Rename the safekeeper scheduling policy "disabled" to "pause".
A rename was requested in
https://github.com/neondatabase/neon/pull/10400#discussion_r1916259124,
as the "disabled" policy is meant to be analogous to the "pause" policy
for pageservers.
Also simplify the `SkSchedulingPolicyArg::from_str` function, relying on
the `from_str` implementation of `SkSchedulingPolicy`. Latter is used
for the database format as well, so it is quite stable. If we ever want
to change the UI, we'll need to duplicate the function again but this is
cheap.
## Problem
Threads spawned in `test_tenant_delete_races_timeline_creation` are not
joined before the test ends, and can generate
`PytestUnhandledThreadExceptionWarning` in other tests.
https://neon-github-public-dev.s3.amazonaws.com/reports/pr-10419/12805365523/index.html#/testresult/53a72568acd04dbd
## Summary of changes
- Wrap threads in ThreadPoolExecutor which will join them before the
test ends
- Remove a spurious deletion call -- the background thread doing
deletion ought to succeed.
## Problem
When multiple changes are grouped in a merge group to be merged as part
of the merge queue, the changes might individually pass
`check-codestyle-rust` but not in their combined form.
## Summary of changes
- Move `check-codestyle-rust` into a reusable workflow that is called
from it's previous location in `build_and_test.yml`, and additionally
call it from `pre_merge_checks.yml`. The additional call does not run on
ARM, only x86, to ensure the merge queue continues being responsive.
- Trigger `pre_merge_checks.yml` on PRs that change any of the workflows
running in `pre_merge_checks.yml`, so that we get feedback on those
early an not only after trying to merge those changes.
This should fix the largest source of flakyness of
test_nbtree_pagesplit_cycleid.
## Problem
https://github.com/neondatabase/neon/issues/10390
## Summary of changes
By using a guaranteed-flushed LSN, we ensure that PS won't have to wait
forever.
(If it does wait forever, we know the issue can't be with Compute's WAL)
## Problem
As part of https://github.com/neondatabase/neon/issues/8614 we need to
pass options to START_WAL_PUSH.
## Summary of changes
Add two options. `allow_timeline_creation`, default true, disables
implicit timeline creation in the connection from compute. Eventually
such creation will be forbidden completely, but as we migrate to
configurations we need to support both: current mode and configurations
enabled where creation by compute is disabled.
`proto_version` specifies compute <-> sk protocol version. We have it
currently in the first greeting package also, but I plan to change tag
size from u64 to u8, which would make it hard to use. Command is more
appropriate place for it anyway.
This reduces pressure on the OS TCP read buffer by increasing the
moments we read data out of the receive buffer, and increasing the
number of bytes we can pull from that buffer when we do reads.
## Problem
A backend may not always consume its prefetch data quick enough
## Summary of changes
We add a new function `prefetch_pump_state` which pulls as many prefetch
requests from the OS TCP receive buffer as possible, but without
blocking.
This thus reduces pressure on OS-level TCP buffers, thus increasing
throughput by limiting throttling caused by full TCP buffers.
## Problem
part of https://github.com/neondatabase/neon/issues/9114
part of investigation of
https://github.com/neondatabase/neon/issues/10049
## Summary of changes
* If `cfg!(test) or cfg!(feature = testing)`, then we will always try
generating an image to ensure the history is replayable, but not put the
image layer into the final layer results, therefore discovering wrong
key history before we hit a read error.
* I suspect it's easier to trigger some races if gc-compaction is
continuously run on a timeline, so I increased the frequency to twice
per 10 churns.
* Also, create branches in gc-compaction smoke tests to get more test
coverage.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Co-authored-by: Arpad Müller <arpad@neon.tech>
## Problem
`postgres` is system database at neon, so we need to do `pg_restore`
into `neondb` instead
https://github.com/neondatabase/cloud/issues/22100
## Summary of changes
Changed fast_import a little bit:
1. After succesfull connection creating `neondb` in postgres instance
2. Changed restore connstring to use new db
3. Added optional `source_connection_string`, which allows to skip
`s3_prefix` and just connect directly.
4. Added `-i` that stops process until sigterm
## TODO
- [x] test image in cplane e2e
- [ ] Change import job image back to latest after this merged (partial
revert of https://github.com/neondatabase/cloud/pull/22338)
## Problem
When a pageserver is receiving high rates of requests, we don't have a
good way to efficiently discover what the client's access pattern is.
Closes: https://github.com/neondatabase/neon/issues/10275
## Summary of changes
- Add
`/v1/tenant/x/timeline/y/page_trace?size_limit_bytes=...&time_limit_secs=...`
API, which returns a binary buffer.
- Add `pagectl page-trace` tool to decode and analyze the output.
---------
Co-authored-by: Erik Grinaker <erik@neon.tech>
Implementing the last missing endpoint of #9981, this adds support to
set the scheduling policy of an individual safekeeper, as specified in
the RFC. However, unlike in the RFC we call the endpoint
`scheduling_policy` not `status`
Closes#9981.
As for why not use the upsert endpoint for this: we want to have the
safekeeper upsert endpoint be used for testing and for deploying new
safekeepers, but not for changes of the scheduling policy. We don't want
to change any of the other fields when marking a safekeeper as
decommissioned for example, so we'd have to first fetch them only to
then specify them again. Of course one can also design an endpoint where
one can omit any field and it doesn't get modified, but it's still not
great for observability to put everything into one big "change something
about this safekeeper" endpoint.
## Problem
Safekeepers currently decode and interpret WAL for each shard
separately.
This is wasteful in terms of CPU memory usage - we've seen this in
profiles.
## Summary of changes
Fan-out interpreted WAL to multiple shards.
The basic is that wal decoding and interpretation happens in a separate
tokio task and senders
attach to it. Senders only receive batches concerning their shard and
only past the Lsn they've last seen.
Fan-out is gated behind the `wal_reader_fanout` safekeeper flag
(disabled by default for now).
When fan-out is enabled, it might be desirable to control the absolute
delta between the
current position and a new shard's desired position (i.e. how far behind
or ahead a shard may be).
`max_delta_for_fanout` is a new optional safekeeper flag which dictates
whether to create a new
WAL reader or attach to the existing one. By default, this behaviour is
disabled. Let's consider enabling
it if we spot the need for it in the field.
## Testing
Tests passed [here](https://github.com/neondatabase/neon/pull/10301)
with wal reader fanout enabled
as of
34f6a71718.
Related: https://github.com/neondatabase/neon/issues/9337
Epic: https://github.com/neondatabase/neon/issues/9329
## Problem
https://github.com/neondatabase/neon/issues/9965
## Summary of changes
Add to safekeeper http endpoint to switch membership configuration. Also
add it to python client for tests, and add simple test itself.
## Problem
Successful `benchmarks` runs doesn't have enough visibility
Ref https://neondb.slack.com/archives/C069Z2199DL/p1736868055094539
## Summary of changes
- Report both successful and failed `benchmarks` to Slack
- Update `slackapi/slack-github-action` action
## Problem
Currently, we call `InterpretedWalRecord::from_bytes_filtered`
from each shard. To serve multiple shards at the same time,
the API needs to allow for enquiring about multiple shards.
## Summary of changes
This commit tweaks it a pretty brute force way. Naively, we could
just generate the shard for a key, but pre and post split shards
may be subscribed at the same time, so doing it efficiently is more
complex.
## Problem
https://github.com/neondatabase/neon/issues/9965
## Summary of changes
Add safekeeper membership configuration struct itself and storing it in
the control file. In passing also add creation timestamp to the control
file (there were cases where I wanted it in the past).
Remove obsolete unused PersistedPeerInfo struct from control file (still
keep it control_file_upgrade.rs to have it in old upgrade code).
Remove the binary representation of cfile in the roundtrip test.
Updating it is annoying, and we still test the actual roundtrip.
Also add configuration to timeline creation http request, currently used
only in one python test. In passing, slightly change LSNs meaning in the
request: normally start_lsn is passed (the same as ancestor_start_lsn in
similar pageserver call), but we allow specifying higher commit_lsn for
manual intervention if needed. Also when given LSN initialize
term_history with it.
## Problem
https://github.com/neondatabase/neon/pull/8455 wasn't specific enough on
migration from current situation to enabling generations.
## Summary of changes
Describe the missing parts, including control plane pushing generation
to compute, which also defines whether generations are enabled -- non
zero value does it.
## Problem
For large deployments, the `control/v1/tenant` listing API can time out
transmitting a monolithic serialized response.
## Summary of changes
- Add `limit` and `start_after` parameters to listing API
- Update storcon_cli to use these parameters and limit requests to 1000
items at a time
## Problem
With upload queue reordering in #10218, we can easily get into a
situation where multiple index uploads are queued back to back, which
can't be parallelized. This will happen e.g. when multiple layer flushes
enqueue layer/index/layer/index/... and the layers skip the queue and
are uploaded in parallel.
These index uploads will incur serial S3 roundtrip latencies, and may
block later operations.
Touches #10096.
## Summary of changes
When multiple back-to-back index uploads are ready to upload, only
upload the most recent index and drop the rest.
## Problem
The upload queue can currently schedule an arbitrary number of tasks.
This can both spawn an unbounded number of Tokio tasks, and also
significantly slow down upload queue scheduling as it's quadratic in
number of operations.
Touches #10096.
## Summary of changes
Limit the number of inprogress tasks to the remote storage upload
concurrency. While this concurrency limit is shared across all tenants,
there's certainly no point in scheduling more than this -- we could even
consider setting the limit lower, but don't for now to avoid
artificially constraining tenants.
By setting PATH in the 'pg-build' layer, all the extension build layers
will inherit. No need to pass PG_CONFIG to all the various make
invocations either: once pg_config is in PATH, the Makefiles will pick
it up from there.
## Problem
The upload queue currently sees significant head-of-line blocking. For
example, index uploads act as upload barriers, and for every layer flush
we schedule a layer and index upload, which effectively serializes layer
uploads.
Resolves#10096.
## Summary of changes
Allow upload queue operations to bypass the queue if they don't conflict
with preceding operations, increasing parallelism.
NB: the upload queue currently schedules an explicit barrier after every
layer flush as well (see #8550). This must be removed to enable
parallelism. This will require a better mechanism for compaction
backpressure, see e.g. #8390 or #5415.
## 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.
