Persist timeline offloaded state to S3.
Right now, as of #8907, at each restart of the pageserver, all offloaded
state is lost, so we load the full timeline again. As it starts with an
empty local directory, we might potentially download some files again,
leading to downloads that are ultimately wasteful.
This patch adds support for persisting the offloaded state, allowing us
to never load offloaded timelines in the first place. The persistence
feature is facilitated via a new file in S3 that is tenant-global, which
contains a list of all offloaded timelines. It is updated each time we
offload or unoffload a timeline, and otherwise never touched.
This choice means that tenants where no offloading is happening will not
immediately get a manifest, keeping the change very minimal at the
start.
We leave generation support for future work. It is important to support
generations, as in the worst case, the manifest might be overwritten by
an older generation after a timeline has been unoffloaded (and
unarchived), so the next pageserver process instantiation might wrongly
believe that some timeline is still offloaded even though it should be
active.
Part of #9386, #8088
Adds a configuration variable for timeline offloading support. The added
pageserver-global config option controls whether the pageserver
automatically offloads timelines during compaction.
Therefore, already offloaded timelines are not affected by this, nor is
the manual testing endpoint.
This allows the rollout of timeline offloading to be driven by the
storage team.
Part of #8088
The current code has forgotten to activate timelines during unoffload,
leading to inability to receive the basebackup, due to the timeline
still being in loading state.
```
stderr:
command failed: compute startup failed: failed to get basebackup@0/0 from pageserver postgresql://no_user@localhost:15014
Caused by:
0: db error: ERROR: Not found: Timeline 508546c79b2b16a84ab609fdf966e0d3/bfc18c24c4b837ecae5dbb5216c80fce is not active, state: Loading
1: ERROR: Not found: Timeline 508546c79b2b16a84ab609fdf966e0d3/bfc18c24c4b837ecae5dbb5216c80fce is not active, state: Loading
```
Therefore, also activate the timeline during unoffloading.
Part of #8088
Add a test for timeline offloading, and subsequent unoffloading.
Also adds a manual endpoint, and issues a proper timeline shutdown
during offloading which prevents a pageserver hang at shutdown.
Part of #8088.
Add wrappers for a few commands that didn't have them before. Move the
logic to generate tenant and timeline IDs from NeonCli to the callers,
so that NeonCli is more purely just a type-safe wrapper around
'neon_local'.
Implement the timeline specific `archival_config` endpoint also in the
storage controller.
It's mostly a copy-paste of the detach handler: the task is the same: do
the same operation on all shards.
Part of #8088.
If a timeline unarchival request comes in, give an error if the parent
timeline is archived. This prevents us from the situation of having an
archived timeline with children that are not archived.
Follow up of #8824
Part of #8088
---------
Co-authored-by: Joonas Koivunen <joonas@neon.tech>
This PR:
* Implements the rule that archived timelines require all of their
children to be archived as well, as specified in the RFC. There is no
fancy locking mechanism though, so the precondition can still be broken.
As a TODO for later, we still allow unarchiving timelines with archived
parents.
* Adds an `is_archived` flag to `TimelineInfo`
* Adds timeline_archival_config to `PageserverHttpClient`
* Adds a new `test_timeline_archive` test, loosely based on
`test_timeline_delete`
Part of #8088
