Not a user-facing change, but can break any existing `.neon` directories
created by neon_local, as the name of the database used by the storage
controller changes.
This PR changes all the locations apart from the path of
`control_plane/attachment_service` (waiting for an opportune moment to
do that one, because it's the most conflict-ish wrt ongoing PRs like
#6676 )
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.
fixes https://github.com/neondatabase/neon/issues/6889
# Problem
The failure in the last 3 flaky runs on `main` is
```
test_runner/regress/test_remote_storage.py:460: in test_remote_timeline_client_calls_started_metric
churn("a", "b")
test_runner/regress/test_remote_storage.py:457: in churn
assert gc_result["layers_removed"] > 0
E assert 0 > 0
```
That's this code
cd449d66ea/test_runner/regress/test_remote_storage.py (L448-L460)
So, the test expects GC to remove some layers but the GC doesn't.
# Fix
My impression is that the VACUUM isn't re-using pages aggressively
enough, but I can't really prove that. Tried to analyze the layer map
dump but it's too complex.
So, this PR:
- Creates more churn by doing the overwrite twice.
- Forces image layer creation.
It also drive-by removes the redundant call to timeline_compact,
because, timeline_checkpoint already does that internally.
* decreases checkpointing and compaction targets for even more layer
files
* write 10 thousand rows 2 times instead of writing 20 thousand rows 1
time so that there is more to GC. Before it was noisily jumping between
1 and 0 layer files, now it's jumping between 19 and 20 layer files. The
0 caused an assertion error that gave the test most of its flakiness.
* larger timeout for the churn while failpoints are active thread: this
is mostly so that the test is more robust on systems with more load
Fixes#3051
refs #6737
# Problem
Before this PR, on-demand downloads weren't measured per tenant_id.
This makes root-cause analysis of latency spikes harder, requiring us to
resort to log scraping for
```
{neon_service="pageserver"} |= `downloading on-demand` |= `$tenant_id`
```
which can be expensive when zooming out in Grafana.
Context: https://neondb.slack.com/archives/C033RQ5SPDH/p1707809037868189
# Solution / Changes
- Remove the calls_started histogram
- I did the dilegence, there are only 2 dashboards using this histogram,
and in fact only one uses it as a histogram, the other just as a
a counter.
- [Link
1](8115b54d9f/neonprod/dashboards/hkXNF7oVz/dashboard-Z31XmM24k.yaml (L1454)):
`Pageserver Thrashing` dashboard, linked from playbook, will fix.
- [Link
2](8115b54d9f/neonprod/dashboards/CEllzAO4z/dashboard-sJqfNFL4k.yaml (L599)):
one of my personal dashboards, unused for a long time, already broken in
other ways, no need to fix.
- replace `pageserver_remote_timeline_client_calls_unfinished` gauge
with a counter pair
- Required `Clone`-able `IntCounterPair`, made the necessary changes in
the `libs/metrics` crate
- fix tests to deal with the fallout
A subsequent PR will remove a timeline-scoped metric to compensate.
Note that we don't need additional global counters for the per-timeline
counters affected by this PR; we can use the `remote_storage` histogram
for those, which, conveniently, also include the secondary-mode
downloads, which aren't covered by the remote timeline client metrics
(should they?).
Commit 9a6c0be823 removed the code that printed these warnings:
marking {} as locally complete, while it doesnt exist in remote index
No timelines to attach received
Remove those warnings from all the allowlists in tests.
## Problem
The code for tenant create and tenant attach was just a special case of
what upsert_location does.
## Summary of changes
- Use `upsert_location` for create and attach APIs
- Clean up error handling in upsert_location so that it can generate
appropriate HTTP response codes
- Update tests that asserted the old non-idempotent behavior of attach
- Rework the `test_ignore_while_attaching` test, and fix tenant shutdown
during activation, which this test was supposed to cover, but it was
actually just waiting for activation to complete.
This is a precursor to:
- https://github.com/neondatabase/neon/pull/6185
While that PR contains big changes to neon_local and attachment_service,
this PR contains a few unrelated standalone changes generated while
working on that branch:
- Fix restarting a pageserver when it contains multiple shards for the
same tenant
- When using location_config api to attach a tenant, create its
timelines dir
- Update test paths where generations were previously optional to make
them always-on: this avoids tests having to spuriously assert that
attachment_service is not None in order to make the linter happy.
- Add a TenantShardId python implementation for subsequent use in test
helpers that will be made shard-aware
- Teach scrubber to read across shards when checking for layer
existence: this is a refactor to track the list of existent layers at
tenant-level rather than locally to each timeline. This is a precursor
to testing shard splitting.
Repeated calls to `.append` don't line up as nicely as they might get
formatted in different ways. Also, it is more characters and the lines
might be longer.
Saw this while working on #5912.
## Problem
Some existing tests are written in a way that's incompatible with tenant
generations.
## Summary of changes
Update all the tests that need updating: this is things like calling
through the NeonPageserver.tenant_attach helper to get a generation
number, instead of calling directly into the pageserver API. There are
various more subtle cases.
Per [feedback], split the Layer metrics, also finally account for lost
and [re-submitted feedback] on `layer_gc` by renaming it to
`layer_delete`, `Layer::garbage_collect_on_drop` renamed to
`Layer::delete_on_drop`. References to "gc" dropped from metric names
and elsewhere.
Also fixes how the cancellations were tracked: there was one rare
counter. Now there is a top level metric for cancelled inits, and the
rare "download failed but failed to communicate" counter is kept.
Fixes: #6027
[feedback]: https://github.com/neondatabase/neon/pull/5809#pullrequestreview-1720043251
[re-submitted feedback]: https://github.com/neondatabase/neon/pull/5108#discussion_r1401867311
This PR adds an `existing_initdb_timeline_id` option to timeline
creation APIs, taking an optional timeline ID.
Follow-up of #5390.
If the `existing_initdb_timeline_id` option is specified via the HTTP
API, the pageserver downloads the existing initdb archive from the given
timeline ID and extracts it, instead of running initdb itself.
---------
Co-authored-by: Christian Schwarz <christian@neon.tech>
Test failure seen here:
https://neon-github-public-dev.s3.amazonaws.com/reports/pr-5860/7032903218/index.html#suites/837740b64a53e769572c4ed7b7a7eeeb/c0f1c79a70a3b9ab
```
E AssertionError: assert not [(302, '2023-11-29T13:23:51.046801Z ERROR request{method=PUT path=/v1/tenant/f6b845de60cb0e92f4426e0d6af1d2ea/timeline/69a8c98004abe71a281cff8642a45274/checkpoint request_id=eca33d8a-7af2-46e7-92ab-c28629feb42c}: Error processing HTTP request: InternalServerError(queue is in state Stopped\n')]
```
This appears to be a legitimate log: the test is issuing checkpoint
requests in the background, and deleting (therefore shutting down) a
timeline.
Quest: https://github.com/neondatabase/neon/issues/4745. Follow-up to
#4938.
- add in locks for compaction and gc, so we don't have multiple
executions at the same time in tests
- remove layer_removal_cs
- remove waiting for uploads in eviction/gc/compaction
- #4938 will keep the file resident until upload completes
Co-authored-by: Christian Schwarz <christian@neon.tech>
Implement a new `struct Layer` abstraction which manages downloadness
internally, requiring no LayerMap locking or rewriting to download or
evict providing a property "you have a layer, you can read it". The new
`struct Layer` provides ability to keep the file resident via a RAII
structure for new layers which still need to be uploaded. Previous
solution solved this `RemoteTimelineClient::wait_completion` which lead
to bugs like #5639. Evicting or the final local deletion after garbage
collection is done using Arc'd value `Drop`.
With a single `struct Layer` the closed open ended `trait Layer`, `trait
PersistentLayer` and `struct RemoteLayer` are removed following noting
that compaction could be simplified by simply not using any of the
traits in between: #4839.
The new `struct Layer` is a preliminary to remove
`Timeline::layer_removal_cs` documented in #4745.
Preliminaries: #4936, #4937, #5013, #5014, #5022, #5033, #5044, #5058,
#5059, #5061, #5074, #5103, epic #5172, #5645, #5649. Related split off:
#5057, #5134.
## Problem
Compaction's source of truth for what layers exist is the LayerManager.
`flush_frozen_layer` updates LayerManager before it has scheduled upload
of the frozen layer.
Compaction can then "see" the new layer, decide to delete it, schedule
uploads of replacement layers, all before `flush_frozen_layer` wakes up
again and schedules the upload. When the upload is scheduled, the local
layer file may be gone, in which case we end up with no such layer in
remote storage, but an entry still added to IndexPart pointing to the
missing layer.
## Summary of changes
Schedule layer uploads inside the `self.layers` lock, so that whenever a
frozen layer is present in LayerManager, it is also present in
RemoteTimelineClient's metadata.
Closes: #5635
Fixes#5172 as it:
- removes recoinciliation with remote index_part.json and accepts remote
index_part.json as the truth, deleting any local progress which is yet
to be reflected in remote
- moves to prefer remote metadata
Additionally:
- tests with single LOCAL_FS parametrization are cleaned up
- adds a test case for branched (non-bootstrap) local only timeline
availability after restart
---------
Co-authored-by: Christian Schwarz <christian@neon.tech>
Co-authored-by: John Spray <john@neon.tech>
## 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>
## Problem
Currently our testing environment only supports running a single
pageserver at a time. This is insufficient for testing failover and
migrations.
- Dependency of writing tests for #5207
## Summary of changes
- `neon_local` and `neon_fixture` now handle multiple pageservers
- This is a breaking change to the `.neon/config` format: any local
environments will need recreating
- Existing tests continue to work unchanged:
- The default number of pageservers is 1
- `NeonEnv.pageserver` is now a helper property that retrieves the first
pageserver if there is only one, else throws.
- Pageserver data directories are now at `.neon/pageserver_{n}` where n
is 1,2,3...
- Compatibility tests get some special casing to migrate neon_local
configs: these are not meant to be backward/forward compatible, but they
were treated that way by the test.
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
- #5050
Closes: https://github.com/neondatabase/neon/issues/5136
## Summary of changes
- A new configuration property `control_plane_api` controls other
functionality in this PR: if it is unset (default) then everything still
works as it does today.
- If `control_plane_api` is set, then on startup we call out to control
plane `/re-attach` endpoint to discover our attachments and their
generations. If an attachment is missing from the response we implicitly
detach the tenant.
- Calls to pageserver `/attach` API may include a `generation`
parameter. If `control_plane_api` is set, then this parameter is
mandatory.
- RemoteTimelineClient's loading of index_part.json is generation-aware,
and will try to load the index_part with the most recent generation <=
its own generation.
- The `neon_local` testing environment now includes a new binary
`attachment_service` which implements the endpoints that the pageserver
requires to operate. This is on by default if running `cargo neon` by
hand. In `test_runner/` tests, it is off by default: existing tests
continue to run with in the legacy generation-less mode.
Caveats:
- The re-attachment during startup assumes that we are only re-attaching
tenants that have previously been attached, and not totally new tenants
-- this relies on the control plane's attachment logic to keep retrying
so that we should eventually see the attach API call. That's important
because the `/re-attach` API doesn't tell us which timelines we should
attach -- we still use local disk state for that. Ref:
https://github.com/neondatabase/neon/issues/5173
- Testing: generations are only enabled for one integration test right
now (test_pageserver_restart), as a smoke test that all the machinery
basically works. Writing fuller tests that stress tenant migration will
come later, and involve extending our test fixtures to deal with
multiple pageservers.
- I'm not in love with "attachment_service" as a name for the neon_local
component, but it's not very important because we can easily rename
these test bits whenever we want.
- Limited observability when in re-attach on startup: when I add
generation validation for deletions in a later PR, I want to wrap up the
control plane API calls in some small client class that will expose
metrics for things like errors calling the control plane API, which will
act as a strong red signal that something is not right.
Co-authored-by: Christian Schwarz <christian@neon.tech>
Co-authored-by: Joonas Koivunen <joonas@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
## Problem
Test failing on a different ERROR log than it anticipated.
Closes: https://github.com/neondatabase/neon/issues/5148
## Summary of changes
Add the "could not flush frozen layer" error log to the permitted
errors.
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
PR #4839 has already reduced the number of b-tree traversals and vec
creations from 3 to 2, but as pointed out in
https://github.com/neondatabase/neon/pull/4839#discussion_r1279167815 ,
we would ideally just traverse the b-tree once during compaction.
Afer #4836, the two vecs created are one for the list of keys, lsns and
sizes, and one for the list of `(key, lsn, value reference)`. However,
they are not equal, as pointed out in
https://github.com/neondatabase/neon/pull/4839#issuecomment-1660418012
and the following comment: the key vec creation combines multiple
entries for which the lsn is changing but the key stays the same into
one, with the size being the sum of the sub-sizes. In SQL, this would
correspond to something like `SELECT key, lsn, SUM(size) FROM b_tree
GROUP BY key;` and `SELECT key, lsn, val_ref FROM b_tree;`. Therefore,
the join operation is non-trivial.
## Summary of changes
This PR merges the two lists of keys and value references into one. It's
not a trivial change and affects the size pattern of the resulting
files, which is why this is in a separate PR from #4839 .
The key vec is used in compaction for determining when to start a new
layer file. The loop uses various thresholds to come to this conclusion,
but the grouping via the key has led to the behaviour that regardless of
the threshold, it only starts a new file when either a new key is
encountered, or a new delta file.
The new code now does the combination after the merging and sorting of
the various keys from the delta files. This *mostly* does the same as
the old code, except for a detail: with the grouping done on a
per-delta-layer basis, the sorted and merged vec would still have
multiple entries for multiple delta files, but now, we don't have an
easy way to tell when a new input delta layer file is encountered, so we
cannot create multiple entries on that basis easily.
To prevent possibly infinite growth, our new grouping code compares the
combined size with the threshold, and if it is exceeded, it cuts a new
entry so that the downstream code can cut a new output file. Here, we
perform a tradeoff however, as if the threshold is too small, we risk
putting entries for the same key into multiple layer files, but if the
threshold is too big, we can in some instances exceed the target size.
Currently, we set the threshold to the target size, so in theory we
would stay below or roughly at double the `target_file_size`.
We also fix the way the size was calculated for the last key. The calculation
was wrong and accounted for the old layer's btree, even though we
already account for the overhead of the in-construction btree.
Builds on top of #4839 .
Previously list_prefixes was incorrectly used for that purpose. Change
to use list_files. Add a test.
Some drive by refactorings on python side to move helpers out of
specific test file to be widely accessible
resolves https://github.com/neondatabase/neon/issues/4499
## Problem
This was set to 5 seconds, which was very close to how long a compaction
took on my workstation, and when deletion is blocked on compaction the
test would fail.
We will fix this to make compactions drop out on deletion, but for the
moment let's stabilize the test.
## Summary of changes
Change timeout on timeline deletion in
`test_timeline_deletion_with_files_stuck_in_upload_queue` from 5 seconds
to 30 seconds.
Originated from test failure where we got SlowDown error from s3.
The patch generalizes `download_retry` to not be download specific.
Resulting `retry` function is moved to utils crate. `download_retries`
is now a thin wrapper around this `retry` function.
To ensure that all needed retries are in place test code now uses
`test_remote_failures=1` setting.
Ref https://neondb.slack.com/archives/C059ZC138NR/p1691743624353009
## 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.
## Problem
close https://github.com/neondatabase/neon/issues/4712
## Summary of changes
Previously, when flushing frozen layers, it was split into two
operations: add delta layer to disk + remove frozen layer from memory.
This would cause a short period of time where we will have the same data
both in frozen and delta layer. In this PR, we merge them into one
atomic operation in layer map manager, therefore simplifying the code.
Note that if we decide to create image layers for L0 flush, it will
still be split into two operations on layer map.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
Co-authored-by: Joonas Koivunen <joonas@neon.tech>
Handle test failures like:
```
AssertionError: assert not ['$ts WARN delete_timeline{tenant_id=X timeline_id=Y}: About to remove 1 files\n']
```
Instead of logging:
```
WARN delete_timeline{tenant_id=X timeline_id=Y}: Found 1 files not bound to index_file.json, proceeding with their deletion
WARN delete_timeline{tenant_id=X timeline_id=Y}: About to remove 1 files
```
For each one operation of timeline deletion, list all unref files with
`info!`, and then continue to delete them with the added spice of
logging the rare/never happening non-utf8 name with `warn!`.
Rationale for `info!` instead of `warn!`: this is a normal operation;
like we had mentioned in `test_import.py` -- basically whenever we
delete a timeline which is not idle.
Rationale for N * (`ìnfo!`|`warn!`): symmetry for the layer deletions;
if we could ever need those, we could also need these for layer files
which are not yet mentioned in `index_part.json`.
---------
Co-authored-by: Christian Schwarz <christian@neon.tech>
This addresses the issue in #4526 by adding a test that reproduces the
race condition that gave rise to the bug (or at least *a* race condition
that gave rise to the same error message), and then implementing a fix
that just prints a message to the log if a file could not been found for
uploading. Even though the underlying race condition is not fixed yet,
this will un-block the upload queue in that situation, greatly reducing
the impact of such a (rare) race.
Fixes#4526.
## Problem
1. During the rollout we got a panic: "timeline that we were deleting
was concurrently removed from 'timelines' map" that was caused by lock
guard not being propagated to the background part of the deletion.
Existing test didnt catch it because failpoint that was used for
verification was placed earlier prior to background task spawning.
2. When looking at surrounding code one more bug was detected. We
removed timeline from the map before deletion is finished, which breaks
client retry logic, because it will indicate 404 before actual deletion
is completed which can lead to client stopping its retry poll earlier.
## Summary of changes
1. Carry the lock guard over to background deletion. Ensure existing
test case fails without applied patch (second deletion becomes stuck
without it, which eventually leads to a test failure).
2. Move delete_all call earlier so timeline is removed from the map is
the last thing done during deletion.
Additionally I've added timeline_id to the `update_gc_info` span,
because `debug_assert_current_span_has_tenant_and_timeline_id` in
`download_remote_layer` was firing when `update_gc_info` lead to
on-demand downloads via `find_lsn_for_timestamp` (caught by @problame).
This is not directly related to the PR but fixes possible flakiness.
Another smaller set of changes involves deletion wrapper used in python
tests. Now there is a simpler wrapper that waits for deletions to
complete `timeline_delete_wait_completed`. Most of the
test_delete_timeline.py tests make negative tests, i.e., "does
ps_http.timeline_delete() fail in this and that scenario".
These can be left alone. Other places when we actually do the deletions,
we need to use the helper that polls for completion.
Discussion
https://neondb.slack.com/archives/C03F5SM1N02/p1686668007396639resolves#4496
---------
Co-authored-by: Christian Schwarz <christian@neon.tech>
Delete data from s3 when timeline deletion is requested
## Summary of changes
UploadQueue is altered to support scheduling of delete operations in
stopped state. This looks weird, and I'm thinking whether there are
better options/refactorings for upload client to make it look better.
Probably can be part of https://github.com/neondatabase/neon/issues/4378
Deletion is implemented directly in existing endpoint because changes are not
that significant. If we want more safety we can separate those or create
feature flag for new behavior.
resolves [#4193](https://github.com/neondatabase/neon/issues/4193)
---------
Co-authored-by: Joonas Koivunen <joonas@neon.tech>
## Problem
Attach failures are not reported in public part of the api (in
`attachment_status` field of TenantInfo).
## Summary of changes
Expose TenantState::Broken as TenantAttachmentStatus::Failed
In the way its written Failed status will be reported even if no
attachment happened. (I e if tenant become broken on startup). This is
in line with other members. I e Active will be resolved to Attached even
if no actual attach took place.
This can be tweaked if needed. At the current stage it would be overengineering without clear motivation
resolves#4344
We have 2 ways of tenant shutdown, we should have just one.
Changes are mostly mechanical simple refactorings.
Added `warn!` on the "shutdown all remaining tasks" should trigger test
failures in the between time of not having solved the "tenant/timeline
owns all spawned tasks" issue.
Cc: #4327.
This is preliminary work for/from #4220 (async
`Layer::get_value_reconstruct_data`).
The motivation is to avoid locking `Tenant::timelines` in places that
can't be `async`, because in #4333 we want to convert Tenant::timelines
from `std::sync::Mutex` to `tokio::sync::Mutex`.
But, the changes here are useful in general because they clean up &
document tenant state transitions.
That also paves the way for #4350, which is an alternative to #4333 that
refactors the pageserver code so that we can keep the
`Tenant::timelines` mutex sync.
This patch consists of the following core insights and changes:
* spawn_load and spawn_attach own the tenant state until they're done
* once load()/attach() calls are done ...
* if they failed, transition them to Broken directly (we know that
there's no background activity because we didn't call activate yet)
* if they succeed, call activate. We can make it infallible. How? Later.
* set_broken() and set_stopping() are changed to wait for spawn_load() /
spawn_attach() to finish.
* This sounds scary because it might hinder detach or shutdown, but
actually, concurrent attach+detach, or attach+shutdown, or
load+shutdown, or attach+shutdown were just racy before this PR.
So, with this change, they're not anymore.
In the future, we can add a `CancellationToken` stored in Tenant to
cancel `load` and `attach` faster, i.e., make `spawn_load` /
`spawn_attach` transition them to Broken state sooner.
See the doc comments on TenantState for the state transitions that are
now possible.
It might seem scary, but actually, this patch reduces the possible state
transitions.
We introduce a new state `TenantState::Activating` to avoid grabbing the
`Tenant::timelines` lock inside the `send_modify` closure.
These were the humble beginnings of this PR (see Motivation section),
and I think it's still the right thing to have this `Activating` state,
even if we decide against async `Tenant::timelines` mutex. The reason is
that `send_modify` locks internally, and by moving locking of
Tenant::timelines out of the closure, the internal locking of
`send_modify` becomes a leaf of the lock graph, and so, we eliminate
deadlock risk.
Co-authored-by: Joonas Koivunen <joonas@neon.tech>
With this patch, the attach handler now follows the same pattern as
tenant create with regards to instantiation of the new tenant:
1. Prepare on-disk state using `create_tenant_files`.
2. Use the same code path as pageserver startup to load it into memory
and start background loops (`schedule_local_tenant_processing`).
It's a bit sad we can't use the
`PageServerConfig::tenant_attaching_mark_file_path` method inside
`create_tenant_files` because it operates in a temporary directory.
However, it's a small price to pay for the gained simplicity.
During implementation, I noticed that we don't handle failures post
`create_tenant_files` well. I left TODO comments in the code linking to
the issue that I created for this [^1].
Also, I'll dedupe the spawn_load and spawn_attach code in a future
commit.
refs https://github.com/neondatabase/neon/issues/1555
part of https://github.com/neondatabase/neon/issues/886 (Tenant
Relocation)
[^1]: https://github.com/neondatabase/neon/issues/4233
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.
