## Problem
In https://github.com/neondatabase/neon/pull/6637, we remove the need to
run migrations externally, but for compat tests to work we can't remove
those invocations from the neon_local binary.
Once that previous PR merges, we can make the followup changes without
upsetting compat tests.
## Problem
Spun off from https://github.com/neondatabase/neon/pull/6394 -- this PR
is just the persistence parts and the changes that enable it to work
nicely
## Summary of changes
- Revert #6444 and #6450
- In neon_local, start a vanilla postgres instance for the attachment
service to use.
- Adopt `diesel` crate for database access in attachment service. This
uses raw SQL migrations as the source of truth for the schema, so it's a
soft dependency: we can switch libraries pretty easily.
- Rewrite persistence.rs to use postgres (via diesel) instead of JSON.
- Preserve JSON read+write at startup and shutdown: this enables using
the JSON format in compatibility tests, so that we don't have to commit
to our DB schema yet.
- In neon_local, run database creation + migrations before starting
attachment service
- Run the initial reconciliation in Service::spawn in the background, so
that the pageserver + attachment service don't get stuck waiting for
each other to start, when restarting both together in a test.
refs https://github.com/neondatabase/neon/issues/6473
Before this PR, if process_started() didn't return Ok(true) until we
ran out of retries, we'd return an error but leave the process running.
Try it by adding a 20s sleep to the pageserver `main()`, e.g., right
before we claim the pidfile.
Without this PR, output looks like so:
```
(.venv) cs@devvm-mbp:[~/src/neon-work-2]: ./target/debug/neon_local start
Starting neon broker at 127.0.0.1:50051.
storage_broker started, pid: 2710939
.
attachment_service started, pid: 2710949
Starting pageserver node 1 at '127.0.0.1:64000' in ".neon/pageserver_1".....
pageserver has not started yet, continuing to wait.....
pageserver 1 start failed: pageserver did not start in 10 seconds
No process is holding the pidfile. The process must have already exited. Leave in place to avoid race conditions: ".neon/pageserver_1/pageserver.pid"
No process is holding the pidfile. The process must have already exited. Leave in place to avoid race conditions: ".neon/safekeepers/sk1/safekeeper.pid"
Stopping storage_broker with pid 2710939 immediately.......
storage_broker has not stopped yet, continuing to wait.....
neon broker stop failed: storage_broker with pid 2710939 did not stop in 10 seconds
Stopping attachment_service with pid 2710949 immediately.......
attachment_service has not stopped yet, continuing to wait.....
attachment service stop failed: attachment_service with pid 2710949 did not stop in 10 seconds
```
and we leak the pageserver process
```
(.venv) cs@devvm-mbp:[~/src/neon-work-2]: ps aux | grep pageserver
cs 2710959 0.0 0.2 2377960 47616 pts/4 Sl 14:36 0:00 /home/cs/src/neon-work-2/target/debug/pageserver -D .neon/pageserver_1 -c id=1 -c pg_distrib_dir='/home/cs/src/neon-work-2/pg_install' -c http_auth_type='Trust' -c pg_auth_type='Trust' -c listen_http_addr='127.0.0.1:9898' -c listen_pg_addr='127.0.0.1:64000' -c broker_endpoint='http://127.0.0.1:50051/' -c control_plane_api='http://127.0.0.1:1234/' -c remote_storage={local_path='../local_fs_remote_storage/pageserver'}
```
After this PR, there is no leaked process.
Part of getpage@lsn benchmark epic:
https://github.com/neondatabase/neon/issues/5771
This PR moves the control plane's spread-all-over-the-place client for
the pageserver management API into a separate module within the
pageserver crate.
I need that client to be async in my benchmarking work, so, this PR
switches to the async version of `reqwest`.
That is also the right direction generally IMO.
The switch to async in turn mandated converting most of the
`control_plane/` code to async.
Note that some of the client methods should be taking `TenantShardId`
instead of `TenantId`, but, none of the callers seem to be
sharding-aware.
Leaving that for another time:
https://github.com/neondatabase/neon/issues/6154
Fixes#4689 by replacing all of `std::Path` , `std::PathBuf` with
`camino::Utf8Path`, `camino::Utf8PathBuf` in
- pageserver
- safekeeper
- control_plane
- libs/remote_storage
Co-authored-by: Joonas Koivunen <joonas@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>
Add infrastructure to dynamically load postgres extensions and shared libraries from remote extension storage.
Before postgres start downloads list of available remote extensions and libraries, and also downloads 'shared_preload_libraries'. After postgres is running, 'compute_ctl' listens for HTTP requests to load files.
Postgres has new GUC 'extension_server_port' to specify port on which 'compute_ctl' listens for requests.
When PostgreSQL requests a file, 'compute_ctl' downloads it.
See more details about feature design and remote extension storage layout in docs/rfcs/024-extension-loading.md
---------
Co-authored-by: Anastasia Lubennikova <anastasia@neon.tech>
Co-authored-by: Alek Westover <alek.westover@gmail.com>
- Add support for splitting async postgres_backend into read and write halfes.
Safekeeper needs this for bidirectional streams. To this end, encapsulate
reading-writing postgres messages to framed.rs with split support without any
additional changes (relying on BufRead for reading and BytesMut out buffer for
writing).
- Use async postgres_backend throughout safekeeper (and in proxy auth link
part).
- In both safekeeper COPY streams, do read-write from the same thread/task with
select! for easier error handling.
- Tidy up finishing CopyBoth streams in safekeeper sending and receiving WAL
-- join split parts back catching errors from them before returning.
Initially I hoped to do that read-write without split at all, through polling
IO:
https://github.com/neondatabase/neon/pull/3522
However that turned out to be more complicated than I initially expected
due to 1) borrow checking and 2) anon Future types. 1) required Rc<Refcell<...>>
which is Send construct just to satisfy the checker; 2) can be workaround with
transmute. But this is so messy that I decided to leave split.
This patch adds a per-timeline periodic task that executes an eviction
policy. The eviction policy is configurable per tenant.
Two policies exist:
- NoEviction (the default one)
- LayerAccessThreshold
The LayerAccessThreshold policy examines the last access timestamp per
layer in the layer map and evicts the layer if that last access is
further in the past than a configurable threshold value.
This policy kind is evaluated periodically at a configurable period.
It logs a summary statistic at `info!()` or `warn!()` level, depending
on whether any evictions failed.
This feature has no explicit killswitch since it's off by default.
This fixes all kinds of problems related to missing params,
like broken timestamps (due to `integer_datetimes`).
This solution is not ideal, but it will help. Meanwhile,
I'm going to dedicate some time to improving connection machinery.
Note that this **does not** fix problems with passing certain parameters
in a reverse direction, i.e. **from client to compute**. This is a
separate matter and will be dealt with in an upcoming PR.
Downsides are:
* We store all components of the config separately. `Url` stores them inside a single
`String` and a bunch of ints which point to different parts of the URL, which is
probably more efficient.
* It is now impossible to pass arbitrary connection strings to the configuration file,
one has to support all components explicitly. However, we never supported anything
except for `host:port` anyway.
Upsides are:
* This significantly restricts the space of possible connection strings, some of which
may be either invalid or unsupported. E.g. Postgres' connection strings may include
a bunch of parameters as query (e.g. `connect_timeout=`, `options=`). These are nether
validated by the current implementation, nor passed to the postgres client library,
Hence, storing separate fields expresses the intention better.
* The same connection configuration may be represented as a URL in multiple ways
(e.g. either `password=` in the query part or a standard URL password).
Now we have a single canonical way.
* Escaping is provided for `options=`.
Other possibilities considered:
* `newtype` with a `String` inside and some validation on creation.
This is more efficient, but harder to log for two reasons:
* Passwords should never end up in logs, so we have to somehow
* Escaped `options=` are harder to read, especially if URL-encoded,
and we use `options=` a lot.
* etcd-client is not updated, since we plan to replace it with another client and the new version errors with some missing prost library error
* clap had released another major update that requires changing every CLI declaration again, deserves a separate PR
Creates new `pageserver_api` and `safekeeper_api` crates to serve as the
shared dependencies. Should reduce both recompile times and cold compile
times.
Decreases the size of the optimized `neon_local` binary: 380M -> 179M.
No significant changes for anything else (mostly as expected).
Seems a bit silly to have a separate crate just for the executable. It
relies on the control plane for everything it does, and it's the only
user of the control plane.
If the 'basebackup' command failed in the middle of building the tar
archive, the client would not report the error, but would attempt to
to start up postgres with the partial contents of the data directory.
That fails because the control file is missing (it's added to the
archive last, precisly to make sure that you cannot start postgres
from a partial archive). But the client doesn't see the proper error
message that caused the basebackup to fail in the server, which is
confusing.
Two issues conspired to cause that:
1. The tar::Builder object that we use in the pageserver to construct
the tar stream has a Drop handler that automatically writes a valid
end-of-archive marker on drop. Because of that, the resulting tarball
looks complete, even if an error happens while we're building it. The
pageserver does send an ErrorResponse after the seemingly-valid
tarball, but:
2. The client stops reading the Copy stream, as soon as it sees the
tar end-of-archive marker. Therefore, it doesn't read the
ErrorResponse that comes after it.
We have two clients that call 'basebackup', one in `control_plane`
used by the `neon_local` binary, and another one in
`compute_tools`. Both had the same issue.
This PR fixes both issues, even though fixing either one would be
enough to fix the problem at hand. The pageserver now doesn't send the
end-of-archive marker on error, and the client now reads the copy
stream to the end, even if it sees an end-of-archive marker.
Fixes github issue #1715
In the passing, change Basebackup to use generic Write rather than
'dyn'.
workspace_hack is needed to avoid recompilation when different crates
inside the workspace depend on the same packages but with different
features being enabled. Problem occurs when you build crates separately
one by one. So this is irrelevant to our CI setup because there we build
all binaries at once, but it may be relevant for local development.
this also changes cargo's resolver version to 2
Have separate routine and http endpoint to create timeline on safekeepers. It is
not used yet, i.e. timeline is still created implicitly, but we'll change that
once infrastructure for learning which tlis are assigned to which safekeepers
will be ready, preventing accidental creation by compute.
Changes format of safekeeper control file, allowing to store set of
peers. Knowing peers provides a part of foundation for peer
recovery (calculating min horizons like truncate_lsn for WAL truncation and
commit_lsn for sync-safekeepers replacement) and proper membership change;
similarly, we don't yet use it for now.
Employing cf file version bump, extracts tenant_id and timeline_id to top level
where it is more suitable. Also adds a bunch of LSNs there and rename
truncate_lsn to more specific peer_horizon_lsn.
to pass current_timeline_size to compute node
Put standby_status_update fields into ZenithFeedback and send them as one message.
Pass values sizes together with keys in ZenithFeedback message.
We depends on rustls in postgres_backend anyway, so might as well use it
for all TLS stuff. Seems better to depend on only one library both from a
security point of view, and because fewer dependencies means less code to
compile. With this commit, we no longer depend on OpenSSL.
this patch adds support for tenants. This touches mostly pageserver.
Directory layout on disk is changed to contain new layer of indirection.
Now path to particular repository has the following structure: <pageserver workdir>/tenants/<tenant
id>. Tenant id has the same format as timeline id. Tenant id is included in
pageserver commands when needed. Also new commands are available in
pageserver: tenant_list, tenant_create. This is also reflected CLI.
During init default tenant is created and it's id is saved in CLI config,
so following commands can use it without extra options. Tenant id is also included in
compute postgres configuration, so it can be passed via ServerInfo to
safekeeper and in connection string to pageserver.
For more info see docs/multitenancy.md.
This patch started as an effort to support CLI working against remote
pageserver, but turned into a pretty big refactoring.
* CLI now does not look into repository files directly. New commands
'branch_create' and 'identify_system' were introduced into page_service to
support that.
* Branch management that was scattered between local_env and
zenith/main.rs is moved into pageserver/branches.rs. That code could better fit
in Repository/Timeline impl, but I'll leave that for a different patch.
* All tests-related code from local_env went into integration_tests/src/lib.rs as an
extension to PostgresNode trait.
* Paths-generating functions were concentrated around corresponding config
types (LocalEnv and PageserverConf).
This isn't just cosmetic, this also fixes one bug: the code in
parse_point_in_time() function used str::parse::<u64>() to parse the
parts of the LSN string (e.g. 0/1A2B3C4D). That's wrong, because the
LSN consists of hex digits, not base-10.
Switch over to a newer version of rust-postgres PR752. A few
minor changes are required:
- PgLsn::UNDEFINED -> PgLsn::from(0)
- PgTimestamp -> SystemTime
Our builds can be a little inconsistent, because Cargo doesn't deal well
with workspaces where there are multiple crates which have different
dependencies that select different features. As a workaround, copy what
other big rust projects do: add a workspace_hack crate.
This crate just pins down a set of dependencies and features that
satisfies all of the workspace crates.
The benefits are:
- running `cargo build` from one of the workspace subdirectories now
works without rebuilding anything.
- running `cargo install` works (without rebuilding anything).
- making small dependency changes is much less likely to trigger large
dependency rebuilds.
Since we are now calling the syscall directly, read_pidfile can now
parse an integer.
We also verify the pid is >= 1, because calling kill on 0 or negative
values goes straight to crazytown.
If there isn't any version specified for a dependency crate, Cargo may
choose a newer version. This could happen when Cargo.lock is updated
("cargo update") but can also happen unexpectedly when adding or
changing other dependencies. This can allow API-breaking changes to be
picked up, breaking the build.
To prevent this, specify versions for all dependencies. Cargo is still
allowed to pick newer versions that are (hopefully) non-breaking, by
analyzing the semver version number.
There are two special cases here:
1. serde_derive::{Serialize, Deserialize} isn't really used any more. It
was only a separate crate in the past because of compiler limitations.
Nowadays, people turn on the "derive" feature of the serde crate and
use serde::{Serialize, Deserialize}.
2. parse_duration is unmaintained and has an open security issue. (gh
iss. 87) That issue probably isn't critical for us because of where we
use that crate, but it's probably still better to pin the version so we
can't get hit with an API-breaking change at an awkward time.
This replaces the page server's "datadir" concept. The Page Server now
always works with a "Zenith Repository". When you initialize a new
repository with "zenith init", it runs initdb and loads an initial
basebackup of the freshly-created cluster into the repository, on "main"
branch. Repository can hold multiple "timelines", which can be given
human-friendly names, making them "branches". One page server simultaneously
serves all timelines stored in the repository, and you can have multiple
Postgres compute nodes connected to the page server, as long they all
operate on a different timeline.
There is a new command "zenith branch", which can be used to fork off
new branches from existing branches.
The repository uses the directory layout desribed as Repository format
v1 in https://github.com/zenithdb/rfcs/pull/5. It it *highly* inefficient:
- we never create new snapshots. So in practice, it's really just a base
backup of the initial empty cluster, and everything else is reconstructed
by redoing all WAL
- when you create a new timeline, the base snapshot and *all* WAL is copied
from the new timeline to the new one. There is no smarts about
referencing the old snapshots/wal from the ancestor timeline.
To support all this, this commit includes a bunch of other changes:
- Implement "basebackup" funtionality in page server. When you initialize
a new compute node with "zenith pg create", it connects to the page
server, and requests a base backup of the Postgres data directory on
that timeline. (the base backup excludes user tables, so it's not
as bad as it sounds).
- Have page server's WAL receiver write the WAL into timeline dir. This
allows running a Page Server and Compute Nodes without a WAL safekeeper,
until we get around to integrate that properly into the system. (Even
after we integrate WAL safekeeper, this is perhaps how this will operate
when you want to run the system on your laptop.)
- restore_datadir.rs was renamed to restore_local_repo.rs, and heavily
modified to use the new format. It now also restores all WAL.
- Page server no longer scans and restores everything into memory at startup.
Instead, when the first request is made for a timeline, the timeline is
slurped into memory at that point.
- The responsibility for telling page server to "callmemaybe" was moved
into Postgres libpqpagestore code. Also, WAL producer connstring cannot
be specified in the pageserver's command line anymore.
- Having multiple "system identifiers" in the same page server is no
longer supported. I repurposed much of that code to support multiple
timelines, instead.
- Implemented very basic, incomplete, support for PostgreSQL's Extended
Query Protocol in page_service.rs. Turns out that rust-postgres'
copy_out() function always uses the extended query protocol to send
out the command, and I'm using that to stream the base backup from the
page server.
TODO: I haven't fixed the WAL safekeeper for this scheme, so all the
integration tests involving safekeepers are failing. My plan is to modify
the safekeeper to know about Zenith timelines, too, and modify it to work
with the same Zenith repository format. It only needs to care about the
'.zenith/timelines/<timeline>/wal' directories.
