The `--timelines-onto-safekeepers` flag is very consequential in the
sense that it controls every single timeline creation. However, we don't
have any automatic insight whether enabling the option will break things
or not.
The main way things can break is by misconfigured safekeepers, say they
are marked as paused in the storcon db. The best input so far we can
obtain via manually connecting via storcon_cli and listing safekeepers,
but this is cumbersome and manual so prone to human error.
So at storcon startup, do a simulated "test creation" in which we call
`timelines_onto_safekeepers` with the configuration provided to us, and
print whether it was successful or not. No actual timeline is created,
and nothing is written into the storcon db. The heartbeat info will not
have reached us at that point yet, but that's okay, because we still
fall back to safekeepers that don't have any heartbeat.
Also print some general scheduling policy stats on initial safekeeper
load.
Part of #11670.
## Problem
For the communicator, we need a rich Pageserver gRPC client.
Touches #11735.
Requires #12434.
## Summary of changes
This patch adds an initial rich Pageserver gRPC client. It supports:
* Sharded tenants across multiple Pageservers.
* Pooling of connections, clients, and streams for efficient resource
use.
* Concurrent use by many callers.
* Internal handling of GetPage bidirectional streams, with pipelining
and error handling.
* Automatic retries.
* Observability.
The client is still under development. In particular, it needs GetPage
batch splitting, shard map updates, and performance optimization. This
will be addressed in follow-up PRs.
The only differentiated handling of it is for `is_critical`, which in
turn is a `matches!()` on several variants of the `enum
CollectKeyspaceError`
which is the value contained insided
`CompactionError::CollectKeyspaceError`.
This PR introduces a new error for `repartition()`, allowing its
immediate
callers to inspect it like `is_critical` did.
A drive-by fix is more precise classification of WaitLsnError::BadState
when mapping to `tonic::Status`.
refs
- https://databricks.atlassian.net/browse/LKB-182
## Problem
close LKB-209
## Summary of changes
- We should not allow lease creation below the applied gc cutoff.
- Also removed the condition for `AttachedSingle`. We should always
check the lease against the gc cutoff in all attach modes.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
We only trim the senders if we tried to send a message to them and
discovered that the channel is closed. This is problematic if the
pageserver keeps connecting while there's nothing to send back for the
shard. In this scenario we never trim down the senders list and can
panic due to the u8 limit.
## Summary of Changes
Trim down the dead senders before adding a new one.
Closes LKB-178
## Problem
We lost capability to explicitly disable the global eviction task (for
testing).
## Summary of changes
Add an `enabled` flag to `DiskUsageEvictionTaskConfig` to indicate
whether we should run the eviction job or not.
## Problem
The communicator will need gRPC channel/client/stream pools for
efficient reuse across many backends.
Touches #11735.
Requires #12396.
## Summary of changes
Adds three nested resource pools:
* `ChannelPool` for gRPC channels (i.e. TCP connections).
* `ClientPool` for gRPC clients (i.e. `page_api::Client`). Acquires
channels from `ChannelPool`.
* `StreamPool` for gRPC GetPage streams. Acquires clients from
`ClientPool`.
These are minimal functional implementations that will need further
improvements and performance optimization. However, the overall
structure is expected to be roughly final, so reviews should focus on
that.
The pools are not yet in use, but will form the foundation of a rich
gRPC Pageserver client used by the communicator (see #12462). This PR
also adds the initial crate scaffolding for that client.
See doc comments for details.
# TLDR
All changes are no-op except
1. publishing additional metrics.
2. problem VI
## Problem I
It has come to my attention that the Neon Storage Controller doesn't
correctly update its "observed" state of tenants previously associated
with PSs that has come back up after a local data loss. It would still
think that the old tenants are still attached to page servers and won't
ask more questions. The pageserver has enough information from the
reattach request/response to tell that something is wrong, but it
doesn't do anything about it either. We need to detect this situation in
production while I work on a fix.
(I think there is just some misunderstanding about how Neon manages
their pageserver deployments which got me confused about all the
invariants.)
## Summary of changes I
Added a `pageserver_local_data_loss_suspected` gauge metric that will be
set to 1 if we detect a problematic situation from the reattch response.
The problematic situation is when the PS doesn't have any local tenants
but received a reattach response containing tenants.
We can set up an alert using this metric. The alert should be raised
whenever this metric reports non-zero number.
Also added a HTTP PUT
`http://pageserver/hadron-internal/reset_alert_gauges` API on the
pageserver that can be used to reset the gauge and the alert once we
manually rectify the situation (by restarting the HCC).
## Problem II
Azure upload is 3x slower than AWS. -> 3x slower ingestion.
The reason for the slower upload is that Azure upload in page server is
much slower => higher flush latency => higher disk consistent LSN =>
higher back pressure.
## Summary of changes II
Use Azure put_block API to uploads a 1 GB layer file in 8 blocks in
parallel.
I set the put_block block size to be 128 MB by default in azure config.
To minimize neon changes, upload function passes the layer file path to
the azure upload code through the storage metadata. This allows the
azure put block to use FileChunkStreamRead to stream read from one
partition in the file instead of loading all file data in memory and
split it into 8 128 MB chunks.
## How is this tested? II
1. rust test_real_azure tests the put_block change.
3. I deployed the change in azure dev and saw flush latency reduces from
~30 seconds to 10 seconds.
4. I also did a bunch of stress test using sqlsmith and 100 GB TPCDS
runs.
## Problem III
Currently Neon limits the compaction tasks as 3/4 * CPU cores. This
limits the overall compaction throughput and it can easily cause
head-of-the-line blocking problems when a few large tenants are
compacting.
## Summary of changes III
This PR increases the limit of compaction tasks as `BG_TASKS_PER_THREAD`
(default 4) * CPU cores. Note that `CONCURRENT_BACKGROUND_TASKS` also
limits some other tasks `logical_size_calculation` and `layer eviction`
. But compaction should be the most frequent and time-consuming task.
## Summary of changes IV
This PR adds the following PageServer metrics:
1. `pageserver_disk_usage_based_eviction_evicted_bytes_total`: captures
the total amount of bytes evicted. It's more straightforward to see the
bytes directly instead of layers.
2. `pageserver_active_storage_operations_count`: captures the active
storage operation, e.g., flush, L0 compaction, image creation etc. It's
useful to visualize these active operations to get a better idea of what
PageServers are spending cycles on in the background.
## Summary of changes V
When investigating data corruptions, it's useful to search the base
image and all WAL records of a page up to an LSN, i.e., a breakdown of
GetPage@LSN request. This PR implements this functionality with two
tools:
1. Extended `pagectl` with a new command to search the layer files for a
given key up to a given LSN from the `index_part.json` file. The output
can be used to download the files from S3 and then search the file
contents using the second tool.
Example usage:
```
cargo run --bin pagectl index-part search --tenant-id 09b99ea3239bbb3b2d883a59f087659d --timeline-id 7bedf4a6995baff7c0421ff9aebbcdab --path ~/Downloads/corruption/index_part.json-0000000c-formatted --key 000000067F000080140000802100000D61BD --lsn 70C/BF3D61D8
```
Example output:
```
tenants/09b99ea3239bbb3b2d883a59f087659d-0304/timelines/7bedf4a6995baff7c0421ff9aebbcdab/000000067F0000801400000B180000000002-000000067F0000801400008028000002FEFF__000007089F0B5381-0000070C7679EEB9-0000000c
tenants/09b99ea3239bbb3b2d883a59f087659d-0304/timelines/7bedf4a6995baff7c0421ff9aebbcdab/000000000000000000000000000000000000-000000067F0000801400008028000002F3F1__000006DD95B6F609-000006E2BA14C369-0000000c
tenants/09b99ea3239bbb3b2d883a59f087659d-0304/timelines/7bedf4a6995baff7c0421ff9aebbcdab/000000067F0000801400000B180000000002-000000067F000080140000802100001B0973__000006D33429F539-000006DD95B6F609-0000000c
tenants/09b99ea3239bbb3b2d883a59f087659d-0304/timelines/7bedf4a6995baff7c0421ff9aebbcdab/000000067F0000801400000B180000000002-000000067F00008014000080210000164D81__000006C6343B2D31-000006D33429F539-0000000b
tenants/09b99ea3239bbb3b2d883a59f087659d-0304/timelines/7bedf4a6995baff7c0421ff9aebbcdab/000000067F0000801400000B180000000002-000000067F0000801400008021000017687B__000006BA344FA7F1-000006C6343B2D31-0000000b
tenants/09b99ea3239bbb3b2d883a59f087659d-0304/timelines/7bedf4a6995baff7c0421ff9aebbcdab/000000067F0000801400000B180000000002-000000067F00008014000080210000165BAB__000006AD34613D19-000006BA344FA7F1-0000000b
tenants/09b99ea3239bbb3b2d883a59f087659d-0304/timelines/7bedf4a6995baff7c0421ff9aebbcdab/000000067F0000801400000B180000000002-000000067F00008014000080210000137A39__0000069F34773461-000006AD34613D19-0000000b
tenants/09b99ea3239bbb3b2d883a59f087659d-0304/timelines/7bedf4a6995baff7c0421ff9aebbcdab/000000067F000080140000802100000D4000-000000067F000080140000802100000F0000__0000069F34773460-0000000b
```
2. Added a unit test to search the layer file contents. It's not
implemented part of `pagectl` because it depends on some test harness
code, which can only be used by unit tests.
Example usage:
```
cargo test --package pageserver --lib -- tenant::debug::test_search_key --exact --nocapture -- --tenant-id 09b99ea3239bbb3b2d883a59f087659d --timeline-id 7bedf4a6995baff7c0421ff9aebbcdab --data-dir /Users/chen.luo/Downloads/corruption --key 000000067F000080140000802100000D61BD --lsn 70C/BF3D61D8
```
Example output:
```
# omitted image for brievity
delta: 69F/769D8180: will_init: false, "OgAAALGkuwXwYp12nwYAAECGAAASIqLHAAAAAH8GAAAUgAAAIYAAAL1hDQD/DLGkuwUDAAAAEAAWAA=="
delta: 69F/769CB6D8: will_init: false, "PQAAALGkuwXotZx2nwYAABAJAAAFk7tpACAGAH8GAAAUgAAAIYAAAL1hDQD/CQUAEAASALExuwUBAAAAAA=="
```
## Problem VI
Currently when page service resolves shards from page numbers, it
doesn't fully support the case that the shard could be split in the
middle. This will lead to query failures during the tenant split for
either commit or abort cases (it's mostly for abort).
## Summary of changes VI
This PR adds retry logic in `Cache::get()` to deal with shard resolution
errors more gracefully. Specifically, it'll clear the cache and retry,
instead of failing the query immediately. It also reduces the internal
timeout to make retries faster.
The PR also fixes a very obvious bug in
`TenantManager::resolve_attached_shard` where the code tries to cache
the computed the shard number, but forgot to recompute when the shard
count is different.
---------
Co-authored-by: William Huang <william.huang@databricks.com>
Co-authored-by: Haoyu Huang <haoyu.huang@databricks.com>
Co-authored-by: Chen Luo <chen.luo@databricks.com>
Co-authored-by: Vlad Lazar <vlad.lazar@databricks.com>
Co-authored-by: Vlad Lazar <vlad@neon.tech>
This patch tightens up `page_api::Client`. It's mostly superficial
changes, but also adds a new constructor that takes an existing gRPC
channel, for use with the communicator connection pool.
## Problem
Some feature flags are used heavily on the critical path and we want the
"get feature flag" operation as cheap as possible.
## Summary of changes
Add a `test_remote_size_flag` as an example of such flags. In the
future, we can use macro to generate all those fields. The flag is
updated in the housekeeping loop. The retrieval of the flag is simply
reading an atomic flag.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
The goal of this code was to test out if resetting the broker
subscription helps alleviate the issues we've been seeing in staging.
Looks like it did the trick. However, the original version was too
eager.
## Summary of Changes
Only reset the stream when:
* we are waiting for WAL
* there's no connection candidates lined up
* we're not already connected to a safekeeper
The only call stack that can emit the `::AlreadyRunning` variant is
```
-> iteration_inner
-> iteration
-> compaction_iteration
-> compaction_loop
-> start_background_loops
```
And on that call stack, the only differentiated handling of it is its
invocations of
`log_compaction_error -> CompactionError::is_cancel()`, which returns
`true` for
`::AlreadyRunning`.
I think the condition of `AlreadyRunning` is severe; it really shouldn't
happen.
So, this PR starts treating it as something that is to be logged at
`ERROR` / `WARN`
level, depending on the `degrate_to_warning` argument to
`log_compaction_error`.
refs
- https://databricks.atlassian.net/browse/LKB-182
## Problem
Grafana Alloy in cluster mode seems to send duplicate "seconds" scrape
URL parameters
when one of its instances is disrupted.
## Summary of changes
Temporarily accept duplicate parameters as long as their value is
identical.
Looks can be deceiving: the match blocks in
`maybe_trip_compaction_breaker`
and at the end of `compact_with_options` seem like differentiated error
handling, but in reality, these branches are unreachable at runtime
because the only source of `CompactionError::Offload` within the
compaction code is at the end of `Tenant::compaction_iteration`.
We can simply map offload cancellation to CompactionError::Cancelled and
all other offload errors to ::Other, since there's no differentiated
handling for them in the compaction code.
Also, the OffloadError::RemoteStorage variant has no differentiated
handling, but was wrapping the remote storage anyhow::Error in a
`anyhow(thiserror(anyhow))` sandwich. This PR removes that variant,
mapping all RemoteStorage errors to `OffloadError::Other`.
Thereby, the sandwich is gone and we will get a proper anyhow backtrace
to the remote storage error location if when we debug-print the
OffloadError (or the CompactionError if we map it to that).
refs
- https://databricks.atlassian.net/browse/LKB-182
- the observation that there's no need for differentiated handling of
CompactionError::Offload was made in
https://databricks.slack.com/archives/C09254R641L/p1751286453930269?thread_ts=1751284317.955159&cid=C09254R641L
Before this PR, macOS builds would get clippy warning
```
warning: `tokio_epoll_uring::thread_local_system` does not refer to an existing function
```
The reason is that the `thread_local_system` function is only defined on
Linux.
Add `allow-invalid = true` to make macOS clippy pass, and manually test
that on Linux builds, clippy still fails when we use it.
refs
- https://databricks.slack.com/archives/C09254R641L/p1751917655527099
Co-authored-by: Christian Schwarz <Christian Schwarz>
## Problem
Deletion process does not calculate preferred nodes correctly - it
doesn't consider current tenant-shard layout among all pageservers.
## Summary of changes
- Added a schedule context calculation for node deletion
Co-authored-by: Aleksandr Sarantsev <aleksandr.sarantsev@databricks.com>
The introduction of the default lease deadline feature 9 months ago made
it so
that after PS restart, `.timeline_gc()` calls in Python tests are no-ops
for 10 minute after pageserver startup: the `gc_iteration()` bails with
`Skipping GC because lsn lease deadline is not reached`.
I did some impact analysis in the following PR. About 30 Python tests
are affected:
- https://github.com/neondatabase/neon/pull/12411
Rust tests that don't explicitly enable periodic GC or invoke GC
manually
are unaffected because we disable periodic GC by default in
the `TenantHarness`'s tenant config.
Two tests explicitly did `start_paused=true` + `tokio::time::advance()`,
but it would add cognitive and code bloat to each existing and future
test case that uses TenantHarness if we took that route.
So, this PR sets the default lease deadline feature in both Python
and Rust tests to zero by default. Tests that test the feature were
thus identified by failing the test:
- Python test `test_readonly_node_gc` + `test_lsn_lease_size`
- Rust test `test_lsn_lease`.
To accomplish the above, I changed the code that computes the initial
lease
deadline to respect the pageserver.toml's default tenant config, which
it didn't before (and I would consider a bug). The Python test harness
and the Rust TenantHarness test harness then simply set the default
tenant
config field to zero.
Drive-by:
- `test_lsn_lease_size` was writing a lot of data unnecessarily; reduce
the amount and speed up the test
refs
- PR that introduced default lease deadline:
https://github.com/neondatabase/neon/pull/9055/files
- fixes https://databricks.atlassian.net/browse/LKB-92
---------
Co-authored-by: Christian Schwarz <Christian Schwarz>
## Problem
Extension tests were previously run sequentially, resulting in
unnecessary wait time and underutilization of available CPU cores.
## Summary of changes
Tests are now executed in a customizable number of parallel threads
using separate database branches. This reduces overall test time by
approximately 50% (e.g., on my laptop, parallel test lasts 173s, while
sequential one lasts 340s) and increases the load on the pageserver,
providing better test coverage.
---------
Co-authored-by: Alexander Bayandin <alexander@neon.tech>
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Alexey Masterov <alexey.masterov@databricks.com>
## Problem
Pageserver now writes errors in the log during the safekeeper migration.
Some errors are added to allowed errors, but "timeline not found in
global map" is not.
- Will be properly fixed in
https://github.com/neondatabase/neon/issues/12191
## Summary of changes
Add "timeline not found in global map" error in a list of allowed errors
in `test_safekeeper_migration_simple`
## Problem
Test is flaky due to the following warning in the logs:
```
Keeping extra secondaries: can't determine which of [NodeId(1), NodeId(2)] to remove (some nodes offline?)
```
Some nodes being offline is expected behavior in this test.
## Summary of changes
- Added `Keeping extra secondaries` to the list of allowed errors
- Improved logging for better debugging experience
Co-authored-by: Aleksandr Sarantsev <aleksandr.sarantsev@databricks.com>
## Problem
The endpoint filter cache is still unused because it's not yet reliable
enough to be used. It only consumes a lot of memory.
## Summary of changes
Remove the code. Needs a new design.
neondatabase/cloud#30634
See #11992 and #11961 for some examples of usecases.
This introduces a JSON serialization lib, designed for more flexibility
than serde_json offers.
## Dynamic construction
Sometimes you have dynamic values you want to serialize, that are not
already in a serde-aware model like a struct or a Vec etc. To achieve
this with serde, you need to implement a lot of different traits on a
lot of different new-types. Because of this, it's often easier to
give-in and pull all the data into a serde-aware model
(serde_json::Value or some intermediate struct), but that is often not
very efficient.
This crate allows full control over the JSON encoding without needing to
implement any extra traits. Just call the relevant functions, and it
will guarantee a correctly encoded JSON value.
## Async construction
Similar to the above, sometimes the values arrive asynchronously. Often
collecting those values in memory is more expensive than writing them as
JSON, since the overheads of `Vec` and `String` is much higher, however
there are exceptions.
Serializing to JSON all in one go is also more CPU intensive and can
cause lag spikes, whereas serializing values incrementally spreads out
the CPU load and reduces lag.
## Problem
We don't log gRPC request errors on the server.
Touches #11728.
## Summary of changes
Automatically log non-OK gRPC response statuses in the observability
middleware, and add corresponding logging for the `get_pages` stream.
Also adds the peer address and gRPC method to the gRPC tracing span.
Example output:
```
2025-07-02T20:18:16.813718Z WARN grpc:pageservice{peer=127.0.0.1:56698 method=CheckRelExists tenant_id=c7b45faa1924b1958f05c5fdee8b0d04 timeline_id=4a36ee64fd2f97781b9dcc2c3cddd51b shard_id=0000}: request failed with NotFound: Tenant c7b45faa1924b1958f05c5fdee8b0d04 not found
```
## Problem
Names are not consistent between safekeeper migration RFC and the actual
implementation.
It's not used anywhere in production yet, so it's safe to rename. We
don't need to worry about backward compatibility.
- Follow up on https://github.com/neondatabase/neon/pull/12432
## Summary of changes
- rename term -> last_log_term in TimelineMembershipSwitchResponse
- add missing fields to TimelineMembershipSwitchResponse in python
## Problem
The safekeeper migration code/logic slightly diverges from the initial
RFC. This PR aims to address these differences.
- Part of https://github.com/neondatabase/neon/issues/12192
## Summary of changes
- Adjust the RFC to reflect that we implemented the safekeeper
reconciler with in-memory queue.
- Add `sk_set_notified_generation` field to the `timelines` table in the
RFC to address the "finish migration atomically" problem.
- Describe how we are going to make the timeline migration handler fully
retriable with in-memory reconciler queue.
- Unify type/field/method names in the code and RFC.
- Fix typos
This doesn't do anything interesting yet, but demonstrates linking Rust
code to the neon Postgres extension, so that we can review and test
drive just the build process changes independently.
Mostly a revert of https://github.com/neondatabase/neon/pull/11851 and
https://github.com/neondatabase/neon/pull/12330 .
Christian suggested reverting his PR to fix the issue
https://github.com/neondatabase/neon/issues/12369 .
Alternatives considered:
1. I have originally wanted to introduce cancellation tokens to
`RequestContext`, but in the end I gave up on them because I didn't find
a select-free way of preventing
`test_layer_download_cancelled_by_config_location` from hanging.
Namely if I put a select around the `get_or_maybe_download` invocation
in `get_values_reconstruct_data`, it wouldn't hang, but if I put it
around the `download_init_and_wait` invocation in
`get_or_maybe_download`, the test would still hang. Not sure why, even
though I made the attached child function of the `RequestContext` create
a child token.
2. Introduction of a `download_cancel` cancellation token as a child of
a timeline token, putting it into `RemoteTimelineClient` together with
the main token, and then putting it into the whole
`RemoteTimelineClient` read path.
3. Greater refactorings, like to make cancellation tokens follow a DAG
structure so you can have tokens cancelled either by say timeline
shutting down or a request ending. It doesn't just represent an effort
that we don't have the engineering budget for, it also causes
interesting questions like what to do about batching (do you cancel the
entire request if only some requests get cancelled?).
We might see a reemergence of
https://github.com/neondatabase/neon/issues/11762, but given that we
have https://github.com/neondatabase/neon/pull/11853 and
https://github.com/neondatabase/neon/pull/12376 now, it is possible that
it will not come back. Looking at some code, it might actually fix the
locations where the error pops up. Let's see.
---------
Co-authored-by: Christian Schwarz <christian@neon.tech>
- Add ComputeSpec flag `offload_lfc_interval_seconds` controlling
whether LFC should be offloaded to endpoint storage. Default value
(None) means "don't offload".
- Add glue code around it for `neon_local` and integration tests.
- Add `autoprewarm` mode for `test_lfc_prewarm` testing
`offload_lfc_interval_seconds` and `autoprewarm` flags in conjunction.
- Rename `compute_ctl_lfc_prewarm_requests_total` and
`compute_ctl_lfc_offload_requests_total` to
`compute_ctl_lfc_prewarms_total`
and `compute_ctl_lfc_offloads_total` to reflect we count prewarms and
offloads, not `compute_ctl` requests of those.
Don't count request in metrics if there is a prewarm/offload already
ongoing.
https://github.com/neondatabase/cloud/issues/19011
Resolves: https://github.com/neondatabase/cloud/issues/30770
Don't build walproposer-lib as a separate job. It only takes a few
seconds, after you have built all its dependencies.
Don't cache the Neon Pg extensions in the per-postgres-version caches.
This is in preparation for the communicator project, which will
introduce Rust parts to the Neon Pg extension, which complicates the
build process. With that, the 'make neon-pg-ext' step requires some of
the Rust bits to be built already, or it will build them on the spot,
which in turn requires all the Rust sources to be present, and we don't
want to repeat that part for each Postgres version anyway. To prepare
for that, rely on "make all" to build the neon extension and the rust
bits in the correct order instead. Building the neon extension doesn't
currently take very long anyway after you have built Postgres itself, so
you don't gain much by caching it. See
https://github.com/neondatabase/neon/pull/12266.
Add an explicit "rustup update" step to update the toolchain. It's not
strictly necessary right now, because currently "make all" will only
invoke "cargo build" once and the race condition described in the
comment doesn't happen. But prepare for the future.
To further simplify the build, get rid of the separate 'build-postgres'
jobs too, and just build Postgres as a step in the main job. That makes
the overall workflow run longer, because we no longer build all the
postgres versions in parallel (although you still get intra-runner
parallelism thanks to `make -j`), but that's acceptable. In the
cache-hit case, it might even be a little faster because there is less
overhead from launching jobs, and in the cache-miss case, it's maybe
5-10 minutes slower altogether.
---------
Co-authored-by: Alexander Bayandin <alexander@neon.tech>
## Problem
The current deletion operation is synchronous and blocking, which is
unsuitable for potentially long-running tasks like. In such cases, the
standard HTTP request-response pattern is not a good fit.
## Summary of Changes
- Added new `storcon_cli` commands: `NodeStartDelete` and
`NodeCancelDelete` to initiate and cancel deletion asynchronously.
- Added corresponding `storcon` HTTP handlers to support the new
start/cancel deletion flow.
- Introduced a new type of background operation: `Delete`, to track and
manage the deletion process outside the request lifecycle.
---------
Co-authored-by: Aleksandr Sarantsev <aleksandr.sarantsev@databricks.com>
## Problem
I suspect that the pageservers get stuck on receiving broker updates.
## Summary of changes
This is a an opportunistic (staging only) patch that resets the
susbscription
stream if it's been idle for a while. This won't go to prod in this
form.
I'll revert or update it before Friday.
## Problem
DEBUG_LOCAL_COMPARE mode allows to detect data corruption.
But it requires rebuild of neon extension (and so requires special
image) and significantly slowdown execution because always fetch pages
from page server.
## Summary of changes
Introduce new GUC `neon.debug_compare_local`, accepting the following
values: " none", "prefetch", "lfc", "all" (by default it is definitely
disabled).
In mode less than "all", neon SMGR will not fetch page from PS if it is
found in local caches.
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
## Problem
The background installed extensions worker relied on `interval.tick()`
to go to sleep for a period of time. This can lead to bugs due to the
interval being updated at the end of the loop as the first tick is
[instantaneous](https://docs.rs/tokio/latest/tokio/time/struct.Interval.html#method.tick).
## Summary of changes
Changed it to a `tokio::time::sleep` to prevent this issue. Now it puts
the thread to sleep and only wakes up after the specified duration
## Problem
Better investigate memory usage during backpressure
## Summary of changes
Print open layer size if backpressure is activated
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
Ancestor detach from a previously detached parent when there were no
writes panics since it tries to upload the tombstone layer twice.
## Summary of Changes
If we're gonna copy the tombstone from the ancestor, don't bother
creating it.
Fixes https://github.com/neondatabase/neon/issues/12458
When deploying new safekeepers, we don't immediately want to send
traffic to them. Maybe they are not ready yet by the time the deploy
script is registering them with the storage controller.
For pageservers, the storcon solves the problem by not scheduling stuff
to them unless there has been a positive heartbeat response. We can't do
the same for safekeepers though, otherwise a single down safekeeper
would mean we can't create new timelines in smaller regions where there
is only three safekeepers in total.
So far we have created safekeepers as `pause` but this adds a manual
step to safekeeper deployment which is prone to oversight. We want
things to be automatted. So we introduce a new state `activating` that
acts just like `pause`, except that we automatically transition the
policy to `active` once we get a positive heartbeat from the safekeeper.
For `pause`, we always keep the safekeeper paused.
## Problem
Currently, if `storcon` (storage controller) reconciliations repeatedly
fail, the system will indefinitely freeze optimizations. This can result
in optimization starvation for several days until the reconciliation
issues are manually resolved. To mitigate this, we should detect
persistently failing reconciliations and exclude them from influencing
the optimization decision.
## Summary of Changes
- A tenant shard reconciliation is now considered "keep-failing" if it
fails 5 consecutive times. These failures are excluded from the
optimization readiness check.
- Added a new metric: `storage_controller_keep_failing_reconciles` to
monitor such cases.
- Added a warning log message when a reconciliation is marked as
"keep-failing".
---------
Co-authored-by: Aleksandr Sarantsev <aleksandr.sarantsev@databricks.com>
## TLDR
This PR is a no-op. The changes are disabled by default.
## Problem
I. Currently we don't have a way to detect disk I/O failures from WAL
operations.
II.
We observe that the offloader fails to upload a segment due to race
conditions on XLOG SWITCH and PG start streaming WALs. wal_backup task
continously failing to upload a full segment while the segment remains
partial on the disk.
The consequence is that commit_lsn for all SKs move forward but
backup_lsn stays the same. Then, all SKs run out of disk space.
III.
We have discovered SK bugs where the WAL offload owner cannot keep up
with WAL backup/upload to S3, which results in an unbounded accumulation
of WAL segment files on the Safekeeper's disk until the disk becomes
full. This is a somewhat dangerous operation that is hard to recover
from because the Safekeeper cannot write its control files when it is
out of disk space. There are actually 2 problems here:
1. A single problematic timeline can take over the entire disk for the
SK
2. Once out of disk, it's difficult to recover SK
IV.
Neon reports certain storage errors as "critical" errors using a marco,
which will increment a counter/metric that can be used to raise alerts.
However, this metric isn't sliced by tenant and/or timeline today. We
need the tenant/timeline dimension to better respond to incidents and
for blast radius analysis.
## Summary of changes
I.
The PR adds a `safekeeper_wal_disk_io_errors ` which is incremented when
SK fails to create or flush WALs.
II.
To mitigate this issue, we will re-elect a new offloader if the current
offloader is lagging behind too much.
Each SK makes the decision locally but they are aware of each other's
commit and backup lsns.
The new algorithm is
- determine_offloader will pick a SK. say SK-1.
- Each SK checks
-- if commit_lsn - back_lsn > threshold,
-- -- remove SK-1 from the candidate and call determine_offloader again.
SK-1 will step down and all SKs will elect the same leader again.
After the backup is caught up, the leader will become SK-1 again.
This also helps when SK-1 is slow to backup.
I'll set the reelect backup lag to 4 GB later. Setting to 128 MB in dev
to trigger the code more frequently.
III.
This change addresses problem no. 1 by having the Safekeeper perform a
timeline disk utilization check check when processing WAL proposal
messages from Postgres/compute. The Safekeeper now rejects the WAL
proposal message, effectively stops writing more WAL for the timeline to
disk, if the existing WAL files for the timeline on the SK disk exceeds
a certain size (the default threshold is 100GB). The disk utilization is
calculated based on a `last_removed_segno` variable tracked by the
background task removing WAL files, which produces an accurate and
conservative estimate (>= than actual disk usage) of the actual disk
usage.
IV.
* Add a new metric `hadron_critical_storage_event_count` that has the
`tenant_shard_id` and `timeline_id` as dimensions.
* Modified the `crtitical!` marco to include tenant_id and timeline_id
as additional arguments and adapted existing call sites to populate the
tenant shard and timeline ID fields. The `critical!` marco invocation
now increments the `hadron_critical_storage_event_count` with the extra
dimensions. (In SK there isn't the notion of a tenant-shard, so just the
tenant ID is recorded in lieu of tenant shard ID.)
I considered adding a separate marco to avoid merge conflicts, but I
think in this case (detecting critical errors) conflicts are probably
more desirable so that we can be aware whenever Neon adds another
`critical!` invocation in their code.
---------
Co-authored-by: Chen Luo <chen.luo@databricks.com>
Co-authored-by: Haoyu Huang <haoyu.huang@databricks.com>
Co-authored-by: William Huang <william.huang@databricks.com>
## Problem
integrating subzero requires a bit of refactoring. To make the
integration PR a bit more manageable, the refactoring is done in this
separate PR.
## Summary of changes
* move common types/functions used in sql_over_http to errors.rs and
http_util.rs
* add the "Local" auth backend to proxy (similar to local_proxy), useful
in local testing
* change the Connect and Send type for the http client to allow for
custom body when making post requests to local_proxy from the proxy
---------
Co-authored-by: Ruslan Talpa <ruslan.talpa@databricks.com>
