proxy: add request context for observability and blocking (#6160)

## Summary of changes

### RequestMonitoring

We want to add an event stream with information on each request for
easier analysis than what we can do with diagnostic logs alone
(neondatabase/cloud#8807). This
RequestMonitoring will keep a record of the final state of a request. On
drop it will be pushed into a queue to be uploaded.

Because this context is a bag of data, I don't want this information to
impact logic of request handling. I personally think that weakly typed
data (such as all these options) makes for spaghetti code. I will
however allow for this data to impact rate-limiting and blocking of
requests, as this does not _really_ change how a request is handled.

### Parquet

Each `RequestMonitoring` is flushed into a channel where it is converted
into `RequestData`, which is accumulated into parquet files. Each file
will have a certain number of rows per row group, and several row groups
will eventually fill up the file, which we then upload to S3.

We will also upload smaller files if they take too long to construct.

Author: conradludgate

Cargo.lock

@@ -107,6 +107,8 @@ opentelemetry = "0.19.0"
 opentelemetry-otlp = { version = "0.12.0", default_features=false, features = ["http-proto", "trace", "http", "reqwest-client"] }
 opentelemetry-semantic-conventions = "0.11.0"
 parking_lot = "0.12"
+parquet = { version = "49.0.0", default-features = false, features = ["zstd"] }
+parquet_derive = "49.0.0"
 pbkdf2 = { version = "0.12.1", features = ["simple", "std"] }
 pin-project-lite = "0.2"
 prometheus = {version = "0.13", default_features=false, features = ["process"]} # removes protobuf dependency
@@ -161,7 +163,7 @@ tracing-error = "0.2.0"
 tracing-opentelemetry = "0.19.0"
 tracing-subscriber = { version = "0.3", default_features = false, features = ["smallvec", "fmt", "tracing-log", "std", "env-filter", "json"] }
 url = "2.2"
-uuid = { version = "1.2", features = ["v4", "serde"] }
+uuid = { version = "1.6.1", features = ["v4", "v7", "serde"] }
 walkdir = "2.3.2"
 webpki-roots = "0.25"
 x509-parser = "0.15"
@@ -215,6 +217,10 @@ tonic-build = "0.9"
 # TODO: we should probably fork `tokio-postgres-rustls` instead.
 tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", branch="neon" }
 
+# bug fixes for UUID
+parquet = { git = "https://github.com/neondatabase/arrow-rs", branch = "neon-fix-bugs" }
+parquet_derive = { git = "https://github.com/neondatabase/arrow-rs", branch = "neon-fix-bugs" }
+
 ################# Binary contents sections
 
 [profile.release]

Cargo.toml

@@ -5,7 +5,7 @@ edition.workspace = true
 license.workspace = true
 
 [features]
-default = []
+default = ["testing"]
 testing = []
 
 [dependencies]
@@ -14,6 +14,7 @@ async-trait.workspace = true
 base64.workspace = true
 bstr.workspace = true
 bytes = { workspace = true, features = ["serde"] }
+camino.workspace = true
 chrono.workspace = true
 clap.workspace = true
 consumption_metrics.workspace = true
@@ -35,13 +36,16 @@ metrics.workspace = true
 once_cell.workspace = true
 opentelemetry.workspace = true
 parking_lot.workspace = true
+parquet.workspace = true
+parquet_derive.workspace = true
 pbkdf2 = { workspace = true, features = ["simple", "std"] }
 pin-project-lite.workspace = true
 postgres_backend.workspace = true
 pq_proto.workspace = true
 prometheus.workspace = true
 rand.workspace = true
 regex.workspace = true
+remote_storage = { version = "0.1", path = "../libs/remote_storage/" }
 reqwest = { workspace = true, features = ["json"] }
 reqwest-middleware.workspace = true
 reqwest-retry.workspace = true
@@ -80,6 +84,7 @@ smol_str.workspace = true
 workspace_hack.workspace = true
 
 [dev-dependencies]
+camino-tempfile.workspace = true
 rcgen.workspace = true
 rstest.workspace = true
 tokio-postgres-rustls.workspace = true