## Problem
The storage scrubber was reporting warnings for lots of timelines like:
```
WARN Missed some shards at count ShardCount(0) tenant_id=25eb7a83d9a2f90ac0b765b6ca84cf4c
```
These were spurious: these tenants are fine. There was a bug in
accumulating the ShardIndex for each tenant, whereby multiple timelines
would lead us to add the same ShardIndex more than one.
Closes: #8646
## Summary of changes
- Accumulate ShardIndex in a BTreeSet instead of a Vec
- Extend the test to reproduce the issue
Part of #8128.
## Problem
Currently, scrubber `scan_metadata` command will return with an error
code if the metadata on remote storage is corrupted with fatal errors.
To safely deploy this command in a cronjob, we want to differentiate
between failures while running scrubber command and the erroneous
metadata. At the same time, we also want our regression tests to catch
corrupted metadata using the scrubber command.
## Summary of changes
- Return with error code only when the scrubber command fails
- Uses explicit checks on errors and warnings to determine metadata
health in regression tests.
**Resolve conflict with `tenant-snapshot` command (after shard split):**
[`test_scrubber_tenant_snapshot`](https://github.com/neondatabase/neon/blob/yuchen/scrubber-scan-cleanup-before-prod/test_runner/regress/test_storage_scrubber.py#L23)
failed before applying 422a8443dd
- When taking a snapshot, the old `index_part.json` in the unsharded
tenant directory is not kept.
- The current `list_timeline_blobs` implementation consider no
`index_part.json` as a parse error.
- During the scan, we are only analyzing shards with highest shard
count, so we will not get a parse error. but we do need to add the
layers to tenant object listing, otherwise we will get index is
referencing a layer that is not in remote storage error.
- **Action:** Add s3_layers from `list_timeline_blobs` regardless of
parsing error
Signed-off-by: Yuchen Liang <yuchen@neon.tech>
## Problem
Previously, when we do a timeline deletion, shards will delete layers
that belong to an ancestor. That is not a correctness issue, because
when we delete a timeline, we're always deleting it from all shards, and
destroying data for that timeline is clearly fine.
However, there exists a race where one shard might start doing this
deletion while another shard has not yet received the deletion request,
and might try to access an ancestral layer. This creates ambiguity over
the "all layers referenced by my index should always exist" invariant,
which is important to detecting and reporting corruption.
Now that we have a GC mode for clearing up ancestral layers, we can rely
on that to clean up such layers, and avoid deleting them right away.
This makes things easier to reason about: there are now no cases where a
shard will delete a layer that belongs to a ShardIndex other than
itself.
## Summary of changes
- Modify behavior of RemoteTimelineClient::delete_all
- Add `test_scrubber_physical_gc_timeline_deletion` to exercise this
case
- Tweak AWS SDK config in the scrubber to enable retries. Motivated by
seeing the test for this feature encounter some transient "service
error" S3 errors (which are probably nothing to do with the changes in
this PR)
Part of #8128, followup to #8480. closes#8421.
Enable scrubber to optionally post metadata scan health results to
storage controller.
Signed-off-by: Yuchen Liang <yuchen@neon.tech>
## Problem
This test relies on writing image layers before the split. It can fail
to do so durably if the image layers are written ahead of the remote
consistent LSN, so we should have been doing a checkpoint rather than
just a compaction
## Problem
This test sometimes found that ancestors were getting cleaned up before
it had done any compaction.
Compaction was happening implicitly via Workload.
Example:
https://neon-github-public-dev.s3.amazonaws.com/reports/pr-8298/10032173390/index.html#testresult/fb04786402f80822/retries
## Summary of changes
- Set upload=False when writing data after shard split, to avoid doing a
checkpoint
- Add a checkpoint_period & explicit wait for uploads so that we ensure
data lands in S3 without doing a checkpoint
Part of #8128.
## Problem
Scrubber uses `scan_metadata` command to flag metadata inconsistencies.
To trust it at scale, we need to make sure the errors we emit is a
reflection of real scenario. One check performed in the scrubber is to
see whether layers listed in the latest `index_part.json` is present in
object listing. Currently, the scrubber does not robustly handle the
case where objects are uploaded/deleted during the scan.
## Summary of changes
**Condition for success:** An object in the index is (1) in the object
listing we acquire from S3 or (2) found in a HeadObject request (new
object).
- Add in the `HeadObject` requests for the layers missing from the
object listing.
- Keep the order of first getting the object listing and then
downloading the layers.
- Update check to only consider shards with highest shard count.
- Skip analyzing a timeline if `deleted_at` tombstone is marked in
`index_part.json`.
- Add new test to see if scrubber actually detect the metadata
inconsistency.
_Misc_
- A timeline with no ancestor should always have some layers.
- Removed experimental histograms
_Caveat_
- Ancestor layer is not cleaned until #8308 is implemented. If ancestor
layers reference non-existing layers in the index, the scrubber will
emit false positives.
Signed-off-by: Yuchen Liang <yuchen@neon.tech>
## Problem
After a shard split, the pageserver leaves the ancestor shard's content
in place. It may be referenced by child shards, but eventually child
shards will de-reference most ancestor layers as they write their own
data and do GC. We would like to eventually clean up those ancestor
layers to reclaim space.
## Summary of changes
- Extend the physical GC command with `--mode=full`, which includes
cleaning up unreferenced ancestor shard layers
- Add test `test_scrubber_physical_gc_ancestors`
- Remove colored log output: in testing this is irritating ANSI code
spam in logs, and in interactive use doesn't add much.
- Refactor storage controller API client code out of storcon_client into
a `storage_controller/client` crate
- During physical GC of ancestors, call into the storage controller to
check that the latest shards seen in S3 reflect the latest state of the
tenant, and there is no shard split in progress.
The S3 scrubber contains "S3" in its name, but we want to make it
generic in terms of which storage is used (#7547). Therefore, rename it
to "storage scrubber", following the naming scheme of already existing
components "storage broker" and "storage controller".
Part of #7547
