Fix Gitaly auto-detection caching

Closes #64802

See merge request gitlab-org/gitlab-ce!30954

(cherry picked from commit eb3f465e)

ec5ceae6 Fix Gitaly auto-detection caching

Whenever we use the rugged implementation, we are going straight to disk
so we want to bypass the disk access check.

Suggests to use a JSON structured log instead

Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/54102

Add a module we use as a singleton to determine whether or not rails is
able to access the disk

The metric was used to correlate Gitaly requests to the Rails controller
and action combination. However, Kibana provides better observability in
this specific metric, and can handle hig cardinality much better.

There's no dashboard in Grafana that currently depends on this metric
being exposed.

The feature flag has been introduced an was turned off by default,
now the it will default to be turned on. That change would still allow
users to turn this feature off by leveraging the Rails console by
running:

`Feature.disable("gitaly_catfile-cache")`

Another option is to manage the number of items the LRU cache will
contain, by updating the `config.toml` for Gitaly. This would be the
`catfile_cache_size`:
https://gitlab.com/gitlab-org/gitaly/blob/0dcb5c579e63754f557aef91a4fa7a00e5b8b127/config.toml.example#L27

Closes: https://gitlab.com/gitlab-org/gitaly/issues/1712

The GitalyClient held a lot of logic which was all very tightly coupled.
In this instance the feature logic was extracted to make it do just a
little less and create a bit more focus in the GitalyClient's
responsibilies.

Zeger-Jan van de Weg authored 5 years ago and Bob Van Landuyt :neckbeard: committed 5 years ago

Delta islands were implemented last released in:
https://gitlab.com/gitlab-org/gitaly/merge_requests/1110. It's been
enabled on production and works as expected.

This change is a fairly straightforward refactor to extract the tracing
and correlation-id code from the gitlab rails codebase into the new
LabKit-Ruby project.

The corresponding import into LabKit-Ruby was in
https://gitlab.com/gitlab-org/labkit-ruby/merge_requests/1

The code itself remains very similar for now.

Extracting it allows us to reuse it in other projects, such as
Gitaly-Ruby. This will give us the advantages of correlation-ids and
distributed tracing in that project too.

This adds the backtrace to a table to show exactly where the Gitaly call
was made to make it easier to understand where the call originated.

This change also collapses the details in the same row to improve the
usability when there is a backtrace.

This avoids the case:

```
allow_ref_name_caching do
  allow_ref_name_caching do
    # using-feature
  end
end
```

For a given merge request, it's quite common to see duplicate FindCommit
Gitaly requests because the Gitaly CommitService caches the request by
the commit SHA, not by the ref name. However, most of the duplicate
requests use the ref name, so the cache is never actually used in
practice. This leads to unnecessary requests that slow performance.

This commit allows certain callers to bypass the ref name to
OID conversion in the cache. We don't do this by default because it's
possible the tip of the branch changes during the commit, which
would cause the caller to get stale data.

This commit also forces the Ci::Pipeline to use the full ref name
so that caching can work for merge requests.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/57083

This makes it easier to debug Gitaly performance issues in the field.

This commit also makes the tracking of query time thread-safe via
RequestStore.

We typically don't want to enforce request limits in production
However, we have some production-like test environments, i.e., ones
where `Rails.env.production?` returns `true`. We do want to be able
to check if the limit is being exceeded while testing in those
environments.

This style change enforces `return if ...` instead of
`return nil if ...` to save maintainers a few minor review points

This reverts commit 00675311.

Zeger-Jan van de Weg authored 6 years ago and James Lopez committed 6 years ago

Prior to this change, 35 Gitaly RPCs were allowed. But recently there's
been a renewed interest in performance. By lowering the number of
calls new N + 1's will pop up.

Later commits will add blocks to ignore the raised errors, followed by
an issue for each to be fixed.

Backport of https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/7434

This change allows the GitLab rails and sidekiq components to receive
tracing spans from upstream services such as Workhorse and pass these
spans on to downstream services including Gitaly and Sidekiq.

This change will also emit traces for incoming and outgoing requests
using the propagated trace information. This will allow operators and
engineers to view traces across the Workhorse, GitLab Rails, Sidekiq and
Gitaly components.

Additional intra-service instrumentation will be added in future
changes.

This reverts commit 3560b119.

This changes `correlation_id` to be `correlation-id` when passed via jobs

The Correlation ID is taken or generated from received X-Request-ID.
Then it is being passed to all executed services (sidekiq workers
or gitaly calls).

The Correlation ID is logged in all structured logs as `correlation_id`.

On HEAD~ we remove the ID from the class, which created a bug. Given we
don't need the ID anymore, it has been removed and simplified.

This reverts merge request !23229

This reverts merge request !23140