## Summary
Whereas currently we send all WAL to all pageserver shards, and each
shard filters out the data that it needs,
in this RFC we add a mechanism to filter the WAL on the safekeeper, so
that each shard receives
only the data it needs.
This will place some extra CPU load on the safekeepers, in exchange for
reducing the network bandwidth
for ingesting WAL back to scaling as O(1) with shard count, rather than
O(N_shards).
Touches #9329.
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
## Checklist before merging
- [ ] Do not forget to reformat commit message to not include the above
checklist
---------
Co-authored-by: Vlad Lazar <vlalazar.vlad@gmail.com>
Co-authored-by: Vlad Lazar <vlad@neon.tech>
## Problem
https://github.com/neondatabase/neon/pull/8455 wasn't specific enough on
migration from current situation to enabling generations.
## Summary of changes
Describe the missing parts, including control plane pushing generation
to compute, which also defines whether generations are enabled -- non
zero value does it.
## 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
Our dockerfiles, for some historical reason, have unconventional names
`Dockerfile.<something>`, and some tools (like GitHub UI) fail to highlight
the syntax in them.
> Some projects may need distinct Dockerfiles for specific purposes. A
common convention is to name these `<something>.Dockerfile`
From: https://docs.docker.com/build/concepts/dockerfile/#filename
## Summary of changes
- Rename `Dockerfile.build-tools` -> `build-tools.Dockerfile`
- Rename `compute/Dockerfile.compute-node` ->
`compute/compute-node.Dockerfile`
* I had to install `m4` in order to be able to run locally
* The docs/docker.md was missing a pointer to where the compute node
code is
(Was originally on #8888 but I am pulling this out)
aux v2 migration is near the end and I rewrote the RFC based on what I
proposed (several months before...) and what I actually implemented.
---------
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
Storage controller upgrades (restarts, more generally) can cause
multi-second availability gaps.
While the storage controller does not sit on the main data path, it's
generally not acceptable
to block management requests for extended periods of time (e.g.
https://github.com/neondatabase/neon/issues/8034).
## Summary of changes
This RFC describes the issues around the current storage controller
restart procedure
and describes an implementation which reduces downtime to a few
milliseconds on the happy path.
Related https://github.com/neondatabase/neon/issues/7797
Our new policy is to use the "rebase" method and slice all the Neon
commits into a nice patch set when doing a new major version, and use
"merge" method on minor version upgrades on the release branches.
"git merge" preserves the git history of Neon commits on the Postgres
branches. While it's nice to rebase all the Neon changes to a logical
patch set against upstream, having to do it between every minor release
is a fair amount work, and it loses the history, and is more
error-prone.
We've had physical replication support for a long time, but we never
created an RFC for the feature. This RFC does that after the fact. Even
though we've already implemented the feature, let's have a design
discussion as if it hadn't done that. It can still be quite insightful.
This is written from a pretty compute-centric viewpoint, not much
on how it works in the control plane.
## Problem
This page had many dead links, and was confusing for folks looking for
documentation about our product.
Closes: https://github.com/neondatabase/neon/issues/8535
## Summary of changes
- Add a link to the product docs up top
- Remove dead/placeholder links
## Problem
We have two No.34 RFC.
## Summary of changes
## Checklist before requesting a review
- [x] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
## Checklist before merging
- [ ] Do not forget to reformat commit message to not include the above
checklist
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
When a tenant creates a new timeline that they will treat as their
'main' history,
it is awkward to permanently retain an 'old main' timeline as its
ancestor. Currently
this is necessary because it is forbidden to delete a timeline which has
descendents.
## Summary of changes
A new pageserver API is proposed to 'adopt' data from a parent timeline
into
one of its children, such that the link between ancestor and child can
be severed,
leaving the parent in a state where it may then be deleted.
---------
Co-authored-by: Joonas Koivunen <joonas@neon.tech>
part of Epic https://github.com/neondatabase/neon/issues/7386
# Motivation
The materialized page cache adds complexity to the code base, which
increases the maintenance burden and risk for subtle and hard to
reproduce bugs such as #8050.
Further, the best hit rate that we currently achieve in production is ca
1% of materialized page cache lookups for
`task_kind=PageRequestHandler`. Other task kinds have hit rates <0.2%.
Last, caching page images in Pageserver rewards under-sized caches in
Computes because reading from Pageserver's materialized page cache over
the network is often sufficiently fast (low hundreds of microseconds).
Such Computes should upscale their local caches to fit their working
set, rather than repeatedly requesting the same page from Pageserver.
Some more discussion and context in internal thread
https://neondb.slack.com/archives/C033RQ5SPDH/p1718714037708459
# Changes
This PR removes the materialized page cache code & metrics.
The infrastructure for different key kinds in `PageCache` is left in
place, even though the "Immutable" key kind is the only remaining one.
This can be further simplified in a future commit.
Some tests started failing because their total runtime was dependent on
high materialized page cache hit rates. This test makes them
fixed-runtime or raises pytest timeouts:
* test_local_file_cache_unlink
* test_physical_replication
* test_pg_regress
# Performance
I focussed on ensuring that this PR will not result in a performance
regression in prod.
* **getpage** requests: our production metrics have shown the
materialized page cache to be irrelevant (low hit rate). Also,
Pageserver is the wrong place to cache page images, it should happen in
compute.
* **ingest** (`task_kind=WalReceiverConnectionHandler`): prod metrics
show 0 percent hit rate, so, removing will not be a regression.
* **get_lsn_by_timestamp**: important API for branch creation, used by
control pane. The clog pages that this code uses are not
materialize-page-cached because they're not 8k. No risk of introducing a
regression here.
We will watch the various nightly benchmarks closely for more results
before shipping to prod.
- Relation size cache was moved to extension
- the changes in visibilitymap.c and freespace.c became unnecessary
with v16, thanks to changes in upstream code
- WALProposer was moved to extension
- The hack in ReadBuffer_common to not throw an error on unexpected
data beyond EOF was removed in v16 rebase. We haven't seen such
errors, so I guess that was some early issue that was fixed long
time ago.
- The ginfast.c diff was made unnecessary by upstream commit 56b662523f
- Fix the dockerhub URLs
- `neondatabase/compute-node` image has been replaced with Postgres
version specific images like `neondatabase/compute-node-v16`
- Use TAG=latest in the example, rather than some old tag. That's a
sensible default for people to copy-past
- For convenience, use a Postgres connection URL in the `psql` example
that also includes the password. That way, there's no need to set up
.pgpass
- Update the image names in `docker ps` example to match what you get
when you follow the example
Not sure if this should actually be a link pointing to the
`persistence.rs` file but following the conventions of the rest of the
file, change `persistence.rs` reference to simply be a file name
mention.
## Problem
External contributors need information on how to use the storage
controller.
## Summary of changes
- Background content on what the storage controller is.
- Deployment information on how to use it.
This is not super-detailed, but should be enough for a well motivated
third party to get started, with an occasional peek at the code.
The binary etc were renamed some time ago, but the path in the source
tree remained "attachment_service" to avoid disruption to ongoing PRs.
There aren't any big PRs out right now, so it's a good time to cut over.
- Rename `attachment_service` to `storage_controller`
- Move it to the top level for symmetry with `storage_broker` & to avoid
mixing the non-prod neon_local stuff (`control_plane/`) with the storage
controller which is a production component.
We need to shard our Tenants to support larger databases without those
large databases dominating our pageservers and/or requiring dedicated
pageservers.
This RFC aims to define an initial capability that will permit creating
large-capacity databases using a static configuration
defined at time of Tenant creation.
Online re-sharding is deferred as future work, as is offloading layers
for historical reads. However, both of these capabilities would be
implementable without further changes to the control plane or compute:
this RFC aims to define the cross-component work needed to bootstrap
sharding end-to-end.
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 )
Usually RFC documents are not modified, but the vast mentions of
"zenith" in early RFC documents make it desirable to update the product
name to today's name, to avoid confusion.
## Problem
Early RFC documents use the old "zenith" product name a lot, which is
not something everyone is aware of after the product was renamed.
## Summary of changes
Replace occurrences of "zenith" with "neon".
Images are excluded.
---------
Co-authored-by: Andreas Scherbaum <andreas@neon.tech>
## Problem
Attachment service does not do auth based on JWT scopes.
## Summary of changes
Do JWT based permission checking for requests coming into the attachment
service.
Requests into the attachment service must use different tokens based on
the endpoint:
* `/control` and `/debug` require `admin` scope
* `/upcall` requires `generations_api` scope
* `/v1/...` requires `pageserverapi` scope
Requests into the pageserver from the attachment service must use
`pageserverapi` scope.
