[ENH]: support export foyer metrics via otel (#3204)

Signed-off-by: MrCroxx <[email protected]>## Description of changes

*Summarize the changes made by this PR.*
 - Improvements & Bug fixes
   - Support otel metrics export

## Test plan
*How are these changes tested?*

- [x] Tests pass locally with `pytest` for python, `yarn test` for js,
`cargo test` for rust

## Documentation Changes
*Are all docstrings for user-facing APIs updated if required? Do we need
to make documentation changes in the [docs
repository](https://github.com/chroma-core/docs)?*

---------

Signed-off-by: MrCroxx <[email protected]>

.taplo.toml

@@ -0,0 +1,2 @@
+[formatting]
+column_width = 65535

Cargo.toml

@@ -1,20 +1,7 @@
 [workspace]
 resolver = "2"
 
-members = [
-   "rust/benchmark",
-   "rust/blockstore",
-   "rust/cache",
-   "rust/chroma",
-   "rust/config",
-   "rust/distance",
-   "rust/error",
-   "rust/index",
-   "rust/load",
-   "rust/storage",
-   "rust/types",
-   "rust/worker",
-]
+members = ["rust/benchmark", "rust/blockstore", "rust/cache", "rust/chroma", "rust/config", "rust/distance", "rust/error", "rust/index", "rust/load", "rust/storage", "rust/types", "rust/worker"]
 
 [workspace.dependencies]
 arrow = "52.2.0"

rust/cache/Cargo.toml

@@ -8,7 +8,7 @@ path = "src/lib.rs"
 
 [dependencies]
 clap = { workspace = true }
-foyer = "0.12"
+foyer = { version = "0.13.1", features = ["opentelemetry_0_27", "tracing"] }
 anyhow = "1.0"
 opentelemetry = { version = "0.27.0", default-features = false, features = [
   "trace",

rust/cache/src/foyer.rs

@@ -1,6 +1,7 @@
 use super::{CacheError, Weighted};
 use chroma_error::ChromaError;
 use clap::Parser;
+use foyer::opentelemetry_0_27::OpenTelemetryMetricsRegistry;
 use foyer::{
     CacheBuilder, DirectFsDeviceOptions, Engine, FifoConfig, FifoPicker, HybridCacheBuilder,
     InvalidRatioPicker, LargeEngineOptions, LfuConfig, LruConfig, RateLimitPicker, S3FifoConfig,
@@ -272,6 +273,7 @@ where
             .with_record_hybrid_fetch_threshold(Duration::from_micros(config.trace_fetch_us as _));
 
         let builder = HybridCacheBuilder::<K, V>::new()
+            .with_metrics_registry(OpenTelemetryMetricsRegistry::new(global::meter("chroma")))
             .with_tracing_options(tracing_options)
             .memory(config.mem)
             .with_shards(config.shards);
@@ -457,13 +459,14 @@ where
             type Key = K;
             type Value = V;
 
-            fn on_memory_release(&self, key: Self::Key, value: Self::Value)
+            fn on_leave(&self, _: foyer::Event, key: &Self::Key, value: &Self::Value)
             where
-                K: Clone + Send + Sync + Eq + PartialEq + Hash + 'static,
+                Self::Key: foyer::Key,
+                Self::Value: foyer::Value,
             {
                 // NOTE(rescrv):  There's no mechanism by which we can error.  We could log a
                 // metric, but this should really never happen.
-                let _ = self.0.send((key, value));
+                let _ = self.0.send((key.clone(), value.clone()));
             }
         }
         let evl = TokioEventListener(tx);