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diff --git a/doc/administration/logs/tracing_correlation_id.md b/doc/administration/logs/tracing_correlation_id.md new file mode 100644 index 00000000000..1d3e4955d3a --- /dev/null +++ b/doc/administration/logs/tracing_correlation_id.md @@ -0,0 +1,202 @@ +--- +stage: Systems +group: Distribution +info: 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 +--- + +# Find relevant log entries with a correlation ID **(FREE SELF)** + +GitLab instances log a unique request tracking ID (known as the +"correlation ID") for most requests. Each individual request to GitLab gets +its own correlation ID, which then gets logged in each GitLab component's logs for that +request. This makes it easier to trace behavior in a +distributed system. Without this ID it can be difficult or +impossible to match correlating log entries. + +## Identify the correlation ID for a request + +The correlation ID is logged in structured logs under the key `correlation_id` +and in all response headers GitLab sends under the header `x-request-id`. +You can find your correlation ID by searching in either place. + +### Getting the correlation ID in your browser + +You can use your browser's developer tools to monitor and inspect network +activity with the site that you're visiting. See the links below for network monitoring +documentation for some popular browsers. + +- [Network Monitor - Firefox Developer Tools](https://developer.mozilla.org/en-US/docs/Tools/Network_Monitor) +- [Inspect Network Activity In Chrome DevTools](https://developer.chrome.com/docs/devtools/network/) +- [Safari Web Development Tools](https://developer.apple.com/safari/tools/) +- [Microsoft Edge Network panel](https://docs.microsoft.com/en-us/microsoft-edge/devtools-guide-chromium/network/) + +To locate a relevant request and view its correlation ID: + +1. Enable persistent logging in your network monitor. Some actions in GitLab redirect you quickly after you submit a form, so this helps capture all relevant activity. +1. To help isolate the requests you are looking for, you can filter for `document` requests. +1. Select the request of interest to view further detail. +1. Go to the **Headers** section and look for **Response Headers**. There you should find an `x-request-id` header with a +value that was randomly generated by GitLab for the request. + +See the following example: + + + +### Getting the correlation ID from your logs + +Another approach to finding the correct correlation ID is to search or watch +your logs and find the `correlation_id` value for the log entry that you're +watching for. + +For example, let's say that you want learn what's happening or breaking when +you reproduce an action in GitLab. You could tail the GitLab logs, filtering +to requests by your user, and then watch the requests until you see what you're +interested in. + +### Getting the correlation ID from curl + +If you're using `curl` then you can use the verbose option to show request and response headers, as well as other debug information. + +```shell +➜ ~ curl --verbose "https://gitlab.example.com/api/v4/projects" +# look for a line that looks like this +< x-request-id: 4rAMkV3gof4 +``` + +#### Using jq + +This example uses [jq](https://stedolan.github.io/jq/) to filter results and +display values we most likely care about. + +```shell +sudo gitlab-ctl tail gitlab-rails/production_json.log | jq 'select(.username == "bob") | "User: \(.username), \(.method) \(.path), \(.controller)#\(.action), ID: \(.correlation_id)"' +``` + +```plaintext +"User: bob, GET /root/linux, ProjectsController#show, ID: U7k7fh6NpW3" +"User: bob, GET /root/linux/commits/master/signatures, Projects::CommitsController#signatures, ID: XPIHpctzEg1" +"User: bob, GET /root/linux/blob/master/README, Projects::BlobController#show, ID: LOt9hgi1TV4" +``` + +#### Using grep + +This example uses only `grep` and `tr`, which are more likely to be installed than `jq`. + +```shell +sudo gitlab-ctl tail gitlab-rails/production_json.log | grep '"username":"bob"' | tr ',' '\n' | egrep 'method|path|correlation_id' +``` + +```plaintext +{"method":"GET" +"path":"/root/linux" +"username":"bob" +"correlation_id":"U7k7fh6NpW3"} +{"method":"GET" +"path":"/root/linux/commits/master/signatures" +"username":"bob" +"correlation_id":"XPIHpctzEg1"} +{"method":"GET" +"path":"/root/linux/blob/master/README" +"username":"bob" +"correlation_id":"LOt9hgi1TV4"} +``` + +## Searching your logs for the correlation ID + +Once you have the correlation ID you can start searching for relevant log +entries. You can filter the lines by the correlation ID itself. +Combining a `find` and `grep` should be sufficient to find the entries you are looking for. + +```shell +# find <gitlab log directory> -type f -mtime -0 exec grep '<correlation ID>' '{}' '+' +find /var/log/gitlab -type f -mtime 0 -exec grep 'LOt9hgi1TV4' '{}' '+' +``` + +```plaintext +/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} +/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"} +/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"} +``` + +### Searching in distributed architectures + +If you have done some horizontal scaling in your GitLab infrastructure, then +you must search across _all_ of your GitLab nodes. You can do this with +some sort of log aggregation software like Loki, ELK, Splunk, or others. + +You can use a tool like Ansible or PSSH (parallel SSH) that can execute identical commands across your servers in +parallel, or craft your own solution. + +### Viewing the request in the Performance Bar + +You can use the [performance bar](../monitoring/performance/performance_bar.md) to view interesting data including calls made to SQL and Gitaly. + +To view the data, the correlation ID of the request must match the same session as the user +viewing the performance bar. For API requests, this means that you must perform the request +using the session cookie of the signed-in user. + +For example, if you want to view the database queries executed for the following API endpoint: + +```shell +https://gitlab.com/api/v4/groups/2564205/projects?with_security_reports=true&page=1&per_page=1 +``` + +First, 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. + +After developer tools have been enabled, obtain a session cookie as follows: + +1. Visit <https://gitlab.com> while logged in. +1. 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. +1. Select the `results?request_id=<some-request-id>` request on the left hand side. +1. The session cookie is displayed under the `Request Headers` section of the `Headers` panel. Right-click on the cookie value and select `Copy value`. + + + +You have the value of the session cookie copied to your clipboard, for example: + +```shell +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 +``` + +Use the value of the session cookie to craft an API request by pasting it into a custom header of a `curl` request: + +```shell +$ curl --include "https://gitlab.com/api/v4/groups/2564205/projects?with_security_reports=true&page=1&per_page=1" \ +--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' + + date: Tue, 28 Sep 2021 03:55:33 GMT + content-type: application/json + ... + x-request-id: 01FGN8P881GF2E5J91JYA338Y3 + ... + [ + { + "id":27497069, + "description":"Analyzer for images used on live K8S containers based on Starboard" + }, + "container_registry_image_prefix":"registry.gitlab.com/gitlab-org/security-products/analyzers/cluster-image-scanning", + "..." + ] +``` + +The 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. + +You can then view the database details for this request: + +1. 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: + +  + +1. 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: + +  + + <!-- vale gitlab.Substitutions = NO --> +1. Select the `pg` link in the Progress Bar to view the database queries executed by the API request: + +  + <!-- vale gitlab.Substitutions = YES --> + + The database query dialog is displayed: + +  |