## Problem
It turns out that `WalStreamDecoder::poll_decode` returns the start LSN
of the next record and not the end LSN of the current record. They are
not always equal. For example, they're not equal when the record in
question is an XLOG SWITCH record.
## Summary of changes
Rename things to reflect that.
In ea32f1d0a3, Matthias added a feature to
our extension to expose more granular wait events. However, due to the
typo, those wait events were never registered, so we used the more
generic wait events instead.
Signed-off-by: Tristan Partin <tristan@neon.tech>
## Problem
We want to serialize interpreted records to send them over the wire from
safekeeper to pageserver.
## Summary of changes
Make `InterpretedWalRecord` ser/de. This is a temporary change to get
the bulk of the lift merged in
https://github.com/neondatabase/neon/pull/9746. For going to prod, we
don't want to use bincode since we can't evolve the schema.
Questions on serialization will be tackled separately.
PR #9308 has modified tenant activation code to take offloaded child
timelines into account for populating the list of `retain_lsn` values.
However, there is more places than just tenant activation where one
needs to update the `retain_lsn`s.
This PR fixes some bugs of the current code that could lead to
corruption in the worst case:
1. Deleting of an offloaded timeline would not get its `retain_lsn`
purged from its parent. With the patch we now do it, but as the parent
can be offloaded as well, the situatoin is a bit trickier than for
non-offloaded timelines which can just keep a pointer to their parent.
Here we can't keep a pointer because the parent might get offloaded,
then unoffloaded again, creating a dangling pointer situation. Keeping a
pointer to the *tenant* is not good either, because we might drop the
offloaded timeline in a context where a `offloaded_timelines` lock is
already held: so we don't want to acquire a lock in the drop code of
OffloadedTimeline.
2. Unoffloading a timeline would not get its `retain_lsn` values
populated, leading to it maybe garbage collecting values that its
children might need. We now call `initialize_gc_info` on the parent.
3. Offloading of a timeline would not get its `retain_lsn` values
registered as offloaded at the parent. So if we drop the `Timeline`
object, and its registration is removed, the parent would not have any
of the child's `retain_lsn`s around. Also, before, the `Timeline` object
would delete anything related to its timeline ID, now it only deletes
`retain_lsn`s that have `MaybeOffloaded::No` set.
Incorporates Chi's reproducer from #9753. cc
https://github.com/neondatabase/cloud/issues/20199
The `test_timeline_retain_lsn` test is extended:
1. it gains a new dimension, duplicating each mode, to either have the
"main" branch be the direct parent of the timeline we archive, or the
"test_archived_parent" branch intermediary, creating a three timeline
structure. This doesn't test anything fixed by this PR in particular,
just explores the vast space of possible configurations a little bit
more.
2. it gains two new modes, `offload-parent`, which tests the second
point, and `offload-no-restart` which tests the third point.
It's easy to verify the test actually is "sharp" by removing one of the
respective `self.initialize_gc_info()`, `gc_info.insert_child()` or
`ancestor_children.push()`.
Part of #8088
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Co-authored-by: Alex Chi Z <chi@neon.tech>
#9764, which adds profiling support to Safekeeper, pulls in the
dependency [`inferno`](https://crates.io/crates/inferno) via
[`pprof-rs`](https://crates.io/crates/pprof). This is licenced under the
[Common Development and Distribution License
1.0](https://spdx.org/licenses/CDDL-1.0.html), which is not allowed by
`cargo-deny`.
This patch allows the CDDL-1.0 license. It is a derivative of the
Mozilla Public License, which we already allow, but avoids some issues
around European copyright law that the MPL had. As such, I don't expect
this to be problematic.
## Problem
We didn't have a neat way to prevent auto-splitting of tenants. This
could be useful during incidents or for testing.
Closes https://github.com/neondatabase/neon/issues/9332
## Summary of changes
- Filter splitting candidates by scheduling policy
Analysis of the LR benchmarking tests indicates that in the duration of
test_subscriber_lag, a leftover 'slotter' replication slot can lead to
retained WAL growing on the publisher. This replication slot is not used
by any subscriber. The only purpose of the slot is to generate snapshot
files for the puspose of test_snap_files.
Signed-off-by: Tristan Partin <tristan@neon.tech>
## Problem
After investigation, we think to make `test_readonly_node_gc` less
flaky, we need to make a proper fix (likely involving persisting part of
the lease state). See https://github.com/neondatabase/neon/issues/9754
for details.
## Summary of changes
- skip the test until proper fix.
Signed-off-by: Yuchen Liang <yuchen@neon.tech>
## Problem
https://github.com/neondatabase/neon/issues/9240
## Summary of changes
Correctly truncate VM page instead just replacing it with zero 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>
## Problem
We are pining our fork of rust-postgres to a commit hash and that
prevents us from making
further changes to it. The latest commit in rust-postgres requires
https://github.com/neondatabase/neon/pull/8747,
but that seems to have gone stale. I reverted rust-postgres `neon`
branch to the pinned commit in
https://github.com/neondatabase/rust-postgres/pull/31.
## Summary of changes
Switch back to using the `neon` branch of the rust-postgres fork.
If WAL truncation fails in the middle it might leave some data on disk
above the write/flush LSN. In theory, concatenated with previous records
it might form bogus WAL (though very unlikely in practice because CRC
would protect from that). To protect from that, set
pending_wal_truncation flag: means before any WAL writes truncation must
be retried until it succeeds. We already did that in case of safekeeper
restart, now extend this mechanism for failures without restart. Also,
importantly, reset LSNs in the beginning of the operation, not in the
end, because once on disk deletion starts previous pointers are wrong.
All this most likely haven't created any problems in practice because
CRC protects from the consequences.
Tests for this are hard; simulation infrastructure might be useful here
in the future, but not yet.
## Problem
Historically, if a control component passed a pageserver "generation: 1"
this could be a quick way to corrupt a tenant by loading a historic
index.
Follows https://github.com/neondatabase/neon/pull/9383Closes#6951
## Summary of changes
- Introduce a Fatal variant to DownloadError, to enable index downloads
to signal when they have encountered a scary enough situation that we
shouldn't proceed to load the tenant.
- Handle this variant by putting the tenant into a broken state (no
matter which timeline within the tenant reported it)
- Add a test for this case
In the event that this behavior fires when we don't want it to, we have
ways to intervene:
- "Touch" an affected index to update its mtime (download+upload S3
object)
- If this behavior is triggered, it indicates we're attaching in some
old generation, so we should be able to fix that by manually bumping
generation numbers in the storage controller database (this should never
happen, but it's an option if it does)
and add /metrics endpoint to compute_ctl to expose such metrics
metric format example for extension pg_rag
with versions 1.2.3 and 1.4.2
installed in 3 and 1 databases respectively:
neon_extensions_installed{extension="pg_rag", version="1.2.3"} = 3
neon_extensions_installed{extension="pg_rag", version="1.4.2"} = 1
------
infra part: https://github.com/neondatabase/flux-fleet/pull/251
---------
Co-authored-by: Tristan Partin <tristan@neon.tech>
## Problem
Followup to https://github.com/neondatabase/neon/pull/9677 which enables
`no_sync` in tests. This can be merged once the next release has
happened.
## Summary of changes
- Always run pageserver with `no_sync = true` in tests.
psycopg2 has the following warning related to autocommit:
> By default, any query execution, including a simple SELECT will start
> a transaction: for long-running programs, if no further action is
> taken, the session will remain “idle in transaction”, an undesirable
> condition for several reasons (locks are held by the session, tables
> bloat…). For long lived scripts, either ensure to terminate a
> transaction as soon as possible or use an autocommit connection.
In the 2.9 release notes, psycopg2 also made the following change:
> `with connection` starts a transaction on autocommit transactions too
Some of these connections are indeed long-lived, so we were retaining
tons of WAL on the endpoints because we had a transaction pinned in the
past.
Link: https://www.psycopg.org/docs/news.html#what-s-new-in-psycopg-2-9
Link: https://github.com/psycopg/psycopg2/issues/941
Signed-off-by: Tristan Partin <tristan@neon.tech>
## Problem
`TimelinePersistentState::empty()`, used for tests and benchmarks, had a
hardcoded 16 MB WAL segment size. This caused confusion when attempting
to change the global segment size.
## Summary of changes
Inherit from `WAL_SEGMENT_SIZE` in `TimelinePersistentState::empty()`.
This GUC will drop replication slots if the size of the
pg_logical/snapshots directory (not including temp snapshot files)
becomes larger than the specified size. Keeping the size of this
directory smaller will help with basebackup size from the pageserver.
Part-of: https://github.com/neondatabase/neon/issues/8619
Signed-off-by: Tristan Partin <tristan@neon.tech>
The original value that we get is measured in microseconds. It comes
from a calculation using Postgres' GetCurrentTimestamp(), whihc is
implemented in terms of gettimeofday(2).
Signed-off-by: Tristan Partin <tristan@neon.tech>
## Problem
WAL segment fsyncs significantly affect WAL ingestion throughput.
`durable_rename()` is used when initializing every 16 MB segment, and
issues 3 fsyncs of which 1 was unnecessary.
## Summary of changes
Remove an fsync in `durable_rename` which is unnecessary with Linux and
ext4 (which we currently use). This improves WAL ingestion throughput by
up to 23% with large appends on my MacBook.
I had an impression that gc-compaction didn't test the case where the
first record of the key history is will_init because of there are some
code path that will panic in this case. Luckily it got fixed in
https://github.com/neondatabase/neon/pull/9026 so we can now implement
such tests.
Part of https://github.com/neondatabase/neon/issues/9114
## Summary of changes
* Randomly changed some images into will_init neon wal record
* Split `test_simple_bottom_most_compaction_deltas` into two test cases,
one of them has the bottom layer as delta layer with will_init flags,
while the other is the original one with image layers.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
The control file is flushed on the WAL ingest path when the commit LSN
advances by one segment, to bound the amount of recovery work in case of
a crash. This involves 3 additional fsyncs, which can have a significant
impact on WAL ingest throughput. This is to some extent mitigated by
`AppendResponse` not being emitted on segment bound flushes, since this
will prevent commit LSN advancement, which will be addressed separately.
## Summary of changes
Don't flush the control file on the WAL ingest path at all. Instead,
leave that responsibility to the timeline manager, but ask it to flush
eagerly if the control file lags the in-memory commit LSN by more than
one segment. This should not cause more than `REFRESH_INTERVAL` (300 ms)
additional latency before flushing the control file, which is
negligible.
Add a test that ensures the `retain_lsn` functionality works. Right now,
there is not a single test that is broken if offloaded or non-offloaded
timelines don't get registered at their parents, preventing gc from
discarding the ancestor_lsns of the children. This PR fills that gap.
The test has four modes:
* `offloaded`: offload the child timeline, run compaction on the parent
timeline, unarchive the child timeline, then try reading from it.
hopefully the data is still there.
* `offloaded-corrupted`: offload the child timeline, corrupts the
manifest in a way that the pageserver believes the timeline was
flattened. This is the closest we can get to pretend the `retain_lsn`
mechanism doesn't exist for offloaded timelines, so we can avoid adding
endpoints to the pageserver that do this manually for tests. The test
then checks that indeed data is corrupted and the endpoint can't be
started. That way we know that the test is actually working, and
actually tests the `retain_lsn` mechanism, instead of say the lsn lease
mechanism, or one of the many other mechanisms that impede gc.
* `archived`: the child timeline gets archived but doesn't get
offloaded. this currently matches the `None` case but we might have
refactors in the future that make archived timelines sufficiently
different from non-archived ones.
* `None`: the child timeline doesn't even get archived. this tests that
normal timelines participate in `retain_lsn`. I've made them locally not
participate in `retain_lsn` (via commenting out the respective
`ancestor_children.push` statement in tenant.rs) and ran the testsuite,
and not a single test failed. So this test is first of its kind.
Part of #8088.
This exporter logs an ERROR if a file called `postgres_exporter.yml` is
not located in its current working directory. We can silence it by
adding an empty config file and pointing the exporter at it.
Signed-off-by: Tristan Partin <tristan@neon.tech>
We found that exporting GH Workflow Runs in batch is more efficient due
to
- better utilisation of Github API
- and gh runners usage is rounded to minutes, so even when ad-hoc export
is done in 5-10 seconds, we billed for one minute usage
So now we introduce batch exporting, with version v0.2.x of github
workflow stats exporter.
How it's expected to work now:
- every 15 minutes we query for the workflow runs, created in last 2
hours
- to avoid missing workflows that ran for more than 2 hours, every night
(00:25) we will query workflows created in past 24 hours and export them
as well
- should we have query for even longer periods?
- lets see how it works with current schedule
- for longer periods like for days or weeks, it may require to adjust
logic and concurrency of querying data, so lets for now use simpler
version
The final patch for partial compaction, part of
https://github.com/neondatabase/neon/issues/9114, close
https://github.com/neondatabase/neon/issues/8921 (note that we didn't
implement parallel compaction or compaction scheduler for partial
compaction -- currently this needs to be scheduled by using a Python
script to split the keyspace, and in the future, automatically split
based on the key partitioning when the pageserver wants to trigger a
gc-compaction)
## Summary of changes
* Update the layer selection algorithm to use the same selection as full
compaction (everything intersect/below gc horizon)
* Update the layer selection algorithm to also generate a list of delta
layers that need to be rewritten
* Add the logic to rewrite delta layers and add them back to the layer
map
* Update test case to do partial compaction on deltas
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Removes some unnecessary initdb arguments, and fixes Neon for MacOS
since it doesn't seem to ship a C.UTF-8 locale.
Signed-off-by: Tristan Partin <tristan@neon.tech>
## Problem
Running `pytest.skip(...)` in a test body instead of marking the test
with `@pytest.mark.skipif(...)` makes all fixtures to be initialised,
which is not necessary if the test is going to be skipped anyway.
Also, some tests are unnecessarily skipped (e.g. `test_layer_bloating`
on Postgres 17, or `test_idle_reconnections` at all) or run (e.g.
`test_parse_project_git_version_output_positive` more than on once
configuration) according to comments.
## Summary of changes
- Move `skip_on_postgres` / `xfail_on_postgres` /
`run_only_on_default_postgres` decorators to `fixture.utils`
- Add new `skip_in_debug_build` and `skip_on_ci` decorators
- Replace `pytest.skip(...)` calls with decorators where possible
## Problem
We have no specific benchmark testing project migration of postgresql
project with existing data into Neon.
Typical steps of such a project migration are
- schema creation in the neon project
- initial COPY of relations
- creation of indexes and constraints
- vacuum analyze
## Summary of changes
Add a periodic benchmark running 9 AM UTC every day.
In each run:
- copy a 200 GiB project that has realistic schema, data, tables,
indexes and constraints from another project into
- a new Neon project (7 CU fixed)
- an existing tenant, (but new branch and new database) that already has
4 TiB of data
- use pgcopydb tool to automate all steps and parallelize COPY and index
creation
- parse pgcopydb output and report performance metrics in Neon
performance test database
## Logs
This benchmark has been tested first manually and then as part of
benchmarking.yml workflow, example run see
https://github.com/neondatabase/neon/actions/runs/11757679870
## Problem
Once we enable the merge queue for the `main` branch, it won't be
possible to adjust the commit message right after pressing the "Squash
and merge" button and the PR title + description will be used as is.
To avoid extra noise in the commits in the `main` with the checklist
leftovers, I propose removing the checklist from the PR template and
keeping only the Problem / Summary of changes.
## Summary of changes
- Remove the checklist from the PR template
## Problem
We don't have a metric capturing the latency of segment initialization.
This can be significant due to fsyncs.
## Summary of changes
Add an `initialize_segment` variant of
`safekeeper_wal_storage_operation_seconds`.
Perf benchmarks produce a lot of layers.
## Summary of changes
Bumping the threshold and ignore the warning.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
GitHub API can return error 500, and it fails jobs that use
`actions/github-script` action.
## Summary of changes
- Add `retry: 500` to all `actions/github-script` usage
## Problem
We wish to stop using admin tokens in the infra repo, but step down
requests use the admin token.
## Summary of Changes
Introduce a new "ControllerPeer" scope and use it for step-down requests.
## Problem
The Merge queue doesn't work because it expects certain jobs, which we
don't have in the `pre-merge-checks` workflow.
But it turns out we can just create jobs/checks with the same names in
any workflow that we run.
## Summary of changes
- Add `conclusion` jobs
- Create `neon-cloud-e2e` status check
- Add a bunch of `if`s to handle cases with no relevant changes found
and prepare the workflow to run rust checks in the future
- List the workflow in `report-workflow-stats` to collect stats about it
It is possible at the point we shutdown the timeline, there are
still layer files we did not upload.
## Summary of changes
* If the queue is not empty, avoid offloading.
* Shutdown the timeline gracefully using the flush mode to
ensure all local files are uploaded before deleting the timeline
directory.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
We saw pageserver OOMs
https://github.com/neondatabase/cloud/issues/19715 for tenants doing
large writes. Add log lines around in-memory layers to hopefully collect
some info during my on-call shift next week.
## Summary of changes
* Estimate in-memory size of an in-mem layer.
* Print frozen layer number if there are too many layers accumulated in
memory.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Right now, our environments create databases with the C locale, which is
really unfortunate for users who have data stored in other languages
that they want to analyze. For instance, show_trgm on Hebrew text
currently doesn't work in staging or production.
I don't envision this being the final solution. I think this is just a
way to set a known value so the pageserver doesn't use its parent
environment. The final solution to me is exposing initdb parameters to
users in the console. Then they could use a different locale or encoding
if they so chose.
Signed-off-by: Tristan Partin <tristan@neon.tech>
## Problem
To prevent breaking main after Python 3.11 PR get merged
we need to enable merge queue and run `check-codestyle-python`
job on it
## Summary of changes
- Move `check-codestyle-python` to a reusable workflow
- Run this workflow on `merge_group` event
