1---
2stage: Enablement
3group: Distribution
4info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
5---
6
7# Finding relevant log entries with a correlation ID **(FREE SELF)**
8
9GitLab instances log a unique request tracking ID (known as the
10"correlation ID") for most requests. Each individual request to GitLab gets
11its own correlation ID, which then gets logged in each GitLab component's logs for that
12request. This makes it easier to trace behavior in a
13distributed system. Without this ID it can be difficult or
14impossible to match correlating log entries.
15
16## Identify the correlation ID for a request
17
18The correlation ID is logged in structured logs under the key `correlation_id`
19and in all response headers GitLab sends under the header `x-request-id`.
20You can find your correlation ID by searching in either place.
21
22### Getting the correlation ID in your browser
23
24You can use your browser's developer tools to monitor and inspect network
25activity with the site that you're visiting. See the links below for network monitoring
26documentation for some popular browsers.
27
28- [Network Monitor - Firefox Developer Tools](https://developer.mozilla.org/en-US/docs/Tools/Network_Monitor)
29- [Inspect Network Activity In Chrome DevTools](https://developer.chrome.com/docs/devtools/network/)
30- [Safari Web Development Tools](https://developer.apple.com/safari/tools/)
31- [Microsoft Edge Network panel](https://docs.microsoft.com/en-us/microsoft-edge/devtools-guide-chromium/network/)
32
33To locate a relevant request and view its correlation ID:
34
351. Enable persistent logging in your network monitor. Some actions in GitLab will redirect you quickly after you submit a form, so this will help capture all relevant activity.
361. To help isolate the requests you are looking for, you can filter for `document` requests.
371. Click the request of interest to view further detail.
381. Go to the **Headers** section and look for **Response Headers**. There you should find an `x-request-id` header with a
39value that was randomly generated by GitLab for the request.
40
41See the following example:
42
43![Firefox's network monitor showing an request ID header](img/network_monitor_xid.png)
44
45### Getting the correlation ID from your logs
46
47Another approach to finding the correct correlation ID is to search or watch
48your logs and find the `correlation_id` value for the log entry that you're
49watching for.
50
51For example, let's say that you want learn what's happening or breaking when
52you reproduce an action in GitLab. You could tail the GitLab logs, filtering
53to requests by your user, and then watch the requests until you see what you're
54interested in.
55
56### Getting the correlation ID from curl
57
58If you're using `curl` then you can use the verbose option to show request and response headers, as well as other debug information.
59
60```shell
61➜  ~ curl --verbose "https://gitlab.example.com/api/v4/projects"
62# look for a line that looks like this
63< x-request-id: 4rAMkV3gof4
64```
65
66#### Using jq
67
68This example uses [jq](https://stedolan.github.io/jq/) to filter results and
69display values we most likely care about.
70
71```shell
72sudo gitlab-ctl tail gitlab-rails/production_json.log | jq 'select(.username == "bob") | "User: \(.username), \(.method) \(.path), \(.controller)#\(.action), ID: \(.correlation_id)"'
73```
74
75```plaintext
76"User: bob, GET /root/linux, ProjectsController#show, ID: U7k7fh6NpW3"
77"User: bob, GET /root/linux/commits/master/signatures, Projects::CommitsController#signatures, ID: XPIHpctzEg1"
78"User: bob, GET /root/linux/blob/master/README, Projects::BlobController#show, ID: LOt9hgi1TV4"
79```
80
81#### Using grep
82
83This example uses only `grep` and `tr`, which are more likely to be installed than `jq`.
84
85```shell
86sudo gitlab-ctl tail gitlab-rails/production_json.log | grep '"username":"bob"' | tr ',' '\n' | egrep 'method|path|correlation_id'
87```
88
89```plaintext
90{"method":"GET"
91"path":"/root/linux"
92"username":"bob"
93"correlation_id":"U7k7fh6NpW3"}
94{"method":"GET"
95"path":"/root/linux/commits/master/signatures"
96"username":"bob"
97"correlation_id":"XPIHpctzEg1"}
98{"method":"GET"
99"path":"/root/linux/blob/master/README"
100"username":"bob"
101"correlation_id":"LOt9hgi1TV4"}
102```
103
104## Searching your logs for the correlation ID
105
106Once you have the correlation ID you can start searching for relevant log
107entries. You can filter the lines by the correlation ID itself.
108Combining a `find` and `grep` should be sufficient to find the entries you are looking for.
109
110```shell
111# find <gitlab log directory> -type f -mtime -0 exec grep '<correlation ID>' '{}' '+'
112find /var/log/gitlab -type f -mtime 0 -exec grep 'LOt9hgi1TV4' '{}' '+'
113```
114
115```plaintext
116/var/log/gitlab/gitlab-workhorse/current:{"correlation_id":"LOt9hgi1TV4","duration_ms":2478,"host":"gitlab.domain.tld","level":"info","method":"GET","msg":"access","proto":"HTTP/1.1","referrer":"https://gitlab.domain.tld/root/linux","remote_addr":"68.0.116.160:0","remote_ip":"[filtered]","status":200,"system":"http","time":"2019-09-17T22:17:19Z","uri":"/root/linux/blob/master/README?format=json\u0026viewer=rich","user_agent":"Mozilla/5.0 (Mac) Gecko Firefox/69.0","written_bytes":1743}
117/var/log/gitlab/gitaly/current:{"correlation_id":"LOt9hgi1TV4","grpc.code":"OK","grpc.meta.auth_version":"v2","grpc.meta.client_name":"gitlab-web","grpc.method":"FindCommits","grpc.request.deadline":"2019-09-17T22:17:47Z","grpc.request.fullMethod":"/gitaly.CommitService/FindCommits","grpc.request.glProjectPath":"root/linux","grpc.request.glRepository":"project-1","grpc.request.repoPath":"@hashed/6b/86/6b86b273ff34fce19d6b804eff5a3f5747ada4eaa22f1d49c01e52ddb7875b4b.git","grpc.request.repoStorage":"default","grpc.request.topLevelGroup":"@hashed","grpc.service":"gitaly.CommitService","grpc.start_time":"2019-09-17T22:17:17Z","grpc.time_ms":2319.161,"level":"info","msg":"finished streaming call with code OK","peer.address":"@","span.kind":"server","system":"grpc","time":"2019-09-17T22:17:19Z"}
118/var/log/gitlab/gitlab-rails/production_json.log:{"method":"GET","path":"/root/linux/blob/master/README","format":"json","controller":"Projects::BlobController","action":"show","status":200,"duration":2448.77,"view":0.49,"db":21.63,"time":"2019-09-17T22:17:19.800Z","params":[{"key":"viewer","value":"rich"},{"key":"namespace_id","value":"root"},{"key":"project_id","value":"linux"},{"key":"id","value":"master/README"}],"remote_ip":"[filtered]","user_id":2,"username":"bob","ua":"Mozilla/5.0 (Mac) Gecko Firefox/69.0","queue_duration":3.38,"gitaly_calls":1,"gitaly_duration":0.77,"rugged_calls":4,"rugged_duration_ms":28.74,"correlation_id":"LOt9hgi1TV4"}
119```
120
121### Searching in distributed architectures
122
123If you have done some horizontal scaling in your GitLab infrastructure, then
124you will need to search across _all_ of your GitLab nodes. You can do this with
125some sort of log aggregation software like Loki, ELK, Splunk, or others.
126
127You can use a tool like Ansible or PSSH (parallel SSH) that can execute identical commands across your servers in
128parallel, or craft your own solution.
129
130### Viewing the request in the Performance Bar
131
132You can use the [performance bar](../monitoring/performance/performance_bar.md) to view interesting data including calls made to SQL and Gitaly.
133
134To view the data, the correlation ID of the request must match the same session as the user
135viewing the performance bar. For API requests, this means that you must perform the request
136using the session cookie of the signed-in user.
137
138For example, if you want to view the database queries executed for the following API endpoint:
139
140```shell
141https://gitlab.com/api/v4/groups/2564205/projects?with_security_reports=true&page=1&per_page=1
142```
143
144First, enable the **Developer Tools** panel. See [Getting the correlation ID in your browser](#getting-the-correlation-id-in-your-browser) for details on how to do this.
145
146After developer tools have been enabled, obtain a session cookie as follows:
147
1481. Visit <https://gitlab.com> while logged in.
1491. Optional. Select **Fetch/XHR** request filter in the **Developer Tools** panel. This step is described for Google Chrome developer tools and is not strictly necessary, it just makes it easier to find the correct request.
1501. Select the `results?request_id=<some-request-id>` request on the left hand side.
1511. The session cookie is displayed under the `Request Headers` section of the `Headers` panel. Right-click on the cookie value and select `Copy value`.
152
153![Obtaining a session cookie for request](img/obtaining-a-session-cookie-for-request_v14_3.png)
154
155You have the value of the session cookie copied to your clipboard, for example:
156
157```shell
158experimentation_subject_id=<subject-id>; _gitlab_session=<session-id>; event_filter=all; visitor_id=<visitor-id>; perf_bar_enabled=true; sidebar_collapsed=true; diff_view=inline; sast_entry_point_dismissed=true; auto_devops_settings_dismissed=true; cf_clearance=<cf-clearance>; collapsed_gutter=false; frequently_used_emojis=clap,thumbsup,rofl,tada,eyes,bow
159```
160
161Use the value of the session cookie to craft an API request by pasting it into a custom header of a `curl` request:
162
163```shell
164$ curl --include "https://gitlab.com/api/v4/groups/2564205/projects?with_security_reports=true&page=1&per_page=1" \
165--header 'cookie: experimentation_subject_id=<subject-id>; _gitlab_session=<session-id>; event_filter=all; visitor_id=<visitor-id>; perf_bar_enabled=true; sidebar_collapsed=true; diff_view=inline; sast_entry_point_dismissed=true; auto_devops_settings_dismissed=true; cf_clearance=<cf-clearance>; collapsed_gutter=false; frequently_used_emojis=clap,thumbsup,rofl,tada,eyes,bow'
166
167  date: Tue, 28 Sep 2021 03:55:33 GMT
168  content-type: application/json
169  ...
170  x-request-id: 01FGN8P881GF2E5J91JYA338Y3
171  ...
172  [
173    {
174      "id":27497069,
175      "description":"Analyzer for images used on live K8S containers based on Starboard"
176    },
177    "container_registry_image_prefix":"registry.gitlab.com/gitlab-org/security-products/analyzers/cluster-image-scanning",
178    "..."
179  ]
180```
181
182The response contains the data from the API endpoint, and a `correlation_id` value, returned in the `x-request-id` header, as described in the [Identify the correlation ID for a request](#identify-the-correlation-id-for-a-request) section.
183
184You can then view the database details for this request:
185
1861. Paste the `x-request-id` value into the `request details` field of the [performance bar](../monitoring/performance/performance_bar.md) and press <kbd>Enter/Return</kbd>. This example uses the `x-request-id` value `01FGN8P881GF2E5J91JYA338Y3`, returned by the above response:
187
188   ![Paste request ID into progress bar](img/paste-request-id-into-progress-bar_v14_3.png)
189
1901. A new request is inserted into the `Request Selector` dropdown on the right-hand side of the Performance Bar. Select the new request to view the metrics of the API request:
191
192   ![Select request ID from request selector drop down menu](img/select-request-id-from-request-selector-drop-down-menu_v14_3.png)
193
194   <!-- vale gitlab.Substitutions = NO -->
1951. Select the `pg` link in the Progress Bar to view the database queries executed by the API request:
196
197   ![View pg database details](img/view-pg-details_v14_3.png)
198   <!-- vale gitlab.Substitutions = YES -->
199
200   The database query dialog is displayed:
201
202   ![Database query dialog](img/database-query-dialog_v14_3.png)
203