## Problem
Neon currently implements several features that guarantee high uptime of
compute nodes:
1. Storage high-availability (HA), i.e. each tenant shard has a
secondary pageserver location, so we can quickly switch over compute to
it in case of primary pageserver failure.
2. Fast compute provisioning, i.e. we have a fleet of pre-created empty
computes, that are ready to serve workload, so restarting unresponsive
compute is very fast.
3. Preemptive NeonVM compute provisioning in case of k8s node
unavailability.
This helps us to be well-within the uptime SLO of 99.95% most of the
time. Problems begin when we go up to multi-TB workloads and 32-64 CU
computes. During restart, compute looses all caches: LFC, shared
buffers, file system cache. Depending on the workload, it can take a lot
of time to warm up the caches, so that performance could be degraded and
might be even unacceptable for certain workloads. The latter means that
although current approach works well for small to
medium workloads, we still have to do some additional work to avoid
performance degradation after restart of large instances.
[Rendered
version](https://github.com/neondatabase/neon/blob/alexk/pg-prewarm-rfc/docs/rfcs/2025-03-17-compute-prewarm.md)
Part of https://github.com/neondatabase/cloud/issues/19011
## Problem
The billing team wants to change the billing events pipeline and use a
common events format in S3 buckets across different event producers.
## Summary of changes
Change the events storage format for billing events from JSON to NDJSON.
Also partition files by hours, rather than days.
Resolves: https://github.com/neondatabase/cloud/issues/29995
We would like to move towards an arena system for JSON encoding the
responses. This change pushes an "out" parameter into the pg-test to
json routines to make swapping in an arena system easier in the future.
(see #11992)
This additionally removes the redundant `column: &[Type]` argument, as
well as rewriting the pg_array parser.
---
I rewrote the pg_array parser since while making these changes I found
it hard to reason about. I went back to the specification and rewrote it
from scratch. There's 4 separate routines:
1. pg_array_parse - checks for any prelude (multidimensional array
ranges)
2. pg_array_parse_inner - only deals with the arrays themselves
3. pg_array_parse_item - parses a single item from the array, this might
be quoted, unquoted, or another nested array.
4. pg_array_parse_quoted - parses a quoted string, following the
relevant string escaping rules.
Don't print errors like:
```
Compaction failed 1 times, retrying in 2s: Failed to offload timeline: Unexpected offload error: Timeline deletion is already in progress
```
Print it at info log level instead.
https://github.com/neondatabase/cloud/issues/30666
## Problem
https://github.com/neondatabase/neon/pull/11712 changed how computes are
started in the test: the lsn is specified, making them read-only static
replicas. Lsn is `last_record_lsn` from pageserver. It works fine with
read-only branches (because their `last_record_lsn` is equal to
`start_lsn` and always valid). But with writable timelines, the
`last_record_lsn` on the pageserver might be stale.
Particularly in this test, after the `detach_branch` operation, the
tenant is reset on the pagesever. It leads to `last_record_lsn` going
back to `disk_consistent_lsn`, so basically rolling back some recent
writes.
If we start a primary compute, it will start at safekeepers' commit Lsn,
which is the correct one , and will wait till pageserver catches up with
this Lsn after reset.
- Closes: https://github.com/neondatabase/neon/issues/12365
## Summary of changes
- Start `primary` compute for writable timelines.
## Problem
Part of #11813
## Summary of changes
* Compute tenant remote size in the housekeeping loop.
* Add a new `TenantFeatureResolver` struct to cache the tenant-specific
properties.
* Evaluate feature flag based on the remote size.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
close https://github.com/neondatabase/neon/issues/11528
## Summary of changes
Gives us better observability of compaction progress.
- Image creation: num of partition processed / total partition
- Gc-compaction: index of the in the queue / total items for a full
compaction
- Shard ancestor compaction: layers to rewrite / total layers
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
L0 compaction currently holds the read lock for a long region while it
doesn't need to.
## Summary of changes
This patch reduces the one long contention region into 2 short ones:
gather the layers to compact at the beginning, and several short read
locks when querying the image coverage.
Co-Authored-By: Chen Luo
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
This PR works on adding dynamic masking support for `anon` v2. It
currently only supports static masking.
## Summary of changes
Added a security definer function that sets the dynamic masking guc to
`true` with superuser permissions.
Added a security definer function that adds `anon` to
`session_preload_libraries` if it's not already present.
Related to: https://github.com/neondatabase/cloud/issues/20456
## Problem
Currently we do not have metrics for autovacuum.
## Summary of changes
Added a metric that extracts the top 5 DBs with oldest mxid and frozen
xid. Tables that were vacuumed recently should have younger value (or
younger age).
Related Issue: https://github.com/neondatabase/cloud/issues/27296
## Problem
#8843
User initiated sql queries are being classified as "postgres" errors,
whereas they're really user errors.
## Summary of changes
Classify user-initiated postgres errors as user errors if they are
related to a sql query that we ran on their behalf. Do not log those
errors.
Add support to transport syslogs over TLS. Since TLS params essentially
require passing host and port separately, add a boolean flag to the
configuration template and also use the same `action` format for
plaintext logs. This allows seamless transition.
The plaintext host:port is picked from `AUDIT_LOGGING_ENDPOINT` (as
earlier) and from `AUDIT_LOGGING_TLS_ENDPOINT`. The TLS host:port is
used when defined and non-empty.
`remote_endpoint` is split separately to hostname and port as required
by `omfwd` module.
Also the address parsing and config content generation are split to more
testable functions with basic tests added.
## Problem
We persist safekeeper host/port in the storcon DB after
https://github.com/neondatabase/neon/pull/11712, so the storcon fails to
ping safekeepers in the compatibility tests, where we start the cluster
from the snapshot.
PR also adds some small code improvements related to the test failure.
- Closes: https://github.com/neondatabase/neon/issues/12339
## Summary of changes
- Update safekeeper ports in the storcon DB when starting the neon from
the dir (snapshot)
- Fail the response on all not-success codes (e.g. 3xx). Should not
happen, but just to be more safe.
- Add `neon_previous/` to .gitignore to make it easier to run compat
tests.
- Add missing EXPORT to the instruction for running compat tests
## Problem
Previously, the background worker that collects the list of installed
extensions across DBs had a timeout set to 1 hour. This cause a problem
with computes that had a `suspend_timeout` > 1 hour as this collection
was treated as activity, preventing compute shutdown.
Issue: https://github.com/neondatabase/cloud/issues/30147
## Summary of changes
Passing the `suspend_timeout` as part of the `ComputeSpec` so that any
updates to this are taken into account by the background worker and
updates its collection interval.
If a hardlink operation inside `detach_ancestor` fails due to the layer
already existing, we delete the layer to make sure the source is one we
know about, and then retry.
But we deleted the wrong file, namely, the one we wanted to use as the
source of the hardlink. As a result, the follow up hard link operation
failed. Our PR corrects this mistake.
## Problem
We don't notify cplane about safekeeper membership change yet. Without
the notification the compute needs to know all the safekeepers on the
cluster to be able to speak to them. Change notifications will allow to
avoid it.
- Closes: https://github.com/neondatabase/neon/issues/12188
## Summary of changes
- Implement `notify_safekeepers` method in `ComputeHook`
- Notify cplane about safekeepers in `safekeeper_migrate` handler.
- Update the test to make sure notifications work.
## Out of scope
- There is `cplane_notified_generation` field in `timelines` table in
strocon's database. It's not needed now, so it's not updated in the PR.
Probably we can remove it.
- e2e tests to make sure it works with a production cplane
## Problem
The gRPC API does not provide LSN leases.
## Summary of changes
* Add LSN lease support to the gRPC API.
* Use gRPC LSN leases for static computes with `grpc://` connstrings.
* Move `PageserverProtocol` into the `compute_api::spec` module and
reuse it.
## Problem
Location config changes can currently result in changes to the shard
identity. Such changes will cause data corruption, as seen with #12217.
Resolves#12227.
Requires #12377.
## Summary of changes
Assert that the shard identity does not change on location config
updates and on (re)attach.
This is currently asserted with `critical!`, in case it misfires in
production. Later, we should reject such requests with an error and turn
this into a proper assertion.
Implicit mapping to an `anyhow::Error` when we do `?` is discouraged
because tooling to find those places isn't great.
As a drive-by, also make SplitImageLayerWriter::new infallible and sync.
I think we should also make ImageLayerWriter::new completely lazy,
then `BatchLayerWriter:new` infallible and async.
Reverts neondatabase/neon#11663 and
https://github.com/neondatabase/neon/pull/11265/
Step Security is not yet approved by Databricks team, in order to
prevent issues during Github org migration, I'll revert this PR to use
the previous action instead of Step Security maintained action.
## Problem
Similarly to #12217, the following endpoints may result in a stripe size
mismatch between the storage controller and Pageserver if an unsharded
tenant has a different stripe size set than the default. This can lead
to data corruption if the tenant is later manually split without
specifying an explicit stripe size, since the storage controller and
Pageserver will apply different defaults. This commonly happens with
tenants that were created before the default stripe size was changed
from 32k to 2k.
* `PUT /v1/tenant/config`
* `PATCH /v1/tenant/config`
These endpoints are no longer in regular production use (they were used
when cplane still managed Pageserver directly), but can still be called
manually or by tests.
## Summary of changes
Retain the current shard parameters when updating the location config in
`PUT | PATCH /v1/tenant/config`.
Also opportunistically derive `Copy` for `ShardParameters`.
## Problem
Some of the design decisions in PR #12256 were influenced by the
requirements of consistency tests. These decisions introduced
intermediate logic that is no longer needed and should be cleaned up.
## Summary of Changes
- Remove the `feature("testing")` flag related to
`kick_secondary_download`.
- Set the default value of `kick_secondary_download` back to false,
reflecting the intended production behavior.
Co-authored-by: Aleksandr Sarantsev <aleksandr.sarantsev@databricks.com>
## Problem
- Closes: https://github.com/neondatabase/neon/issues/12298
## Summary of changes
- Set `timeline_safekeeper_count` in `neon_local` if we have less than 3
safekeepers
- Remove `cfg!(feature = "testing")` code from
`safekeepers_for_new_timeline`
- Change `timeline_safekeeper_count` type to `usize`
## Problem
`compute_ctl` should support gRPC base backups.
Requires #12111.
Requires #12243.
Touches #11926.
## Summary of changes
Support `grpc://` connstrings for `compute_ctl` base backups.
## Problem
The problem has been well described in already-commited PR #11853.
tl;dr: BufferedWriter is sensitive to cancellation, which the previous
approach was not.
The write path was most affected (ingest & compaction), which was mostly
fixed in #11853:
it introduced `PutError` and mapped instances of `PutError` that were
due to cancellation of underlying buffered writer into
`CreateImageLayersError::Cancelled`.
However, there is a long tail of remaining errors that weren't caught by
#11853 that result in `CompactionError::Other`s, which we log with great
noise.
## Solution
The stack trace logging for CompactionError::Other added in #11853
allows us to chop away at that long tail using the following pattern:
- look at the stack trace
- from leaf up, identify the place where we incorrectly map from the
distinguished variant X indicating cancellation to an `anyhow::Error`
- follow that anyhow further up, ensuring it stays the same anyhow all
the way up in the `CompactionError::Other`
- since it stayed one anyhow chain all the way up, root_cause() will
yield us X
- so, in `log_compaction_error`, add an additional `downcast_ref` check
for X
This PR specifically adds checks for
- the flush task cancelling (FlushTaskError, BlobWriterError)
- opening of the layer writer (GateError)
That should cover all the reports in issues
- https://github.com/neondatabase/cloud/issues/29434
- https://github.com/neondatabase/neon/issues/12162
## Refs
- follow-up to #11853
- fixup of / fixes https://github.com/neondatabase/neon/issues/11762
- fixes https://github.com/neondatabase/neon/issues/12162
- refs https://github.com/neondatabase/cloud/issues/29434
We don't have cancellation support for timeline deletions. In other
words, timeline deletion might still go on in an older generation while
we are attaching it in a newer generation already, because the
cancellation simply hasn't reached the deletion code.
This has caused us to hit a situation with offloaded timelines in which
the timeline was in an unrecoverable state: always returning an accepted
response, but never a 404 like it should be.
The detailed description can be found in
[here](https://github.com/neondatabase/cloud/issues/30406#issuecomment-3008667859)
(private repo link).
TLDR:
1. we ask to delete timeline on old pageserver/generation, starts
process in background
2. the storcon migrates the tenant to a different pageserver.
- during attach, the pageserver still finds an index part, so it adds it
to `offloaded_timelines`
4. the timeline deletion finishes, removing the index part in S3
5. there is a retry of the timeline deletion endpoint, sent to the new
pageserver location. it is bound to fail however:
- as the index part is gone, we print `Timeline already deleted in
remote storage`.
- the problem is that we then return an accepted response code, and not
a 404.
- this confuses the code calling us. it thinks the timeline is not
deleted, so keeps retrying.
- this state never gets recovered from until a reset/detach, because of
the `offloaded_timelines` entry staying there.
This is where this PR fixes things: if no index part can be found, we
can safely assume that the timeline is gone in S3 (it's the last thing
to be deleted), so we can remove it from `offloaded_timelines` and
trigger a reupload of the manifest. Subsequent retries will pick that
up.
Why not improve the cancellation support? It is a more disruptive code
change, that might have its own risks. So we don't do it for now.
Fixes https://github.com/neondatabase/cloud/issues/30406
Mainly for general readability. Some notable changes:
- Postgres can be built without the rest of the repository, and in
particular without any of the Rust bits. Some CI scripts took advantage
of that, so let's make that more explicit by separating those parts.
Also add an explicit comment about that in the new postgres.mk file.
- Add a new PG_INSTALL_CACHED variable. If it's set, `make all` and
other top-Makefile targets skip checking if Postgres is up-to-date. This
is also to be used in CI scripts that build and cache Postgres as
separate steps. (It is currently only used in the macos walproposer-lib
rule, but stay tuned for more.)
- Introduce a POSTGRES_VERSIONS variable that lists all supported
PostgreSQL versions. Refactor a few Makefile rules to use that.
## Problem
In large oltp test run
https://github.com/neondatabase/neon/actions/runs/15905488707/job/44859116742
we see that the `Benchmark database maintenance` step is skipped in all
3 strategy variants, however it should be executed in two.
This is due to treating the `test_maintenance` boolean type in the
strategy in the condition of the `Benchmark database maintenance` step
## Summary of changes
Use a boolean condition instead of a string comparison
## Test run from this pull request branch
https://github.com/neondatabase/neon/actions/runs/15923605412
## Problem
When resolving a shard during a split we might have multiple attached
shards with the old shard count (i.e. not all of them are marked in
progress and ignored). Hence, we can compute the desired shard number
based on the old shard count and misroute the request.
## Summary of Changes
Recompute the desired shard every time the shard count changes during
the iteration
# Problem
In #12335 I moved the `authenticate` method outside of the
`connect_to_compute` loop. This triggered [e2e tests to become
flaky](https://github.com/neondatabase/cloud/pull/30533). This
highlighted an edge case we forgot to consider with that change.
When we connect to compute, the compute IP might be cached. This cache
hit might however be stale. Because we can't validate the IP is
associated with a specific compute-id☨, we will succeed the
connect_to_compute operation and fail when it comes to password
authentication☨☨. Before the change, we were invalidating the cache and
triggering wake_compute if the authentication failed.
Additionally, I noticed some faulty logic I introduced 1 year ago
https://github.com/neondatabase/neon/pull/8141/files#diff-5491e3afe62d8c5c77178149c665603b29d88d3ec2e47fc1b3bb119a0a970afaL145-R147
☨ We can when we roll out TLS, as the certificate common name includes
the compute-id.
☨☨ Technically password authentication could pass for the wrong compute,
but I think this would only happen in the very very rare event that the
IP got reused **and** the compute's endpoint happened to be a
branch/replica.
# Solution
1. Fix the broken logic
2. Simplify cache invalidation (I don't know why it was so convoluted)
3. Add a loop around connect_to_compute + authenticate to re-introduce
the wake_compute invalidation we accidentally removed.
I went with this approach to try and avoid interfering with
https://github.com/neondatabase/neon/compare/main...cloneable/proxy-pglb-connect-compute-split.
The changes made in commit 3 will move into `handle_client_request` I
suspect,
## Problem
Some pageservers hit `max_size_entries` limit in staging with only ~25
MiB storage used by basebackup cache. The limit is too strict. It should
be safe to relax it.
- Part of https://github.com/neondatabase/cloud/issues/29353
## Summary of changes
- Increase the default `max_size_entries` from 1000 to 10000
## Problem
Druing shard splits we shut down the remote client early and allow the
parent shard to keep ingesting data. While ingesting data, the wal
receiver task may wait for the current flush to complete in order to
apply backpressure. Notifications are delivered via
`Timeline::layer_flush_done_tx`.
When the remote client was being shut down the flush loop exited
whithout delivering a notification. This left
`Timeline::wait_flush_completion` hanging indefinitely which blocked the
shutdown of the wal receiver task, and, hence, the shard split.
## Summary of Changes
Deliver a final notification when the flush loop is shutting down
without the timeline cancel cancellation token having fired. I tried
writing a test for this, but got stuck in failpoint hell and decided
it's not worth it.
`test_sharding_autosplit`, which reproduces this reliably in CI, passed
with the proposed fix in
https://github.com/neondatabase/neon/pull/12304.
Closes https://github.com/neondatabase/neon/issues/12060
Make the safekeeper `pull_timeline` endpoint support timelines that
haven't had any writes yet. In the storcon managed sk timelines world,
if a safekeeper goes down temporarily, the storcon will schedule a
`pull_timeline` call. There is no guarantee however that by when the
safekeeper is online again, there have been writes to the timeline yet.
The `snapshot` endpoint gives an error if the timeline hasn't had
writes, so we avoid calling it if `timeline_start_lsn` indicates a
freshly created timeline.
Fixes#11422
Part of #11670
## Problem
gRPC base backups do not use the base backup cache.
Touches https://github.com/neondatabase/neon/issues/11728.
## Summary of changes
Integrate gRPC base backups with the base backup cache.
Also fixes a bug where the base backup cache did not differentiate
between primary/replica base backups (at least I think that's a bug?).
## Problem
In our infra config, we have to split server_api_key and other fields in
two files: the former one in the sops file, and the latter one in the
normal config. It creates the situation that we might misconfigure some
regions that it only has part of the fields available, causing
storcon/pageserver refuse to start.
## Summary of changes
Allow PostHog config to have part of the fields available. Parse it
later.
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
Basebackup cache now uses unbounded channel for prepare requests. In
theory it can grow large if the cache is hung and does not process the
requests.
- Part of https://github.com/neondatabase/cloud/issues/29353
## Summary of changes
- Replace an unbounded channel with a bounded one, the size is
configurable.
- Add `pageserver_basebackup_cache_prepare_queue_size` to observe the
size of the queue.
- Refactor a bit to move all metrics logic to `basebackup_cache.rs`
I was looking at how we could expose our proxy config as toml again, and
as I was writing out the schema format, I noticed some cruft in our CLI
args that no longer seem to be in use.
The redis change is the most complex, but I am pretty sure it's sound.
Since https://github.com/neondatabase/cloud/pull/15613 cplane longer
publishes to the global redis instance.
## Problem
If LFC generation is changed then `lfc_readv_select` will return -1 but
pages are still marked as available in bitmap.
## Summary of changes
Update bitmap after generation check.
Co-authored-by: Kosntantin Knizhnik <konstantin.knizhnik@databricks.com>
## Problem
Fix for https://github.com/neondatabase/neon/pull/12324
## Summary of changes
Need `serde(default)` to allow this field not present in the config,
otherwise there will be a config deserialization error.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
