debian-mirror-gitlab/doc/administration/troubleshooting/log_parsing.md
2020-05-24 23:13:21 +05:30

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# Parsing GitLab logs with `jq`
We recommend using log aggregation and search tools like Kibana and Splunk whenever possible,
but if they are not available you can still quickly parse
[GitLab logs](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/26311) in JSON format
(the default since GitLab 12.0) using [`jq`](https://stedolan.github.io/jq/).
## What is JQ?
As noted in its [manual](https://stedolan.github.io/jq/manual/), jq is a command-line JSON processor. The following examples
include use cases targeted for parsing GitLab log files.
## Parsing Logs
### General Commands
#### Pipe colorized `jq` output into `less`
```shell
jq . <FILE> -C | less -R
```
#### Search for a term and pretty-print all matching lines
```shell
grep <TERM> <FILE> | jq .
```
#### Skip invalid lines of JSON
```shell
jq -cR 'fromjson?' file.json | jq <COMMAND>
```
By default `jq` will error out when it encounters a line that is not valid JSON.
This skips over all invalid lines and parses the rest.
### Parsing `production_json.log` and `api_json.log`
#### Find all requests with a 5XX status code
```shell
jq 'select(status >= 500)' <FILE>
```
#### Top 10 slowest requests
```shell
jq -s 'sort_by(-.duration) | limit(10; .[])' <FILE>
```
#### Find and pretty print all requests related to a project
```shell
grep <PROJECT_NAME> <FILE> | jq .
```
#### Find all requests with a total duration > 5 seconds
```shell
jq 'select(.duration > 5000)' <FILE>
```
#### Find all project requests with more than 5 rugged calls
```shell
grep <PROJECT_NAME> <FILE> | jq 'select(.rugged_calls > 5)'
```
#### Find all requests with a Gitaly duration > 10 seconds
```shell
jq 'select(.gitaly_duration > 10000)' <FILE>
```
#### Find all requests with a queue duration > 10 seconds
```shell
jq 'select(.queue_duration > 10000)' <FILE>
```
#### Top 10 requests by # of Gitaly calls
```shell
jq -s 'map(select(.gitaly_calls != null)) | sort_by(-.gitaly_calls) | limit(10; .[])' <FILE>
```
### Parsing `production_json.log`
#### Print the top three controller methods by request volume and their three longest durations
```shell
jq -s -r 'group_by(.controller+.action) | sort_by(-length) | limit(3; .[]) | sort_by(-.duration) | "CT: \(length)\tMETHOD: \(.[0].controller)#\(.[0].action)\tDURS: \(.[0].duration), \(.[1].duration), \(.[2].duration)"' production_json.log
```
**Example output**
```plaintext
CT: 2721 METHOD: SessionsController#new DURS: 844.06, 713.81, 704.66
CT: 2435 METHOD: MetricsController#index DURS: 299.29, 284.01, 158.57
CT: 1328 METHOD: Projects::NotesController#index DURS: 403.99, 386.29, 384.39
```
### Parsing `api_json.log`
#### Print top three routes with request count and their three longest durations
```shell
jq -s -r 'group_by(.route) | sort_by(-length) | limit(3; .[]) | sort_by(-.duration) | "CT: \(length)\tROUTE: \(.[0].route)\tDURS: \(.[0].duration), \(.[1].duration), \(.[2].duration)"' api_json.log
```
**Example output**
```plaintext
CT: 2472 ROUTE: /api/:version/internal/allowed DURS: 56402.65, 38411.43, 19500.41
CT: 297 ROUTE: /api/:version/projects/:id/repository/tags DURS: 731.39, 685.57, 480.86
CT: 190 ROUTE: /api/:version/projects/:id/repository/commits DURS: 1079.02, 979.68, 958.21
```
### Parsing `gitaly/current`
#### Find all Gitaly requests sent from web UI
```shell
jq 'select(."grpc.meta.client_name" == "gitlab-web")' current
```
#### Find all failed Gitaly requests
```shell
jq 'select(."grpc.code" != null and ."grpc.code" != "OK")' current
```
#### Find all requests that took longer than 30 seconds
```shell
jq 'select(."grpc.time_ms" > 30000)' current
```
#### Print top three projects by request volume and their three longest durations
```shell
jq -s -r 'map(select(."grpc.request.glProjectPath" != null and ."grpc.request.glProjectPath" != "" and ."grpc.time_ms" != null)) | group_by(."grpc.request.glProjectPath") | sort_by(-length) | limit(3; .[]) | sort_by(-."grpc.time_ms") | "CT: \(length)\tPROJECT: \(.[0]."grpc.request.glProjectPath")\tDURS: \(.[0]."grpc.time_ms"), \(.[1]."grpc.time_ms"), \(.[2]."grpc.time_ms")"' current
```
**Example output**
```plaintext
CT: 635 PROJECT: groupA/project1 DURS: 4292.269, 4228.853, 2885.548
CT: 462 PROJECT: groupB/project5 DURS: 4368.981, 3623.553, 361.399
CT: 455 PROJECT: groupC/project7 DURS: 387.295, 381.874, 373.988
```