fix: address correctness, safety, and concurrency issues (#2327)

Co-authored-by: heihutu <heihutu@gmail.com>
Co-authored-by: houseme <housemecn@gmail.com>

crates/metrics/src/format.rs

@@ -28,10 +28,7 @@ static HELP_CACHE: OnceLock<Mutex<HashMap<String, &'static str>>> = OnceLock::ne
 
 fn intern_string(cache: &OnceLock<Mutex<HashMap<String, &'static str>>>, value: &str) -> &'static str {
     let cache = cache.get_or_init(Default::default);
-    let mut cache = match cache.lock() {
-        Ok(guard) => guard,
-        Err(poisoned) => poisoned.into_inner(),
-    };
+    let mut cache = cache.lock().unwrap_or_else(|poisoned| poisoned.into_inner());
 
     if let Some(existing) = cache.get(value) {
         existing

crates/metrics/src/global.rs

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 use tokio_util::sync::CancellationToken;
+use tracing::info;
 
 /// Initializes the global metrics system. This should be called once at the start of the application.
 /// The provided `CancellationToken` will be used to gracefully shut down the metrics system when needed.
@@ -33,7 +34,7 @@ use tokio_util::sync::CancellationToken;
 /// ```
 /// Note: This function should only be called once during the application's lifecycle. Calling it multiple times may lead to unexpected behavior.
 pub fn init_metrics_system(token: CancellationToken) {
-    tracing::info!("init metrics system start");
+    info!("init metrics system start");
     crate::collectors::init_metrics_collectors(token);
-    tracing::info!("init metrics system done");
+    info!("init metrics system done");
 }