## Problem
See
https://neondb.slack.com/archives/C04DGM6SMTM/p1707149618314539?thread_ts=1707081520.140049&cid=C04DGM6SMTM
## Summary of changes
Perform checkpoint check after processing `ingest_batch_size` (default
100) WAL records.
## 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>
Fix several test flakes:
- test_sharding_service_smoke had log failures on "Dropped LSN updates"
- test_emergency_mode had log failures on a deletion queue shutdown
check, where the check was incorrect because it was expecting channel
receiver to stay alive after cancellation token was fired.
- test_secondary_mode_eviction had racing heatmap uploads because the
test was using a live migration hook to set up locations, where that
migration was itself uploading heatmaps and generally making the
situation more complex than it needed to be.
These are the failure modes that I saw when spot checking the last few
failures of each test.
This will mostly/completely address #6511, but I'll leave that ticket
open for a couple days and then check if either of the tests named in
that ticket are flaky.
Related #6511
Cleanups from https://github.com/neondatabase/neon/pull/6394
- There was a rogue `*` breaking the `GET /tenant/:tenant_id`, which
passes through to shard zero
- There was a duplicate migrate endpoint
- There are un-prefixed API endpoints that were only needed for compat
tests and can now be removed.
Before tenant migration it made sense to leak broken tenants in the
metrics until restart. Nowdays it makes less sense because on
cancellations we set the tenant broken. The set metric still allows
filterable alerting.
Fixes: #6507
I was on-call this week, these would had made me understand more/faster
of the system:
- move stray attaching start logging inside the span it starts, add
generation
- log ancestor timeline_id or bootstrapping in the beginning of timeline
creation
## Problem
I didn't know about `wait_until` and was relying on `sleep` to wait for
stuff. This caused some tests to be flaky.
https://github.com/neondatabase/neon/issues/6561
## Summary of changes
Switch to `wait_until`, this should make it tests less flaky
At the end of ApplyRecord(), we called pfree on the decoded record, if
it was "oversized". However, we had alread linked it to the "decode
queue" list in XLogReaderState. If we later called XLogBeginRead(), it
called ResetDecoder and tried to free the same record again.
The conditions to hit this are:
- a large WAL record (larger than aboue 64 kB I think, per
DEFAULT_DECODE_BUFFER_SIZE), and
- another WAL record processed by the same WAL redo process after the
large one.
I think the reason we haven't seen this earlier is that you don't get
WAL records that large that are sent to the WAL redo process, except
when logical replication is enabled. Logical replication adds data to
the WAL records, making them larger.
To fix, allocate the buffer ourselves, and don't link it to the decode
queue. Alternatively, we could perhaps have just removed the pfree(),
but frankly I'm a bit scared about the whole queue thing.
## Problem
When we change which physical pageservers a tenant is attached to, we
must update the control plane so that it can update computes. This will
be done via an HTTP hook, as described in
https://www.notion.so/neondatabase/Sharding-Service-Control-Plane-interface-6de56dd310a043bfa5c2f5564fa98365#1fe185a35d6d41f0a54279ac1a41bc94
## Summary of changes
- Optional CLI args `--control-plane-jwt-token` and `-compute-hook-url`
are added. If these are set, then we will use this HTTP endpoint,
instead of trying to use neon_local LocalEnv to update compute
configuration.
- Implement an HTTP-driven version of ComputeHook that calls into the
configured URL
- Notify for all tenants on startup, to ensure that we don't miss
notifications if we crash partway through a change, and carry a
`pending_compute_notification` flag at runtime to allow notifications to
fail without risking never sending the update.
- Add a test for all this
One might wonder: why not do a "forever" retry for compute hook
notifications, rather than carrying a flag on the shard to call
reconcile() again later. The reason is that we will later limit
concurreny of reconciles, when dealing with larger numbers of shards,
and if reconcile is stuck waiting for the control plane to accept a
notification request, it could jam up the whole system and prevent us
making other changes. Anyway: from the perspective of the outside world,
we _do_ retry forever, but we don't retry forever within a given
Reconciler lifetime.
The `pending_compute_notification` logic is predicated on later adding a
background task that just calls `Service::reconcile_all` on a schedule
to make sure that anything+everything that can fail a
Reconciler::reconcile call will eventually be retried.
This test became flaky when postgres retry handling was fixed to use
backoff delays -- each iteration in this test's loop was taking much
longer because pgbench doesn't fail until postgres has given up on
retrying to the pageserver.
We are just removing it, because the condition it tests is no longer
risky: we reload all metadata from remote storage on restart, so
crashing directly between making local changes and doing remote uploads
isn't interesting any more.
Closes: https://github.com/neondatabase/neon/issues/2856
Closes: https://github.com/neondatabase/neon/issues/5329
in `test_statvfs_pressure_{usage,min_avail_bytes}` we now race against
initial logical size calculation on-demand downloading the layers. first
wait out the initial logical sizes, then change the final asserts to be
"eventual", which is not great but it is faster than failing and
retrying.
this issue seems to happen only in debug mode tests.
Fixes: #6510
Adds an endpoint to the pageserver to S3-recover an entire tenant to a
specific given timestamp.
Required input parameters:
* `travel_to`: the target timestamp to recover the S3 state to
* `done_if_after`: a timestamp that marks the beginning of the recovery
process. retries of the query should keep this value constant. it *must*
be after `travel_to`, and also after any changes we want to revert, and
must represent a point in time before the endpoint is being called, all
of these time points in terms of the time source used by S3. these
criteria need to hold even in the face of clock differences, so I
recommend waiting a specific amount of time, then taking
`done_if_after`, then waiting some amount of time again, and only then
issuing the request.
Also important to note: the timestamps in S3 work at second accuracy, so
one needs to add generous waits before and after for the process to work
smoothly (at least 2-3 seconds).
We ignore the added test for the mocked S3 for now due to a limitation
in moto: https://github.com/getmoto/moto/issues/7300 .
Part of https://github.com/neondatabase/cloud/issues/8233
## Problem
Currently we have no retry mechanism for fetching basebackup. If there's
an unstable connection, starting compute will just fail.
## Summary of changes
Adds an exponential backoff with 7 retries to get the basebackup.
Don't require AWS access keys (AWS_ACCESS_KEY_ID and
AWS_SECRET_ACCESS_KEY) for S3 usage in the pytests, and also allow
AWS_PROFILE to be passed.
One of the two methods is required however.
This allows local development like:
```
aws sso login --profile dev
export ENABLE_REAL_S3_REMOTE_STORAGE=nonempty REMOTE_STORAGE_S3_REGION=eu-central-1 REMOTE_STORAGE_S3_BUCKET=neon-github-ci-tests AWS_PROFILE=dev
cargo build_testing && RUST_BACKTRACE=1 ./scripts/pytest -k debug-pg16 test_runner/regress/test_tenant_delete.py::test_tenant_delete_smoke
```
related earlier PR for the cargo unit tests of the `remote_storage` crate: #6202
---------
Co-authored-by: Alexander Bayandin <alexander@neon.tech>
changes:
- two messages instead of message every second when gate was closing
- replace the gate name string by using a pointer
- slow GateGuards are likely to log who they were (see example)
example found in regress tests: <https://github.com/neondatabase/neon/pull/6542#issuecomment-1919009256>
## Problem
See https://github.com/neondatabase/cloud/issues/8673
## Summary of changes
Download missed SLRU segments from page server
## 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>
Some tests which are unit test alike do not need to run on different pg
versions. Logging test is one of them which I found for unrelated
reasons.
Co-authored-by: Alexander Bayandin <alexander@neon.tech>
Depends on: https://github.com/neondatabase/neon/pull/6468
## Problem
The sharding service will be used as a "virtual pageserver" by the
control plane -- so it needs the set of pageserver APIs that the control
plane uses, and to present them under identical URLs, including prefix
(/v1).
## Summary of changes
- Add missing APIs:
- Tenant deletion
- Timeline deletion
- Node list (used in test now, later in tools)
- `/location_config` API (for migrating tenants into the sharding
service)
- Rework attachment service URLs:
- `/v1` prefix is used for pageserver-compatible APIs
- `/upcall/v1` prefix is used for APIs that are called by the pageserver
(re-attach and validate)
- `/debug/v1` prefix is used for endpoints that are for testing
- `/control/v1` prefix is used for new sharding service APIs that do not
mimic a pageserver API, such as registering and configuring nodes.
- Add test_sharding_service. The sharding service already had some
collateral coverage from its use in general tests, but this is the first
dedicated testing for it.
## Problem
We currently can't create subscriptions in PG14 and PG15 because only
superusers can, and PG16 requires adding roles to
pg_create_subscription.
## Summary of changes
I added changes to PG14 and PG15 that allow neon_superuser to bypass the
superuser requirement. For PG16, I didn't do that but added a migration
that adds neon_superuser to pg_create_subscription. Also added a test to
make sure it works.
Since fdatasync is used for flushing WAL, changing file size is unsafe. Make
segment creation atomic by using tmp file + rename to avoid using partially
initialized segments.
fixes https://github.com/neondatabase/neon/issues/6402
## Problem
See https://neondb.slack.com/archives/C06F5UJH601/p1706373716661439
## Summary of changes
Use None instead of 0 as initial accumulator value for calculating
maximal multixact XID.
## 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
Spun off from https://github.com/neondatabase/neon/pull/6394 -- this PR
is just the persistence parts and the changes that enable it to work
nicely
## Summary of changes
- Revert #6444 and #6450
- In neon_local, start a vanilla postgres instance for the attachment
service to use.
- Adopt `diesel` crate for database access in attachment service. This
uses raw SQL migrations as the source of truth for the schema, so it's a
soft dependency: we can switch libraries pretty easily.
- Rewrite persistence.rs to use postgres (via diesel) instead of JSON.
- Preserve JSON read+write at startup and shutdown: this enables using
the JSON format in compatibility tests, so that we don't have to commit
to our DB schema yet.
- In neon_local, run database creation + migrations before starting
attachment service
- Run the initial reconciliation in Service::spawn in the background, so
that the pageserver + attachment service don't get stuck waiting for
each other to start, when restarting both together in a test.
## Problem
The support for sharding in the pageserver was written before
https://github.com/neondatabase/neon/pull/6205 landed, so when it landed
we couldn't directly test sharding.
## Summary of changes
- Add `test_sharding_smoke` which tests the basics of creating a
sharding tenant, creating a timeline within it, checking that data
within it is distributed.
- Add modes to pg_regress tests for running with 4 shards as well as
with 1.
Refactor out test_disk_usage_eviction tenant creation and add a custom
case with 4 tenants, 3 made with pgbench scale=1 and 1 made with pgbench
scale=4.
Because the tenants are created in order of scales [1, 1, 1, 4] this is
simple enough to demonstrate the problem with using absolute access
times, because on a disk usage based eviction run we will
disproportionally target the *first* scale=1 tenant(s), and the later
larger tenant does not lose anything.
This test is not enough to show the difference between `relative_equal`
and `relative_spare` (the fudge factor); much larger scale will be
needed for "the large tenant", but that will make debug mode tests
slower.
Cc: #5304
## Problem
For #6423, creating a reproducer turned out to be very easy, as an
extension to test_ondemand_activation.
However, before I had diagnosed the issue, I was starting with a more
brute force approach of running creation API calls in the background
while restarting a pageserver, and that shows up a bunch of other
interesting issues.
In this PR:
- Add the reproducer for #6423 by extending `test_ondemand_activation`
(confirmed that this test fails if I revert the fix from
https://github.com/neondatabase/neon/pull/6430)
- In timeline creation, return 503 responses when we get an error and
the tenant's cancellation token is set: this covers the cases where we
get an anyhow::Error from something during timeline creation as a result
of shutdown.
- While waiting for tenants to become active during creation, don't
.map_err() the result to a 500: instead let the `From` impl map the
result to something appropriate (this includes mapping shutdown to 503)
- During tenant creation, we were calling `Tenant::load_local` because
no Preload object is provided. This is usually harmless because the
tenant dir is empty, but if there are some half-created timelines in
there, bad things can happen. Propagate the SpawnMode into
Tenant::attach, so that it can properly skip _any_ attempt to load
timelines if creating.
- When we call upsert_location, there's a SpawnMode that tells us
whether to load from remote storage or not. But if the operation is a
retry and we already have the tenant, it is not correct to skip loading
from remote storage: there might be a timeline there. This isn't
strictly a correctness issue as long as the caller behaves correctly
(does not assume that any timelines are persistent until the creation is
acked), but it's a more defensive position.
- If we shut down while the task in Tenant::attach is running, it can
end up spawning rogue tasks. Fix this by holding a GateGuard through
here, and in upsert_location shutting down a tenant after calling
tenant_spawn if we can't insert it into tenants_map. This fixes the
expected behavior that after shutdown_all_tenants returns, no tenant
tasks are running.
- Add `test_create_churn_during_restart`, which runs tenant & timeline
creations across pageserver restarts.
- Update a couple of tests that covered cancellation, to reflect the
cleaner errors we now return.
## Problem
The initdb cancellation added in #5921 is not sufficient to reliably
abort the entire initdb process. Initdb also spawns children. The tests
added by #6310 (#6385) and #6436 now do initdb cancellations on a more
regular basis.
In #6385, I attempted to issue `killpg` (after giving it a new process
group ID) to kill not just the initdb but all its spawned subprocesses,
but this didn't work. Initdb doesn't take *that* long in the end either,
so we just wait until it concludes.
## Summary of changes
* revert initdb cancellation support added in #5921
* still return `Err(Cancelled)` upon cancellation, but this is just to
not have to remove the cancellation infrastructure
* fixes to the `test_tenant_delete_races_timeline_creation` test to make
it reliably pass
Fixes#6385
## Problem
There is "neon.pageserver_connstring" GUC with PGC_SIGHUP option,
allowing to change it using
pg_reload_conf(). It is used by control plane to update pageserver
connection string if page server is crashed,
relocated or new shards are added.
It is copied to shared memory because config can not be loaded during
query execution and we need to
reestablish connection to page server.
## Summary of changes
Copying connection string to shared memory is done by postmaster. And
other backends
should check update counter to determine of connection URL is changed
and connection needs to be reestablished.
We can not use standard Postgres LW-locks, because postmaster has proc
entry and so can not wait
on this primitive. This is why lockless access algorithm is implemented
using two atomic counters to enforce
consistent reading of connection string value from shared memory.
## 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>
update_next_xid() doesn't have any special treatment for the invalid or
other special XIDs, so it will treat InvalidTransactionId (0) as a
regular XID. If old nextXid is smaller than 2^31, 0 will look like a
very old XID, and nothing happens. But if nextXid is greater than 2^31 0
will look like a very new XID, and update_next_xid() will incorrectly
bump up nextXID.
In the most straightforward way; safekeeper performs it in DELETE endpoint
implementation, with no coordination between sks.
delete_force endpoint in the code is renamed to delete as there is only one way
to delete.
