## Problem
We saw a tenant get stuck when it had been put into Pause scheduling
mode to pin it to a pageserver, then it was left idle for a while and
the control plane tried to detach it.
Close: https://github.com/neondatabase/neon/issues/9957
## Summary of changes
- When changing policy to Detached or Secondary, set the scheduling
policy to Active.
- Add a test that exercises this
- When persisting tenant shards, set their `generation_pageserver` to
null if the placement policy is not Attached (this enables consistency
checks to work, and avoids leaving state in the DB that could be
confusing/misleading in future)
## Problem
Sharded tenants should be run in a single AZ for best performance, so
that computes have AZ-local latency to all the shards.
Part of https://github.com/neondatabase/neon/issues/8264
## Summary of changes
- When we split a tenant, instead of updating each shard's preferred AZ
to wherever it is scheduled, propagate the preferred AZ from the parent.
- Drop the check in `test_shard_preferred_azs` that asserts shards end
up in their preferred AZ: this will not be true again until the
optimize_attachment logic is updated to make this so. The existing check
wasn't testing anything about scheduling, it was just asserting that we
set preferred AZ in a way that matches the way things happen to be
scheduled at time of split.
Before this PR, the storcon_cli didn't have a way to show the
tenant-wide information of the TenantDescribeResponse.
Sadly, the `Serialize` impl for the tenant config doesn't skip on
`None`, so, the output becomes a bit bloated.
Maybe we can use `skip_serializing_if(Option::is_none)` in the future.
=> https://github.com/neondatabase/neon/issues/9983
## Problem
I was touching `test_storage_controller_node_deletion` because for AZ
scheduling work I was adding a change to the storage controller (kick
secondaries during optimisation) that made a FIXME in this test defunct.
While looking at it I also realized that we can easily fix the way node
deletion currently doesn't use a proper ScheduleContext, using the
iterator type recently added for that purpose.
## Summary of changes
- A testing-only behavior in storage controller where if a secondary
location isn't yet ready during optimisation, it will be actively
polled.
- Remove workaround in `test_storage_controller_node_deletion` that
previously was needed because optimisation would get stuck on cold
secondaries.
- Update node deletion code to use a `TenantShardContextIterator` and
thereby a proper ScheduleContext
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
We use a pretty old version of `mypy` 1.3 (released 1.5 years ago), it
produces false positives for `typing.Self`.
## Summary of changes
- Bump `mypy` from 1.3 to 1.13
- Fix new warnings and errors
- Use `typing.Self` whenever we `return self`
## 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
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 haven't historically taken this API route where we would onboard a
tenant to the controller in detached state. It worked, but we didn't
have test coverage.
## Summary of changes
- Add a test that onboards a tenant to the storage controller in
Detached mode, and checks that deleting it without attaching it works as
expected.
## Problem
If something goes wrong with a live migration, we currently only have
awkward ways to interrupt that:
- Restart the storage controller
- Ask it to do some other modification/migration on the shard, which we
don't really want.
## Summary of changes
- Add a new `/cancel` control API, and storcon_cli wrapper for it, which
fires the Reconciler's cancellation token. This is just for on-call use
and we do not expect it to be used by any other services.
## Problem
Previously, figuring out how many tenant shards were managed by a
storage controller was typically done by peeking at the database or
calling into the API. A metric makes it easier to monitor, as
unexpectedly increasing shard counts can be indicative of problems
elsewhere in the system.
## Summary of changes
- Add metrics `storage_controller_pageserver_nodes` (updated on node
CRUD operations from Service) and `storage_controller_tenant_shards`
(updated RAII-style from TenantShard)
## Problem
If we migrate A->B, then B->A, and the notification of A->B fails, then
we might have retained state that makes us think "A" is the last state
we sent to the compute hook, whereas when we migrate B->A we should
really be sending a fresh notification in case our earlier failed
notification has actually mutated the remote compute config.
Closes: #9417
## Summary of changes
- Add a reproducer for the bug
(`test_storage_controller_compute_hook_revert`)
- Refactor compute hook code to represent remote state with
`ComputeRemoteState` which stores a boolean for whether the compute has
fully applied the change as well as the request that the compute
accepted.
- The actual bug fix: after sending a compute notification, if we got a
423 response then update our ComputeRemoteState to reflect that we have
mutated the remote state. This way, when we later try and notify for our
historic location, we will properly see that as a change and send the
notification.
Co-authored-by: Vlad Lazar <vlad@neon.tech>
## Problem
We faced the problem of incompatibility of the different components of
different versions.
This should be detected automatically to prevent production bugs.
## Summary of changes
The test for this situation was implemented
Co-authored-by: Alexander Bayandin <alexander@neon.tech>
## Problem
Creation of a timelines during a reconciliation can lead to
unavailability if the user attempts to
start a compute before the storage controller has notified cplane of the
cut-over.
## Summary of changes
Create timelines on all currently attached locations. For the latest
location, we still look
at the database (this is a previously). With this change we also look
into the observed state
to find *other* attached locations.
Related https://github.com/neondatabase/neon/issues/9144
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'.
## Problem
We don't have an alert for long running reconciles. Stuck reconciles are
problematic
as we've seen in a recent incident.
## Summary of changes
Add a new metric `storage_controller_reconcile_long_running_total` with
labels: `{tenant_id, shard_number, seq}`.
The metric is removed after the long running reconcile finishes. These
events should be rare, so we won't break
the bank on cardinality.
Related https://github.com/neondatabase/neon/issues/9150
## Problem
If a timeline was deleted right before waiting for LSNs to catch up
before the cut-over,
then we would wait forever.
## Summary of changes
Fix the issue and add a test for timeline deletions mid migration.
Related https://github.com/neondatabase/neon/issues/9144
## Problem
The live migration code waits forever for the compute notification hook,
on the basis that until it succeeds, the compute is probably using the
old location and we shouldn't detach it.
However, if a pageserver stops or restarts in the background, then this
original location might no longer be available, so there is no point
waiting. Waiting is also actively harmful, because it prevents other
reconciliations happening for the tenant shard, such as during an
upgrade where a stuck "drain" migration might prevent the later "fill"
migration from moving the shard back to its original location.
## Summary of changes
- Refactor the notification wait loop into a function
- Add a checks during the loop, for the origin node's cancellation token
and an explicit HTTP request to the origin node to confirm the shard is
still attached there.
Closes: https://github.com/neondatabase/neon/issues/8901
## Problem
These commits are split off from
https://github.com/neondatabase/neon/pull/8971/commits where I was
fixing this to make a better scale test pass -- Vlad also independently
recognized these issues with cloudbench in
https://github.com/neondatabase/neon/issues/9062.
1. The storage controller proxies GET requests to pageservers based on
their intent, not the ground truth of where they're really attached.
2. Proxied requests can race with scheduling to tenants, resulting in
404 responses if the request hits the wrong pageserver.
Closes: https://github.com/neondatabase/neon/issues/9062
## Summary of changes
1. If a shard has a running reconciler, then use the database
generation_pageserver to decide who to proxy the request to
2. If such a request gets a 404 response and its scheduled node has
changed since the request was dispatched.
Part of #7497, closes https://github.com/neondatabase/neon/issues/8890.
## Problem
Since leases are in-memory objects, we need to take special care of them
after pageserver restarts and while doing a live migration. The approach
we took for pageserver restart is to wait for at least lease duration
before doing first GC. We want to do the same for live migration. Since
we do not do any GC when a tenant is in `AttachedStale` or
`AttachedMulti` mode, only the transition from `AttachedMulti` to
`AttachedSingle` requires this treatment.
## Summary of changes
- Added `lsn_lease_deadline` field in `GcBlock::reasons`: the tenant is
temporarily blocked from GC until we reach the deadline. This
information does not persist to S3.
- In `GCBlock::start`, skip the GC iteration if we are blocked by the
lsn lease deadline.
- In `TenantManager::upsert_location`, set the lsn_lease_deadline to
`Instant::now() + lsn_lease_length` so the granted leases have a chance
to be renewed before we run GC for the first time after transitioned
from AttachedMulti to AttachedSingle.
Signed-off-by: Yuchen Liang <yuchen@neon.tech>
Co-authored-by: Joonas Koivunen <joonas@neon.tech>
There's currently no way to just start/stop broker from `neon_local`.
This PR
* adds a sub-command
* uses that sub-command from the test suite instead of the pre-existing
Python `subprocess` based approach.
Found this useful during investigation
https://github.com/neondatabase/cloud/issues/16886.
## Problem
It turns out that we can't rely on external orchestration to promptly
route trafic to the new leader. This is downtime inducing.
Forwarding provides a safe way out.
## Safety
We forward when:
1. Request is not one of ["/control/v1/step_down", "/status", "/ready",
"/metrics"]
2. Current instance is in [`LeadershipStatus::SteppedDown`] state
3. There is a leader in the database to forward to
4. Leader from step (3) is not the current instance
If a storcon instance is persisted in the database, then we know that it
is the current leader.
There's one exception: time between handling step-down request and the
new leader updating the
database.
Let's treat the happy case first. The stepped down node does not produce
any side effects,
since all request handling happens on the leader.
As for the edge case, we are guaranteed to always have a maximum of two
running instances.
Hence, if we are in the edge case scenario the leader persisted in the
database is the
stepped down instance that received the request. Condition (4) above
covers this scenario.
## Summary of changes
* Conversion utilities for reqwest <-> hyper. I'm not happy with these,
but I don't see a better way. Open to suggestions.
* Add request forwarding logic
* Update each request handler. Again, not happy with this. If anyone
knows a nice to wrap the handlers, lmk. Me and Joonas tried :/
* Update each handler to maybe forward
* Tweak tests to showcase new behaviour
For control-plane managed tenants, we have the page in the admin console
that lists all tenants on a specific pageserver. But for
storage-controller managed ones, we don't have that functionality for
now.
## Summary of changes
Adds an API that lists all shards on a given node (intention + observed)
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
We want to do AZ aware scheduling, but don't have enough metadata.
## Summary of changes
Introduce a `preferred_az_id` concept for each managed tenant shard.
In a future PR, the scheduler will use this as a soft preference.
The idea is to try and keep the shard attachments within the same AZ.
Under the assumption that the compute was placed in the correct AZ,
this reduces the chances of cross AZ trafic from between compute and PS.
In terms of code changes we:
1. Add a new nullable `preferred_az_id` column to the `tenant_shards`
table. Also include an in-memory counterpart.
2. Populate the preferred az on tenant creation and shard splits.
3. Add an endpoint which allows to bulk-set preferred AZs.
(3) gives us the migration path. I'll write a script which queries the
cplane db in the region and sets the preferred az of all shards with an
active compute to the AZ of said compute. For shards without an active compute,
I'll use the AZ of the currently attached pageserver
since this is what cplane uses now to schedule computes.
## Problem
The initial implementation of the validate API treats the in-memory
generations as authoritative.
- This is true when only one storage controller is running, but if a
rogue controller was running that hadn't been shut down properly, and
some pageserver requests were routed to that bad controller, it could
incorrectly return valid=true for stale generations.
- The generation in the main in-memory map gets out of date while a live
migration is in flight, and if the origin location for the migration
tries to do some deletions even though it is in AttachedStale (for
example because it had already started compaction), these might be
wrongly validated + executed.
## Summary of changes
- Continue to do the in-memory check: if this returns valid=false it is
sufficient to reject requests.
- When valid=true, do an additional read from the database to confirm
the generation is fresh.
- Revise behavior for validation on missing shards: this used to always
return valid=true as a convenience for deletions and shard splits, so
that pageservers weren't prevented from completing any enqueued
deletions for these shards after they're gone. However, this becomes
unsafe when we consider split brain scenarios. We could reinstate this
in future if we wanted to store some tombstones for deleted shards.
- Update test_scrubber_physical_gc to cope with the behavioral change:
they must now explicitly flush the deletion queue before splits, to
avoid tripping up on deletions that are enqueued at the time of the
split (these tests assert "scrubber deletes nothing", which check fails
if the split leaves behind some remote objects that are legitimately
GC'able)
- Add `test_storage_controller_validate_during_migration`, which uses
failpoints to create a situation where incorrect generation validation
during a live migration could result in a corruption
The rate of validate calls for tenants is pretty low: it happens as a
consequence deletions from GC and compaction, which are both
concurrency-limited on the pageserver side.
We currently do not record safekeepers in the storage controller
database. We want to migrate timelines across safekeepers eventually, so
start recording the safekeepers on deploy.
Cc: #8698
## Problem
- If a reconciler was waiting to be able to notify computes about a
change, but the control plane was waiting for the controller to finish a
timeline creation/deletion, the overall system can deadlock.
- If a tenant shard was migrated concurrently with a timeline
creation/deletion, there was a risk that the timeline operation could be
applied to a non-latest-generation location, and thereby not really be
persistent. This has never happened in practice, but would eventually
happen at scale.
Closes: #8743
## Summary of changes
- Introduce `Service::tenant_remote_mutation` helper, which looks up
shards & generations and passes them into an inner function that may do
remote I/O to pageservers. Before returning success, this helper checks
that generations haven't incremented, to guarantee that changes are
persistent.
- Convert tenant_timeline_create, tenant_timeline_delete, and
tenant_timeline_detach_ancestor to use this helper.
- These functions no longer block on ensure_attached unless the tenant
was never attached at all, so they should make progress even if we can't
complete compute notifications.
This increases the database load from timeline/create operations, but
only with cheap read transactions.
## Problem
Storage controllers did not have the right token to speak to their peers
for leadership transitions.
## Summary of changes
Accept a peer jwt token for the storage controller.
Epic: https://github.com/neondatabase/cloud/issues/14701
## Problem
https://github.com/neondatabase/neon/pull/8588 implemented the mechanism
for storage controller
leadership transfers. However, there's no tests that exercise the
behaviour.
## Summary of changes
1. Teach `neon_local` how to handle multiple storage controller
instances. Each storage controller
instance gets its own subdirectory (`storage_controller_1, ...`).
`storage_controller start|stop` subcommands
have also been extended to optionally accept an instance id.
2. Add a storage controller proxy test fixture. It's a basic HTTP server
that forwards requests from pageserver
and test env to the currently configured storage controller.
3. Add a test which exercises storage controller leadership transfer.
4. Finally fix a couple bugs that the test surfaced
Per #8674, disallow node configuration while drain/fill are ongoing.
Implement it by adding a only-http wrapper
`Service::external_node_configure` which checks for operation existing
before configuring.
Additionally:
- allow cancelling drain/fill after a pageserver has restarted and
transitioned to WarmingUp
Fixes: #8674
## Problem
Migrations of tenant shards with cold secondaries are holding up drains
in during production deployments.
## Summary of changes
If a secondary locations is lagging by more than 256MiB (configurable,
but that's the default), then skip cutting it over to the secondary as part of the node drain.
Part of #8128, followed by #8502.
## Problem
Currently we lack mechanism to alert unhealthy `scan_metadata` status if
we start running this scrubber command as part of a cronjob. With the
storage controller client introduced to storage scrubber in #8196, it is
viable to set up alert by storing health status in the storage
controller database.
We intentionally do not store the full output to the database as the
json blobs potentially makes the table really huge. Instead, only a
health status and a timestamp recording the last time metadata health
status is posted on a tenant shard.
Signed-off-by: Yuchen Liang <yuchen@neon.tech>
## Problem
We are missing the step-down primitive required to implement rolling
restarts of the storage controller.
## Summary of changes
Add `/control/v1/step_down` endpoint which puts the storage controller
into a state where it rejects
all API requests apart from `/control/v1/step_down`, `/status` and
`/metrics`. When receiving the request,
storage controller cancels all pending reconciles and waits for them to
exit gracefully. The response contains
a snapshot of the in-memory observed state.
Related:
* https://github.com/neondatabase/cloud/issues/14701
* https://github.com/neondatabase/neon/issues/7797
* https://github.com/neondatabase/neon/pull/8310
## Problem
Re-attach blocks the pageserver http server from starting up. Hence, it
can't reply to heartbeats
until that's done. This makes the storage controller mark the node
off-line (not good). We worked
around this by setting the interval after which nodes are marked offline
to 5 minutes. This isn't a
long term solution.
## Summary of changes
* Introduce a new `NodeAvailability` state: `WarmingUp`. This state
models the following time interval:
* From receiving the re-attach request until the pageserver replies to
the first heartbeat post re-attach
* The heartbeat delta generator becomes aware of this state and uses a
separate longer interval
* Flag `max-warming-up-interval` now models the longer timeout and
`max-offline-interval` the shorter one to
match the names of the states
Closes https://github.com/neondatabase/neon/issues/7552
## Problem
In anticipation of later adding a really nice drain+delete API, I
initially only added an intentionally basic `/drop` API that is just
about usable for deleting nodes in a pinch, but requires some ugly
storage controller restarts to persuade it to restart secondaries.
## Summary of changes
I started making a few tiny fixes, and ended up writing the delete
API...
- Quality of life nit: ordering of node + tenant listings in storcon_cli
- Papercut: Fix the attach_hook using the wrong operation type for
reporting slow locks
- Make Service::spawn tolerate `generation_pageserver` columns that
point to nonexistent node IDs. I started out thinking of this as a
general resilience thing, but when implementing the delete API I
realized it was actually a legitimate end state after the delete API is
called (as that API doesn't wait for all reconciles to succeed).
- Add a `DELETE` API for nodes, which does not gracefully drain, but
does reschedule everything. This becomes safe to use when the system is
in any state, but will incur availability gaps for any tenants that
weren't already live-migrated away. If tenants have already been
drained, this becomes a totally clean + safe way to decom a node.
- Add a test and a storcon_cli wrapper for it
This is meant to be a robust initial API that lets us remove nodes
without doing ugly things like restarting the storage controller -- it's
not quite a totally graceful node-draining routine yet. There's more
work in https://github.com/neondatabase/neon/issues/8333 to get to our
end-end state.
## Problem
When generations were new, these messages were an important way of
noticing if something unexpected was going on. We found some real issues
when investigating tests that unexpectedly tripped them.
At time has gone on, this code is now pretty battle-tested, and as we do
more live migrations etc, it's fairly normal to see the occasional
message from a node with a stale generation.
At this point the cognitive load on developers to selectively allow-list
these logs outweighs the benefit of having them at warn severity.
Closes: https://github.com/neondatabase/neon/issues/8080
## Summary of changes
- Downgrade "Dropped remote consistent LSN updates" and "Dropping stale
deletions" messages to INFO
- Remove all the allow-list entries for these logs.
## Problem
For some time, we have created tenants with calls to location_conf. The
legacy "POST /v1/tenant" path was only used in some tests.
## Summary of changes
- Remove the API
- Relocate TenantCreateRequest to the controller API file (this used to
be used in both pageserver and controller APIs)
- Rewrite tenant_create test helper to use location_config API, as
control plane and storage controller do
- Update docker-compose test script to create tenants with
location_config API (this small commit is also present in
https://github.com/neondatabase/neon/pull/7947)
## Problem
Background node operations take a long time for loaded nodes.
## Summary of changes
Increase number of concurrent reconciles an operation is allowed to
spawn.
This should make drain and fill operations faster and the new value is
still well below the total limit of concurrent reconciles.
## Problem
There's no way to cancel drain and fill operations.
## Summary of changes
Implement HTTP endpoints to allow cancelling of background operations.
When the operationis cancelled successfully, the node scheduling policy will revert to
`Active`.
In #7957 we enabled deletion without attachment, but retained the
old-style deletion (return 202, delete in background) for attached
tenants. In this PR, we remove the old-style deletion path, such that if
the tenant delete API is invoked while a tenant is detached, it is
simply detached before completing the deletion.
This intentionally doesn't rip out all the old deletion code: in case a
deletion was in progress at time of upgrade, we keep around the code for
finishing it for one release cycle. The rest of the code removal happens
in https://github.com/neondatabase/neon/pull/8091
Now that deletion will always be via the new path, the new path is also
updated to use some retries around remote storage operations, to
tripping up the control plane with 500s if S3 has an intermittent issue.
## Problem
When creating a new shard the storage controller schedules via
Scheduler::schedule_shard. This does not take into account the number of
attached shards. What it does take into account is the node affinity:
when a shard is scheduled, all its nodes (primaries and secondaries) get
their affinity incremented.
For two node clusters and shards with one secondary we have a
pathological case where all primaries are scheduled on the same node.
Now that we track the count of attached shards per node, this is trivial
to fix. Still, the "proper" fix is to use the pageserver's utilization
score.
Closes https://github.com/neondatabase/neon/issues/8041
## Summary of changes
Use attached shard count when deciding which node to schedule a fresh
shard on.
