Introduce a separate `postgres_ffi_types` crate which contains a few
types and functions that were used in the API. `postgres_ffi_types` is a
much small crate than `postgres_ffi`, and it doesn't depend on bindgen
or the Postgres C headers.
Move NeonWalRecord and Value types to wal_decoder crate. They are only
used in the pageserver-safekeeper "ingest" API. The rest of the ingest
API types are defined in wal_decoder, so move these there as well.
## Problem
The cache was introduced as a hackathon project and the only supported
limit was the number of entries.
The basebackup entry size may vary. We need to have more control over
disk space usage to ship it to production.
- Part of https://github.com/neondatabase/cloud/issues/29353
## Summary of changes
- Store the size of entries in the cache and use it to limit
`max_total_size_bytes`
- Add the size of the cache in bytes to metrics.
## Problem
Pageservers now expose a gRPC API on a separate address and port. This
must be registered with the storage controller such that it can be
plumbed through to the compute via cplane.
Touches #11926.
## Summary of changes
This patch registers the gRPC address and port with the storage
controller:
* Add gRPC address to `nodes` database table and `NodePersistence`, with
a Diesel migration.
* Add gRPC address in `NodeMetadata`, `NodeRegisterRequest`,
`NodeDescribeResponse`, and `TenantLocateResponseShard`.
* Add gRPC address flags to `storcon_cli node-register`.
These changes are backwards-compatible, since all structs will ignore
unknown fields during deserialization.
## Problem
The location config (which includes the stripe size) is stored on
pageserver disk.
For unsharded tenants we [do not include the shard identity in the
serialized
description](ad88ec9257/pageserver/src/tenant/config.rs (L64-L66)).
When the pageserver restarts, it reads that configuration and will use
the stripe size from there
and rely on storcon input from reattach for generation and mode.
The default deserialization is ShardIdentity::unsharded. This has the
new default stripe size of 2048.
Hence, for unsharded tenants we can be running with a stripe size
different from that the one in the
storcon observed state. This is not a problem until we shard split
without specifying a stripe size (i.e. manual splits via the UI or
storcon_cli). When that happens the new shards will use the 2048 stripe
size until storcon realises and switches them back. At that point it's
too late, since we've ingested data with the wrong stripe sizes.
## Summary of changes
Ideally, we would always have the full shard identity on disk. To
achieve this over two releases we do:
1. Always persist the shard identity in the location config on the PS.
2. Storage controller includes the stripe size to use in the re attach
response.
After the first release, we will start persisting correct stripe sizes
for any tenant shard that the storage controller
explicitly sends a location_conf. After the second release, the
re-attach change kicks in and we'll persist the
shard identity for all shards.
## Problem
Removed nodes can re-add themselves on restart if not properly
tombstoned. We need a mechanism (e.g. soft-delete flag) to prevent this,
especially in cases where the node is unreachable.
More details there: #12036
## Summary of changes
- Introduced `NodeLifecycle` enum to represent node lifecycle states.
- Added a string representation of `NodeLifecycle` to the `nodes` table.
- Implemented node removal using a tombstone mechanism.
- Introduced `/debug/v1/tombstone*` handlers to manage the tombstone
state.
## Problem
We support two ingest protocols on the pageserver: vanilla and
interpreted.
Interpreted has been the only protocol in use for a long time.
## Summary of changes
* Remove the ingest handling of the vanilla protocol
* Remove tenant and pageserver configuration for it
* Update all tests that tweaked the ingest protocol
## Compatibility
Backward compatibility:
* The new pageserver version can read the existing pageserver
configuration and it will ignore the unknown field.
* When the tenant config is read from the storcon db or from the
pageserver disk, the extra field will be ignored.
Forward compatiblity:
* Both the pageserver config and the tenant config map missing fields to
their default value.
I'm not aware of any tenant level override that was made for this knob.
## Problem
We want to repro an OOM situation, but large partial reads are required.
## Summary of Changes
Make the max partial read size configurable for import jobs.
## Problem
This is already the default in production and in our test suite.
## Summary of changes
Set the default proto to interpreted to reduce friction when spinning up
new regions or cells.
## Problem
Setting `max_batch_size` to anything higher than
`Timeline::MAX_GET_VECTORED_KEYS` will cause runtime error. We should
rather fail fast at startup if this is the case.
## Summary of changes
* Create `max_get_vectored_keys` as a new configuration (default to 32);
* Validate `max_batch_size` against `max_get_vectored_keys` right at
config parsing and validation.
Closes https://github.com/neondatabase/neon/issues/11994
## Problem
We should expose the page service over gRPC.
Requires #12093.
Touches #11728.
## Summary of changes
This patch adds an initial page service implementation over gRPC. It
ties in with the existing `PageServerHandler` request logic, to avoid
the implementations drifting apart for the core read path.
This is just a bare-bones functional implementation. Several important
aspects have been omitted, and will be addressed in follow-up PRs:
* Limited observability: minimal tracing, no logging, limited metrics
and timing, etc.
* Rate limiting will currently block.
* No performance optimization.
* No cancellation handling.
* No tests.
I've only done rudimentary testing of this, but Pagebench passes at
least.
## Problem
We need gRPC support in Pagebench to benchmark the new gRPC Pageserver
implementation.
Touches #11728.
## Summary of changes
Adds a `Client` trait to make the client transport swappable, and a gRPC
client via a `--protocol grpc` parameter. This must also specify the
connstring with the gRPC port:
```
pagebench get-page-latest-lsn --protocol grpc --page-service-connstring grpc://localhost:51051
```
The client is implemented using the raw Tonic-generated gRPC client, to
minimize client overhead.
## Problem
Import planning takes a job size limit as its input. Previously, the job
size came from a pageserver config field. This field may change while
imports are in progress. If this happens, plans will no longer be
identical and the import would fail permanently.
## Summary of Changes
Bake the job size into the import progress reported to the storage
controller. For new imports, use the value from the pagesever config,
and, for existing imports, use the value present in the shard progress.
This value is identical for all shards, but we want it to be versioned
since future versions of the planner might split the jobs up
differently. Hence, it ends up in `ShardImportProgress`.
Closes https://github.com/neondatabase/neon/issues/11983
Support timeline creations on the storage controller to opt out from
their creation on the safekeepers, introducing the read-only timelines
concept. Read only timelines:
* will never receive WAL of their own, so it's fine to not create them
on the safekeepers
* the property is non-transitive. children of read-only timelines aren't
neccessarily read-only themselves.
This feature can be used for snapshots, to prevent the safekeepers from
being overloaded by empty timelines that won't ever get written to. In
the current world, this is not a problem, because timelines are created
implicitly by the compute connecting to a safekeeper that doesn't have
the timeline yet. In the future however, where the storage controller
creates timelines eagerly, we should watch out for that.
We represent read-only timelines in the storage controller database so
that we ensure that they never touch the safekeepers at all. Especially
we don't want them to cause a mess during the importing process of the
timelines from the cplane to the storcon database.
In a hypothetical future where we have a feature to detach timelines
from safekeepers, we'll either need to find a way to distinguish the
two, or if not, asking safekeepers to list the (empty) timeline prefix
and delete everything from it isn't a big issue either.
This patch will unconditionally hit the new safekeeper timeline creation
path for read-only timelines, without them needing the
`--timelines-onto-safekeepers` flag enabled. This is done because it's
lower risk (no safekeepers or computes involved at all) and gives us
some initial way to verify at least some parts of that code in prod.
https://github.com/neondatabase/cloud/issues/29435https://github.com/neondatabase/neon/issues/11670
## Problem
part of https://github.com/neondatabase/neon/issues/11813
## Summary of changes
* Integrate feature store with tenant structure.
* gc-compaction picks up the current strategy from the feature store.
* We only log them for now for testing purpose. They will not be used
until we have more patches to support different strategies defined in
PostHog.
* We don't support property-based evaulation for now; it will be
implemented later.
* Evaluating result of the feature flag is not cached -- it's not
efficient and cannot be used on hot path right now.
* We don't report the evaluation result back to PostHog right now.
I plan to enable it in staging once we get the patch merged.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
We want to expose the page service over gRPC, for use with the
communicator.
Requires #11995.
Touches #11728.
## Summary of changes
This patch wires up a gRPC server in the Pageserver, using Tonic. It
does not yet implement the actual page service.
* Adds `listen_grpc_addr` and `grpc_auth_type` config options (disabled
by default).
* Enables gRPC by default with `neon_local`.
* Stub implementation of `page_api.PageService`, returning unimplemented
errors.
* gRPC reflection service for use with e.g. `grpcurl`.
Subsequent PRs will implement the actual page service, including
authentication and observability.
Notably, TLS support is not yet implemented. Certificate reloading
requires us to reimplement the entire Tonic gRPC server.
## Problem
Basebackup cache is on the hot path of compute startup and is generated
on every request (may be slow).
- Issue: https://github.com/neondatabase/cloud/issues/29353
## Summary of changes
- Add `BasebackupCache` which stores basebackups on local disk.
- Basebackup prepare requests are triggered by
`XLOG_CHECKPOINT_SHUTDOWN` records in the log.
- Limit the size of the cache by number of entries.
- Add `basebackup_cache_enabled` feature flag to TenantConfig.
- Write tests for the cache
## Not implemented yet
- Limit the size of the cache by total size in bytes
---------
Co-authored-by: Aleksandr Sarantsev <aleksandr@neon.tech>
## Problem
See
Discussion:
https://neondb.slack.com/archives/C033RQ5SPDH/p1746645666075799
Issue: https://github.com/neondatabase/cloud/issues/28609
Relation size cache is not correctly updated at PS in case of replicas.
## Summary of changes
1. Have two caches for relation size in timeline:
`rel_size_primary_cache` and `rel_size_replica_cache`.
2. `rel_size_primary_cache` is actually what we have now. The only
difference is that it is not updated in `get_rel_size`, only by WAL
ingestion
3. `rel_size_replica_cache` has limited size (LruCache) and it's key is
`(Lsn,RelTag)` . It is updated in `get_rel_size`. Only strict LSN
matches are accepted as cache hit.
---------
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
## Problem
The gRPC page service API will require decoupling the `PageHandler` from
the libpq protocol implementation. As preparation for this, avoid
passing in the entire server config to `PageHandler`, and instead
explicitly pass in the relevant fields.
Touches https://github.com/neondatabase/neon/issues/11728.
## Summary of changes
* Change `PageHandler` to take a `GetVectoredConcurrentIo` instead of
the entire config.
* Change `IoConcurrency::spawn_from_conf` to take a
`GetVectoredConcurrentIo`.
This PR commits the benchmarks I ran to qualify concurrent IO before we
released it.
Changes:
- Add `l0stack` fixture; a reusable abstraction for creating a stack of
L0 deltas
each of which has 1 Value::Delta per page.
- Such a stack of L0 deltas is a good and understandable demo for
concurrent IO
because to reconstruct any page, $layer_stack_height` Values need to be
read.
Before concurrent IO, the reads were sequential.
With concurrent IO, they are executed concurrently.
- So, switch `test_latency` to use the l0stack.
- Teach `pagebench`, which is used by `test_latency`, to limit itself to
the blocks of the relation created by the l0stack abstraction.
- Additional parametrization of `test_latency` over dimensions
`ps_io_concurrency,l0_stack_height,queue_depth`
- Use better names for the tests to reflect what they do, leave
interpretation of the (now quite high-dimensional) results to the reader
- `test_{throughput => postgres_seqscan}`
- `test_{latency => random_reads}`
- Cut down on permutations to those we use in production. Runtime is
about 2min.
Refs
- concurrent IO epic https://github.com/neondatabase/neon/issues/9378
- batching task: fixes https://github.com/neondatabase/neon/issues/9837
---------
Co-authored-by: Peter Bendel <peterbendel@neon.tech>
## Problem
Imports don't support schema evolution nicely. If we want to change the
stuff we keep in storcon,
we'd have to carry the old cruft around.
## Summary of changes
Version import progress. Note that the import progress version
determines the version of the import
job split and execution. This means that we can also use it as a
mechanism for deploying new import
implementations in the future.
## Problem
Timeline imports do not have progress checkpointing. Any time that the
tenant is shut-down, all progress is lost
and the import restarts from the beginning when the tenant is
re-attached.
## Summary of changes
This PR adds progress checkpointing.
### Preliminaries
The **unit of work** is a `ChunkProcessingJob`. Each
`ChunkProcessingJob` deals with the import for a set of key ranges. The
job split is done by using an estimation of how many pages each job will
produce.
The planning stage must be **pure**: given a fixed set of contents in
the import bucket, it will always yield the same plan. This property is
enforced by checking that the hash of the plan is identical when
resuming from a checkpoint.
The storage controller tracks the progress of each shard in the import
in the database in the form of the **latest
job** that has has completed.
### Flow
This is the high level flow for the happy path:
1. On the first run of the import task, the import task queries storcon
for the progress and sees that none is recorded.
2. Execute the preparatory stage of the import
3. Import jobs start running concurrently in a `FuturesOrdered`. Every
time the checkpointing threshold of jobs has been reached, notify the
storage controller.
4. Tenant is detached and re-attached
5. Import task starts up again and gets the latest progress checkpoint
from the storage controller in the form of a job index.
6. The plan is computed again and we check that the hash matches with
the original plan.
7. Jobs are spawned from where the previous import task left off. Note
that we will not report progress after the completion of each job, so
some jobs might run twice.
Closes https://github.com/neondatabase/neon/issues/11568
Closes https://github.com/neondatabase/neon/issues/11664
## Problem
Import up-calls did not enforce the usage of the latest generation. The
import might have finished in one previous generation, but not in the
latest one. Hence, the controller might try to activate a timeline
before it is ready. In theory, that would be fine, but it's tricky to
reason about.
## Summary of Changes
Pageserver provides the current generation in the upcall to the storage
controller and the later validates the generation. If the generation is
stale, we return an error which stops progress of the import job. Note
that the import job will retry the upcall until the stale location is
detached.
I'll add some proper tests for this as part of the [checkpointing
PR](https://github.com/neondatabase/neon/pull/11862).
Closes https://github.com/neondatabase/neon/issues/11884
Use the current production config for batching & concurrent IO.
Remove the permutation testing for unit tests from CI.
(The pageserver unit test matrix takes ~10min for debug builds).
Drive-by-fix use of `if cfg!(test)` inside crate `pageserver_api`.
It is ineffective for early-enabling new defaults for pageserver unit
tests only.
The reason is that the `test` cfg is only set for the crate under test
but not its dependencies.
So, `cargo test -p pageserver` will build `pageserver_api` with
`cfg!(test) == false`.
Resort to checking for feature flag `testing` instead, since all our
unit tests are run with `--feature testing`.
refs
- `scattered-lsn` batching has been implemented and rolled out in all
envs, cf https://github.com/neondatabase/neon/issues/10765
- preliminary for https://github.com/neondatabase/neon/pull/10466
- epic https://github.com/neondatabase/neon/issues/9377
- epic https://github.com/neondatabase/neon/issues/9378
- drive-by fix
https://neondb.slack.com/archives/C0277TKAJCA/p1746821515504219
## Problem
Hopefully resolves `test_gc_feedback` flakiness.
## Summary of changes
`accumulated_values` should not exceed 512MB to avoid OOM. Previously we
only use number of items, which is not a good estimation.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
This PR adds a runtime validation mode to check adherence to alignment
and size-multiple requirements at the VirtualFile level.
This can help prevent alignment bugs from slipping into production
because test systems may have more lax requirements than production.
(This is not the case today, but it could change in the future).
It also allows catching O_DIRECT bugs on systems that don't have
O_DIRECT (macOS).
Consequently, we can now accept
`virtual_file_io_mode={direct,direct-rw}` on macOS now.
This has the side benefit of removing some annoying conditional
compilation around `IoMode`.
A third benefit is that it helped weed out size-multiple requirement
violation bugs in how the VirtualFile unit tests exercise read and write
APIs.
I seized the opportunity to trim these tests down to what actually
matters, i.e., exercising of the `OpenFiles` file descriptor cache.
Lastly, this PR flips the binary-built-in default to `DirectRw` so that
when running Python regress tests and benchmarks without specifying
`PAGESERVER_VIRTUAL_FILE_IO_MODE`, one gets the production behavior.
Refs
- fixes https://github.com/neondatabase/neon/issues/11676
## Problem
Import code is one big block. Separating planning and execution will
help with reporting
progress of import to storcon (building block for resuming import).
## Summary of changes
Split up the import into planning and execution.
A concurrency limit driven by PS config is also added.
## Problem
Shard splits break timeline imports.
## Summary of Changes
Ensure mutual exclusion for imports and shard splits.
On the shard split code path:
1. Right before shard splitting, check the database to ensure that
no-import is on-going for the tenant. Exclusion is guaranteed because
this validation is done while holding the exclusive tenant lock.
Timeline creation (and import creation implicitly) requires a shared
tenant lock.
2. When selecting a shard to split, use the in-mem state to exclude
shards with an on-going import. This is opportunistic since an import
might start after the check, but allows shard splits to make progres
instead of continously retrying to split the same shard.
On the timeline creation code path:
1. Check the in-memory splitting flag on all shards of the tenant. If
any of them are splitting, error out asking the client to retry. On the
happy path this is not required, due to the tenant lock set-up described
above, but it covers the case where we restart with a pending
shard-split.
Closes https://github.com/neondatabase/neon/issues/11567
# Problem
The Pageserver read path exclusively uses direct IO if
`virtual_file_io_mode=direct`.
The write path is half-finished. Here is what the various writing
components use:
|what|buffering|flags on <br/>`v_f_io_mode`<br/>=`buffered`|flags on
<br/>`virtual_file_io_mode`<br/>=`direct`|
|-|-|-|-|
|`DeltaLayerWriter`| BlobWriter<BUFFERED=true> | () | () |
|`ImageLayerWriter`| BlobWriter<BUFFERED=false> | () | () |
|`download_layer_file`|BufferedWriter|()|()|
|`InMemoryLayer`|BufferedWriter|()|O_DIRECT|
The vehicle towards direct IO support is `BufferedWriter` which
- largely takes care of O_DIRECT alignment & size-multiple requirements
- double-buffering to mask latency
`DeltaLayerWriter`, `ImageLayerWriter` use `blob_io::BlobWriter` , which
has neither of these.
# Changes
## High-Level
At a high-level this PR makes the following primary changes:
- switch the two layer writer types to use `BufferedWriter` & make
sensitive to `virtual_file_io_mode` (via open_with_options_**v2**)
- make `download_layer_file` sensitive to `virtual_file_io_mode` (also
via open_with_options_**v2**)
- add `virtual_file_io_mode=direct-rw` as a feature gate
- we're hackish-ly piggybacking on OpenOptions's ask for write access
here
- this means with just `=direct` InMemoryLayer reads and writes no
longer uses O_DIRECT
- this is transitory and we'll remove the `direct-rw` variant once the
rollout is complete
(The `_v2` APIs for opening / creating VirtualFile are those that are
sensitive to `virtual_file_io_mode`)
The result is:
|what|uses <br/>`BufferedWriter`|flags on
<br/>`v_f_io_mode`<br/>=`buffered`|flags on
<br/>`v_f_io_mode`<br/>=`direct`|flags on
<br/>`v_f_io_mode`<br/>=`direct-rw`|
|-|-|-|-|-|
|`DeltaLayerWriter`| ~~Blob~~BufferedWriter | () | () | O_DIRECT |
|`ImageLayerWriter`| ~~Blob~~BufferedWriter | () | () | O_DIRECT |
|`download_layer_file`|BufferedWriter|()|()|O_DIRECT|
|`InMemoryLayer`|BufferedWriter|()|~~O_DIRECT~~()|O_DIRECT|
## Code-Level
The main change is:
- Switch `blob_io::BlobWriter` away from its own buffering method to use
`BufferedWriter`.
Additional prep for upholding `O_DIRECT` requirements:
- Layer writer `finish()` methods switched to use IoBufferMut for
guaranteed buffer address alignment. The size of the buffers is PAGE_SZ
and thereby implicitly assumed to fulfill O_DIRECT requirements.
For the hacky feature-gating via `=direct-rw`:
- Track `OpenOptions::write(true|false)` in a field; bunch of mechanical
churn.
- Consolidate the APIs in which we "open" or "create" VirtualFile for
better overview over which parts of the code use the `_v2` APIs.
Necessary refactorings & infra work:
- Add doc comments explaining how BufferedWriter ensures that writes are
compliant with O_DIRECT alignment & size constraints. This isn't new,
but should be spelled out.
- Add the concept of shutdown modes to `BufferedWriter::shutdown` to
make writer shutdown adhere to these constraints.
- The `PadThenTruncate` mode might not be necessary in practice because
I believe all layer files ever written are sized in multiples `PAGE_SZ`
and since `PAGE_SZ` is larger than the current alignment requirements
(512/4k depending on platform), it won't be necesary to pad.
- Some test (I believe `round_trip_test_compressed`?) required it though
- [ ] TODO: decide if we want to accept that complexity; if we do then
address TODO in the code to separate alignment requirement from buffer
capacity
- Add `set_len` (=`ftruncate`) VirtualFile operation to support the
above.
- Allow `BufferedWriter` to start at a non-zero offset (to make room for
the summary block).
Cleanups unlocked by this change:
- Remove non-positional APIs from VirtualFile (e.g. seek, write_full,
read_full)
Drive-by fixes:
- PR https://github.com/neondatabase/neon/pull/11585 aimed to run unit
tests for all `virtual_file_io_mode` combinations but didn't because of
a missing `_` in the env var.
# Performance
This section assesses this PR's impact on deployments with current
production setting (`=direct`) and anticipated impact of switching to
(`=direct-rw`).
For `DeltaLayerWriter`, `=direct` should remain unchanged to slightly
improved on throughput because the `BlobWriter`'s buffer had the same
size as the `BufferedWriter`'s buffer, but it didn't have the
double-buffering that `BufferedWriter` has.
The `=direct-rw` enables direct IO; throughput should not be suffering
because of double-buffering; benchmarks will show if this is true.
The `ImageLayerWriter` was previously not doing any buffering
(`BUFFERED=false`).
It went straight to issuing the IO operation to the underlying
VirtualFile and the buffering was done by the kernel.
The switch to `BufferedWriter` under `=direct` adds an additional memcpy
into the BufferedWriter's buffer.
We will win back that memcpy when enabling direct IO via `=direct-rw`.
A nice win from the switch to `BufferedWriter` is that ImageLayerWriter
performs >=16x fewer write operations to VirtualFile (the BlobWriter
performs one write per len field and one write per image value).
This should save low tens of microseconds of CPU overhead from doing all
these syscalls/io_uring operations, regardless of `=direct` or
`=direct-rw`.
Aside from problems with alignment, this write frequency without
double-buffering is prohibitive if we actually have to wait for the
disk, which is what will happen when we enable direct IO via
(`=direct-rw`).
Throughput should not be suffering because of BufferedWrite's
double-buffering; benchmarks will show if this is true.
`InMemoryLayer` at `=direct` will flip back to using buffered IO but
remain on BufferedWriter.
The buffered IO adds back one memcpy of CPU overhead.
Throughput should not suffer and will might improve on
not-memory-pressured Pageservers but let's remember that we're doing the
whole direct IO thing to eliminate global memory pressure as a source of
perf variability.
## bench_ingest
I reran `bench_ingest` on `im4gn.2xlarge` and `Hetzner AX102`.
Use `git diff` with `--word-diff` or similar to see the change.
General guidance on interpretation:
- immediate production impact of this PR without production config
change can be gauged by comparing the same `io_mode=Direct`
- end state of production switched over to `io_mode=DirectRw` can be
gauged by comparing old results' `io_mode=Direct` to new results'
`io_mode=DirectRw`
Given above guidance, on `im4gn.2xlarge`
- immediate impact is a significant improvement in all cases
- end state after switching has same significant improvements in all
cases
- ... except `ingest/io_mode=DirectRw volume_mib=128 key_size_bytes=8192
key_layout=Sequential write_delta=Yes` which only achieves `238 MiB/s`
instead of `253.43 MiB/s`
- this is a 6% degradation
- this workload is typical for image layer creation
# Refs
- epic https://github.com/neondatabase/neon/issues/9868
- stacked atop
- preliminary refactor https://github.com/neondatabase/neon/pull/11549
- bench_ingest overhaul https://github.com/neondatabase/neon/pull/11667
- derived from https://github.com/neondatabase/neon/pull/10063
Co-authored-by: Yuchen Liang <yuchen@neon.tech>
## Problem
Pageservers notify control plane directly when a shard import has
completed.
Control plane has to download the status of each shard from S3 and
figure out if everything is truly done,
before proceeding with branch activation.
Issues with this approach are:
* We can't control shard split behaviour on the storage controller side.
It's unsafe to split
during import.
* Control plane needs to know about shards and implement logic to check
all timelines are indeed ready.
## Summary of changes
In short, storage controller coordinates imports, and, only when
everything is done, notifies control plane.
Big rocks:
1. Store timeline imports in the storage controller database. Each
import stores the status of its shards in the database.
We hook into the timeline creation call as our entry point for this.
2. Pageservers get a new upcall endpoint to notify the storage
controller of shard import updates.
3. Storage controller handles these updates by updating persisted state.
If an update finalizes the import,
then poll pageservers until timeline activation, and, then, notify the
control plane that the import is complete.
Cplane side change with new endpoint is in
https://github.com/neondatabase/cloud/pull/26166
Closes https://github.com/neondatabase/neon/issues/11566
# Add --dev CLI flag to pageserver and safekeeper binaries
This PR adds the `--dev` CLI flag to both the pageserver and safekeeper
binaries without implementing any functionality yet. This is a precursor
to PR #11517, which will implement the full functionality to require
authentication by default unless the `--dev` flag is specified.
## Changes
- Add `dev_mode` config field to pageserver binary
- Add `--dev` CLI flag to safekeeper binary
This PR is needed for forward compatibility tests to work properly, when
we try to merge #11517
Link to Devin run:
https://app.devin.ai/sessions/ad8231b4e2be430398072b6fc4e85d46
Requested by: John Spray (john@neon.tech)
---------
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: John Spray <john@neon.tech>
## Problem
We saw OOMs due to L0 compaction happening simultaneously for all shards
of the same tenant right after the shard split.
## Summary of changes
Lower the threshold so that we compact fewer files.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
Splits of large tenants (several TB) can cause a huge amount of shard
ancestor compaction work, which can overload Pageservers.
Touches https://github.com/neondatabase/cloud/issues/22532.
## Summary of changes
Add a setting `compaction_shard_ancestor` (default `true`) to disable
shard ancestor compaction on a per-tenant basis.
## Problem
Get page batching stops when we encounter requests at different LSNs.
We are leaving batching factor on the table.
## Summary of changes
The goal is to support keys with different LSNs in a single batch and
still serve them with a single vectored get.
Important restriction: the same key at different LSNs is not supported
in one batch. Returning different key
versions is a much more intrusive change.
Firstly, the read path is changed to support "scattered" queries. This
is a conceptually simple step from
https://github.com/neondatabase/neon/pull/11463. Instead of initializing
the fringe for one keyspace,
we do it for multiple at different LSNs and let the logic already
present into the fringe handle selection.
Secondly, page service code is updated to support batching at different
LSNs. Eeach request parsed from the wire determines its effective
request LSN and keeps it in mem for the batcher toinspect. The batcher
allows keys at
different LSNs in one batch as long one key is not requested at
different LSNs.
I'd suggest doing the first pass commit by commit to get a feel for the
changes.
## Results
I used the batching test from [Christian's
PR](https://github.com/neondatabase/neon/pull/11391) which increases the
change of batch breaks. Looking at the logs I think the new code is at
the max batching factor for the workload (we
only break batches due to them being oversized or because the executor
is idle).
```
Main:
Reasons for stopping batching: {'LSN changed': 22843, 'of batch size': 33417}
test_throughput[release-pg16-50-pipelining_config0-30-100-128-batchable {'max_batch_size': 32, 'execution': 'concurrent-futures', 'mode': 'pipelined'}].perfmetric.batching_factor: 14.6662
My branch:
Reasons for stopping batching: {'of batch size': 37024}
test_throughput[release-pg16-50-pipelining_config0-30-100-128-batchable {'max_batch_size': 32, 'execution': 'concurrent-futures', 'mode': 'pipelined'}].perfmetric.batching_factor: 19.8333
```
Related: https://github.com/neondatabase/neon/issues/10765
## Problem
Part of #9114
There was a debug-mode verification mode that verifies at every
retain_lsn. However, the code was tangled within the actual history
generation itself and it's hard to reason about correctness. This patch
adds a separate post-verification of the gc-compaction result that redos
logs at every retain_lsn and every record above the GC horizon. This
ensures that all key history we produce with gc-compaction is readable,
and if there're read errors after gc-compaction, it can only be
read-path errors instead of gc-compaction bugs.
## Summary of changes
* Add gc_compaction_verification flag, default to true.
* Implement a post-verification process.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Introduces a `WalIngestError` struct together with a
`WalIngestErrorKind` enum, to be used for walingest related failures and
errors.
* the enum captures backtraces, so we don't regress in comparison to
`anyhow::Error`s (backtraces might be a bit shorter if we use one of the
`anyhow::Error` wrappers)
* it explicitly lists most/all of the potential cases that can occur.
I've originally been inspired to do this in #11496, but it's a
longer-term TODO.
## Problem
Page service doesn't use TLS for incoming requests.
- Closes: https://github.com/neondatabase/cloud/issues/27236
## Summary of changes
- Add option `enable_tls_page_service_api` to pageserver config
- Propagate `tls_server_config` to `page_service` if the option is
enabled
No integration tests for now because I didn't find out how to call page
service API from python and AFAIK computes don't support TLS yet
## Problem
The current stripe size of 256 MB is a bit large, and can cause load
imbalances across shards. A stripe size of 16 MB appears more reasonable
to avoid hotspots, although we don't see evidence of this in benchmarks.
Resolves https://github.com/neondatabase/cloud/issues/25634.
Touches https://github.com/neondatabase/cloud/issues/21870.
## Summary of changes
* Change the default stripe size to 16 MB.
* Remove `ShardParameters::DEFAULT_STRIPE_SIZE`, and only use
`pageserver_api::shard::DEFAULT_STRIPE_SIZE`.
* Update a bunch of tests that assumed a certain stripe size.
## Problem
`tenant_import`, used to import an existing tenant from remote storage
into a storage controller for support and debugging, assumed
`DEFAULT_STRIPE_SIZE` since this can't be recovered from remote storage.
In #11168, we are changing the stripe size, which will break
`tenant_import`.
Resolves#11175.
## Summary of changes
* Add `stripe_size` to the tenant manifest.
* Add `TenantScanRemoteStorageShard::stripe_size` and return from
`tenant_scan_remote` if present.
* Recover the stripe size during`tenant_import`, or fall back to 32768
(the original default stripe size).
* Add tenant manifest compatibility snapshot:
`2025-04-08-pgv17-tenant-manifest-v1.tar.zst`
There are no cross-version concerns here, since unknown fields are
ignored during deserialization where relevant.
## Problem
For future gc-compaction tests when we support
https://github.com/neondatabase/neon/issues/10395
## Summary of changes
Add a new type of neon test WAL record that is conditionally applied
(i.e., only when image == the specified value). We can use this to mock
the situation where we lose some records in the middle, firing an error,
and see how gc-compaction reacts to it.
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
If a tenant is cancelled (e.g. due to Pageserver shutdown) during
attach, it is set to `Broken`. This results both in error log spam and
500 responses for clients -- shutdown is supposed to return 503
responses which can be retried.
This becomes more likely to happen with #11328, where we perform tenant
manifest downloads/uploads during attach.
## Summary of changes
Set tenant state to `Stopping` when attach fails and the tenant is
cancelled, downgrading the log messages to INFO. This introduces two
variants of `Stopping` -- with and without a caller barrier -- where the
latter is used to signal attach cancellation.
# Refs
- refs https://github.com/neondatabase/neon/issues/8915
- discussion thread:
https://neondb.slack.com/archives/C033RQ5SPDH/p1742406381132599
- stacked atop https://github.com/neondatabase/neon/pull/11298
- corresponding internal docs update that illustrates how this PR
removes friction: https://github.com/neondatabase/docs/pull/404
# Problem
Rejecting `pageserver.toml`s with unknown fields adds friction,
especially when using `pageserver.toml` fields as feature flags that
need to be decommissioned.
See the added paragraphs on `pageserver_api::models::ConfigToml` for
details on what kind of friction it causes.
Also read the corresponding internal docs update linked above to see a
more imperative guide for using `pageserver.toml` flags as feature
flags.
# Solution
## Ignoring unknown fields
Ignoring is the serde default behavior.
So, just remove `serde(deny_unknown_fields)` from all structs in
`pageserver_api::config::ConfigToml`
`pageserver_api::config::TenantConfigToml`.
I went through all the child fields and verified they don't use
`deny_unknown_fields` either, including those shared with
`pageserver_api::models`.
## Warning about unknown fields
We still want to warn about unknown fields to
- be informed about typos in the config template
- be reminded about feature-flag style configs that have been cleaned up
in code but not yet in config templates
We tried `serde_ignore` (cf draft #11319) but it doesn't work with
`serde(flatten)`.
The solution we arrived at is to compare the on-disk TOML with the TOML
that we produce if we serialize the `ConfigToml` again.
Any key specified in the on-disk TOML but not present in the serialized
TOML is flagged as an ignored key.
The mechanism to do it is a tiny recursive decent visitor on the
`toml_edit::DocumentMut`.
# Future Work
Invalid config _values_ in known fields will continue to fail pageserver
startup.
See
- https://github.com/neondatabase/cloud/issues/24349
for current worst case impact to deployments & ideas to improve.
## Problem
https://github.com/neondatabase/neon/pull/11140 introduces performance
tracing with OTEL
and a pageserver config which configures the sampling ratio of get page
requests.
Enabling a non-zero sampling ratio on a per region basis is too
aggressive and comes with perf
impact that isn't very well understood yet.
## Summary of changes
Add a `sampling_ratio` tenant level config which overrides the
pageserver level config.
Note that we do not cache the config and load it on every get page
request such that changes propagate
timely.
Note that I've had to remove the `SHARD_SELECTION` span to get this to
work. The tracing library doesn't
expose a neat way to drop a span if one realises it's not needed at
runtime.
Closes https://github.com/neondatabase/neon/issues/11392
Based on https://github.com/neondatabase/neon/pull/11139
## Problem
We want to export performance traces from the pageserver in OTEL format.
End goal is to see them in Grafana.
## Summary of changes
https://github.com/neondatabase/neon/pull/11139 introduces the
infrastructure required to run the otel collector alongside the
pageserver.
### Design
Requirements:
1. We'd like to avoid implementing our own performance tracing stack if
possible and use the `tracing` crate if possible.
2. Ideally, we'd like zero overhead of a sampling rate of zero and be a
be able to change the tracing config for a tenant on the fly.
3. We should leave the current span hierarchy intact. This includes
adding perf traces without modifying existing tracing.
To satisfy (3) (and (2) in part) a separate span hierarchy is used.
`RequestContext` gains an optional `perf_span` member
that's only set when the request was chosen by sampling. All perf span
related methods added to `RequestContext` are no-ops for requests that
are not sampled.
This on its own is not enough for (3), so performance spans use a
separate tracing subscriber. The `tracing` crate doesn't have great
support for this, so there's a fair amount of boilerplate to override
the subscriber at all points of the perf span lifecycle.
### Perf Impact
[Periodic
pagebench](https://neonprod.grafana.net/d/ddqtbfykfqfi8d/e904990?orgId=1&from=2025-02-08T14:15:59.362Z&to=2025-03-10T14:15:59.362Z&timezone=utc)
shows no statistically significant regression with a sample ratio of 0.
There's an annotation on the dashboard on 2025-03-06.
### Overview of changes:
1. Clean up the `RequestContext` API a bit. Namely, get rid of the
`RequestContext::extend` API and use the builder instead.
2. Add pageserver level configs for tracing: sampling ratio, otel
endpoint, etc.
3. Introduce some perf span tracking utilities and expose them via
`RequestContext`. We add a `tracing::Span` wrapper to be used for perf
spans and a `tracing::Instrumented` equivalent for it. See doc comments
for reason.
4. Set up OTEL tracing infra according to configuration. A separate
runtime is used for the collector.
5. Add perf traces to the read path.
## Refs
- epic https://github.com/neondatabase/neon/issues/9873
---------
Co-authored-by: Christian Schwarz <christian@neon.tech>
## Problem
Previously, L0 flushes would wait for uploads, as a simple form of
backpressure. However, this prevented flush pipelining and upload
parallelism. It has since been disabled by default and replaced by L0
compaction backpressure.
Touches https://github.com/neondatabase/cloud/issues/24664.
## Summary of changes
This patch removes L0 flush upload waits, along with the
`l0_flush_wait_upload`. This can't be merged until the setting has been
removed across the fleet.
## Problem
part of https://github.com/neondatabase/neon/issues/11279
## Summary of changes
The invisible flag is used to exclude a timeline from synthetic size
calculation. For the first step, let's persist this flag. Most of the
code are following the `is_archived` modification flow.
Signed-off-by: Alex Chi Z <chi@neon.tech>
