use a connection pool for remote execution

Cargo.toml

@@ -202,6 +202,7 @@ hashbrown = { version = "0.14.3", features = ["raw"] }
 hex = "0.4.3"
 hostname = "0.3.1"
 http = "1.3.1"
+http-body = "1.0"
 http-body-util = "0.1.0"
 httparse = "1.7.1"
 httptest = "0.16"

app/buck2_re_configuration/src/lib.rs

@@ -457,6 +457,12 @@ pub struct Buck2OssReConfiguration {
     pub grpc_keepalive_timeout_secs: Option<u64>,
     /// Whether to send HTTP/2 pings when connection is idle.
     pub grpc_keepalive_while_idle: Option<bool>,
+    /// Minimum number of HTTP/2 connections per host in the connection pool.
+    pub min_connections: Option<usize>,
+    /// Maximum number of HTTP/2 connections per host in the connection pool.
+    pub max_connections: Option<usize>,
+    /// Maximum concurrent streams per connection.
+    pub max_concurrency_per_connection: Option<usize>,
 }
 
 #[derive(Clone, Debug, Default, Allocative)]
@@ -574,6 +580,18 @@ impl Buck2OssReConfiguration {
                 section: BUCK2_RE_CLIENT_CFG_SECTION,
                 property: "grpc_keepalive_while_idle",
             })?,
+            min_connections: legacy_config.parse(BuckconfigKeyRef {
+                section: BUCK2_RE_CLIENT_CFG_SECTION,
+                property: "min_connections",
+            })?,
+            max_connections: legacy_config.parse(BuckconfigKeyRef {
+                section: BUCK2_RE_CLIENT_CFG_SECTION,
+                property: "max_connections",
+            })?,
+            max_concurrency_per_connection: legacy_config.parse(BuckconfigKeyRef {
+                section: BUCK2_RE_CLIENT_CFG_SECTION,
+                property: "max_concurrency_per_connection",
+            })?,
         })
     }
 }

remote_execution/oss/re_grpc/Cargo.toml

@@ -13,6 +13,8 @@ dupe = { workspace = true }
 futures = { workspace = true }
 gazebo = { workspace = true }
 http = { workspace = true }
+http-body = { workspace = true }
+http-body-util = { workspace = true }
 hyper = { workspace = true }
 hyper-util = { workspace = true }
 lru = { workspace = true }