Merge branch 'an/log-documentation' into 'master'

Update documentation WRT to request parameters

See merge request gitlab-org/gitlab-ce!17469

doc/administration/logs.md

@@ -23,7 +23,7 @@ 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":{"namespace_id":"gitlab","project_id":"gitlab-ce","id":"1234"},"remote_ip":"18.245.0.1","user_id":1,"username":"admin"}
+{"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}
 ```
 In this example, you can see this was a GET request for a specific issue. Notice each line also contains performance data:
@@ -31,6 +31,7 @@ In this example, you can see this was a GET request for a specific issue. Notice
 1. `duration`: the total time taken to retrieve the request
 2. `view`: total time taken inside the Rails views
 3. `db`: total time to retrieve data from the database
+4. `gitaly_calls`: total number of calls made to Gitaly
 User clone/fetch activity using http transport appears in this log as `action: git_upload_pack`.