## Problem
We don't take advantage of queue depth generated by the compute
on the pageserver. We can process getpage requests more efficiently
by batching them.
## Summary of changes
Batch up incoming getpage requests that arrive within a configurable
time window (`server_side_batch_timeout`).
Then process the entire batch via one `get_vectored` timeline operation.
By default, no merging takes place.
## Testing
* **Functional**: https://github.com/neondatabase/neon/pull/9792
* **Performance**: will be done in staging/pre-prod
# Refs
* https://github.com/neondatabase/neon/issues/9377
* https://github.com/neondatabase/neon/issues/9376
Co-authored-by: Christian Schwarz <christian@neon.tech>
ref https://github.com/neondatabase/neon/issues/9441
The metrics from LR publisher testing project: ~300KB aux key deltas per
256MB files. Therefore, I think we can do compaction more aggressively
as these deltas are small and compaction can reduce layer download
latency. We also have a read path perf fix
https://github.com/neondatabase/neon/pull/9631 but I'd still combine the
read path fix with the reduce of the compaction threshold.
## Summary of changes
* reduce metadata compaction threshold
* use num of L1 delta layers as an indicator for metadata compaction
* dump more logs
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
https://github.com/neondatabase/neon/pull/9524 split the decoding and
interpretation step from ingestion.
The output of the first phase is a `wal_decoder::models::InterpretedWalRecord`.
Before this patch set that struct contained a list of `Value` instances.
We wish to lift the decoding and interpretation step to the safekeeper,
but it would be nice if the safekeeper gave us a batch containing the raw data instead of actual values.
## Summary of changes
Main goal here is to make `InterpretedWalRecord` hold a raw buffer which
contains pre-serialized Values.
For this we do:
1. Add a `SerializedValueBatch` type. This is `inmemory_layer::SerializedBatch` with some
extra functionality for extension, observing values for shard 0 and tests.
2. Replace `inmemory_layer::SerializedBatch` with `SerializedValueBatch`
3. Make `DatadirModification` maintain a `SerializedValueBatch`.
### `DatadirModification` changes
`DatadirModification` now maintains a `SerializedValueBatch` and extends
it as new WAL records come in (to avoid flushing to disk on every
record).
In turn, this cascaded into a number of modifications to
`DatadirModification`:
1. Replace `pending_data_pages` and `pending_zero_data_pages` with `pending_data_batch`.
2. Removal of `pending_zero_data_pages` and its cousin `on_wal_record_end`
3. Rename `pending_bytes` to `pending_metadata_bytes` since this is what it tracks now.
4. Adapting of various utility methods like `len`, `approx_pending_bytes` and `has_dirty_data_pages`.
Removal of `pending_zero_data_pages` and the optimisation associated
with it ((1) and (2)) deserves more detail.
Previously all zero data pages went through `pending_zero_data_pages`.
We wrote zero data pages when filling gaps caused by relation extension
(case A) and when handling special wal records (case B). If it happened
that the same WAL record contained a non zero write for an entry in
`pending_zero_data_pages` we skipped the zero write.
Case A: We handle this differently now. When ingesting the
`SerialiezdValueBatch` associated with one PG WAL record, we identify the gaps and fill the
them in one go. Essentially, we move from a per key process (gaps were filled after each
new key), and replace it with a per record process. Hence, the optimisation is not
required anymore.
Case B: When the handling of a special record needs to zero out a key,
it just adds that to the current batch. I inspected the code, and I
don't think the optimisation kicked in here.
## Problem
We wish to have high level WAL decoding logic in `wal_decoder::decoder`
module.
## Summary of Changes
For this we need the `Value` and `NeonWalRecord` types accessible there, so:
1. Move `Value` and `NeonWalRecord` to `pageserver::value` and
`pageserver::record` respectively.
2. Get rid of `pageserver::repository` (follow up from (1))
3. Move PG specific WAL record types to `postgres_ffi::walrecord`. In
theory they could live in `wal_decoder`, but it would create a circular
dependency between `wal_decoder` and `postgres_ffi`. Long term it makes
sense for those types to be PG version specific, so that will work out nicely.
4. Move higher level WAL record types (to be ingested by pageserver)
into `wal_decoder::models`
Related: https://github.com/neondatabase/neon/issues/9335
Epic: https://github.com/neondatabase/neon/issues/9329
## Problem
We have some known N^2 behaviors when it comes to large relation counts,
due to the monolithic encoding and full rewrites of of RelDirectory each
time a relation is added. Ordinarily our backpressure mechanisms give
"slow but steady" performance when creating/dropping/truncating
relations. However, in the case of a transaction abort, it is possible
for a single WAL record to drop an unbounded number of relations. The
results in an unavailable compute, as when it sends one of these
records, it can stall the pageserver's ingest for many minutes, even
though the compute only sent a small amount of WAL.
Closes https://github.com/neondatabase/neon/issues/9505
## Summary of changes
- Rewrite relation-dropping code to do one read/modify/write cycle of
RelDirectory, instead of doing it separately for each relation in a
loop.
- Add a test for the bug scenario encountered:
`test_tx_abort_with_many_relations`
The test has ~40s runtime on my workstation. About 1 second of that is
the part where we wait for ingest to catch up after a rollback, the rest
is the slowness of creating and truncating a large number of relations.
---------
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
Part of the aux v1 retirement
https://github.com/neondatabase/neon/issues/8623
## Summary of changes
Remove write/read path for aux v1, but keeping the config item and the
index part field for now.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
There is double update of resize cache in `put_rel_truncation`
Also `page_server_request` contains check that fork is MAIN_FORKNUM
which
1. is incorrect (because Vm/FSM pages are shreded in the same way as
MAIN fork pages and
2. is redundant because `page_server_request` is never called for `get
page` request so first part to OR condition is always true.
## Summary of changes
Remove redundant code
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
## Checklist before merging
- [ ] Do not forget to reformat commit message to not include the above
checklist
---------
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
Part of https://github.com/neondatabase/neon/issues/8002
Close https://github.com/neondatabase/neon/issues/8920
Legacy compaction (as well as gc-compaction) rely on the GC process to
remove unused layer files, but this relies on many factors (i.e., key
partition) to ensure data in a dropped table can be eventually removed.
In gc-compaction, we consider the keyspace information when doing the
compaction process. If a key is not in the keyspace, we will skip that
key and not include it in the final output.
However, this is not easy to implement because gc-compaction considers
branch points (i.e., retain_lsns) and the retained keyspaces could
change across different LSNs. Therefore, for now, we only remove aux v1
keys in the compaction process.
## Summary of changes
* Add `FilterIterator` to filter out keys.
* Integrate `FilterIterator` with gc-compaction.
* Add `collect_gc_compaction_keyspace` for a spec of keyspaces that can
be retained during the gc-compaction process.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
This adds preliminary PG17 support to Neon, based on RC1 / 2024-09-04
07b828e9d4
NOTICE: The data produced by the included version of the PostgreSQL fork
may not be compatible with the future full release of PostgreSQL 17 due to
expected or unexpected future changes in magic numbers and internals.
DO NOT EXPECT DATA IN V17-TENANTS TO BE COMPATIBLE WITH THE 17.0
RELEASE!
Co-authored-by: Anastasia Lubennikova <anastasia@neon.tech>
Co-authored-by: Alexander Bayandin <alexander@neon.tech>
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
## Problem
In https://github.com/neondatabase/neon/pull/8621, validation of keys
during ingest was removed because the places where we actually store
keys are now past the point where we have already converted them to
CompactKey (i128) representation.
## Summary of changes
Reinstate validation at an earlier stage in ingest. This doesn't cover
literally every place we write a key, but it covers most cases where
we're trusting postgres to give us a valid key (i.e. one that doesn't
try and use a custom spacenode).
Addresses the 1.82 beta clippy lint `too_long_first_doc_paragraph` by
adding newlines to the first sentence if it is short enough, and making
a short first sentence if there is the need.
Part of https://github.com/neondatabase/neon/issues/8623
## Summary of changes
It seems that we have tenants with aux policy set to v1 but don't have
any aux files in the storage. It is still safe to force migrate them
without notifying the customers. This patch adds more details to the
warning to identify the cases where we have to reach out to the users
before retiring aux v1.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
Currently, DatadirModification keeps a key-indexed map of all pending
writes, even though we (almost) never need to read back dirty pages for
anything other than metadata pages (e.g. relation sizes).
Related: https://github.com/neondatabase/neon/issues/6345
## Summary of changes
- commit() modifications before ingesting database creation wal records,
so that they are guaranteed to be able to get() everything they need
directly from the underlying Timeline.
- Split dirty pages in DatadirModification into pending_metadata_pages
and pending_data_pages. The data ones don't need to be in a
key-addressable format, so they just go in a Vec instead.
- Special case handling of zero-page writes in DatadirModification,
putting them in a map which is flushed on the end of a WAL record. This
handles the case where during ingest, we might first write a zero page,
and then ingest a postgres write to that page. We used to do this via
the key-indexed map of writes, but in this PR we change the data page
write path to not bother indexing these by key.
My least favorite thing about this PR is that I needed to change the
DatadirModification interface to add the on_record_end call. This is not
very invasive because there's really only one place we use it, but it
changes the object's behaviour from being clearly an aggregation of many
records to having some per-record state. I could avoid this by
implicitly doing the work when someone calls set_lsn or commit -- I'm
open to opinions on whether that's cleaner or dirtier.
## Performance
There may be some efficiency improvement here, but the primary
motivation is to enable an earlier stage of ingest to operate without
access to a Timeline. The `pending_data_pages` part is the "fast path"
bulk write data that can in principle be generated without a Timeline,
in parallel with other ingest batches, and ultimately on the safekeeper.
`test_bulk_insert` on AX102 shows approximately the same results as in
the previous PR #8591:
```
------------------------------ Benchmark results -------------------------------
test_bulk_insert[neon-release-pg16].insert: 23.577 s
test_bulk_insert[neon-release-pg16].pageserver_writes: 5,428 MB
test_bulk_insert[neon-release-pg16].peak_mem: 637 MB
test_bulk_insert[neon-release-pg16].size: 0 MB
test_bulk_insert[neon-release-pg16].data_uploaded: 1,922 MB
test_bulk_insert[neon-release-pg16].num_files_uploaded: 8
test_bulk_insert[neon-release-pg16].wal_written: 1,382 MB
test_bulk_insert[neon-release-pg16].wal_recovery: 18.264 s
test_bulk_insert[neon-release-pg16].compaction: 0.052 s
```
It's better to reject invalid keys on the write path than storing it and
panic-ing the pageserver.
https://github.com/neondatabase/neon/issues/8636
## Summary of changes
If a key cannot be represented using i128, we don't allow writing that
key into the pageserver.
There are two versions of the check valid function: the normal one that
simply rejects i128 keys, and the stronger one that rejects all keys
that we don't support.
The current behavior when a key gets rejected is that safekeeper will
keep retrying streaming that key to the pageserver. And once such key
gets written, no new computes can be started. Therefore, there could be
a large amount of pageserver warnings if a key cannot be ingested. To
validate this behavior by yourself, the reviewer can (1) use the
stronger version of the valid check (2) run the following SQL.
```
set neon.regress_test_mode = true;
CREATE TABLESPACE regress_tblspace LOCATION '/Users/skyzh/Work/neon-test/tablespace';
CREATE SCHEMA testschema;
CREATE TABLE testschema.foo (i int) TABLESPACE regress_tblspace;
insert into testschema.foo values (1), (2), (3);
```
For now, I'd like to merge the patch with only rejecting non-i128 keys.
It's still unknown whether the stronger version covers all the cases
that basebackup doesn't support. Furthermore, the behavior of rejecting
a key will produce large amounts of warnings due to safekeeper retry.
Therefore, I'd like to reject the minimum set of keys that we don't
support (i128 ones) for now. (well, erroring out is better than panic on
`to_compact_key`)
The next step is to fix the safekeeper behavior (i.e., on such key
rejections, stop streaming WAL), so that we can properly stop writing.
An alternative solution is to simply drop these keys on the write path.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
part of https://github.com/neondatabase/neon/issues/8623
We want to discover potential aux v1 customers that we might have missed
from the migrations.
## Summary of changes
Log warnings on basebackup, load timeline, and the first put_file.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem/Solution
TimelineWriter::put_batch is simply a loop over individual puts. Each
put acquires and releases locks, and checks for potentially starting a
new layer. Batching these is more efficient, but more importantly
unlocks future changes where we can pre-build serialized buffers much
earlier in the ingest process, potentially even on the safekeeper
(imagine a future model where some variant of DatadirModification lives
on the safekeeper).
Ensuring that the values in put_batch are written to one layer also
enables a simplification upstream, where we no longer need to write
values in LSN-order. This saves us a sort, but also simplifies follow-on
refactors to DatadirModification: we can store metadata keys and data
keys separately at that level without needing to zip them together in
LSN order later.
## Why?
In this PR, these changes are simplify optimizations, but they are
motivated by evolving the ingest path in the direction of disentangling
extracting DatadirModification from Timeline. It may not obvious how
right now, but the general idea is that we'll end up with three phases
of ingest:
- A) Decode walrecords and build a datadirmodification with all the
simple data contents already in a big serialized buffer ready to write
to an ephemeral layer **<-- this part can be pipelined and parallelized,
and done on a safekeeper!**
- B) Let that datadirmodification see a Timeline, so that it can also
generate all the metadata updates that require a read-modify-write of
existing pages
- C) Dump the results of B into an ephemeral layer.
Related: https://github.com/neondatabase/neon/issues/8452
## Caveats
Doing a big monolithic buffer of values to write to disk is ordinarily
an anti-pattern: we prefer nice streaming I/O. However:
- In future, when we do this first decode stage on the safekeeper, it
would be inefficient to serialize a Vec of Value, and then later
deserialize it just to add blob size headers while writing into the
ephemeral layer format. The idea is that for bulk write data, we will
serialize exactly once.
- The monolithic buffer is a stepping stone to pipelining more of this:
by seriailizing earlier (rather than at the final put_value), we will be
able to parallelize the wal decoding and bulk serialization of data page
writes.
- The ephemeral layer's buffered writer already stalls writes while it
waits to flush: so while yes we'll stall for a couple milliseconds to
write a couple megabytes, we already have stalls like this, just
distributed across smaller writes.
## Benchmarks
This PR is primarily a stepping stone to safekeeper ingest filtering,
but also provides a modest efficiency improvement to the `wal_recovery`
part of `test_bulk_ingest`.
test_bulk_ingest:
```
test_bulk_insert[neon-release-pg16].insert: 23.659 s
test_bulk_insert[neon-release-pg16].pageserver_writes: 5,428 MB
test_bulk_insert[neon-release-pg16].peak_mem: 626 MB
test_bulk_insert[neon-release-pg16].size: 0 MB
test_bulk_insert[neon-release-pg16].data_uploaded: 1,922 MB
test_bulk_insert[neon-release-pg16].num_files_uploaded: 8
test_bulk_insert[neon-release-pg16].wal_written: 1,382 MB
test_bulk_insert[neon-release-pg16].wal_recovery: 18.981 s
test_bulk_insert[neon-release-pg16].compaction: 0.055 s
vs. tip of main:
test_bulk_insert[neon-release-pg16].insert: 24.001 s
test_bulk_insert[neon-release-pg16].pageserver_writes: 5,428 MB
test_bulk_insert[neon-release-pg16].peak_mem: 604 MB
test_bulk_insert[neon-release-pg16].size: 0 MB
test_bulk_insert[neon-release-pg16].data_uploaded: 1,922 MB
test_bulk_insert[neon-release-pg16].num_files_uploaded: 8
test_bulk_insert[neon-release-pg16].wal_written: 1,382 MB
test_bulk_insert[neon-release-pg16].wal_recovery: 23.586 s
test_bulk_insert[neon-release-pg16].compaction: 0.054 s
```
We can get CompactionError::Other(Cancelled) via the error handling with
a few ways.
[evidence](https://neon-github-public-dev.s3.amazonaws.com/reports/pr-8655/10301613380/index.html#suites/cae012a1e6acdd9fdd8b81541972b6ce/653a33de17802bb1/).
Hopefully fix it by:
1. replace the `map_err` which hid the
`GetReadyAncestorError::Cancelled` with `From<GetReadyAncestorError> for
GetVectoredError` conversion
2. simplifying the code in pgdatadir_mapping to eliminate the token
anyhow wrapping for deserialization errors
3. stop wrapping GetVectoredError as anyhow errors
4. stop wrapping PageReconstructError as anyhow errors
Additionally, produce warnings if we treat any other error (as was legal
before this PR) as missing key.
Cc: #8708.
## Problem
Postgres is using `access()` function in `GetNewRelFileNumber` to check
if assigned relfilenumber is not used for any other relation. This check
will not work in Neon, because we do not have all files in local
storage.
## Summary of changes
Use smgrexists() instead which will check at page server if such
relfilenode is used.
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
## Checklist before merging
- [ ] Do not forget to reformat commit message to not include the above
checklist
---------
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
PR #8299 has switched the storage scrubber to use
`DefaultCredentialsChain`. Now we do this for `remote_storage`, as it
allows us to use `remote_storage` from inside kubernetes. Most of the
diff is due to `GenericRemoteStorage::from_config` becoming `async fn`.
## Problem
new clippy warnings on nightly.
## Summary of changes
broken up each commit by warning type.
1. Remove some unnecessary refs.
2. In edition 2024, inference will default to `!` and not `()`.
3. Clippy complains about doc comment indentation
4. Fix `Trait + ?Sized` where `Trait: Sized`.
5. diesel_derives triggering `non_local_defintions`
## Problem
Rarely, a dbdir entry can exist with no `relmap_file_key` data. This
causes compaction to fail, because it assumes that if the database
exists, then so does the relmap file.
Basebackup already handled this using a boolean to record whether such a
key exists, but `collect_keyspace` didn't.
## Summary of changes
- Respect the flag for whether a relfilemap exists in collect_keyspace
- The reproducer for this issue will merge separately in
https://github.com/neondatabase/neon/pull/8232
## Problem
Sparse keyspaces were constructed with ranges out of order: this didn't break things obviously, but meant that users of KeySpace functions that assume ordering would assert out.
Closes https://github.com/neondatabase/neon/issues/8277
## Summary of changes
make sure the sparse keyspace has ordered keyspace parts
Some test cases add random keys into the timeline, but it is not part of
the `collect_keyspace`, this will cause compaction remove the keys.
The pull request adds a field to supply extra keyspaces during unit
tests.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Closes#7406.
## Problem
When a `get_lsn_by_timestamp` request is cancelled, an anyhow error is
exposed to handle that case, which verbosely logs the error. However, we
don't benefit from having the full backtrace provided by anyhow in this
case.
## Summary of changes
This PR introduces a new `ApiError` type to handle errors caused by
cancelled request more robustly.
- A new enum variant `ApiError::Cancelled`
- Currently the cancelled request is mapped to status code 500.
- Need to handle this error in proxy's `http_util` as well.
- Added a failpoint test to simulate cancelled `get_lsn_by_timestamp`
request.
Signed-off-by: Yuchen Liang <yuchen@neon.tech>
Store logical replication origin in KV storage
## Problem
See #6977
## Summary of changes
* Extract origin_lsn from commit WAl record
* Add ReplOrigin key to KV storage and store origin_lsn
* In basebackup replace snapshot origin_lsn with last committed
origin_lsn at basebackup LSN
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
## Checklist before merging
- [ ] Do not forget to reformat commit message to not include the above
checklist
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
Co-authored-by: Alex Chi Z <chi@neon.tech>
The keyspace utils like `is_rel_size_key` or `is_rel_fsm_block_key` and
many others are free functions and have to be either imported separately
or specified with the full path starting in `pageserver_api:🔑:`.
This is less convenient than if these functions were just inherent
impls.
Follow-up of #7890Fixes#6438
## Problem
In all cases, AncestorStopping is equivalent to Cancelled.
This became more obvious in
https://github.com/neondatabase/neon/pull/7912#discussion_r1620582309
when updating these error types.
## Summary of changes
- Remove AncestorStopping, always use Cancelled instead
## Problem
Looking at several noisy shutdown logs:
- In https://github.com/neondatabase/neon/issues/7861 we're hitting a
log error with `InternalServerError(timeline shutting down\n'` on the
checkpoint API handler.
- In the field, we see initial_logical_size_calculation errors on
shutdown, via DownloadError
- In the field, we see errors logged from layer download code
(independent of the error propagated) during shutdown
Closes: https://github.com/neondatabase/neon/issues/7861
## Summary of changes
The theme of these changes is to avoid propagating anyhow::Errors for
cases that aren't really unexpected error cases that we might want a
stacktrace for, and avoid "Other" error variants unless we really do
have unexpected error cases to propagate.
- On the flush_frozen_layers path, use the `FlushLayerError` type
throughout, rather than munging it into an anyhow::Error. Give
FlushLayerError an explicit from_anyhow helper that checks for timeline
cancellation, and uses it to give a Cancelled error instead of an Other
error when the timeline is shutting down.
- In logical size calculation, remove BackgroundCalculationError (this
type was just a Cancelled variant and an Other variant), and instead use
CalculateLogicalSizeError throughout. This can express a
PageReconstructError, and has a From impl that translates cancel-like
page reconstruct errors to Cancelled.
- Replace CalculateLogicalSizeError's Other(anyhow::Error) variant case
with a Decode(DeserializeError) variant, as this was the only kind of
error we actually used in the Other case.
- During layer download, drop out early if the timeline is shutting
down, so that we don't do an `error!()` log of the shutdown error in
this case.
Consider the following sequence of migration:
```
1. user starts compute
2. force migrate to v2
3. user continues to write data
```
At the time of (3), the compute node is not aware that the page server
does not contain replication states any more, and might continue to
ingest neon-file records into the safekeeper. This will leave the
pageserver store a partial replication state and cause some errors. For
example, the compute could issue a deletion of some aux files in v1, but
this file does not exist in v2. Therefore, we should ignore all these
errors until everyone is migrated to v2.
Also note that if we see this warning in prod, it is likely because we
did not fully suspend users' compute when flipping the v1/v2 flag.
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
If an existing user already has some aux v1 files, we don't want to
switch them to the global tenant-level config.
Part of #7462
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Part of https://github.com/neondatabase/neon/issues/7462
Sparse keyspace does not generate image layers for now. This pull
request adds support for generating image layers for sparse keyspace.
## Summary of changes
* Use the scan interface to generate compaction data for sparse
keyspace.
* Track num of delta layers reads during scan.
* Read-trigger compaction: when a scan on the keyspace touches too many
delta files, generate an image layer. There are one hard-coded threshold
for now: max delta layers we want to touch for a scan.
* L0 compaction does not need to compute holes for metadata keyspace.
Know issue: the scan interface currently reads past the image layer,
which causes `delta_layer_accessed` keeps increasing even if image
layers are generated. The pull request to fix that will be separate, and
orthogonal to this one.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Part of https://github.com/neondatabase/neon/issues/7462
## Summary of changes
Tenant config is not persisted unless it's attached on the storage
controller. In this pull request, we persist the aux file policy flag in
the `index_part.json`.
Admins can set `switch_aux_file_policy` in the storage controller or
using the page server API. Upon the first aux file gets written, the
write path will compare the aux file policy target with the current
policy. If it is switch-able, we will do the switch. Otherwise, the
original policy will be used. The test cases show what the admins can do
/ cannot do.
The `last_aux_file_policy` is stored in `IndexPart`. Updates to the
persisted policy are done via
`schedule_index_upload_for_aux_file_policy_update`. On the write path,
the writer will update the field.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Co-authored-by: Joonas Koivunen <joonas@neon.tech>
ref https://github.com/neondatabase/neon/issues/7443
## Summary of changes
This pull request adds a size estimator for aux files. Each timeline
stores a cached `isize` for the estimated total size of aux files. It
gets reset on basebackup, and gets updated for each aux file
modification. TODO: print a warning when it exceeds the size.
The size metrics is not accurate. Race between `on_basebackup` and other
functions could create a negative basebackup size, but the chance is
rare. Anyways, this does not impose any extra I/Os to the storage as
everything is computed in-memory.
The aux files are only stored on shard 0. As basebackups are only
generated on shard 0, only shard 0 will report this metrics.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
This pull request adds the new basebackup read path + aux file write
path. In the regression test, all logical replication tests are run with
matrix aux_file_v2=false/true.
Also fixed the vectored get code path to correctly return missing key
error when being called from the unified sequential get code path.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
We keep the practice of keeping the compiler up to date, pointing to the
latest release. This is done by many other projects in the Rust
ecosystem as well.
Release notes: https://blog.rust-lang.org/2024/05/02/Rust-1.78.0.html
Prior update was in #7198
extracted (and tested) from
https://github.com/neondatabase/neon/pull/7468, part of
https://github.com/neondatabase/neon/issues/7462.
The current codebase assumes the keyspace is dense -- which means that
if we have a keyspace of 0x00-0x100, we assume every key (e.g., 0x00,
0x01, 0x02, ...) exists in the storage engine. However, the assumption
does not hold any more in metadata keyspace. The metadata keyspace is
sparse. It is impossible to do per-key check.
Ideally, we should not have the assumption of dense keyspace at all, but
this would incur a lot of refactors. Therefore, we split the keyspaces
we have to dense/sparse and handle them differently in the code for now.
At some point in the future, we should assume all keyspaces are sparse.
## Summary of changes
* Split collect_keyspace to return dense+sparse keyspace.
* Do not allow generating image layers for sparse keyspace (for now --
will fix this next week, we need image layers anyways).
* Generate delta layers for sparse keyspace.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Implements an approach different from the one #7488 chose: We now return
`past` instead of `present` (or`future`) when encountering the edge case
where commit_lsn < min_lsn. In my opinion, both `past` and `present` are
correct responses, but past is slightly better as the lsn returned by
`present` with #7488 is one too "new". In practice, this shouldn't
matter much, but shrug.
We agreed in slack that this is the better approach:
https://neondb.slack.com/archives/C03F5SM1N02/p1713871064147029
The 'latest' argument was passed to the functions in
pgdatadir_mapping.rs to know when they can update the relsize
cache. Commit e69ff3fc00 changed how the relsize cache is updated,
making the 'latest' argument unused.
There was an edge case where
`get_lsn_by_timestamp`/`find_lsn_for_timestamp` could have returned an
lsn that is before the limits we enforce: when we did find SLRU entries
with timestamps before the one we search for.
The API contract of `get_lsn_by_timestamp` is to not return something
before the anchestor lsn.
cc https://neondb.slack.com/archives/C03F5SM1N02/p1713871064147029
Extracted from https://github.com/neondatabase/neon/pull/7375. We assume
everything >= 0x80 are metadata keys. AUX file keys are part of the
metadata keys, and we use `0x90` as the prefix for AUX file keys.
The AUX file encoding is described in the code comment. We use xxhash128
as the hash algorithm. It seems to be portable according to the
introduction,
> xxHash is an Extremely fast Hash algorithm, processing at RAM speed
limits. Code is highly portable, and produces hashes identical across
all platforms (little / big endian).
...though whether the Rust version follows the same convention is
unknown and might need manual review of the library. Anyways, we can
always change the hash algorithm before rolling it out in
staging/end-user, and I made a quick decision to use xxhash here because
it generates 128b hash + portable. We can save the discussion of which
hash algorithm to use later.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Instead of trusting that a request with latest == true means that the
request LSN was at least last_record_lsn, remember explicitly when the
relation cache was initialized.
Incidentally, this allows updating the relation size cache also on reads
from read-only endpoints, when the endpoint is at a relatively recent
LSN (more recent than the end of the timeline when the timeline was
loaded in the pageserver).
Add a comment to wait_or_get_last_lsn() that it might be better to use
an older LSN when possible. Note that doing that would be unsafe,
without the relation cache changes in this commit!
As part of https://github.com/neondatabase/neon/pull/7375 and to improve
the current vectored get implementation, we separate the missing key
error out. This also saves us several Box allocations in the get page
implementation.
## Summary of changes
* Create a caching field of layer traversal id for each of the layer.
* Remove box allocations for layer traversal id retrieval and implement
MissingKey error message as before. This should be a little bit faster.
* Do not format error message until `Display`.
* For in-mem layer, the descriptor is different before/after frozen. I'm
using once lock for that.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
We reverted https://github.com/neondatabase/neon/pull/6661 a few days
ago. The change led to OOMs in
benchmarks followed by large WAL reingests.
The issue was that we removed [this
code](d04af08567/pageserver/src/tenant/timeline/walreceiver/walreceiver_connection.rs (L409-L417)).
That call may trigger a roll of the open layer due to
the keepalive messages received from the safekeeper. Removing it meant
that enforcing
of checkpoint timeout became even more lax and led to using up large
amounts of memory
for the in memory layer indices.
## Summary of changes
Piggyback on keep alive messages to enforce checkpoint timeout. This is
a hack, but it's exactly what
the current code is doing.
## Alternatives
Christhian, Joonas and myself sketched out a timer based approach
[here](https://github.com/neondatabase/neon/pull/6940). While discussing
it further, it became obvious that's also a bit of a hack and not the
desired end state. I chose not
to take that further since it's not what we ultimately want and it'll be
harder to rip out.
Right now it's unclear what the ideal system behaviour is:
* early flushing on memory pressure, or ...
* detaching tenants on memory pressure
## Problem
The value reconstruct of AUX_FILES_KEY from records is not deterministic
since it uses a hash map under the hood. This caused vectored get validation
failures when enabled in staging.
## Summary of changes
Deserialise AUX_FILES_KEY blobs comparing. All other keys should
reconstruct deterministically, so we simply compare the blobs.
