Adds in a barrier for the duration of the `Tenant::shutdown`.
`pageserver_shutdown` will join this await, `detach`es and `ignore`s
will not.
Fixes#4429.
---------
Co-authored-by: Christian Schwarz <christian@neon.tech>
## Problem
`cargo +nightly doc` is giving a lot of warnings: broken links, naked
URLs, etc.
## Summary of changes
* update the `proc-macro2` dependency so that it can compile on latest
Rust nightly, see https://github.com/dtolnay/proc-macro2/pull/391 and
https://github.com/dtolnay/proc-macro2/issues/398
* allow the `private_intra_doc_links` lint, as linking to something
that's private is always more useful than just mentioning it without a
link: if the link breaks in the future, at least there is a warning due
to that. Also, one might enable
[`--document-private-items`](https://doc.rust-lang.org/cargo/commands/cargo-doc.html#documentation-options)
in the future and make these links work in general.
* fix all the remaining warnings given by `cargo +nightly doc`
* make it possible to run `cargo doc` on stable Rust by updating
`opentelemetry` and associated crates to version 0.19, pulling in a fix
that previously broke `cargo doc` on stable:
https://github.com/open-telemetry/opentelemetry-rust/pull/904
* Add `cargo doc` to CI to ensure that it won't get broken in the
future.
Fixes#2557
## Future work
* Potentially, it might make sense, for development purposes, to publish
the generated rustdocs somewhere, like for example [how the rust
compiler does
it](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_driver/index.html).
I will file an issue for discussion.
Tests cannot be ran without configuring tracing. Split from #4678.
Does not nag about the span checks when there is no subscriber
configured, because then the spans will have no links and nothing can be
checked. Sadly the `SpanTrace::status()` cannot be used for this.
`tracing` is always configured in regress testing (running with
`pageserver` binary), which should be enough.
Additionally cleans up the test code in span checks to be in the test
code. Fixes a `#[should_panic]` test which was flaky before these
changes, but the `#[should_panic]` hid the flakyness.
Rationale for need: Unit tests might not be testing only the public or
`feature="testing"` APIs which are only testable within `regress` tests
so not all spans might be configured.
- Remove repeated tenant & timeline from span
- Demote logging of the path to debug level
- Log completion at info level, in the same function where we log errors
- distinguish between layer file download success & on-demand download
succeeding as a whole in the log message wording
- Assert that the span contains a tenant id and a timeline id
fixes https://github.com/neondatabase/neon/issues/3945
Before:
```
INFO compaction_loop{tenant_id=$TENANT_ID}:compact_timeline{timeline=$TIMELINE_ID}:download_remote_layer{tenant_id=$TENANT_ID timeline_id=$TIMELINE_ID layer=000000000000000000000000000000000000-FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF__00000000020C8A71-00000000020CAF91}: download complete: /storage/pageserver/data/tenants/$TENANT_ID/timelines/$TIMELINE_ID/000000000000000000000000000000000000-FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF__00000000020C8A71-00000000020CAF91
INFO compaction_loop{tenant_id=$TENANT_ID}:compact_timeline{timeline=$TIMELINE_ID}:download_remote_layer{tenant_id=$TENANT_ID timeline_id=$TIMELINE_ID layer=000000000000000000000000000000000000-FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF__00000000020C8A71-00000000020CAF91}: Rebuilt layer map. Did 9 insertions to process a batch of 1 updates.
```
After:
```
INFO compaction_loop{tenant_id=$TENANT_ID}:compact_timeline{timeline=$TIMELINE_ID}:download_remote_layer{layer=000000000000000000000000000000000000-FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF__00000000020C8A71-00000000020CAF91}: layer file download finished
INFO compaction_loop{tenant_id=$TENANT_ID}:compact_timeline{timeline=$TIMELINE_ID}:download_remote_layer{layer=000000000000000000000000000000000000-FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF__00000000020C8A71-00000000020CAF91}: Rebuilt layer map. Did 9 insertions to process a batch of 1 updates.
INFO compaction_loop{tenant_id=$TENANT_ID}:compact_timeline{timeline=$TIMELINE_ID}:download_remote_layer{layer=000000000000000000000000000000000000-FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF__00000000020C8A71-00000000020CAF91}: on-demand download successful
```
