@ -12,6 +12,8 @@
 #include "Tracer.h"
 #include "log/Log.h"
 
+#include <iomanip>
+#include <iostream>
 #include <utility>
 
 #include "opentelemetry/exporters/jaeger/jaeger_exporter_factory.h"
@@ -149,20 +151,40 @@ EmptySpanID(const TraceContext* ctx) {
 }
 
 std::string
-GetTraceIDAsStr(const TraceContext* ctx) {
+BytesToHex(const uint8_t* input, const size_t len) {
+    std::stringstream ss;
+    ss << std::hex << std::setfill('0');
+    for (size_t i = 0; i < len; i++) {
+        ss << std::setw(2) << static_cast<int>(input[i]);
+    }
+    return ss.str();
+}
+
+std::string
+HexToString(const std::string& input) {
+    std::string output;
+    std::stringstream ss;
+    for (size_t i = 0; i < input.length(); i += 2) {
+        std::string byteString = input.substr(i, 2);
+        char byte = static_cast<char>(std::stoi(byteString, nullptr, 16));
+        output += byte;
+    }
+    return output;
+}
+
+std::string
+GetTraceIDAsHex(const TraceContext* ctx) {
     if (ctx != nullptr && !EmptyTraceID(ctx)) {
-        return std::string((char*)ctx->traceID,
-                           opentelemetry::trace::TraceId::kSize);
+        return BytesToHex(ctx->traceID, opentelemetry::trace::TraceId::kSize);
     } else {
         return std::string();
     }
 }
 
 std::string
-GetSpanIDAsStr(const TraceContext* ctx) {
+GetSpanIDAsHex(const TraceContext* ctx) {
     if (ctx != nullptr && !EmptySpanID(ctx)) {
-        return std::string((char*)ctx->spanID,
-                           opentelemetry::trace::SpanId::kSize);
+        return BytesToHex(ctx->spanID, opentelemetry::trace::SpanId::kSize);
     } else {
         return std::string();
     }

internal/core/src/common/Tracer.h

@@ -62,9 +62,15 @@ bool
 EmptySpanID(const TraceContext* ctx);
 
 std::string
-GetTraceIDAsStr(const TraceContext* ctx);
+BytesToHex(const uint8_t* input, const size_t len);
 
 std::string
-GetSpanIDAsStr(const TraceContext* ctx);
+HexToString(const std::string& input);
+
+std::string
+GetTraceIDAsHex(const TraceContext* ctx);
+
+std::string
+GetSpanIDAsHex(const TraceContext* ctx);
 
 }  // namespace milvus::tracer

internal/core/src/index/VectorIndex.h

@@ -124,9 +124,9 @@ class VectorIndex : public IndexBase {
         // if (search_info.trace_ctx_.traceID != nullptr &&
         //     search_info.trace_ctx_.spanID != nullptr) {
         //     search_cfg[knowhere::meta::TRACE_ID] =
-        //         tracer::GetTraceIDAsStr(&search_info.trace_ctx_);
+        //         tracer::GetTraceIDAsHex(&search_info.trace_ctx_);
         //     search_cfg[knowhere::meta::SPAN_ID] =
-        //         tracer::GetSpanIDAsStr(&search_info.trace_ctx_);
+        //         tracer::GetSpanIDAsHex(&search_info.trace_ctx_);
         //     search_cfg[knowhere::meta::TRACE_FLAGS] =
         //         search_info.trace_ctx_.traceFlags;
         // }

internal/core/src/query/SearchBruteForce.cpp

@@ -54,9 +54,9 @@ PrepareBFSearchParams(const SearchInfo& search_info) {
     // if (search_info.trace_ctx_.traceID != nullptr &&
     //     search_info.trace_ctx_.spanID != nullptr) {
     //     search_cfg[knowhere::meta::TRACE_ID] =
-    //         tracer::GetTraceIDAsStr(&search_info.trace_ctx_);
+    //         tracer::GetTraceIDAsHex(&search_info.trace_ctx_);
     //     search_cfg[knowhere::meta::SPAN_ID] =
-    //         tracer::GetSpanIDAsStr(&search_info.trace_ctx_);
+    //         tracer::GetSpanIDAsHex(&search_info.trace_ctx_);
     //     search_cfg[knowhere::meta::TRACE_FLAGS] =
     //         search_info.trace_ctx_.traceFlags;
     // }

internal/core/unittest/test_tracer.cpp

@@ -12,10 +12,12 @@
 
 #include <gtest/gtest.h>
 #include <memory>
-#include <random>
+#include <string.h>
 
 #include "common/Tracer.h"
 #include "common/EasyAssert.h"
+#include "knowhere/comp/index_param.h"
+#include "knowhere/config.h"
 
 using namespace milvus;
 using namespace milvus::tracer;
@@ -27,7 +29,7 @@ TEST(Tracer, Init) {
     config->nodeID = 1;
     initTelemetry(*config);
     auto span = StartSpan("test");
-    Assert(span->IsRecording());
+    ASSERT_TRUE(span->IsRecording());
 
     config = std::make_shared<TraceConfig>();
     config->exporter = "jaeger";
@@ -35,7 +37,7 @@ TEST(Tracer, Init) {
     config->nodeID = 1;
     initTelemetry(*config);
     span = StartSpan("test");
-    Assert(span->IsRecording());
+    ASSERT_TRUE(span->IsRecording());
 }
 
 TEST(Tracer, Span) {
@@ -66,7 +68,48 @@ TEST(Tracer, Span) {
     ctx->traceFlags = 1;
     auto span = StartSpan("test", ctx.get());
 
-    Assert(span->GetContext().trace_id() == trace::TraceId({ctx->traceID, 16}));
+    ASSERT_TRUE(span->GetContext().trace_id() ==
+                trace::TraceId({ctx->traceID, 16}));
+
+    delete[] ctx->traceID;
+    delete[] ctx->spanID;
+}
+
+TEST(Tracer, Hex) {
+    auto ctx = std::make_shared<TraceContext>();
+    ctx->traceID = new uint8_t[16]{0x01,
+                                   0x23,
+                                   0x45,
+                                   0x67,
+                                   0x89,
+                                   0xab,
+                                   0xcd,
+                                   0xef,
+                                   0xfe,
+                                   0xdc,
+                                   0xba,
+                                   0x98,
+                                   0x76,
+                                   0x54,
+                                   0x32,
+                                   0x10};
+    ctx->spanID =
+        new uint8_t[8]{0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef};
+    ctx->traceFlags = 1;
+
+    knowhere::Json search_cfg = {};
+
+    // save trace context into search conf
+    search_cfg[knowhere::meta::TRACE_ID] = tracer::GetTraceIDAsHex(ctx.get());
+    search_cfg[knowhere::meta::SPAN_ID] = tracer::GetSpanIDAsHex(ctx.get());
+    search_cfg[knowhere::meta::TRACE_FLAGS] = ctx->traceFlags;
+    std::cout << "search config: " << search_cfg.dump() << std::endl;
+
+    auto trace_id_str = HexToString(search_cfg[knowhere::meta::TRACE_ID]);
+    auto span_id_str = HexToString(search_cfg[knowhere::meta::SPAN_ID]);
+
+    ASSERT_TRUE(strncmp((char*)ctx->traceID, trace_id_str.c_str(), 16) == 0);
+    ASSERT_TRUE(strncmp((char*)ctx->spanID, span_id_str.c_str(), 8) == 0);
 
     delete[] ctx->traceID;
     delete[] ctx->spanID;