198 lines
8.6 KiB
Markdown
198 lines
8.6 KiB
Markdown
---
|
|
stage: Systems
|
|
group: Gitaly
|
|
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/product/ux/technical-writing/#assignments
|
|
---
|
|
|
|
# Housekeeping **(FREE SELF)**
|
|
|
|
GitLab supports and automates housekeeping tasks in Git repositories to ensure
|
|
that they can be served as efficiently as possible. Housekeeping tasks include:
|
|
|
|
- Compressing Git objects and revisions.
|
|
- Removing unreachable objects.
|
|
- Removing stale data like lock files.
|
|
- Maintaining data structures that improve performance.
|
|
- Updating object pools to improve object deduplication across forks.
|
|
|
|
WARNING:
|
|
Do not manually execute Git commands to perform housekeeping in Git
|
|
repositories that are controlled by GitLab. Doing so may lead to corrupt
|
|
repositories and data loss.
|
|
|
|
## Housekeeping strategy
|
|
|
|
Gitaly can perform housekeeping tasks in a Git repository in two ways:
|
|
|
|
- [Eager housekeeping](#eager-housekeeping) executes specific housekeeping tasks
|
|
independent of the state a repository is in.
|
|
- [Heuristical housekeeping](#heuristical-housekeeping) executes housekeeping
|
|
tasks based on a set of heuristics that determine what housekeeping tasks need
|
|
to be executed based on the repository state.
|
|
|
|
### Eager housekeeping
|
|
|
|
The "eager" housekeeping strategy executes housekeeping tasks in a repository
|
|
independent of the repository state. This is the default strategy as used by the
|
|
[manual trigger](#manual-trigger) and the push-based trigger.
|
|
|
|
The eager housekeeping strategy is controlled by the GitLab application.
|
|
Depending on the trigger that caused the housekeeping job to run, GitLab asks
|
|
Gitaly to perform specific housekeeping tasks. Gitaly performs these tasks even
|
|
if the repository is in an optimized state. As a result, this strategy can be
|
|
inefficient in large repositories where performing the housekeeping tasks may
|
|
be slow.
|
|
|
|
### Heuristical housekeeping
|
|
|
|
> - [Introduced](https://gitlab.com/gitlab-org/gitaly/-/issues/2634) in GitLab 14.9 for the [manual trigger](#manual-trigger) and the push-based trigger [with a flag](feature_flags.md) named `optimized_housekeeping`. Enabled by default.
|
|
> - [Enabled on GitLab.com](https://gitlab.com/gitlab-org/gitlab/-/issues/353607) in GitLab 14.10.
|
|
> - [Generally available](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/107661) in GitLab 15.8. Feature flag `optimized_housekeeping` removed.
|
|
|
|
The heuristical (or "opportunistic") housekeeping strategy analyzes the
|
|
repository's state and executes housekeeping tasks only when it finds one or
|
|
more data structures are insufficiently optimized. This is the strategy used by
|
|
[scheduled housekeeping](#scheduled-housekeeping).
|
|
|
|
Heuristical housekeeping uses the following information to decide on the tasks
|
|
it needs to run:
|
|
|
|
- The number of loose and stale objects.
|
|
- The number of packfiles that contain already-compressed objects.
|
|
- The number of loose references.
|
|
- The presence of a commit-graph.
|
|
|
|
The decision whether any of the analyzed data structures need to be optimized is
|
|
based on the size of the repository:
|
|
|
|
- Objects are repacked frequently the bigger the total size of all objects.
|
|
- References are repacked less frequently the more references there are in
|
|
total.
|
|
|
|
Gitaly does this to offset the fact that optimizing those data structures takes
|
|
more time the bigger they get. It is especially important in large
|
|
monorepos (which receive a lot of traffic) to avoid optimizing them too
|
|
frequently.
|
|
|
|
You can change how often Gitaly is asked to optimize a repository.
|
|
|
|
1. On the top bar, select **Main menu > Admin**.
|
|
1. On the left sidebar, select **Settings > Repository**.
|
|
1. Expand **Repository maintenance**.
|
|
1. In the **Housekeeping** section, configure the housekeeping options.
|
|
1. Select **Save changes**.
|
|
|
|
- **Enable automatic repository housekeeping**: Regularly ask Gitaly to run repository optimization. If you
|
|
keep this setting disabled for a long time, Git repository access on your GitLab server becomes
|
|
slower and your repositories use more disk space.
|
|
- **Optimize repository period**: Number of Git pushes after which Gitaly is asked to optimize a repository.
|
|
|
|
## Running housekeeping tasks
|
|
|
|
There are different ways in which GitLab runs housekeeping tasks:
|
|
|
|
- A project's administrator can [manually trigger](#manual-trigger) repository
|
|
housekeeping tasks.
|
|
- GitLab can automatically schedule housekeeping tasks after a number of Git pushes.
|
|
- GitLab can [schedule a job](#scheduled-housekeeping) that runs housekeeping
|
|
tasks for all repositories in a configurable time frame.
|
|
|
|
### Manual trigger
|
|
|
|
Administrators of repositories can manually trigger housekeeping tasks in a
|
|
repository. In general this is not required as GitLab knows to automatically run
|
|
housekeeping tasks. The manual trigger can be useful when either:
|
|
|
|
- A repository is known to require housekeeping.
|
|
- Automated push-based scheduling of housekeeping tasks has been disabled.
|
|
|
|
To trigger housekeeping tasks manually:
|
|
|
|
1. On the top bar, select **Main menu > Projects** and find your project.
|
|
1. On the left sidebar, select **Settings > General**.
|
|
1. Expand **Advanced**.
|
|
1. Select **Run housekeeping**.
|
|
|
|
This starts an asynchronous background worker for the project's repository. The
|
|
background worker asks Gitaly to perform a number of optimizations.
|
|
|
|
Housekeeping also [removes unreferenced LFS files](../raketasks/cleanup.md#remove-unreferenced-lfs-files)
|
|
from your project every `200` push, freeing up storage space for your project.
|
|
|
|
### Scheduled housekeeping
|
|
|
|
While GitLab automatically performs housekeeping tasks based on the number of
|
|
pushes, it does not maintain repositories that don't receive any pushes at all.
|
|
As a result, inactive repositories or repositories that are only getting read
|
|
requests may not benefit from improvements in the repository housekeeping
|
|
strategy.
|
|
|
|
Administrators can enable a background job that performs housekeeping in all
|
|
repositories at a customizable interval to remedy this situation. This
|
|
background job processes all repositories hosted by a Gitaly node in a random
|
|
order and eagerly performs housekeeping tasks on them. The Gitaly node will stop
|
|
processing repositories if it takes longer than the configured interval.
|
|
|
|
#### Configure scheduled housekeeping
|
|
|
|
Background maintenance of Git repositories is configured in Gitaly. By default,
|
|
Gitaly performs background repository maintenance every day at 12:00 noon for a
|
|
duration of 10 minutes.
|
|
|
|
You can change this default in Gitaly configuration. The following snippet
|
|
enables daily background repository maintenance starting at 23:00 for 1 hour
|
|
for the `default` storage:
|
|
|
|
```toml
|
|
[daily_maintenance]
|
|
start_hour = 23
|
|
start_minute = 00
|
|
duration = 1h
|
|
storages = ["default"]
|
|
```
|
|
|
|
Use the following snippet to completely disable background repository
|
|
maintenance:
|
|
|
|
```toml
|
|
[daily_maintenance]
|
|
disabled = true
|
|
```
|
|
|
|
## Object pool repositories
|
|
|
|
Object pool repositories are used by GitLab to deduplicate objects across forks
|
|
of a repository. When creating the first fork, we:
|
|
|
|
1. Create an object pool repository that contains all objects of the repository
|
|
that is about to be forked.
|
|
1. Link the repository to this new object pool via Git's alternates mechanism.
|
|
1. Repack the repository so that it uses objects from the object pool. It thus
|
|
can drop its own copy of the objects.
|
|
|
|
Any forks of this repository can now link against the object pool and thus only
|
|
have to keep objects that diverge from the primary repository.
|
|
|
|
GitLab needs to perform special housekeeping operations in object pools:
|
|
|
|
- Gitaly cannot ever delete unreachable objects from object pools because they
|
|
might be used by any of the forks that are connected to it.
|
|
- Gitaly must keep all objects reachable due to the same reason. Object pools
|
|
thus maintain references to unreachable "dangling" objects so that they don't
|
|
ever get deleted.
|
|
- GitLab must update object pools regularly to pull in new objects that have
|
|
been added in the primary repository. Otherwise, an object pool will become
|
|
increasingly inefficient at deduplicating objects.
|
|
|
|
These housekeeping operations are performed by the specialized
|
|
`FetchIntoObjectPool` RPC that handles all of these special tasks while also
|
|
executing the regular housekeeping tasks we execute for normal Git
|
|
repositories.
|
|
|
|
Object pools are getting optimized automatically whenever the primary member is
|
|
getting garbage collected. Therefore, the cadence can be configured using the
|
|
same Git GC period in that project.
|
|
|
|
If you need to manually invoke the RPC from a [Rails console](operations/rails_console.md),
|
|
you can call `project.pool_repository.object_pool.fetch`. This is a potentially
|
|
long-running task, though Gitaly times out after about 8 hours.
|