## Problem
A high rate of short-lived connections means that there a lot of cancel
keys in Redis with TTL=10min that could be avoided by having a much
shorter initial TTL.
## Summary of changes
* Introduce an initial TTL of 1min used with the SET command.
* Fix: don't delay repushing cancel data when expired.
* Prepare for exponentially increasing TTLs.
## Alternatives
A best-effort UNLINK command on connection termination would clean up
cancel keys right away. This needs a bigger refactor due to how batching
is handled.
## Problem
When refreshing cancellation data we resend the entire value again just
to reset the TTL, which causes unnecessary load in proxy, on network and
possibly on redis side.
## Summary of changes
* Switch from using SET with full value to using EXPIRE to reset TTL.
* Add a tiny delay between retries to prevent busy loop.
* Shorten CancelKeyOp variants: drop redundant suffix.
* Retry SET when EXPIRE failed.
## Problem
When a connection terminates its maintain_cancel_key task keeps running
until the CANCEL_KEY_REFRESH sleep finishes and then it triggers another
cancel key TTL refresh before exiting.
## Summary of changes
* Check for cancellation while sleeping and interrupt sleep.
* If cancelled, break the loop, don't send a refresh cmd.
## Problem
To store cancellation data we send two commands to redis because the
redis server version doesn't support HSET with EX. Also, HSET is not
really needed.
## Summary of changes
* Replace the HSET + EXPIRE command pair with one SET .. EX command.
* Replace HGET with GET.
* Leave a workaround for old keys set with HSET.
* Replace some anyhow errors with specific errors to surface the
WRONGTYPE error from redis.
## Problem
https://github.com/neondatabase/cloud/issues/30539
If the current leader cancels the `call` function, then it has removed
the jobs from the queue, but will never finish sending the responses.
Because of this, it is not cancellation safe.
## Summary of changes
Document these functions as not cancellation safe. Move cancellation of
the queued jobs into the queue itself.
## Alternatives considered
1. We could spawn the task that runs the batch, since that won't get
cancelled.
* This requires `fn call(self: Arc<Self>)` or `fn call(&'static self)`.
2. We could add another scopeguard and return the requests back to the
queue.
* This requires that requests are always retry safe, and also requires
requests to be `Clone`.
See #11942
Idea:
* if connections are short lived, they can get enqueued and then also
remove themselves later if they never made it to redis. This reduces the
load on the queue.
* short lived connections (<10m, most?) will only issue 1 command, we
remove the delete command and rely on ttl.
* we can enqueue as many commands as we want, as we can always cancel
the enqueue, thanks to the ~~intrusive linked lists~~ `BTreeMap`.
## Problem
PGLB/Neonkeeper needs to separate the concerns of connecting to compute,
and authenticating to compute.
Additionally, the code within `connect_to_compute` is rather messy,
spending effort on recovering the authentication info after
wake_compute.
## Summary of changes
Split `ConnCfg` into `ConnectInfo` and `AuthInfo`. `wake_compute` only
returns `ConnectInfo` and `AuthInfo` is determined separately from the
`handshake`/`authenticate` process.
Additionally, `ConnectInfo::connect_raw` is in-charge or establishing
the TLS connection, and the `postgres_client::Config::connect_raw` is
configured to use `NoTls` which will force it to skip the TLS
negotiation. This should just work.
Precursor to https://github.com/neondatabase/cloud/issues/28333.
We want per-endpoint configuration for rate limits, which will be
distributed via the `GetEndpointAccessControl` API. This lays some of
the ground work.
1. Allow the endpoint rate limiter to accept a custom leaky bucket
config on check.
2. Remove the unused auth rate limiter, as I don't want to think about
how it fits into this.
3. Refactor the caching of `GetEndpointAccessControl`, as it adds
friction for adding new cached data to the API.
That third one was rather large. I couldn't find any way to split it up.
The core idea is that there's now only 2 cache APIs.
`get_endpoint_access_controls` and `get_role_access_controls`.
I'm pretty sure the behaviour is unchanged, except I did a drive by
change to fix#8989 because it felt harmless. The change in question is
that when a password validation fails, we eagerly expire the role cache
if the role was cached for 5 minutes. This is to allow for edge cases
where a user tries to connect with a reset password, but the cache never
expires the entry due to some redis related quirk (lag, or
misconfiguration, or cplane error)
libs/pqproto is designed for safekeeper/pageserver with maximum
throughput.
proxy only needs it for handshakes/authentication where throughput is
not a concern but memory efficiency is. For this reason, we switch to
using read_exact and only allocating as much memory as we need to.
All reads return a `&'a [u8]` instead of a `Bytes` because accidental
sharing of bytes can cause fragmentation. Returning the reference
enforces all callers only hold onto the bytes they absolutely need. For
example, before this change, `pqproto` was allocating 8KiB for the
initial read `BytesMut`, and proxy was holding the `Bytes` in the
`StartupMessageParams` for the entire connection through to passthrough.
## Problem
For `StoreCancelKey`, we were inserting 2 commands, but we were not
inserting two replies. This mismatch leads to errors when decoding the
response.
## Summary of changes
Abstract the command + reply pipeline so that commands and replies are
registered at the same time.
I like to run nightly clippy every so often to make our future rust
upgrades easier. Some notable changes:
* Prefer `next_back()` over `last()`. Generic iterators will implement
`last()` to run forward through the iterator until the end.
* Prefer `io::Error::other()`.
* Use implicit returns
One case where I haven't dealt with the issues is the now
[more-sensitive "large enum variant"
lint](https://github.com/rust-lang/rust-clippy/pull/13833). I chose not
to take any decisions around it here, and simply marked them as allow
for now.
This upgrades the `proxy/` crate as well as the forked libraries in
`libs/proxy/` to edition 2024.
Also reformats the imports of those forked libraries via:
```
cargo +nightly fmt -p proxy -p postgres-protocol2 -p postgres-types2 -p tokio-postgres2 -- -l --config imports_granularity=Module,group_imports=StdExternalCrate,reorder_imports=true
```
It can be read commit-by-commit: the first commit has no formatting
changes, only changes to accomodate the new edition.
Part of #10918
ref: https://github.com/neondatabase/cloud/issues/23385
Adds a direction flag as well as private-link ID to the traffic
reporting pipeline. We do not yet actually count ingress, but we include
the flag anyway.
I have additionally moved vpce_id string parsing earlier, since we
expect it to be utf8 (ascii).
- Wired up filtering on VPC endpoints
- Wired up block access from public internet / VPC depending on per
project flag
- Added cache invalidation for VPC endpoints (partially based on PR from
Raphael)
- Removed BackendIpAllowlist trait
---------
Co-authored-by: Ivan Efremov <ivan@neon.tech>
## Problem
Because dashmap 6 switched to hashbrown RawTable API, it required us to
use unsafe code in the upgrade:
https://github.com/neondatabase/neon/pull/8107
## Summary of changes
Switch to clashmap, a fork maintained by me which removes much of the
unsafe and ultimately switches to HashTable instead of RawTable to
remove much of the unsafe requirement on us.
## Problem
The approach of having CancelMap as an in-memory structure increases
code complexity,
as well as putting additional load for Redis streams.
## Summary of changes
- Implement a set of KV ops for Redis client;
- Remove cancel notifications code;
- Send KV ops over the bounded channel to the handling background task
for removing and adding the cancel keys.
Closes#9660
This PR removes the direct dependency of the IP allowlist from
CancelClosure, allowing for more scalable and flexible IP restrictions
and enabling the future use of Redis-based CancelMap storage.
Changes:
- Introduce a new BackendAuth async trait that retrieves the IP
allowlist through existing authentication methods;
- Improve cancellation error handling by instrument() async
cancel_sesion() rather than dropping it.
- Set and store IP allowlist for SCRAM Proxy to consistently perform IP
allowance check
Relates to #9660
Now that we construct the TLS client config for cancellation as well as
connect, it feels appropriate to construct the same config once and
re-use it elsewhere. It might also help should #7500 require any extra
setup, so we can easily add it to all the appropriate call sites.
As the title says, I updated the lint rules to no longer allow unwrap or
unimplemented.
Three special cases:
* Tests are allowed to use them
* std::sync::Mutex lock().unwrap() is common because it's usually
correct to continue panicking on poison
* `tokio::spawn_blocking(...).await.unwrap()` is common because it will
only error if the blocking fn panics, so continuing the panic is also
correct
I've introduced two extension traits to help with these last two, that
are a bit more explicit so they don't need an expect message every time.
(stacked on #9990 and #9995)
Partially fixes#1287 with a custom option field to enable the fixed
behaviour. This allows us to gradually roll out the fix without silently
changing the observed behaviour for our customers.
related to https://github.com/neondatabase/cloud/issues/15284
Keeping the `mock` postgres cplane adaptor using "stock" tokio-postgres
allows us to remove a lot of dead weight from our actual postgres
connection logic.
## Problem
For cancellation, a connection is open during all the cancel checks.
## Summary of changes
Spawn cancellation checks in the background, and close connection
immediately.
Use task_tracker for cancellation checks.
## Problem
The RequestContext::span shouldn't live for the entire postgres
connection, only the handshake.
## Summary of changes
* Slight refactor to the RequestContext to discard the span upon
handshake completion.
* Make sure the temporary future for the handshake is dropped (not bound
to a variable)
* Runs our nightly fmt script
See https://github.com/neondatabase/cloud/issues/14378
In collaboration with @cloneable and @awarus, we sifted through logs and
simply demoted some logs to debug. This is not at all finished and there
are more logs to review, but we ran out of time in the session we
organised. In any slightly more nuanced cases, we didn't touch the log,
instead leaving a TODO comment.
## Problem
My benchmarks show that prometheus is not very good.
https://github.com/conradludgate/measured
We're already using it in storage_controller and it seems to be working
well.
## Summary of changes
Replace prometheus with my new measured crate in proxy only.
Apologies for the large diff. I tried to keep it as minimal as I could.
The label types add a bit of boiler plate (but reduce the chance we
mistype the labels), and some of our custom metrics like CounterPair and
HLL needed to be rewritten.
## Problem
stack overflow in blanket impl for `CancellationPublisher`
## Summary of changes
Removes `async_trait` and fixes the impl order to make it non-recursive.
## Problem
Support of IAM Roles for Service Accounts for authentication.
## Summary of changes
* Obtain aws 15m-long credentials
* Retrieve redis password from credentials
* Update every 1h to keep connection for more than 12h
* For now allow to have different endpoints for pubsub/stream redis.
TODOs:
* PubSub doesn't support credentials refresh, consider using stream
instead.
* We need an AWS role for proxy to be able to connect to both: S3 and
elasticache.
Credentials obtaining and connection refresh was tested on xenon
preview.
https://github.com/neondatabase/cloud/issues/10365
## Problem
Taking my ideas from https://github.com/neondatabase/neon/pull/6283 and
doing a bit less radical changes. smaller commits.
We currently don't report error classifications in proxy as the current
error handling made it hard to do so.
## Summary of changes
1. Add a `ReportableError` trait that all errors will implement. This
provides the error classification functionality.
2. Handle Client requests a strongly typed error
* this error is a `ReportableError` and is logged appropriately
3. The handle client error only has a few possible error types, to
account for the fact that at this point errors should be returned to the
user.
## Problem
Taking my ideas from https://github.com/neondatabase/neon/pull/6283 and
doing a bit less radical changes. smaller commits.
Proxy flow was quite deeply nested, which makes adding more interesting
error handling quite tricky.
## Summary of changes
I recommend reviewing commit by commit.
1. move handshake logic into a separate file
2. move passthrough logic into a separate file
3. no longer accept a closure in CancelMap session logic
4. Remove connect_to_db, copy logic into handle_client
5. flatten auth_and_wake_compute in authenticate
6. record info for link auth
## Problem
Every database request locks this cancel map rwlock. At high requests
per second this would have high contention
## Summary of changes
Switch to dashmap which has a sharded rwlock to reduce contention
## Problem
`cargo +nightly doc` is giving a lot of warnings: broken links, naked
URLs, etc.
## Summary of changes
* update the `proc-macro2` dependency so that it can compile on latest
Rust nightly, see https://github.com/dtolnay/proc-macro2/pull/391 and
https://github.com/dtolnay/proc-macro2/issues/398
* allow the `private_intra_doc_links` lint, as linking to something
that's private is always more useful than just mentioning it without a
link: if the link breaks in the future, at least there is a warning due
to that. Also, one might enable
[`--document-private-items`](https://doc.rust-lang.org/cargo/commands/cargo-doc.html#documentation-options)
in the future and make these links work in general.
* fix all the remaining warnings given by `cargo +nightly doc`
* make it possible to run `cargo doc` on stable Rust by updating
`opentelemetry` and associated crates to version 0.19, pulling in a fix
that previously broke `cargo doc` on stable:
https://github.com/open-telemetry/opentelemetry-rust/pull/904
* Add `cargo doc` to CI to ensure that it won't get broken in the
future.
Fixes#2557
## Future work
* Potentially, it might make sense, for development purposes, to publish
the generated rustdocs somewhere, like for example [how the rust
compiler does
it](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_driver/index.html).
I will file an issue for discussion.
This patch adds a timed LRU cache implementation and a compute node info cache on top of that.
Cache entries might expire on their own (default ttl=5mins) or become invalid due to real-world events,
e.g. compute node scale-to-zero event, so we add a connection retry loop with a wake-up call.
Solved problems:
- [x] Find a decent LRU implementation.
- [x] Implement timed LRU on top of that.
- [x] Cache results of `proxy_wake_compute` API call.
- [x] Don't invalidate newer cache entries for the same key.
- [x] Add cmdline configuration knobs (requires some refactoring).
- [x] Add failed connection estab metric.
- [x] Refactor auth backends to make things simpler (retries, cache
placement, etc).
- [x] Address review comments (add code comments + cleanup).
- [x] Retry `/proxy_wake_compute` if we couldn't connect to a compute
(e.g. stalled cache entry).
- [x] Add high-level description for `TimedLru`.
TODOs (will be addressed later):
- [ ] Add cache metrics (hit, spurious hit, miss).
- [ ] Synchronize http requests across concurrent per-client tasks
(https://github.com/neondatabase/neon/pull/3331#issuecomment-1399216069).
- [ ] Cache results of `proxy_get_role_secret` API call.
