## 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.
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.
## Problem
It is called context/ctx everywhere and the Monitoring suffix needlessly
confuses with proper monitoring code.
## Summary of changes
* Rename RequestMonitoring to RequestContext
* Rename RequestMonitoringInner to RequestContextInner
I think I meant to make these changes over 6 months ago. alas, better
late than never.
1. should_reject doesn't eagerly intern the endpoint string
2. Rate limiter uses a std Mutex instead of a tokio Mutex.
3. Recently I introduced a `-local-proxy` endpoint suffix. I forgot to
add this to normalize.
4. Random but a small cleanup making the ControlPlaneEvent deser
directly to the interned strings.
## Problem
1. Hard to correlate startup parameters with the endpoint that provided
them.
2. Some configurations are not needed in the `ProxyConfig` struct.
## Summary of changes
Because of some borrow checker fun, I needed to switch to an
interior-mutability implementation of our `RequestMonitoring` context
system. Using https://docs.rs/try-lock/latest/try_lock/ as a cheap lock
for such a use-case (needed to be thread safe).
Removed the lock of each startup message, instead just logging only the
startup params in a successful handshake.
Also removed from values from `ProxyConfig` and kept as arguments.
(needed for local-proxy config)
## Problem
Sometimes rejected metric might record invalid events.
## Summary of changes
* Only record it `rejected` was explicitly set.
* Change order in logs.
* Report metrics if not under high-load.
## Problem
Actually read redis events.
## Summary of changes
This is revert of https://github.com/neondatabase/neon/pull/7350 +
fixes.
* Fixed events parsing
* Added timeout after connection failure
* Separated regional and global redis clients.
## Problem
Proxy doesn't know about existing endpoints.
## Summary of changes
* Added caching of all available endpoints.
* On the high load, use it before going to cplane.
* Report metrics for the outcome.
* For rate limiter and credentials caching don't distinguish between
`-pooled` and not
TODOs:
* Make metrics more meaningful
* Consider integrating it with the endpoint rate limiter
* Test it together with cplane in preview
