## Problem
Since https://github.com/neondatabase/neon/pull/9916, the preferred AZ
of a tenant is much more impactful, and we would like to make it more
visible in tooling.
## Summary of changes
- Include AZ in node describe API
- Include AZ info in node & tenant outputs in CLI
- Add metrics for per-node shard counts, labelled by AZ
- Add a CLI for setting preferred AZ on a tenant
- Extend AZ-setting API+CLI to handle None for clearing preferred AZ
## Problem
Before this PR, the pagestream throttle was applied weighted on a
per-batch basis.
This had several problems:
1. The throttle occurence counters were only bumped by `1` instead of
`batch_size`.
2. The throttle wait time aggregator metric only counted one wait time,
irrespective
of `batch_size`. That makes sense in some ways of looking at it but not
in others.
3. If the last request in the batch runs into the throttle, the other
requests in the
batch are also throttled, i.e., over-throttling happens (theoretical,
didn't measure
it in practice).
## Solution
It occured to me that we can simply push the throttling upwards into
`pagestream_read_message`.
This has the added benefit that in pipeline mode, the `executor` stage
will, if it is idle,
steal whatever requests already made it into the `spsc_fold` and execute
them; before this
change, that was not the case - the throttling happened in the
`executor` stage instead of
the `batcher` stage.
## Code Changes
There are two changes in this PR:
1. Lifting up the throttling into the `pagestream_read_message` method.
2. Move the throttling metrics out of the `Throttle` type into
`SmgrOpMetrics`.
Unlike the other smgr metrics, throttling is per-tenant, hence the Arc.
3. Refactor the `SmgrOpTimer` implementation to account for the new
observation states,
and simplify its design.
4. Drive-by-fix flush time metrics. It was using the same `now` in the
`observe_guard` every time.
The `SmgrOpTimer` is now a state machine.
Each observation point moves the state machine forward.
If a timer object is dropped early some "pair"-like metrics still
require an increment or observation.
That's done in the Drop implementation, by driving the state machine to
completion.
## Problem
Discovered during the relation dir refactor work.
If we do not create images as in this patch, we would get two set of
image layers:
```
0000...METADATA_KEYS
0000...REL_KEYS
```
They overlap at the same LSN and would cause data loss for relation
keys. This doesn't happen in prod because initial image layer generation
is never called, but better to be fixed to avoid future issues with the
reldir refactors.
## Summary of changes
* Consolidate create_image_layers call into a single one.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
Because of https://github.com/Azure/azure-sdk-for-rust/issues/1739, our
identity token file was not being refreshed. This caused our uploads to
start failing when the storage token expired.
## Summary of changes
Drop and recreate the remote storage config every time we upload in
order to force reload the identity token file.
## Problem
See https://github.com/neondatabase/neon/issues/10167
Too small number of `max_connections` (2) can cause failures of
test_physical_replication_config_mismatch_too_many_known_xids test
## Summary of changes
Increase `max_connections` to 5
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
## Problem
We want to do a more robust job of scheduling tenants into their home
AZ: https://github.com/neondatabase/neon/issues/8264.
Closes: https://github.com/neondatabase/neon/issues/8969
## Summary of changes
### Scope
This PR combines prioritizing AZ with a larger rework of how we do
optimisation. The rationale is that just bumping AZ in the order of
Score attributes is a very tiny change: the interesting part is lining
up all the optimisation logic to respect this properly, which means
rewriting it to use the same scores as the scheduler, rather than the
fragile hand-crafted logic that we had before. Separating these changes
out is possible, but would involve doing two rounds of test updates
instead of one.
### Scheduling optimisation
`TenantShard`'s `optimize_attachment` and `optimize_secondary` methods
now both use the scheduler to pick a new "favourite" location. Then
there is some refined logic for whether + how to migrate to it:
- To decide if a new location is sufficiently "better", we generate
scores using some projected ScheduleContexts that exclude the shard
under consideration, so that we avoid migrating from a node with
AffinityScore(2) to a node with AffinityScore(1), only to migrate back
later.
- Score types get a `for_optimization` method so that when we compare
scores, we will only do an optimisation if the scores differ by their
highest-ranking attributes, not just because one pageserver is lower in
utilization. Eventually we _will_ want a mode that does this, but doing
it here would make scheduling logic unstable and harder to test, and to
do this correctly one needs to know the size of the tenant that one is
migrating.
- When we find a new attached location that we would like to move to, we
will create a new secondary location there, even if we already had one
on some other node. This handles the case where we have a home AZ A, and
want to migrate the attachment between pageservers in that AZ while
retaining a secondary location in some other AZ as well.
- A unit test is added for
https://github.com/neondatabase/neon/issues/8969, which is implicitly
fixed by reworking optimisation to use the same scheduling scores as
scheduling.
## Problem
In preparation to https://github.com/neondatabase/neon/issues/9516. We
need to store rel size and directory data in the sparse keyspace, but it
does not support inheritance yet.
## Summary of changes
Add a new type of keyspace "sparse but inherited" into the system.
On the read path: we don't remove the key range when we descend into the
ancestor. The search will stop when (1) the full key range is covered by
image layers (which has already been implemented before), or (2) we
reach the end of the ancestor chain.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Generally ed25519 seems to be much preferred for cryptographic strength
to P256 nowadays, and it is NIST approved finally. We should use it
where we can as it's also faster than p256.
This PR makes the re-signed JWTs between local_proxy and pg_session_jwt
use ed25519.
This does introduce a new dependency on ed25519, but I do recall some
Neon Authorise customers asking for support for ed25519, so I am
justifying this dependency addition in the context that we can then
introduce support for customer ed25519 keys
sources:
* https://csrc.nist.gov/pubs/fips/186-5/final subsection 7 (EdDSA)
* https://datatracker.ietf.org/doc/html/rfc8037#section-3.1
## Problem
Currently, if we want to move a secondary there isn't a neat way to do
that: we just have migration API for the attached location, and it is
only clean to use that if you've manually created a secondary via
pageserver API in the place you're going to move it to.
Secondary migration API enables:
- Moving the secondary somewhere because we would like to later move the
attached location there.
- Move the secondary location because we just want to reclaim some disk
space from its current location.
## Summary of changes
- Add `/migrate_secondary` API
- Add `tenant-shard-migrate-secondary` CLI
- Add tests for above
## Problem
We would sometimes fail to retry compute notifications:
1. Try and send, set compute_notify_failure if we can't
2. On next reconcile, reconcile() fails for some other reason (e.g.
tried to talk to an offline node), and we fail the `result.is_ok() &&
must_notify` condition around the re-sending.
Closes: https://github.com/neondatabase/cloud/issues/22612
## Summary of changes
- Clarify the meaning of the reconcile result: it should be Ok(()) if
configuring attached location worked, even if secondary or detach
locations cannot be reached.
- Skip trying to talk to secondaries if they're offline
- Even if reconcile fails and we can't send the compute notification (we
can't send it because we're not sure if it's really attached), make sure
we save the `compute_notify_failure` flag so that subsequent reconciler
runs will try again
- Add a regression test for the above
Taking continuous profiles every 20 seconds is likely too expensive (in
dollar terms). Let's try 60-second profiles. We can now interrupt
running profiles via `?force=true`, so this should be fine.
For testing the proxy's websockets support.
I wrote this to test https://github.com/neondatabase/neon/issues/3822.
Unfortunately, that bug can *not* be reproduced with this tunnel. The
bug only appears when the client pipelines the first query with the
authentication messages. The tunnel doesn't do that.
---
Update (@conradludgate 2025-01-10):
We have since added some websocket tests, but they manually implemented
a very simplistic setup of the postgres protocol. Introducing the tunnel
would make more complex testing simpler in the future.
---------
Co-authored-by: Conrad Ludgate <conradludgate@gmail.com>
## Problem
Limitations found while using this to investigate
https://github.com/neondatabase/neon/issues/10234:
- If we hit a node consistency issue, we drop out and don't check shards
for consistency
- The messages printed after a shard consistency issue are huge, and
grafana appears to drop them.
## Summary of changes
- Defer node consistency errors until the end of the function, so that
we always proceed to check shards for consistency
- Print out smaller log lines that just point out the diffs between
expected and persistent state
With a new beta build of the rust compiler, it's good to check out the
new lints. Either to find false positives, or find flaws in our code.
Additionally, it helps reduce the effort required to update to 1.85 in 6
weeks.
## Problem
It's only possible to take one CPU profile at a time. With Grafana
continuous profiling, a (low-frequency) CPU profile will always be
running, making it hard to take an ad hoc CPU profile at the same time.
Resolves#10072.
## Summary of changes
Add a `force` parameter for `/profile/cpu` which will end and return an
already running CPU profile, starting a new one for the current caller.
## Problem
Currently, the heap profiling frequency is every 1 MB allocated. Taking
a profile stack trace takes about 1 µs, and allocating 1 MB takes about
15 µs, so the overhead is about 6.7% which is a bit high. This is a
fixed cost regardless of whether heap profiles are actually accessed.
## Summary of changes
Increase the heap profiling sample frequency from 1 MB to 2 MB, which
reduces the overhead to about 3.3%. This seems acceptable, considering
performance-sensitive code will avoid allocations as far as possible
anyway.
There used to be some pg version dependencies in these extensions, but
now that there isn't, follow the simpler pattern used in other
extensions. No change in the produced images.
We don't need or want the `active` column. Remove it. Vlad pointed out
that this is safe.
Thanks to the separation of the schemata in earlier PRs, this is easy.
follow-up of #10205
Part of https://github.com/neondatabase/neon/issues/9981
When we moved throttling up from Timeline::get into page_service,
we stopped being sensitive to `Timeline::cancel`, even though we're
holding a Handle and thus a guard on the `Timeline::gate` open.
This PR rectifies the situation.
Refs
- Found while investigating #10309 (hung detach because gate kept open),
but not expected to be the root cause of that issue because the
affected tenants are not being throttled according to their metrics.
## Problem
https://github.com/neondatabase/infra/pull/2725 updated the scrubber to
use a non-host
port endpoint for storcon. That breaks when unwrapping the port.
## Summary of changes
Support both `host:port` and `host` formats for the storcon api.
## Problem
These two tests came up in #9537 as doing multi-gigabyte I/O, and from
inspection of the tests it doesn't seem like they need that to fulfil
their purpose.
## Summary of changes
- In test_local_file_cache_unlink, run fewer background threads with a
smaller number of rows. These background threads AFAICT exist to make
sure some I/O is going on while we unlink the LFC directory, but 5
threads should be enough for "some".
- In test_lfc_resize, tweak the test to validate that the cache size is
larger than the final size before resizing it, so that we're sure we're
writing enough data to really be doing something. Then decrease the
pgbench scale.
## Problem
When poetry v2 (released Jan 5) is used it needs `packaging.metadata`
module, but we downgrade `packaging` to 23.0. `packaging==23.1`
introduced the metadata submodule.
## Summary of changes
Update `packaging` to 24.2.
## Problem
This test writes ~5GB of data. It is not suitable to run in parallel
with all the other small tests in test_runner/regress.
via #9537
## Summary of changes
- Move test_parallel_copy into the performance directory, so that it
does not run in parallel with other tests
## Problem
I noticed in https://github.com/neondatabase/neon/pull/9537 that tests
which work with compat snapshots were writing several hundred MB of
data, which isn't really necessary.
Also, the snapshots are large but don't have the proper variety of
storage format features, e.g. they could just have L0 deltas.
## Summary of changes
- Use smaller scale factor and runtime to generate less data
- Configure a small layer size and use force image layer generation so
that our output contains L1 deltas and image layers, and has a decent
number of entries in the layer map
## Problem
Unlike CPU profiles, the `/profile/heap` endpoint can't automatically
generate SVG flamegraphs. This requires the user to install and use
`pprof` tooling, which is unnecessary and annoying.
Resolves#10203.
## Summary of changes
Add `format=svg` for the `/profile/heap` route, and generate an SVG
flamegraph using the `inferno` crate, similarly to what `pprof-rs`
already does for CPU profiles.
# Problem
Before this PR, there were cases where send() in state
SenderWaitsForReceiverToConsume would never be woken up
by the receiver, because it never registered with `wake_sender`.
Example Scenario 1: we stop polling a send() future A that was waiting
for the receiver to consume. We drop A and create a new send() future B.
B would return Poll::Pending and never regsister a waker.
Example Scenario 2: a send() future A transitions from HasData
to SenderWaitsForReceiverToConsume. This registers the context X
with `wake_sender`. But before the Receiver consumes the data,
we poll A from a different context Y.
The state is still SenderWaitsForReceiverToConsume, but we wouldn't
register the new context with `wake_sender`.
When the Receiver comes around to consume and `wake_sender.notify()`s,
it wakes the old context X instead of Y.
# Fix
Register the waker in the case where we're polled in
state `SenderWaitsForReceiverToConsume`.
# Relation to #10309
I found this bug while investigating #10309.
There was never proof that this bug here is the root cause for #10309.
In the meantime we found a more probably hypothesis
for the root cause than what is being fixed here.
Regardless, let's walk through my thought process about
how it might have been relevant:
There (in page_service), Scenario 1 does not apply because
we poll the send() future to completion.
Scenario 2 (`tokio::join!`) also does not apply with the
current `tokio::join!()` impl, because it will just poll each
future every time, each with the same context.
Although if we ever used something like a FuturesUnordered anywhere,
that will be using a different context, so, in that case,
the bug might materialize.
Regarding tokio & spurious poll in general:
@conradludgate is not aware of any spurious wakeup cases in current
tokio,
but within a `tokio::join!()`, any wake meant for one future will poll
all
the futures, so that can appear as a spurious wake up to the N-1 futures
of the `tokio::join!()`.
## Problem
We were incorrectly constructing the ComputeUserInfo, used for
cancellation checks, based on the return parameters from postgres. This
didn't contain the correct info.
## Summary of changes
Propagate down the existing ComputeUserInfo.
## Problem
When the proxy receives a `Notification` with an unknown topic it's
supposed to use the `UnknownTopic` unit variant. Unfortunately, in
adjacently tagged enums serde will not simply ignore the configured
content if found and try to deserialize a map/object instead.
## Summary of changes
* Use a custom deserialize function to ignore variant content.
* Add a little unit test covering both cases.
## Problem
Auto-offloading as requested by the compaction task is racy with
unarchival, in that the compaction task might attempt to offload an
unarchived timeline. By that point it will already have set the timeline
to the `Stopping` state however, which makes it unusable for any
purpose. For example:
1. compaction task decides to offload timeline
2. timeline gets unarchived
3. `offload_timeline` gets called by compaction task
* sets timeline's state to `Stopping`
* realizes that the timeline can't be unarchived, errors out
6. endpoint can't be started as the timeline is `Stopping` and thus
'can't be found'.
A future iteration of the compaction task can't "heal" this state either
as the timeline will still not be archived, same goes for other
automatic stuff. The only way to heal this is a tenant detach+attach, or
alternatively a pageserver restart.
Furthermore, the compaction task is especially amenable for such races
as it first stores `can_offload` into a variable, figures out whether
compaction is needed (which takes some time), and only then does it
attempt an offload operation: the time difference between "check" and
"use" is non-trivially small.
To make it even worse, we start the compaction task right after attach
of a tenant, and it is a common pattern by pageserver users to attach a
tenant to then immediately unarchive a timeline, so that an endpoint can
be started.
## Solutions not adopted
The simplest solution is to move the `can_offload` check to right before
attempting of the offload. But this is not a good solution, as no lock
is held between that check and timeline shutdown. So races would still
be possible, just become less likely.
I explored using the timeline state for this, as in adding an additional
enum variant. But `Timeline::set_state` is racy (#10297).
## Adopted solution
We use the lock on the timeline's upload queue as an arbiter: either
unarchival gets to it first and sours the state for auto-offloading, or
auto-offloading shuts it down, which stops any parallel unarchival in
its tracks. The key part is not releasing the upload queue's lock
between the check whether the timeline is archived or not, and shutting
it down (the actual implementation only sets `shutting_down` but it has
the same effect on `initialized_mut()` as a full shutdown). The rest of
the patch is stuff that follows from this.
We also move the part where we set the state to `Stopping` to after that
arbiter has decided the fate of the timeline. For deletions, we do keep
it inside `DeleteTimelineFlow::prepare` however, so that it is called
with all of the the timelines locks held that the function allocates
(timelines lock most importantly). This is only a precautionary measure
however, as I didn't want to analyze deletion related code for possible
races.
## Future changes
It might make sense to move `can_offload` to right before the offload
attempt. Maybe some other properties might have changed as well.
Although this will not be perfect either as no lock is held. I want to
keep it out of this change to emphasize that this move wasn't the main
reason we are race free now.
Fixes#10220
This is a refactor to create better abstractions related to our
management server. It cleans up the code, and prepares everything for
authorized communication to and from the control plane.
Signed-off-by: Tristan Partin <tristan@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://releases.rs/docs/1.84.0/).
Prior update was in #9926.
## Problem
In Postgres, one cannot drop a role if it has any dependent objects in
the DB. In `compute_ctl`, we automatically reassign all dependent
objects in every DB to the corresponding DB owner. Yet, it seems that it
doesn't help with some implicit permissions. The issue is reproduced by
installing a `postgis` extension because it creates some views and
tables in the public schema.
## Summary of changes
Added a repro test without using a `postgis`: i) create a role via
`compute_ctl` (with `neon_superuser` grant); ii) create a test role, a
table in schema public, and grant permissions via the role in
`neon_superuser`.
To fix the issue, I added a new `compute_ctl` code that removes such
dangling permissions before dropping the role. It's done in the least
invasive way, i.e., only touches the schema public, because i) that's
the problem we had with PostGIS; ii) it creates a smaller chance of
messing anything up and getting a stuck operation again, just for a
different reason.
Properly, any API-based catalog operations should fail gracefully and
provide an actionable error and status code to the control plane,
allowing the latter to unwind the operation and propagate an error
message and hint to the user. In this sense, it's aligned with another
feature request https://github.com/neondatabase/cloud/issues/21611Resolveneondatabase/cloud#13582
## Problem
Initially we defaulted this to zero to reduce risk. We have now been
using pooling in staging for some time without issues, so let's make it
the default for anyone using this software without setting the config
explicitly.
Closes: https://github.com/neondatabase/cloud/issues/20971
## Summary of changes
- Set Azure blob storage connection pool size to 8 by default
## Problem
Occasionally we see an unexpected error like:
```
ERROR spawn_heartbeat_driver: Failed to update node state 1 after heartbeat round: Shutting down\n')
Hint: use scripts/check_allowed_errors.sh to test any new allowed_error you add
```
https://neon-github-public-dev.s3.amazonaws.com/reports/pr-10324/12690404952/index.html#/testresult/63406a0687bf6eca
## Summary of changes
- Explicitly handle ApiError::ShuttingDown as a no-op when mutating node
status
## Problem
If for some reasons we already garbage-collected the data under an LSN
but the caller uses a past LSN for the find_time_cutoff function, now we
will report a missing key error and GC will never proceed.
Note that missing key error can also happen if the key is really missing
(i.e., during the past offload incidents)
## Summary of changes
Make sure GC proceeds by bumping the LSN. When time_cutoff=None, we will
not increase the time_cutoff (it will be set to latest_gc_cutoff). If we
really need to bump the GC LSN for maintenance purpose, we need a
separate API to do that.
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
We have several serious data corruption incidents caused by mismatch of
get-age requests:
https://neondb.slack.com/archives/C07FJS4QF7V/p1723032720164359
We hope that the problem is fixed now. But it is better to prevent such
kind of problems in future.
Part of https://github.com/neondatabase/cloud/issues/16472
## Summary of changes
This PR introduce new V3 version of compute<->pageserver protocol,
adding tag to getpage response.
So now compute is able to check if it really gets response to the
requested page.
## 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>
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
