Merge pull request #3486 from DataDog/tonycthsu/fast-correlation

Improve log correlation performance

lib/datadog/tracing/correlation.rb

@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 
 require_relative 'utils'
-require_relative 'metadata/ext'
 require_relative '../core/logging/ext'
 
 module Datadog
@@ -36,11 +35,11 @@ def initialize(
           version: nil
         )
           # Dup and freeze strings so they aren't modified by reference.
-          @env = Core::Utils::SafeDup.frozen_dup(env || Datadog.configuration.env)
-          @service = Core::Utils::SafeDup.frozen_dup(service || Datadog.configuration.service)
+          @env = env || Datadog.configuration.env
+          @service = service || Datadog.configuration.service
           @span_id = (span_id || 0).to_s
           @trace_id = trace_id || 0
-          @version = Core::Utils::SafeDup.frozen_dup(version || Datadog.configuration.version)
+          @version = version || Datadog.configuration.version
         end
 
         def to_h

lib/datadog/tracing/trace_operation.rb

@@ -8,6 +8,7 @@
 require_relative 'sampling/ext'
 require_relative 'span_operation'
 require_relative 'trace_digest'
+require_relative 'correlation'
 require_relative 'trace_segment'
 require_relative 'utils'
 
@@ -306,6 +307,17 @@ def to_digest
         ).freeze
       end
 
+      def to_correlation
+        # Resolve current span ID
+        span_id = @active_span && @active_span.id
+        span_id ||= @parent_span_id unless finished?
+
+        Correlation::Identifier.new(
+          trace_id: @id,
+          span_id: span_id
+        )
+      end
+
       # Returns a copy of this trace suitable for forks (w/o spans.)
       # Used for continuation of traces across forks.
       def fork_clone

lib/datadog/tracing/tracer.rb

@@ -224,9 +224,10 @@ def active_span(key = nil)
       # @return [Datadog::Tracing::Correlation::Identifier] correlation object
       def active_correlation(key = nil)
         trace = active_trace(key)
-        Correlation.identifier_from_digest(
-          trace && trace.to_digest
-        )
+
+        return Datadog::Tracing::Correlation::Identifier.new unless trace
+
+        trace.to_correlation
       end
 
       # Setup a new trace to continue from where another

spec/datadog/tracing/correlation_spec.rb

@@ -22,14 +22,7 @@
     let(:env) { 'dev' }
     let(:service) { 'acme-api' }
     let(:span_id) { Datadog::Tracing::Utils.next_id }
-    let(:span_name) { 'active_record.sql' }
-    let(:span_resource) { 'SELECT * FROM users;' }
-    let(:span_service) { 'acme-mysql' }
-    let(:span_type) { 'db' }
     let(:trace_id) { Datadog::Tracing::Utils::TraceId.next_id }
-    let(:trace_name) { 'rack.request' }
-    let(:trace_resource) { 'GET /users' }
-    let(:trace_service) { 'acme-api' }
     let(:version) { '0.1' }
   end
 
@@ -52,10 +45,10 @@
         )
       end
 
-      it 'has frozen copies of strings' do
-        expect(identifier.env).to be_a_frozen_copy_of(default_env)
-        expect(identifier.service).to be_a_frozen_copy_of(default_service)
-        expect(identifier.version).to be_a_frozen_copy_of(default_version)
+      it 'has strings' do
+        expect(identifier.env).to eq(default_env)
+        expect(identifier.service).to eq(default_service)
+        expect(identifier.version).to eq(default_version)
       end
     end
 
@@ -66,14 +59,7 @@
         instance_double(
           Datadog::Tracing::TraceDigest,
           span_id: span_id,
-          span_name: span_name,
-          span_resource: span_resource,
-          span_service: span_service,
-          span_type: span_type,
           trace_id: trace_id,
-          trace_name: trace_name,
-          trace_resource: trace_resource,
-          trace_service: trace_service
         )
       end
 
@@ -87,10 +73,10 @@
         )
       end
 
-      it 'has frozen copies of strings' do
-        expect(identifier.env).to be_a_frozen_copy_of(default_env)
-        expect(identifier.service).to be_a_frozen_copy_of(default_service)
-        expect(identifier.version).to be_a_frozen_copy_of(default_version)
+      it 'has strings' do
+        expect(identifier.env).to eq(default_env)
+        expect(identifier.service).to eq(default_service)
+        expect(identifier.version).to eq(default_version)
       end
     end
   end
@@ -110,10 +96,10 @@
           )
         end
 
-        it 'has frozen copies of strings' do
-          expect(identifier.env).to be_a_frozen_copy_of(default_env)
-          expect(identifier.service).to be_a_frozen_copy_of(default_service)
-          expect(identifier.version).to be_a_frozen_copy_of(default_version)
+        it 'has strings' do
+          expect(identifier.env).to eq(default_env)
+          expect(identifier.service).to eq(default_service)
+          expect(identifier.version).to eq(default_version)
         end
       end
 
@@ -140,10 +126,10 @@
           )
         end
 
-        it 'has frozen copies of strings' do
-          expect(identifier.env).to be_a_frozen_copy_of(env)
-          expect(identifier.service).to be_a_frozen_copy_of(service)
-          expect(identifier.version).to be_a_frozen_copy_of(version)
+        it 'has strings' do
+          expect(identifier.env).to eq(env)
+          expect(identifier.service).to eq(service)
+          expect(identifier.version).to eq(version)
         end
       end
     end