From 7c9bd542a679c38149014e2137ec41207aea6b29 Mon Sep 17 00:00:00 2001
From: Elizabeth Murray <elizabeth@neon.tech>
Date: Mon, 26 May 2025 06:30:48 -0700
Subject: [PATCH] Fix compile warnings, minor cleanup.

---
 pageserver/client_grpc/Cargo.toml             |  2 +-
 pageserver/client_grpc/src/client_cache.rs    | 31 ++-----------------
 pageserver/client_grpc/src/lib.rs             |  2 +-
 .../pagebench/src/cmd/getpage_latest_lsn.rs   |  2 +-
 4 files changed, 6 insertions(+), 31 deletions(-)

diff --git a/pageserver/client_grpc/Cargo.toml b/pageserver/client_grpc/Cargo.toml
index 3955ef579f..d0e162fbbe 100644
--- a/pageserver/client_grpc/Cargo.toml
+++ b/pageserver/client_grpc/Cargo.toml
@@ -12,7 +12,7 @@ tonic.workspace = true
 tracing.workspace = true
 tokio = { version = "1.43.1", features = ["full", "macros", "net", "io-util", "rt", "rt-multi-thread"] }
 uuid = { version = "1", features = ["v4"] }
-tower = {  version = "0.4", features = ["timeout"] }
+tower = {  version = "0.4", features = ["timeout", "util"] }
 rand = "0.8"
 tokio-util = { version = "0.7", features = ["compat"] }
 hyper-util = "0.1.9"
diff --git a/pageserver/client_grpc/src/client_cache.rs b/pageserver/client_grpc/src/client_cache.rs
index bb8befa1ce..cb496148ee 100644
--- a/pageserver/client_grpc/src/client_cache.rs
+++ b/pageserver/client_grpc/src/client_cache.rs
@@ -1,8 +1,7 @@
 use std::{
-    collections::{BinaryHeap, HashMap},
+    collections::{HashMap},
     sync::{
         Arc,
-        atomic::{AtomicUsize, Ordering},
     },
     time::{Duration, Instant},
     io::{self, Error, ErrorKind},
@@ -11,7 +10,7 @@ use std::{
 use priority_queue::PriorityQueue;
 
 use tokio::{
-    sync::{Mutex, mpsc, watch, Semaphore, OwnedSemaphorePermit},
+    sync::{Mutex, Semaphore, OwnedSemaphorePermit},
     time::sleep,
     net::TcpStream,
     io::{AsyncRead, AsyncWrite, ReadBuf},
@@ -32,31 +31,10 @@ use rand::{
     SeedableRng
 };
 
-use tower::service_fn;
 use http::Uri;
 use hyper_util::rt::TokioIo;
 use bytes::BytesMut;
-use futures::future;
-use http::Uri;
-use hyper_util::rt::TokioIo;
-use rand::{Rng, SeedableRng, rngs::StdRng};
-use std::io::{self, Error, ErrorKind};
-use std::{
-    pin::Pin,
-    task::{Context, Poll},
-};
-use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
-use tokio::net::TcpStream;
 use tower::service_fn;
-use uuid;
-
-use metrics::{
-    {Encoder, TextEncoder},
-    proto::MetricFamily,
-};
-
-// use info
-use tracing::info;
 
 use tokio_util::sync::CancellationToken;
 
@@ -240,7 +218,6 @@ pub struct PooledClient {
     pool: Arc<ConnectionPool>,
     id: uuid::Uuid,
     permit: OwnedSemaphorePermit,
-    is_ok: bool,
 }
 
 impl ConnectionPool {
@@ -356,7 +333,7 @@ impl ConnectionPool {
 
         // Pop the highest-active-consumers connection. There are no connections
         // in the heap that have more than max_consumers active consumers.
-        if let Some((id, cons)) = inner.pq.pop() {
+        if let Some((id, _cons)) = inner.pq.pop() {
             let entry = inner.entries.get_mut(&id)
                 .expect("pq and entries got out of sync");
 
@@ -369,7 +346,6 @@ impl ConnectionPool {
                 pool: Arc::clone(&self),
                 id,
                 permit: permit,
-                is_ok: true,
             };
 
             // re‐insert with updated priority
@@ -437,7 +413,6 @@ impl ConnectionPool {
                         let mut inner = self_clone.inner.lock().await;
                         inner.waiters += 1;
                         if inner.waiters >= (inner.in_progress * self_clone.max_consumers) {
-                            semaphore = Arc::clone(&self_clone.channel_semaphore);
                             let self_clone_spawn = Arc::clone(&self_clone);
                             tokio::task::spawn(async move {
                                 self_clone_spawn.create_connection().await;
diff --git a/pageserver/client_grpc/src/lib.rs b/pageserver/client_grpc/src/lib.rs
index 2a15e59786..4c1a4a5185 100644
--- a/pageserver/client_grpc/src/lib.rs
+++ b/pageserver/client_grpc/src/lib.rs
@@ -22,7 +22,7 @@ use utils::shard::ShardIndex;
 use std::fmt::Debug;
 mod client_cache;
 
-use metrics::{IntCounter, IntCounterVec, core::Collector};
+use metrics::{IntCounterVec, core::Collector};
 
 #[derive(Error, Debug)]
 pub enum PageserverClientError {
diff --git a/pageserver/pagebench/src/cmd/getpage_latest_lsn.rs b/pageserver/pagebench/src/cmd/getpage_latest_lsn.rs
index 071c952e0d..f49ad68b2c 100644
--- a/pageserver/pagebench/src/cmd/getpage_latest_lsn.rs
+++ b/pageserver/pagebench/src/cmd/getpage_latest_lsn.rs
@@ -171,7 +171,7 @@ pub(crate) fn main(args: Args) -> anyhow::Result<()> {
     })
 }
 async fn get_metrics(State(state): State<Arc<pageserver_client_grpc::PageserverClientAggregateMetrics>>) -> Response {
-    use metrics::core::Collector;
+
     let metrics = state.collect();
 
     info!("metrics: {metrics:?}");