refactor: Holds histogram in the timer to avoid clone labels if possible (#1653)

* feat: use Histogram struct to impl Timer * fix: fix compile errors * feat: downgrade metrics-process * fix: compiler errors
2026-05-19 06:20:38 +00:00 · 2023-05-26 17:12:03 +08:00
parent c042723fc9
commit 89366ba939
14 changed files with 121 additions and 147 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1222,7 +1222,7 @@ dependencies = [
 "lazy_static",
 "log-store",
 "meta-client",
- "metrics 0.21.0",
+ "metrics",
 "mito",
 "moka 0.11.0",
 "object-store",
@@ -1860,7 +1860,7 @@ dependencies = [
 "async-trait",
 "common-error",
 "common-telemetry",
- "metrics 0.21.0",
+ "metrics",
 "once_cell",
 "paste",
 "snafu",
@@ -1876,7 +1876,7 @@ dependencies = [
 "backtrace",
 "common-error",
 "console-subscriber",
- "metrics 0.21.0",
+ "metrics",
 "metrics-exporter-prometheus",
 "metrics-util",
 "once_cell",
@@ -2577,7 +2577,7 @@ dependencies = [
 "log-store",
 "meta-client",
 "meta-srv",
- "metrics 0.21.0",
+ "metrics",
 "mito",
 "object-store",
 "pin-project",
@@ -3149,7 +3149,7 @@ dependencies = [
 "meta-srv",
 "meter-core",
 "meter-macros",
- "metrics 0.21.0",
+ "metrics",
 "mito",
 "moka 0.9.7",
 "object-store",
@@ -4263,7 +4263,7 @@ checksum = "cef509aa9bc73864d6756f0d34d35504af3cf0844373afe9b8669a5b8005a729"
 dependencies = [
 "console",
 "number_prefix",
- "portable-atomic 0.3.19",
+ "portable-atomic",
 "unicode-width",
 ]

@@ -4988,7 +4988,7 @@ dependencies = [
 "h2",
 "http-body",
 "lazy_static",
- "metrics 0.21.0",
+ "metrics",
 "once_cell",
 "parking_lot",
 "prost",
@@ -5034,32 +5034,22 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7b9b8653cec6897f73b519a43fba5ee3d50f62fe9af80b428accdcc093b4a849"
 dependencies = [
 "ahash 0.7.6",
- "metrics-macros 0.6.0",
- "portable-atomic 0.3.19",
-]
-
-[[package]]
-name = "metrics"
-version = "0.21.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aa8ebbd1a9e57bbab77b9facae7f5136aea44c356943bf9a198f647da64285d6"
-dependencies = [
- "ahash 0.8.3",
- "metrics-macros 0.7.0",
- "portable-atomic 1.3.2",
+ "metrics-macros",
+ "portable-atomic",
 ]

 [[package]]
 name = "metrics-exporter-prometheus"
-version = "0.12.1"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8a4964177ddfdab1e3a2b37aec7cf320e14169abb0ed73999f558136409178d5"
+checksum = "8603921e1f54ef386189335f288441af761e0fc61bcb552168d9cedfe63ebc70"
 dependencies = [
- "base64 0.21.0",
 "indexmap",
- "metrics 0.21.0",
+ "metrics",
 "metrics-util",
- "quanta 0.11.0",
+ "parking_lot",
+ "portable-atomic",
+ "quanta 0.10.1",
 "thiserror",
 ]

@@ -5074,26 +5064,15 @@ dependencies = [
 "syn 1.0.109",
 ]

-[[package]]
-name = "metrics-macros"
-version = "0.7.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ddece26afd34c31585c74a4db0630c376df271c285d682d1e55012197830b6df"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn 2.0.15",
-]
-
 [[package]]
 name = "metrics-process"
-version = "1.0.10"
+version = "1.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "767e7caea6cb64b66f96f7ab0e5f8bd8334d72dbbc522c99bed71d8a382d515f"
+checksum = "99eab79be9f7c18565e889d6eaed6f1ebdafb2b6a88aef446d2fee5e7796ed10"
 dependencies = [
 "libproc",
 "mach2",
- "metrics 0.21.0",
+ "metrics",
 "once_cell",
 "procfs",
 "rlimit",
@@ -5102,19 +5081,21 @@ dependencies = [

 [[package]]
 name = "metrics-util"
-version = "0.15.0"
+version = "0.14.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "111cb375987443c3de8d503580b536f77dc8416d32db62d9456db5d93bd7ac47"
+checksum = "f7d24dc2dbae22bff6f1f9326ffce828c9f07ef9cc1e8002e5279f845432a30a"
 dependencies = [
 "aho-corasick 0.7.20",
 "crossbeam-epoch",
 "crossbeam-utils",
- "hashbrown 0.13.2",
+ "hashbrown 0.12.3",
 "indexmap",
- "metrics 0.21.0",
+ "metrics",
 "num_cpus",
- "ordered-float 3.7.0",
- "quanta 0.11.0",
+ "ordered-float 2.10.0",
+ "parking_lot",
+ "portable-atomic",
+ "quanta 0.10.1",
 "radix_trie",
 "sketches-ddsketch",
 ]
@@ -5634,7 +5615,7 @@ dependencies = [
 "futures",
 "lru 0.9.0",
 "md5",
- "metrics 0.21.0",
+ "metrics",
 "opendal",
 "pin-project",
 "tokio",
@@ -5692,7 +5673,7 @@ dependencies = [
 "hyper",
 "log",
 "md-5",
- "metrics 0.20.1",
+ "metrics",
 "once_cell",
 "parking_lot",
 "percent-encoding",
@@ -6298,12 +6279,6 @@ version = "0.3.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "26f6a7b87c2e435a3241addceeeff740ff8b7e76b74c13bf9acb17fa454ea00b"

-[[package]]
-name = "portable-atomic"
-version = "1.3.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc59d1bcc64fc5d021d67521f818db868368028108d37f0e98d74e33f68297b5"
-
 [[package]]
 name = "postgres-protocol"
 version = "0.6.5"
@@ -6770,7 +6745,7 @@ dependencies = [
 "futures",
 "futures-util",
 "humantime",
- "metrics 0.21.0",
+ "metrics",
 "num",
 "num-traits",
 "object-store",
@@ -8186,7 +8161,7 @@ dependencies = [
 "humantime-serde",
 "hyper",
 "influxdb_line_protocol",
- "metrics 0.21.0",
+ "metrics",
 "metrics-process",
 "mime_guess",
 "mysql_async",
@@ -8646,7 +8621,7 @@ dependencies = [
 "futures-util",
 "lazy_static",
 "log-store",
- "metrics 0.21.0",
+ "metrics",
 "object-store",
 "parquet",
 "paste",
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -84,7 +84,7 @@ tokio = { version = "1.28", features = ["full"] }
 tokio-util = { version = "0.7", features = ["io-util", "compat"] }
 tonic = { version = "0.9", features = ["tls"] }
 uuid = { version = "1", features = ["serde", "v4", "fast-rng"] }
-metrics = "0.21"
+metrics = "0.20"
 meter-core = { git = "https://github.com/GreptimeTeam/greptime-meter.git", rev = "f0798c4c648d89f51abe63e870919c75dd463199" }

 [workspace.dependencies.meter-macros]
--- a/src/common/telemetry/Cargo.toml
+++ b/src/common/telemetry/Cargo.toml
@@ -12,8 +12,8 @@ deadlock_detection = ["parking_lot"]
 backtrace = "0.3"
 common-error = { path = "../error" }
 console-subscriber = { version = "0.1", optional = true }
-metrics-exporter-prometheus = { version = "0.12", default-features = false }
-metrics-util = "0.15"
+metrics-exporter-prometheus = { version = "0.11", default-features = false }
+metrics-util = "0.14"
 metrics.workspace = true
 once_cell = "1.10"
 opentelemetry = { version = "0.17", default-features = false, features = [
--- a/src/common/telemetry/src/metric.rs
+++ b/src/common/telemetry/src/metric.rs
@@ -17,7 +17,7 @@
 use std::sync::{Arc, Once, RwLock};
 use std::time::{Duration, Instant};

-use metrics::histogram;
+use metrics::{register_histogram, Histogram, IntoLabels};
 use metrics_exporter_prometheus::PrometheusBuilder;
 pub use metrics_exporter_prometheus::PrometheusHandle;
 use metrics_util::layers::{Layer, PrefixLayer};
@@ -58,38 +58,45 @@ pub fn try_handle() -> Option<PrometheusHandle> {
    PROMETHEUS_HANDLE.as_ref().read().unwrap().clone()
 }

+/// A Histogram timer that emits the elapsed time to the histogram on drop.
 #[must_use = "Timer should be kept in a variable otherwise it cannot observe duration"]
-#[derive(Debug)]
 pub struct Timer {
    start: Instant,
-    name: &'static str,
-    labels: Vec<(String, String)>,
+    histogram: Histogram,
+}
+
+impl From<Histogram> for Timer {
+    fn from(histogram: Histogram) -> Timer {
+        Timer::from_histogram(histogram)
+    }
 }

 impl Timer {
+    /// Creates a timer from given histogram.
+    pub fn from_histogram(histogram: Histogram) -> Self {
+        Self {
+            start: Instant::now(),
+            histogram,
+        }
+    }
+
+    /// Creates a timer from given `name`.
    pub fn new(name: &'static str) -> Self {
        Self {
            start: Instant::now(),
-            name,
-            labels: Vec::new(),
+            histogram: register_histogram!(name),
        }
    }

-    pub fn new_with_labels<S: Into<String> + Clone>(name: &'static str, labels: &[(S, S)]) -> Self {
+    /// Creates a timer from given `name`.
+    pub fn new_with_labels<L: IntoLabels>(name: &'static str, labels: L) -> Self {
        Self {
            start: Instant::now(),
-            name,
-            labels: labels
-                .iter()
-                .map(|(k, v)| (k.clone().into(), v.clone().into()))
-                .collect::<Vec<_>>(),
+            histogram: register_histogram!(name, labels),
        }
    }

-    pub fn labels_mut(&mut self) -> &mut Vec<(String, String)> {
-        self.labels.as_mut()
-    }
-
+    /// Returns the elapsed duration from the time this timer created.
    pub fn elapsed(&self) -> Duration {
        self.start.elapsed()
    }
@@ -97,11 +104,7 @@ impl Timer {

 impl Drop for Timer {
    fn drop(&mut self) {
-        if !self.labels.is_empty() {
-            histogram!(self.name, self.start.elapsed(), &self.labels);
-        } else {
-            histogram!(self.name, self.start.elapsed());
-        }
+        self.histogram.record(self.elapsed())
    }
 }

@@ -110,7 +113,7 @@ macro_rules! timer {
    ($name: expr) => {
        $crate::metric::Timer::new($name)
    };
-    ($name:expr,$labels:expr) => {
+    ($name:expr, $labels:expr) => {
        $crate::metric::Timer::new_with_labels($name, $labels)
    };
 }
@@ -123,8 +126,7 @@ mod tests {
    fn test_elapsed_timer() {
        init_default_metrics_recorder();
        {
-            let t = Timer::new("test_elapsed_timer_a");
-            drop(t);
+            let _t = timer!("test_elapsed_timer_a");
        }
        let handle = try_handle().unwrap();
        let text = handle.render();
@@ -141,8 +143,7 @@ mod tests {
    fn test_elapsed_timer_with_label() {
        init_default_metrics_recorder();
        {
-            let t = Timer::new("test_elapsed_timer_a");
-            drop(t);
+            let _t = timer!("test_elapsed_timer_a");
        }
        let handle = try_handle().unwrap();
        let text = handle.render();
@@ -150,34 +151,16 @@ mod tests {
        assert!(!text.contains("test_elapsed_timer_b"));
        let label_a = "label_a";
        let label_b = "label_b";
-        let label_c = "label_c";
-        let label_d = "label_d";
-        let label_e = "label_e";
        assert!(!text.contains(label_a));
        assert!(!text.contains(label_b));

        {
-            let mut timer_b = timer!("test_elapsed_timer_b", &[(label_a, "a"), (label_b, "b")]);
-            let labels = timer_b.labels_mut();
-            labels.push((label_c.to_owned(), "d".to_owned()));
+            let _t = timer!("test_elapsed_timer_b", &[(label_a, "a"), (label_b, "b")]);
        }
        let text = handle.render();
        assert!(text.contains("test_elapsed_timer_a"));
        assert!(text.contains("test_elapsed_timer_b"));
        assert!(text.contains(label_a));
        assert!(text.contains(label_b));
-        assert!(text.contains(label_c));
-
-        {
-            let mut timer_c = timer!("test_elapsed_timer_c");
-            let labels = timer_c.labels_mut();
-            labels.push((label_d.to_owned(), "d".to_owned()));
-            labels.push((label_e.to_owned(), "e".to_owned()));
-        }
-
-        let text = handle.render();
-        assert!(text.contains("test_elapsed_timer_c"));
-        assert!(text.contains(label_d));
-        assert!(text.contains(label_e));
    }
 }
--- a/src/meta-srv/src/service/router.rs
+++ b/src/meta-srv/src/service/router.rs
@@ -47,7 +47,10 @@ impl router_server::Router for MetaSrv {

        let _timer = timer!(
            METRIC_META_ROUTE_REQUEST,
-            &[("op", "create"), ("cluster_id", &cluster_id.to_string())]
+            &[
+                ("op", "create".to_string()),
+                ("cluster_id", cluster_id.to_string())
+            ]
        );

        let table_name = table_name.clone().context(error::EmptyTableNameSnafu)?;
@@ -73,7 +76,10 @@ impl router_server::Router for MetaSrv {

        let _timer = timer!(
            METRIC_META_ROUTE_REQUEST,
-            &[("op", "route"), ("cluster_id", &cluster_id.to_string())]
+            &[
+                ("op", "route".to_string()),
+                ("cluster_id", cluster_id.to_string())
+            ]
        );

        let ctx = self.new_ctx();
@@ -88,7 +94,10 @@ impl router_server::Router for MetaSrv {

        let _timer = timer!(
            METRIC_META_ROUTE_REQUEST,
-            &[("op", "delete"), ("cluster_id", &cluster_id.to_string())]
+            &[
+                ("op", "delete".to_string()),
+                ("cluster_id", cluster_id.to_string())
+            ]
        );

        let ctx = self.new_ctx();
--- a/src/meta-srv/src/service/store/etcd.rs
+++ b/src/meta-srv/src/service/store/etcd.rs
@@ -65,9 +65,9 @@ impl KvStore for EtcdStore {
        let _timer = timer!(
            METRIC_META_KV_REQUEST,
            &[
-                ("target", "etcd"),
-                ("op", "range"),
-                ("cluster_id", &cluster_id.to_string())
+                ("target", "etcd".to_string()),
+                ("op", "range".to_string()),
+                ("cluster_id", cluster_id.to_string())
            ]
        );

@@ -103,9 +103,9 @@ impl KvStore for EtcdStore {
        let _timer = timer!(
            METRIC_META_KV_REQUEST,
            &[
-                ("target", "etcd"),
-                ("op", "put"),
-                ("cluster_id", &cluster_id.to_string())
+                ("target", "etcd".to_string()),
+                ("op", "put".to_string()),
+                ("cluster_id", cluster_id.to_string())
            ]
        );

@@ -132,9 +132,9 @@ impl KvStore for EtcdStore {
        let _timer = timer!(
            METRIC_META_KV_REQUEST,
            &[
-                ("target", "etcd"),
-                ("op", "batch_get"),
-                ("cluster_id", &cluster_id.to_string())
+                ("target", "etcd".to_string()),
+                ("op", "batch_get".to_string()),
+                ("cluster_id", cluster_id.to_string())
            ]
        );

@@ -175,9 +175,9 @@ impl KvStore for EtcdStore {
        let _timer = timer!(
            METRIC_META_KV_REQUEST,
            &[
-                ("target", "etcd"),
-                ("op", "batch_put"),
-                ("cluster_id", &cluster_id.to_string())
+                ("target", "etcd".to_string()),
+                ("op", "batch_put".to_string()),
+                ("cluster_id", cluster_id.to_string())
            ]
        );

@@ -220,9 +220,9 @@ impl KvStore for EtcdStore {
        let _timer = timer!(
            METRIC_META_KV_REQUEST,
            &[
-                ("target", "etcd"),
-                ("op", "batch_delete"),
-                ("cluster_id", &cluster_id.to_string())
+                ("target", "etcd".to_string()),
+                ("op", "batch_delete".to_string()),
+                ("cluster_id", cluster_id.to_string())
            ]
        );

@@ -269,9 +269,9 @@ impl KvStore for EtcdStore {
        let _timer = timer!(
            METRIC_META_KV_REQUEST,
            &[
-                ("target", "etcd"),
-                ("op", "compare_and_put"),
-                ("cluster_id", &cluster_id.to_string())
+                ("target", "etcd".to_string()),
+                ("op", "compare_and_put".to_string()),
+                ("cluster_id", cluster_id.to_string())
            ]
        );

@@ -329,9 +329,9 @@ impl KvStore for EtcdStore {
        let _timer = timer!(
            METRIC_META_KV_REQUEST,
            &[
-                ("target", "etcd"),
-                ("op", "delete_range"),
-                ("cluster_id", &cluster_id.to_string())
+                ("target", "etcd".to_string()),
+                ("op", "delete_range".to_string()),
+                ("cluster_id", cluster_id.to_string())
            ]
        );

@@ -367,9 +367,9 @@ impl KvStore for EtcdStore {
        let _timer = timer!(
            METRIC_META_KV_REQUEST,
            &[
-                ("target", "etcd"),
-                ("op", "move_value"),
-                ("cluster_id", &cluster_id.to_string())
+                ("target", "etcd".to_string()),
+                ("op", "move_value".to_string()),
+                ("cluster_id", cluster_id.to_string())
            ]
        );

--- a/src/servers/Cargo.toml
+++ b/src/servers/Cargo.toml
@@ -40,7 +40,8 @@ humantime-serde = "1.1"
 hyper = { version = "0.14", features = ["full"] }
 influxdb_line_protocol = { git = "https://github.com/evenyag/influxdb_iox", branch = "feat/line-protocol" }
 metrics.workspace = true
-metrics-process = "1"
+# metrics-process 1.0.10 depends on metrics-0.21 but opendal depends on metrics-0.20.1
+metrics-process = "<1.0.10"
 mime_guess = "2.0"
 num_cpus = "1.13"
 once_cell = "1.16"
--- a/src/servers/src/grpc/handler.rs
+++ b/src/servers/src/grpc/handler.rs
@@ -62,7 +62,7 @@ impl GreptimeRequestHandler {

        let _timer = timer!(
            crate::metrics::METRIC_SERVER_GRPC_DB_REQUEST_TIMER,
-            &[(crate::metrics::METRIC_DB_LABEL, &query_ctx.get_db_string())]
+            &[(crate::metrics::METRIC_DB_LABEL, query_ctx.get_db_string())]
        );
        let handler = self.handler.clone();

--- a/src/servers/src/grpc/prom_query_gateway.rs
+++ b/src/servers/src/grpc/prom_query_gateway.rs
@@ -72,7 +72,7 @@ impl PrometheusGateway for PrometheusGatewayService {
            crate::metrics::METRIC_SERVER_GRPC_PROM_REQUEST_TIMER,
            &[(
                crate::metrics::METRIC_DB_LABEL,
-                &query_context.get_db_string()
+                query_context.get_db_string()
            )]
        );
        let result = self.handler.do_query(&prom_query, query_context).await;
--- a/src/servers/src/http/handler.rs
+++ b/src/servers/src/http/handler.rs
@@ -51,7 +51,10 @@ pub async fn sql(
    let db = query_params.db.or(form_params.db);
    let _timer = timer!(
        crate::metrics::METRIC_HTTP_SQL_ELAPSED,
-        &[(crate::metrics::METRIC_DB_LABEL, db.as_deref().unwrap_or(""))]
+        &[(
+            crate::metrics::METRIC_DB_LABEL,
+            db.clone().unwrap_or_default()
+        )]
    );

    let resp = if let Some(sql) = &sql {
@@ -104,7 +107,10 @@ pub async fn promql(
    let db = params.db.clone();
    let _timer = timer!(
        crate::metrics::METRIC_HTTP_PROMQL_ELAPSED,
-        &[(crate::metrics::METRIC_DB_LABEL, db.as_deref().unwrap_or(""))]
+        &[(
+            crate::metrics::METRIC_DB_LABEL,
+            db.clone().unwrap_or_default()
+        )]
    );

    let prom_query = params.into();
--- a/src/servers/src/http/influxdb.rs
+++ b/src/servers/src/http/influxdb.rs
@@ -51,7 +51,7 @@ pub async fn influxdb_write(
        .unwrap_or_else(|| DEFAULT_SCHEMA_NAME.to_string());
    let _timer = timer!(
        crate::metrics::METRIC_HTTP_INFLUXDB_WRITE_ELAPSED,
-        &[(crate::metrics::METRIC_DB_LABEL, &db)]
+        &[(crate::metrics::METRIC_DB_LABEL, db.clone())]
    );
    let (catalog, schema) = parse_catalog_and_schema_from_client_database_name(&db);
    let ctx = Arc::new(QueryContext::with(catalog, schema));
--- a/src/servers/src/http/prometheus.rs
+++ b/src/servers/src/http/prometheus.rs
@@ -57,7 +57,7 @@ pub async fn remote_write(
        crate::metrics::METRIC_HTTP_PROMETHEUS_WRITE_ELAPSED,
        &[(
            crate::metrics::METRIC_DB_LABEL,
-            params.db.as_deref().unwrap_or("")
+            params.db.clone().unwrap_or_default()
        )]
    );
    let ctx = if let Some(db) = params.db {
@@ -97,7 +97,7 @@ pub async fn remote_read(
        crate::metrics::METRIC_HTTP_PROMETHEUS_READ_ELAPSED,
        &[(
            crate::metrics::METRIC_DB_LABEL,
-            params.db.as_deref().unwrap_or("")
+            params.db.clone().unwrap_or_default()
        )]
    );
    let ctx = if let Some(db) = params.db {
--- a/src/servers/src/mysql/handler.rs
+++ b/src/servers/src/mysql/handler.rs
@@ -206,11 +206,11 @@ impl<W: AsyncWrite + Send + Sync + Unpin> AsyncMysqlShim<W> for MysqlInstanceShi
            &[
                (
                    crate::metrics::METRIC_MYSQL_SUBPROTOCOL_LABEL,
-                    crate::metrics::METRIC_MYSQL_BINQUERY
+                    crate::metrics::METRIC_MYSQL_BINQUERY.to_string()
                ),
                (
                    crate::metrics::METRIC_DB_LABEL,
-                    &self.session.context().get_db_string()
+                    self.session.context().get_db_string()
                )
            ]
        );
@@ -254,11 +254,11 @@ impl<W: AsyncWrite + Send + Sync + Unpin> AsyncMysqlShim<W> for MysqlInstanceShi
            &[
                (
                    crate::metrics::METRIC_MYSQL_SUBPROTOCOL_LABEL,
-                    crate::metrics::METRIC_MYSQL_TEXTQUERY
+                    crate::metrics::METRIC_MYSQL_TEXTQUERY.to_string()
                ),
                (
                    crate::metrics::METRIC_DB_LABEL,
-                    &self.session.context().get_db_string()
+                    self.session.context().get_db_string()
                )
            ]
        );
--- a/src/servers/src/postgres/handler.rs
+++ b/src/servers/src/postgres/handler.rs
@@ -51,11 +51,11 @@ impl SimpleQueryHandler for PostgresServerHandler {
            &[
                (
                    crate::metrics::METRIC_POSTGRES_SUBPROTOCOL_LABEL,
-                    crate::metrics::METRIC_POSTGRES_SIMPLE_QUERY
+                    crate::metrics::METRIC_POSTGRES_SIMPLE_QUERY.to_string()
                ),
                (
                    crate::metrics::METRIC_DB_LABEL,
-                    &self.query_ctx.get_db_string()
+                    self.query_ctx.get_db_string()
                )
            ]
        );
@@ -357,11 +357,11 @@ impl ExtendedQueryHandler for PostgresServerHandler {
            &[
                (
                    crate::metrics::METRIC_POSTGRES_SUBPROTOCOL_LABEL,
-                    crate::metrics::METRIC_POSTGRES_EXTENDED_QUERY
+                    crate::metrics::METRIC_POSTGRES_EXTENDED_QUERY.to_string()
                ),
                (
                    crate::metrics::METRIC_DB_LABEL,
-                    &self.query_ctx.get_db_string()
+                    self.query_ctx.get_db_string()
                )
            ]
        );