fix: run upkeep manually

crates/node/builder/src/launch/common.rs

@@ -2,6 +2,11 @@
 
 use std::{sync::Arc, thread::available_parallelism};
 
+use crate::{
+    components::{NodeComponents, NodeComponentsBuilder},
+    hooks::OnComponentInitializedHook,
+    BuilderContext, NodeAdapter,
+};
 use alloy_primitives::{BlockNumber, B256};
 use eyre::{Context, OptionExt};
 use rayon::ThreadPoolBuilder;
@@ -34,6 +39,7 @@ use reth_node_core::{
 use reth_node_metrics::{
     chain::ChainSpecInfo,
     hooks::Hooks,
+    recorder::install_prometheus_recorder,
     server::{MetricServer, MetricServerConfig},
     version::VersionInfo,
 };
@@ -58,12 +64,6 @@ use tokio::sync::{
     oneshot, watch,
 };
 
-use crate::{
-    components::{NodeComponents, NodeComponentsBuilder},
-    hooks::OnComponentInitializedHook,
-    BuilderContext, NodeAdapter,
-};
-
 /// Allows to set a tree viewer for a configured blockchain provider.
 // TODO: remove this helper trait once the engine revamp is done, the new
 // blockchain provider won't require a TreeViewer.
@@ -509,6 +509,9 @@ where
 
     /// Starts the prometheus endpoint.
     pub async fn start_prometheus_endpoint(&self) -> eyre::Result<()> {
+        // ensure recorder runs upkeep periodically
+        install_prometheus_recorder().spawn_upkeep();
+
         let listen_addr = self.node_config().metrics;
         if let Some(addr) = listen_addr {
             info!(target: "reth::cli", "Starting metrics endpoint at {}", addr);

crates/node/metrics/src/recorder.rs

@@ -3,25 +3,78 @@
 use eyre::WrapErr;
 use metrics_exporter_prometheus::{PrometheusBuilder, PrometheusHandle};
 use metrics_util::layers::{PrefixLayer, Stack};
-use std::sync::LazyLock;
+use std::sync::{atomic::AtomicBool, LazyLock};
 
 /// Installs the Prometheus recorder as the global recorder.
-pub fn install_prometheus_recorder() -> &'static PrometheusHandle {
+///
+/// Note: This must be installed before any metrics are `described`.
+///
+/// Caution: This only configures the global recorder and does not spawn the exporter.
+/// Callers must run [`PrometheusRecorder::spawn_upkeep`] manually.
+pub fn install_prometheus_recorder() -> &'static PrometheusRecorder {
     &PROMETHEUS_RECORDER_HANDLE
 }
 
 /// The default Prometheus recorder handle. We use a global static to ensure that it is only
 /// installed once.
-static PROMETHEUS_RECORDER_HANDLE: LazyLock<PrometheusHandle> =
+static PROMETHEUS_RECORDER_HANDLE: LazyLock<PrometheusRecorder> =
     LazyLock::new(|| PrometheusRecorder::install().unwrap());
 
-/// Prometheus recorder installer
+/// A handle to the Prometheus recorder.
+///
+/// This is intended to be used as the global recorder.
+/// Callers must ensure that [`PrometheusRecorder::spawn_upkeep`] is called once.
 #[derive(Debug)]
-pub struct PrometheusRecorder;
+pub struct PrometheusRecorder {
+    handle: PrometheusHandle,
+    upkeep: AtomicBool,
+}
 
 impl PrometheusRecorder {
+    const fn new(handle: PrometheusHandle) -> Self {
+        Self { handle, upkeep: AtomicBool::new(false) }
+    }
+
+    /// Returns a reference to the [`PrometheusHandle`].
+    pub const fn handle(&self) -> &PrometheusHandle {
+        &self.handle
+    }
+
+    /// Spawns the upkeep task if there hasn't been one spawned already.
+    ///
+    /// ## Panics
+    ///
+    /// This method must be called from within an existing Tokio runtime or it will panic.
+    ///
+    /// See also [`PrometheusHandle::run_upkeep`]
+    pub fn spawn_upkeep(&self) {
+        if self
+            .upkeep
+            .compare_exchange(
+                false,
+                true,
+                std::sync::atomic::Ordering::SeqCst,
+                std::sync::atomic::Ordering::Acquire,
+            )
+            .is_err()
+        {
+            return;
+        }
+
+        let handle = self.handle.clone();
+        tokio::spawn(async move {
+            loop {
+                tokio::time::sleep(std::time::Duration::from_secs(5)).await;
+                handle.run_upkeep();
+            }
+        });
+    }
+
     /// Installs Prometheus as the metrics recorder.
-    pub fn install() -> eyre::Result<PrometheusHandle> {
+    ///
+    /// Caution: This only configures the global recorder and does not spawn the exporter.
+    /// Callers must run [`Self::spawn_upkeep`] manually.
+    pub fn install() -> eyre::Result<Self> {
         let recorder = PrometheusBuilder::new().build_recorder();
         let handle = recorder.handle();
 
@@ -31,7 +84,7 @@ impl PrometheusRecorder {
             .install()
             .wrap_err("Couldn't set metrics recorder.")?;
 
-        Ok(handle)
+        Ok(Self::new(handle))
     }
 }
 
@@ -52,7 +105,7 @@ mod tests {
         process.describe();
         process.collect();
 
-        let metrics = PROMETHEUS_RECORDER_HANDLE.render();
+        let metrics = PROMETHEUS_RECORDER_HANDLE.handle.render();
         assert!(metrics.contains("process_cpu_seconds_total"), "{metrics:?}");
     }
 }

crates/node/metrics/src/server.rs

@@ -103,7 +103,7 @@ impl MetricServer {
                 let hook = hook.clone();
                 let service = tower::service_fn(move |_| {
                     (hook)();
-                    let metrics = handle.render();
+                    let metrics = handle.handle().render();
                     let mut response = Response::new(metrics);
                     response
                         .headers_mut()