1 files changed, 70 insertions, 0 deletions
diff --git a/lib/gitlab/instrumentation/redis.rb b/lib/gitlab/instrumentation/redis.rb
new file mode 100644
index 00000000000..f9a6fdc05aa
--- /dev/null
+++ b/lib/gitlab/instrumentation/redis.rb
@@ -0,0 +1,70 @@
+# frozen_string_literal: true
+
+require 'redis'
+
+module Gitlab
+  module Instrumentation
+    module RedisInterceptor
+      def call(*args, &block)
+        start = Time.now
+        super(*args, &block)
+      ensure
+        duration = (Time.now - start)
+
+        if ::RequestStore.active?
+          ::Gitlab::Instrumentation::Redis.increment_request_count
+          ::Gitlab::Instrumentation::Redis.add_duration(duration)
+          ::Gitlab::Instrumentation::Redis.add_call_details(duration, args)
+        end
+      end
+    end
+
+    class Redis
+      REDIS_REQUEST_COUNT = :redis_request_count
+      REDIS_CALL_DURATION = :redis_call_duration
+      REDIS_CALL_DETAILS = :redis_call_details
+
+      def self.get_request_count
+        ::RequestStore[REDIS_REQUEST_COUNT] || 0
+      end
+
+      def self.increment_request_count
+        ::RequestStore[REDIS_REQUEST_COUNT] ||= 0
+        ::RequestStore[REDIS_REQUEST_COUNT] += 1
+      end
+
+      def self.detail_store
+        ::RequestStore[REDIS_CALL_DETAILS] ||= []
+      end
+
+      def self.query_time_ms
+        (self.query_time * 1000).round(2)
+      end
+
+      def self.query_time
+        ::RequestStore[REDIS_CALL_DURATION] || 0
+      end
+
+      def self.add_duration(duration)
+        total_time = query_time + duration
+        ::RequestStore[REDIS_CALL_DURATION] = total_time
+      end
+
+      def self.add_call_details(duration, args)
+        return unless Gitlab::PerformanceBar.enabled_for_request?
+        # redis-rb passes an array (e.g. [:get, key])
+        return unless args.length == 1
+
+        detail_store << {
+          cmd: args.first,
+          duration: duration,
+          backtrace: ::Gitlab::BacktraceCleaner.clean_backtrace(caller)
+        }
+      end
+    end
+  end
+end
+
+class ::Redis::Client
+  prepend ::Gitlab::Instrumentation::RedisInterceptor
+end