## Problem
Disk usage eviction isn't sensitive to layers of imported timelines.
## Summary of changes
Hook importing timelines up into eviction and add a test for it.
I don't think we need any special eviction logic for this. These layers
will all be visible and
their access time will be their creation time. Hence, we'll remove
covered layers first
and get to the imported layers if there's still disk pressure.
## Problem
`TYPE_CHECKING` is used inconsistently across Python tests.
## Summary of changes
- Update `ruff`: 0.7.0 -> 0.11.2
- Enable TC (flake8-type-checking):
https://docs.astral.sh/ruff/rules/#flake8-type-checking-tc
- (auto)fix all new issues
## Problem
Cplane and storage controller tenant config changes are not additive.
Any change overrides all existing tenant configs. This would be fine if
both did client side patching, but that's not the case.
Once this merges, we must update cplane to use the PATCH endpoint.
## Summary of changes
### High Level
Allow for patching of tenant configuration with a `PATCH
/v1/tenant/config` endpoint.
It takes the same data as it's PUT counterpart. For example the payload
below will update `gc_period` and unset `compaction_period`. All other
fields are left in their original state.
```
{
"tenant_id": "1234",
"gc_period": "10s",
"compaction_period": null
}
```
### Low Level
* PS and storcon gain `PATCH /v1/tenant/config` endpoints. PS endpoint
is only used for cplane managed instances.
* `storcon_cli` is updated to have separate commands for
`set-tenant-config` and `patch-tenant-config`
Related https://github.com/neondatabase/cloud/issues/21043
Before this PR, some override callbacks used `.default()`, others
used `.setdefault()`.
As of this PR, all callbacks use `.setdefault()` which I think is least
prone to failure.
Aligning on a single way will set the right example for future tests
that need such customization.
The `test_pageserver_getpage_throttle.py` technically is a change in
behavior: before, it replaced the `tenant_config` field, now it just
configures the throttle. This is what I believe is intended anyway.
Improves `wait_until` by:
* Use `timeout` instead of `iterations`. This allows changing the
timeout/interval parameters independently.
* Make `timeout` and `interval` optional (default 20s and 0.5s). Most
callers don't care.
* Only output status every 1s by default, and add optional
`status_interval` parameter.
* Remove `show_intermediate_error`, this was always emitted anyway.
Most callers have been updated to use the defaults, except where they
had good reason otherwise.
## Problem
On Debian 12 (Bookworm), Python 3.11 is the latest available version.
## Summary of changes
- Update Python to 3.11 in build-tools
- Fix ruff check / format
- Fix mypy
- Use `StrEnum` instead of pair `str`, `Enum`
- Update docs
Problem
-------
Tests that directly call the Pageserver Management API to set tenant
config are flaky if the Pageserver is managed by Storcon because Storcon
is the source of truth and may (theoretically) reconcile a tenant at any
time.
Solution
--------
Switch all users of
`set_tenant_config`/`patch_tenant_config_client_side`
to use the `env.storage_controller.pageserver_api()`
Future Work
-----------
Prevent regressions from creeping in.
And generally clean up up tenant configuration.
Maybe we can avoid the Pageserver having a default tenant config at all
and put the default into Storcon instead?
* => https://github.com/neondatabase/neon/issues/9621
Refs
----
fixes https://github.com/neondatabase/neon/issues/9522
Add wrappers for a few commands that didn't have them before. Move the
logic to generate tenant and timeline IDs from NeonCli to the callers,
so that NeonCli is more purely just a type-safe wrapper around
'neon_local'.
This should generally be faster when running tests, especially those
that run with higher scales.
Ignoring test_lfc_resize since it seems like we are hitting a query
timeout for some reason that I have yet to investigate. A little bit of
improvemnt is better than none.
Signed-off-by: Tristan Partin <tristan@neon.tech>
## Problem
This test was destabilized by
https://github.com/neondatabase/neon/pull/8431. The threshold is
arbitrary & failures are still quite close to it. At a high level the
test is asserting "eviction was approximately fair to these tenants",
which appears to still be the case when the abs diff between ratios is
slightly higher at ~0.6-0.7.
## Summary of changes
- Change threshold from 0.06 to 0.065. Based on the last ~10 failures
that should be sufficient.
## Problem
LayerAccessStats contains a lot of detail that we don't use: short
histories of most recent accesses, specifics on what kind of task
accessed a layer, etc. This is all stored inside a Mutex, which is
locked every time something accesses a layer.
## Summary of changes
- Store timestamps at a very low resolution (to the nearest second),
sufficient for use on the timescales of eviction.
- Pack access time and last residence change time into a single u64
- Use the high bits of the u64 for other flags, including the new layer
visibility concept.
- Simplify the external-facing model for access stats to just include
what we now track.
Note that the `HistoryBufferWithDropCounter` is removed here because it
is no longer used. I do not dislike this type, we just happen not to use
it for anything else at present.
Co-authored-by: Christian Schwarz <christian@neon.tech>
## Problem
Deployed pageserver configurations are all like this:
```
disk_usage_based_eviction:
max_usage_pct: 85
min_avail_bytes: 0
period: "10s"
eviction_order:
type: "RelativeAccessed"
args:
highest_layer_count_loses_first: true
```
But we're maintaining this optional absolute order eviction, with test
cases etc.
## Summary of changes
- Remove absolute order eviction. Make the default eviction policy the
same as how we really deploy pageservers.
Successor of #8288 , just enable zstd in tests. Also adds a test that
creates easily compressable data.
Part of #5431
---------
Co-authored-by: John Spray <john@neon.tech>
Co-authored-by: Joonas Koivunen <joonas@neon.tech>
## Problem
This test would sometimes violate the min resident size during disk
eviction and fail due to the generate warning log.
Disk usage candidate collection only takes into account active tenants.
However, the statvfs call takes into account the entire tenants
directory, which includes tenants which haven't become active yet.
After re-starting the pageserver, disk usage eviction may kick in
*before* both tenants have become active. Hence, the logic will try to satisfy
thedisk usage requirements by evicting everything belonging to the active
tenant, and hence violating the tenant minimum resident size.
## Summary of changes
Allow the warning
As seen with the pgvector 0.7.0 index builds, we can receive large
batches of images, leading to very large L0 layers in the range of 1GB.
These large layers are produced because we are only able to roll the
layer after we have witnessed two different Lsns in a single
`DataDirModification::commit`. As the single Lsn batches of images can
span over multiple `DataDirModification` lifespans, we will rarely get
to write two different Lsns in a single `put_batch` currently.
The solution is to remember the TimelineWriterState instead of eagerly
forgetting it until we really open the next layer or someone else
flushes (while holding the write_guard).
Additional changes are test fixes to avoid "initdb image layer
optimization" or ignoring initdb layers for assertion.
Cc: #7197 because small `checkpoint_distance` will now trigger the
"initdb image layer optimization"
The test has been flaky since 2024-04-11 for unknown reason, and the
logging was off. Fix the logging and raise the limit a bit. The
problematic ratio reproduces with pg14 and added sleep (not included)
but not on pg15. The new ratio abs diff limit works for all inspected
examples.
Cc: #7536
Preceding PR https://github.com/neondatabase/neon/pull/7613 reduced the
usage of `--pageserver-config-override`.
This PR builds on top of that work and fully removes the `neon_local
--pageserver-config-override`.
Tests that need a non-default `pageserver.toml` control it using two
options:
1. Specify `NeonEnvBuilder.pageserver_config_override` before
`NeonEnvBuilder.init_start()`. This uses a new `neon_local init
--pageserver-config` flag.
2. After `init_start()`: `env.pageserver.stop()` +
`NeonPageserver.edit_config_toml()` + `env.pageserver.start()`
A few test cases were using
`env.pageserver.start(overrides=("--pageserver-config-override...",))`.
I changed them to use one of the options above.
Future Work
-----------
The `neon_local init --pageserver-config` flag still uses `pageserver
--config-override` under the hood. In the future, neon_local should just
write the `pageserver.toml` directly.
The `NeonEnvBuilder.pageserver_config_override` field should be renamed
to `pageserver_initial_config`. Let's save this churn for a separate
refactor commit.
Extracted from https://github.com/neondatabase/neon/pull/6953
Part of https://github.com/neondatabase/neon/issues/5899
Core Change
-----------
In #6953, we need the ability to scan the log _after_ a specific line
and ignore anything before that line.
This PR changes `log_contains` to returns a tuple of `(matching line,
cursor)`.
Hand that cursor to a subsequent `log_contains` call to search the log
for the next occurrence of the pattern.
Other Changes
-------------
- Inspect all the callsites of `log_contains` to handle the new tuple
return type.
- Above inspection unveiled many callers aren't using `assert
log_contains(...) is not None` but some weaker version of the code that
breaks if `log_contains` ever returns a not-None but falsy value. Fix
that.
- Above changes unveiled that `test_remote_storage_upload_queue_retries`
was using `wait_until` incorrectly; after fixing the usage, I had to
raise the `wait_until` timeout. So, maybe this will fix its flakiness.
## Problem
Test sometimes fails with `used_blocks > total_blocks`, because when
using mocked statvfs with the total blocks set to the size of data on
disk before starting, we are implicitly asserting that nothing at all
can be written to disk between startup and calling statvfs.
Related: https://github.com/neondatabase/neon/issues/6511
## Summary of changes
- Use HTTP API to invoke disk usage eviction instead of mocked statvfs
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
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
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
I just failed to see this earlier on #6136. layer counts are used as an
abstraction, and each of the two tenants lose proportionally about the
same amount of layers. sadly there is no difference in between
`relative_spare` and `relative_equal` as both of these end up evicting
the exact same amount of layers, but I'll try to add later another test
for those.
Cc: #5304
## Problem
To test sharding, we need something to control it. We could write python
code for doing this from the test runner, but this wouldn't be usable
with neon_local run directly, and when we want to write tests with large
number of shards/tenants, Rust is a better fit efficiently handling all
the required state.
This service enables automated tests to easily get a system with
sharding/HA without the test itself having to set this all up by hand:
existing tests can be run against sharded tenants just by setting a
shard count when creating the tenant.
## Summary of changes
Attachment service was previously a map of TenantId->TenantState, where
the principal state stored for each tenant was the generation and the
last attached pageserver. This enabled it to serve the re-attach and
validate requests that the pageserver requires.
In this PR, the scope of the service is extended substantially to do
overall management of tenants in the pageserver, including
tenant/timeline creation, live migration, evacuation of offline
pageservers etc. This is done using synchronous code to make declarative
changes to the tenant's intended state (`TenantState.policy` and
`TenantState.intent`), which are then translated into calls into the
pageserver by the `Reconciler`.
Top level summary of modules within
`control_plane/attachment_service/src`:
- `tenant_state`: structure that represents one tenant shard.
- `service`: implements the main high level such as tenant/timeline
creation, marking a node offline, etc.
- `scheduler`: for operations that need to pick a pageserver for a
tenant, construct a scheduler and call into it.
- `compute_hook`: receive notifications when a tenant shard is attached
somewhere new. Once we have locations for all the shards in a tenant,
emit an update to postgres configuration via the neon_local `LocalEnv`.
- `http`: HTTP stubs. These mostly map to methods on `Service`, but are
separated for readability and so that it'll be easier to adapt if/when
we switch to another RPC layer.
- `node`: structure that describes a pageserver node. The most important
attribute of a node is its availability: marking a node offline causes
tenant shards to reschedule away from it.
This PR is a precursor to implementing the full sharding service for
prod (#6342). What's the difference between this and a production-ready
controller for pageservers?
- JSON file persistence to be replaced with a database
- Limited observability.
- No concurrency limits. Marking a pageserver offline will try and
migrate every tenant to a new pageserver concurrently, even if there are
thousands.
- Very simple scheduler that only knows to pick the pageserver with
fewest tenants, and place secondary locations on a different pageserver
than attached locations: it does not try to place shards for the same
tenant on different pageservers. This matters little in tests, because
picking the least-used pageserver usually results in round-robin
placement.
- Scheduler state is rebuilt exhaustively for each operation that
requires a scheduler.
- Relies on neon_local mechanisms for updating postgres: in production
this would be something that flows through the real control plane.
---------
Co-authored-by: Arpad Müller <arpad-m@users.noreply.github.com>
Follows #6123
Closes: https://github.com/neondatabase/neon/issues/5342
The approach here is to avoid using `Layer` from secondary tenants, and
instead make the eviction types (e.g. `EvictionCandidate`) have a
variant that carries a Layer for attached tenants, and a different
variant for secondary tenants.
Other changes:
- EvictionCandidate no longer carries a `Timeline`: this was only used
for providing a witness reference to remote timeline client.
- The types for returning eviction candidates are all in
disk_usage_eviction_task.rs now, whereas some of them were in
timeline.rs before.
- The EvictionCandidate type replaces LocalLayerInfoForDiskUsageEviction
type, which was basically the same thing.
Adds a new disk usage based eviction option, EvictionOrder, which
selects whether to use the current `AbsoluteAccessed` or this new
proposed but not yet tested `RelativeAccessed`. Additionally a fudge
factor was noticed while implementing this, which might help sparing
smaller tenants at the expense of targeting larger tenants.
Cc: #5304
Co-authored-by: Arpad Müller <arpad@neon.tech>
Fixes#3978. `test_partial_evict_tenant` can fail multiple times so even
though we retry it as flaky, it will still haunt us.
Originally was going to just relax the comparison, then ended up
replacing warming up to use full table scans instead of `pgbench
--select-only`. This seems to help by producing the expected layer
accesses. There might be something off with how many layers pg16
produces compared to pg14 and pg15. Created #5392.
## Problem
In many places in test code, paths are built manually from what
NeonEnv.tenant_dir and NeonEnv.timeline_dir could do.
## Summary of changes
1. NeonEnv.tenant_dir and NeonEnv.timeline_dir moved under class
NeonPageserver as the path they use is per-pageserver instance.
2. Used these everywhere to replace manual path building
Closes#5258
---------
Signed-off-by: Rahul Modpur <rmodpur2@gmail.com>
Remote storage cleanup split from #5198:
- pageserver, extensions, and safekeepers now have their separate remote
storage
- RemoteStorageKind has the configuration code
- S3Storage has the cleanup code
- with MOCK_S3, pageserver, extensions, safekeepers use different
buckets
- with LOCAL_FS, `repo_dir / "local_fs_remote_storage" / $user` is used
as path, where $user is `pageserver`, `safekeeper`
- no more `NeonEnvBuilder.enable_xxx_remote_storage` but one
`enable_{pageserver,extensions,safekeeper}_remote_storage`
Should not have any real changes. These will allow us to default to
`LOCAL_FS` for pageserver on the next PR, remove
`RemoteStorageKind.NOOP`, work towards #5172.
Co-authored-by: Alexander Bayandin <alexander@neon.tech>
## Problem
Tests using remote storage have manually entered `test_name` parameters,
which:
- Are easy to accidentally duplicate when copying code to make a new
test
- Omit parameters, so don't actually create unique S3 buckets when
running many tests concurrently.
## Summary of changes
- Use the `request` fixture in neon_env_builder fixture to get the test
name, then munge that into an S3 compatible bucket name.
- Remove the explicit `test_name` parameters to enable_remote_storage
I made a mistake when I adding `env.initial_timeline:
Optional[TimelineId]` in the #3839, should had just generated it and
used it to create a specific timeline. This PR fixes those mistakes, and
some extra calling into psql which must be slower than python field
access.
## Problem
neon_fixtures.py has grown to unmanageable size. It attracts conflicts.
When adding specific utils under for example `fixtures/pageserver`
things sometimes need to import stuff from `neon_fixtures.py` which
creates circular import. This is usually only needed for type
annotations, so `typing.TYPE_CHECKING` flag can mask the issue.
Nevertheless I believe that splitting neon_fixtures.py into smaller
parts is a better approach.
Currently the PR contains small things, but I plan to continue and move
NeonEnv to its own `fixtures.env` module. To keep the diff small I think
this PR can already be merged to cause less conflicts.
UPD: it looks like currently its not really possible to fully avoid
usage of `typing.TYPE_CHECKING`, because some components directly depend
on each other. I e Env -> Cli -> Env cycle. But its still worth it to
avoid it in as many places as possible. And decreasing neon_fixture's
size still makes sense.
Initial logical size calculation could still hinder our fast startup
efforts in #4397. See #4183. In deployment of 2023-06-06
about a 200 initial logical sizes were calculated on hosts which
took the longest to complete initial load (12s).
Implements the three step/tier initialization ordering described in
#4397:
1. load local tenants
2. do initial logical sizes per walreceivers for 10s
3. background tasks
Ordering is controlled by:
- waiting on `utils::completion::Barrier`s on background tasks
- having one attempt for each Timeline to do initial logical size
calculation
- `pageserver/src/bin/pageserver.rs` releasing background jobs after
timeout or completion of initial logical size calculation
The timeout is there just to safeguard in case a legitimate non-broken
timeline initial logical size calculation goes long. The timeout is
configurable, by default 10s, which I think would be fine for production
systems. In the test cases I've been looking at, it seems that these
steps are completed as fast as possible.
Co-authored-by: Christian Schwarz <christian@neon.tech>
Await for upload to complete before returning 201 Created on
`branch_timeline` or when `bootstrap_timeline` happens. Should either of
those waits fail, then on the retried request await for uploads again.
This should work as expected assuming control-plane does not start to
use timeline creation as a wait_for_upload mechanism.
Fixes#3865, started from
https://github.com/neondatabase/neon/pull/3857/files#r1144468177
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
We use the term "endpoint" in for compute Postgres nodes in the web UI
and user-facing documentation now. Adjust the nomenclature in the code.
This changes the name of the "neon_local pg" command to "neon_local
endpoint". Also adjust names of classes, variables etc. in the python
tests accordingly.
This also changes the directory structure so that endpoints are now
stored in:
.neon/endpoints/<endpoint id>
instead of:
.neon/pgdatadirs/tenants/<tenant_id>/<endpoint (node) name>
The tenant ID is no longer part of the path. That means that you
cannot have two endpoints with the same name/ID in two different
tenants anymore. That's consistent with how we treat endpoints in the
real control plane and proxy: the endpoint ID must be globally unique.
This patch adds a pageserver-global background loop that evicts layers
in response to a shortage of available bytes in the $repo/tenants
directory's filesystem.
The loop runs periodically at a configurable `period`.
Each loop iteration uses `statvfs` to determine filesystem-level space
usage. It compares the returned usage data against two different types
of thresholds. The iteration tries to evict layers until app-internal
accounting says we should be below the thresholds. We cross-check this
internal accounting with the real world by making another `statvfs` at
the end of the iteration. We're good if that second statvfs shows that
we're _actually_ below the configured thresholds. If we're still above
one or more thresholds, we emit a warning log message, leaving it to the
operator to investigate further.
There are two thresholds:
- `max_usage_pct` is the relative available space, expressed in percent
of the total filesystem space. If the actual usage is higher, the
threshold is exceeded.
- `min_avail_bytes` is the absolute available space in bytes. If the
actual usage is lower, the threshold is exceeded.
The iteration evicts layers in LRU fashion with a reservation of up to
`tenant_min_resident_size` bytes of the most recent layers per tenant.
The layers not part of the per-tenant reservation are evicted
least-recently-used first until we're below all thresholds. The
`tenant_min_resident_size` can be overridden per tenant as
`min_resident_size_override` (bytes).
In addition to the loop, there is also an HTTP endpoint to perform one
loop iteration synchronous to the request. The endpoint takes an
absolute number of bytes that the iteration needs to evict before
pressure is relieved. The tests use this endpoint, which is a great
simplification over setting up loopback-mounts in the tests, which would
be required to test the statvfs part of the implementation. We will rely
on manual testing in staging to test the statvfs parts.
The HTTP endpoint is also handy in emergencies where an operator wants
the pageserver to evict a given amount of space _now. Hence, it's
arguments documented in openapi_spec.yml. The response type isn't
documented though because we don't consider it stable. The endpoint
should _not_ be used by Console but it could be used by on-call.
Co-authored-by: Joonas Koivunen <joonas@neon.tech>
Co-authored-by: Dmitry Rodionov <dmitry@neon.tech>
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
