178 lines
7.5 KiB
Markdown
178 lines
7.5 KiB
Markdown
---
|
|
stage: Verify
|
|
group: Runner
|
|
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/#designated-technical-writers
|
|
type: reference
|
|
---
|
|
|
|
# Job logs
|
|
|
|
> [Renamed from job traces to job logs](https://gitlab.com/gitlab-org/gitlab/-/issues/29121) in GitLab 12.5.
|
|
|
|
Job logs are sent by GitLab Runner while it's processing a job. You can see
|
|
logs in job pages, pipelines, email notifications, etc.
|
|
|
|
## Data flow
|
|
|
|
In general, there are two states for job logs: `log` and `archived log`.
|
|
In the following table you can see the phases a log goes through:
|
|
|
|
| Phase | State | Condition | Data flow | Stored path |
|
|
| -------------- | ------------ | ----------------------- | -----------------------------------------| ----------- |
|
|
| 1: patching | log | When a job is running | GitLab Runner => Puma => file storage | `#{ROOT_PATH}/gitlab-ci/builds/#{YYYY_mm}/#{project_id}/#{job_id}.log` |
|
|
| 2: overwriting | log | When a job is finished | GitLab Runner => Puma => file storage | `#{ROOT_PATH}/gitlab-ci/builds/#{YYYY_mm}/#{project_id}/#{job_id}.log` |
|
|
| 3: archiving | archived log | After a job is finished | Sidekiq moves log to artifacts folder | `#{ROOT_PATH}/gitlab-rails/shared/artifacts/#{disk_hash}/#{YYYY_mm_dd}/#{job_id}/#{job_artifact_id}/job.log` |
|
|
| 4: uploading | archived log | After a log is archived | Sidekiq moves archived log to [object storage](#uploading-logs-to-object-storage) (if configured) | `#{bucket_name}/#{disk_hash}/#{YYYY_mm_dd}/#{job_id}/#{job_artifact_id}/job.log` |
|
|
|
|
The `ROOT_PATH` varies per environment. For Omnibus GitLab it
|
|
would be `/var/opt/gitlab`, and for installations from source
|
|
it would be `/home/git/gitlab`.
|
|
|
|
## Changing the job logs local location
|
|
|
|
To change the location where the job logs will be stored, follow the steps below.
|
|
|
|
**In Omnibus installations:**
|
|
|
|
1. Edit `/etc/gitlab/gitlab.rb` and add or amend the following line:
|
|
|
|
```ruby
|
|
gitlab_ci['builds_directory'] = '/mnt/to/gitlab-ci/builds'
|
|
```
|
|
|
|
1. Save the file and [reconfigure GitLab](restart_gitlab.md#omnibus-gitlab-reconfigure) for the
|
|
changes to take effect.
|
|
|
|
**In installations from source:**
|
|
|
|
1. Edit `/home/git/gitlab/config/gitlab.yml` and add or amend the following lines:
|
|
|
|
```yaml
|
|
gitlab_ci:
|
|
# The location where build logs are stored (default: builds/).
|
|
# Relative paths are relative to Rails.root.
|
|
builds_path: path/to/builds/
|
|
```
|
|
|
|
1. Save the file and [restart GitLab](restart_gitlab.md#installations-from-source) for the changes
|
|
to take effect.
|
|
|
|
## Uploading logs to object storage
|
|
|
|
Archived logs are considered as [job artifacts](job_artifacts.md).
|
|
Therefore, when you [set up the object storage integration](job_artifacts.md#object-storage-settings),
|
|
job logs are automatically migrated to it along with the other job artifacts.
|
|
|
|
See "Phase 4: uploading" in [Data flow](#data-flow) to learn about the process.
|
|
|
|
## How to remove job logs
|
|
|
|
There isn't a way to automatically expire old job logs, but it's safe to remove
|
|
them if they're taking up too much space. If you remove the logs manually, the
|
|
job output in the UI will be empty.
|
|
|
|
For example, to delete all job logs older than 60 days, run the following from a shell in your GitLab instance:
|
|
|
|
DANGER: **Danger:**
|
|
This command will permanently delete the log files and is irreversible.
|
|
|
|
```shell
|
|
find /var/opt/gitlab/gitlab-rails/shared/artifacts -name "job.log" -mtime +60 -delete
|
|
```
|
|
|
|
## New incremental logging architecture
|
|
|
|
> - [Introduced](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/18169) in GitLab 10.4.
|
|
> - [Announced as generally available](https://gitlab.com/gitlab-org/gitlab-foss/-/issues/46097) in GitLab 11.0.
|
|
|
|
NOTE: **Note:**
|
|
This feature is off by default. See below for how to [enable or disable](#enabling-incremental-logging) it.
|
|
|
|
By combining the process with object storage settings, we can completely bypass
|
|
the local file storage. This is a useful option if GitLab is installed as
|
|
cloud-native, for example on Kubernetes.
|
|
|
|
The data flow is the same as described in the [data flow section](#data-flow)
|
|
with one change: _the stored path of the first two phases is different_. This incremental
|
|
log architecture stores chunks of logs in Redis and a persistent store (object storage or database) instead of
|
|
file storage. Redis is used as first-class storage, and it stores up-to 128KB
|
|
of data. Once the full chunk is sent, it is flushed to a persistent store, either object storage (temporary directory) or database.
|
|
After a while, the data in Redis and a persistent store will be archived to [object storage](#uploading-logs-to-object-storage).
|
|
|
|
The data are stored in the following Redis namespace: `Gitlab::Redis::SharedState`.
|
|
|
|
Here is the detailed data flow:
|
|
|
|
1. GitLab Runner picks a job from GitLab
|
|
1. GitLab Runner sends a piece of log to GitLab
|
|
1. GitLab appends the data to Redis
|
|
1. Once the data in Redis reach 128KB, the data is flushed to a persistent store (object storage or the database).
|
|
1. The above steps are repeated until the job is finished.
|
|
1. Once the job is finished, GitLab schedules a Sidekiq worker to archive the log.
|
|
1. The Sidekiq worker archives the log to object storage and cleans up the log
|
|
in Redis and a persistent store (object storage or the database).
|
|
|
|
### Enabling incremental logging
|
|
|
|
The following commands are to be issued in a Rails console:
|
|
|
|
```shell
|
|
# Omnibus GitLab
|
|
gitlab-rails console
|
|
|
|
# Installation from source
|
|
cd /home/git/gitlab
|
|
sudo -u git -H bin/rails console -e production
|
|
```
|
|
|
|
**To check if incremental logging (trace) is enabled:**
|
|
|
|
```ruby
|
|
Feature.enabled?(:ci_enable_live_trace)
|
|
```
|
|
|
|
**To enable incremental logging (trace):**
|
|
|
|
```ruby
|
|
Feature.enable(:ci_enable_live_trace)
|
|
```
|
|
|
|
NOTE: **Note:**
|
|
The transition period will be handled gracefully. Upcoming logs will be
|
|
generated with the incremental architecture, and on-going logs will stay with the
|
|
legacy architecture, which means that on-going logs won't be forcibly
|
|
re-generated with the incremental architecture.
|
|
|
|
**To disable incremental logging (trace):**
|
|
|
|
```ruby
|
|
Feature.disable('ci_enable_live_trace')
|
|
```
|
|
|
|
NOTE: **Note:**
|
|
The transition period will be handled gracefully. Upcoming logs will be generated
|
|
with the legacy architecture, and on-going incremental logs will stay with the incremental
|
|
architecture, which means that on-going incremental logs won't be forcibly re-generated
|
|
with the legacy architecture.
|
|
|
|
### Potential implications
|
|
|
|
In some cases, having data stored on Redis could incur data loss:
|
|
|
|
1. **Case 1: When all data in Redis are accidentally flushed**
|
|
- On going incremental logs could be recovered by re-sending logs (this is
|
|
supported by all versions of the GitLab Runner).
|
|
- Finished jobs which have not archived incremental logs will lose the last part
|
|
(~128KB) of log data.
|
|
|
|
1. **Case 2: When Sidekiq workers fail to archive (e.g., there was a bug that
|
|
prevents archiving process, Sidekiq inconsistency, etc.)**
|
|
- Currently all log data in Redis will be deleted after one week. If the
|
|
Sidekiq workers can't finish by the expiry date, the part of log data will be lost.
|
|
|
|
Another issue that might arise is that it could consume all memory on the Redis
|
|
instance. If the number of jobs is 1000, 128MB (128KB * 1000) is consumed.
|
|
|
|
Also, it could pressure the database replication lag. `INSERT`s are generated to
|
|
indicate that we have log chunk. `UPDATE`s with 128KB of data is issued once we
|
|
receive multiple chunks.
|