Merge pull request #2996 from rmosolgo/statsd-tracing

Add Statsd tracing

Author: Robert Mosolgo

lib/graphql/tracing.rb

@@ -7,6 +7,7 @@
 require "graphql/tracing/new_relic_tracing"
 require "graphql/tracing/scout_tracing"
 require "graphql/tracing/skylight_tracing"
+require "graphql/tracing/statsd_tracing"
 require "graphql/tracing/prometheus_tracing"
 
 if defined?(PrometheusExporter::Server)

lib/graphql/tracing/platform_tracing.rb

@@ -32,17 +32,19 @@ def trace(key, data)
             trace_field = true # implemented with instrumenter
           else
             field = data[:field]
-            cache = platform_key_cache(data.fetch(:query).context)
-            platform_key = cache.fetch(field) do
-              cache[field] = platform_field_key(data[:owner], field)
-            end
-
             return_type = field.type.unwrap
             trace_field = if return_type.kind.scalar? || return_type.kind.enum?
               (field.trace.nil? && @trace_scalars) || field.trace
             else
               true
             end
+
+            platform_key = if trace_field
+              context = data.fetch(:query).context
+              cached_platform_key(context, field) { platform_field_key(data[:owner], field) }
+            else
+              nil
+            end
           end
 
           if platform_key && trace_field
@@ -53,20 +55,16 @@ def trace(key, data)
             yield
           end
         when "authorized", "authorized_lazy"
-          cache = platform_key_cache(data.fetch(:context))
           type = data.fetch(:type)
-          platform_key = cache.fetch(type) do
-            cache[type] = platform_authorized_key(type)
-          end
+          context = data.fetch(:context)
+          platform_key = cached_platform_key(context, type) { platform_authorized_key(type) }
           platform_trace(platform_key, key, data) do
             yield
           end
         when "resolve_type", "resolve_type_lazy"
-          cache = platform_key_cache(data.fetch(:context))
           type = data.fetch(:type)
-          platform_key = cache.fetch(type) do
-            cache[type] = platform_resolve_type_key(type)
-          end
+          context = data.fetch(:context)
+          platform_key = cached_platform_key(context, type) { platform_resolve_type_key(type) }
           platform_trace(platform_key, key, data) do
             yield
           end
@@ -119,8 +117,20 @@ def transaction_name(query)
 
       attr_reader :options
 
-      def platform_key_cache(ctx)
-        ctx.namespace(self.class)[:platform_key_cache] ||= {}
+      # Different kind of schema objects have different kinds of keys:
+      #
+      # - Object types: `.authorized`
+      # - Union/Interface types: `.resolve_type`
+      # - Fields: execution
+      #
+      # So, they can all share one cache.
+      #
+      # If the key isn't present, the given block is called and the result is cached for `key`.
+      #
+      # @return [String]
+      def cached_platform_key(ctx, key)
+        cache = ctx.namespace(self.class)[:platform_key_cache] ||= {}
+        cache.fetch(key) { cache[key] = yield }
       end
     end
   end

lib/graphql/tracing/statsd_tracing.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+module GraphQL
+  module Tracing
+    class StatsdTracing < PlatformTracing
+      self.platform_keys = {
+        'lex' => "graphql.lex",
+        'parse' => "graphql.parse",
+        'validate' => "graphql.validate",
+        'analyze_query' => "graphql.analyze_query",
+        'analyze_multiplex' => "graphql.analyze_multiplex",
+        'execute_multiplex' => "graphql.execute_multiplex",
+        'execute_query' => "graphql.execute_query",
+        'execute_query_lazy' => "graphql.execute_query_lazy",
+      }
+
+      # @param statsd [Object] A statsd client
+      def initialize(statsd:, **rest)
+        @statsd = statsd
+        super(**rest)
+      end
+
+      def platform_trace(platform_key, key, data)
+        @statsd.time(platform_key) do
+          yield
+        end
+      end
+
+      def platform_field_key(type, field)
+        "graphql.#{type.graphql_name}.#{field.graphql_name}"
+      end
+
+      def platform_authorized_key(type)
+        "graphql.authorized.#{type.graphql_name}"
+      end
+
+      def platform_resolve_type_key(type)
+        "graphql.resolve_type.#{type.graphql_name}"
+      end
+    end
+  end
+end

spec/graphql/tracing/statsd_tracing_spec.rb

@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+require "spec_helper"
+
+describe GraphQL::Tracing::StatsdTracing do
+  module MockStatsd
+    class << self
+      def time(key)
+        self.timings << key
+        yield
+      end
+
+      def timings
+        @timings
+      end
+
+      def clear
+        @timings = []
+      end
+    end
+  end
+
+  class StatsdTestSchema < GraphQL::Schema
+    class Query < GraphQL::Schema::Object
+      field :int, Integer, null: false
+
+      def int
+        1
+      end
+    end
+
+    query(Query)
+
+    use GraphQL::Execution::Interpreter
+    use GraphQL::Analysis::AST
+    use GraphQL::Tracing::StatsdTracing, statsd: MockStatsd
+  end
+
+  before do
+    MockStatsd.clear
+  end
+
+  it "gathers timings" do
+    StatsdTestSchema.execute("query X { int }")
+    expected_timings = [
+      "graphql.execute_multiplex",
+      "graphql.analyze_multiplex",
+      "graphql.lex",
+      "graphql.parse",
+      "graphql.validate",
+      "graphql.analyze_query",
+      "graphql.execute_query",
+      "graphql.authorized.Query",
+      "graphql.execute_query_lazy"
+    ]
+    assert_equal expected_timings, MockStatsd.timings
+  end
+end