Log Gitaly RPC duration to api_json.log and production_json.log

This makes it easier to debug Gitaly performance issues in the field.

This commit also makes the tracking of query time thread-safe via
RequestStore.

changelogs/unreleased/sh-add-gitaly-duration-logs.yml

+---
+title: Log Gitaly RPC duration to api_json.log and production_json.log
+merge_request: 26652
+author:
+type: other

config/initializers/lograge.rb

@@ -28,7 +28,12 @@ unless Sidekiq.server?
       }
 
       gitaly_calls = Gitlab::GitalyClient.get_request_count
-      payload[:gitaly_calls] = gitaly_calls if gitaly_calls > 0
+
+      if gitaly_calls > 0
+        payload[:gitaly_calls] = gitaly_calls
+        payload[:gitaly_duration] = Gitlab::GitalyClient.query_time_ms
+      end
+
       payload[:response] = event.payload[:response] if event.payload[:response]
       payload[Gitlab::CorrelationId::LOG_KEY] = Gitlab::CorrelationId.current_id
 

doc/administration/logs.md

@@ -23,16 +23,19 @@ requests from the API are logged to a separate file in `api_json.log`.
 Each line contains a JSON line that can be ingested by Elasticsearch, Splunk, etc. For example:
 
 ```json
-{"method":"GET","path":"/gitlab/gitlab-ce/issues/1234","format":"html","controller":"Projects::IssuesController","action":"show","status":200,"duration":229.03,"view":174.07,"db":13.24,"time":"2017-08-08T20:15:54.821Z","params":[{"key":"param_key","value":"param_value"}],"remote_ip":"18.245.0.1","user_id":1,"username":"admin","gitaly_calls":76,"queue_duration": 112.47}
+{"method":"GET","path":"/gitlab/gitlab-ce/issues/1234","format":"html","controller":"Projects::IssuesController","action":"show","status":200,"duration":229.03,"view":174.07,"db":13.24,"time":"2017-08-08T20:15:54.821Z","params":[{"key":"param_key","value":"param_value"}],"remote_ip":"18.245.0.1","user_id":1,"username":"admin","gitaly_calls":76,"gitaly_duration":7.41,"queue_duration": 112.47}
 ```
 
-In this example, you can see this was a GET request for a specific issue. Notice each line also contains performance data:
+In this example, you can see this was a GET request for a specific
+issue. Notice each line also contains performance data. All times are in
+milliseconds:
 
-1. `duration`: total time in milliseconds taken to retrieve the request
-1. `queue_duration`: total time in milliseconds that the request was queued inside GitLab Workhorse
+1. `duration`: total time taken to retrieve the request
+1. `queue_duration`: total time that the request was queued inside GitLab Workhorse
 1. `view`: total time taken inside the Rails views
 1. `db`: total time to retrieve data from the database
 1. `gitaly_calls`: total number of calls made to Gitaly
+1. `gitaly_duration`: total time taken by Gitaly calls
 
 User clone/fetch activity using http transport appears in this log as `action: git_upload_pack`.
 
@@ -85,7 +88,7 @@ Introduced in GitLab 10.0, this file lives in
 It helps you see requests made directly to the API. For example:
 
 ```json
-{"time":"2018-10-29T12:49:42.123Z","severity":"INFO","duration":709.08,"db":14.59,"view":694.49,"status":200,"method":"GET","path":"/api/v4/projects","params":[{"key":"action","value":"git-upload-pack"},{"key":"changes","value":"_any"},{"key":"key_id","value":"secret"},{"key":"secret_token","value":"[FILTERED]"}],"host":"localhost","ip":"::1","ua":"Ruby","route":"/api/:version/projects","user_id":1,"username":"root","queue_duration":100.31,"gitaly_calls":30}
+{"time":"2018-10-29T12:49:42.123Z","severity":"INFO","duration":709.08,"db":14.59,"view":694.49,"status":200,"method":"GET","path":"/api/v4/projects","params":[{"key":"action","value":"git-upload-pack"},{"key":"changes","value":"_any"},{"key":"key_id","value":"secret"},{"key":"secret_token","value":"[FILTERED]"}],"host":"localhost","ip":"::1","ua":"Ruby","route":"/api/:version/projects","user_id":1,"username":"root","queue_duration":100.31,"gitaly_calls":30,"gitaly_duration":5.36}
 ```
 
 This entry above shows an access to an internal endpoint to check whether an

lib/gitlab/gitaly_client.rb

@@ -33,12 +33,6 @@ module Gitlab
 
     MUTEX = Mutex.new
 
-    class << self
-      attr_accessor :query_time
-    end
-
-    self.query_time = 0
-
     define_histogram :gitaly_controller_action_duration_seconds do
       docstring "Gitaly endpoint histogram by controller and action combination"
       base_labels Gitlab::Metrics::Transaction::BASE_LABELS.merge(gitaly_service: nil, rpc: nil)
@@ -174,6 +168,18 @@ module Gitlab
       add_call_details(feature: "#{service}##{rpc}", duration: duration, request: request_hash, rpc: rpc)
     end
 
+    def self.query_time
+      SafeRequestStore[:gitaly_query_time] ||= 0
+    end
+
+    def self.query_time=(duration)
+      SafeRequestStore[:gitaly_query_time] = duration
+    end
+
+    def self.query_time_ms
+      (self.query_time * 1000).round(2)
+    end
+
     def self.current_transaction_labels
       Gitlab::Metrics::Transaction.current&.labels || {}
     end

lib/gitlab/grape_logging/loggers/perf_logger.rb

@@ -6,7 +6,10 @@ module Gitlab
     module Loggers
       class PerfLogger < ::GrapeLogging::Loggers::Base
         def parameters(_, _)
-          { gitaly_calls: Gitlab::GitalyClient.get_request_count }
+          {
+            gitaly_calls: Gitlab::GitalyClient.get_request_count,
+            gitaly_duration: Gitlab::GitalyClient.query_time_ms
+          }
         end
       end
     end