Added latency metrics for REST endpoint.

This PR also makes it possible to set specific buckets for
histograms.

Cloes #4932

quickwit/quickwit-cli/src/metrics.rs

@@ -33,6 +33,7 @@ impl Default for CliMetrics {
                 "cli",
                 &[],
                 [],
+                quickwit_common::metrics::exponential_buckets(5.0, 5.0, 5).unwrap(),
             ),
         }
     }

quickwit/quickwit-common/src/metrics.rs

@@ -21,11 +21,12 @@ use std::collections::{BTreeMap, HashMap};
 use std::sync::OnceLock;
 
 use once_cell::sync::Lazy;
-use prometheus::{Encoder, HistogramOpts, Opts, TextEncoder};
 pub use prometheus::{
-    Histogram, HistogramTimer, HistogramVec as PrometheusHistogramVec, IntCounter,
-    IntCounterVec as PrometheusIntCounterVec, IntGauge, IntGaugeVec as PrometheusIntGaugeVec,
+    exponential_buckets, Histogram, HistogramTimer, HistogramVec as PrometheusHistogramVec,
+    IntCounter, IntCounterVec as PrometheusIntCounterVec, IntGauge,
+    IntGaugeVec as PrometheusIntGaugeVec,
 };
+use prometheus::{Encoder, HistogramOpts, Opts, TextEncoder};
 
 #[derive(Clone)]
 pub struct HistogramVec<const N: usize> {
@@ -146,10 +147,11 @@ pub fn new_gauge_vec<const N: usize>(
     IntGaugeVec { underlying }
 }
 
-pub fn new_histogram(name: &str, help: &str, subsystem: &str) -> Histogram {
+pub fn new_histogram(name: &str, help: &str, subsystem: &str, buckets: Vec<f64>) -> Histogram {
     let histogram_opts = HistogramOpts::new(name, help)
         .namespace("quickwit")
-        .subsystem(subsystem);
+        .subsystem(subsystem)
+        .buckets(buckets);
     let histogram = Histogram::with_opts(histogram_opts).expect("failed to create histogram");
     prometheus::register(Box::new(histogram.clone())).expect("failed to register histogram");
     histogram
@@ -161,6 +163,7 @@ pub fn new_histogram_vec<const N: usize>(
     subsystem: &str,
     const_labels: &[(&str, &str)],
     label_names: [&str; N],
+    buckets: Vec<f64>,
 ) -> HistogramVec<N> {
     let owned_const_labels: HashMap<String, String> = const_labels
         .iter()
@@ -169,7 +172,8 @@ pub fn new_histogram_vec<const N: usize>(
     let histogram_opts = HistogramOpts::new(name, help)
         .namespace("quickwit")
         .subsystem(subsystem)
-        .const_labels(owned_const_labels);
+        .const_labels(owned_const_labels)
+        .buckets(buckets);
     let underlying = PrometheusHistogramVec::new(histogram_opts, &label_names)
         .expect("failed to create histogram vec");
 

quickwit/quickwit-common/src/tower/metrics.rs

@@ -23,6 +23,7 @@ use std::time::Instant;
 
 use futures::{ready, Future};
 use pin_project::{pin_project, pinned_drop};
+use prometheus::exponential_buckets;
 use tower::{Layer, Service};
 
 use crate::metrics::{
@@ -103,6 +104,7 @@ impl GrpcMetricsLayer {
                 subsystem,
                 &[("kind", kind)],
                 ["rpc", "status"],
+                exponential_buckets(0.001, 2.0, 12).unwrap(),
             ),
         }
     }

quickwit/quickwit-ingest/src/ingest_v2/metrics.rs

@@ -20,8 +20,8 @@
 use mrecordlog::ResourceUsage;
 use once_cell::sync::Lazy;
 use quickwit_common::metrics::{
-    new_counter_vec, new_gauge, new_gauge_vec, new_histogram_vec, HistogramVec, IntCounterVec,
-    IntGauge, IntGaugeVec,
+    exponential_buckets, new_counter_vec, new_gauge, new_gauge_vec, new_histogram_vec,
+    HistogramVec, IntCounterVec, IntGauge, IntGaugeVec,
 };
 
 pub(super) struct IngestV2Metrics {
@@ -69,6 +69,7 @@ impl Default for IngestV2Metrics {
                 "ingest",
                 &[],
                 ["operation", "type"],
+                exponential_buckets(0.001, 2.0, 12).unwrap(),
             ),
             wal_disk_used_bytes: new_gauge(
                 "wal_disk_used_bytes",

quickwit/quickwit-jaeger/src/metrics.rs

@@ -18,7 +18,7 @@
 // along with this program. If not, see <http://www.gnu.org/licenses/>.
 
 use once_cell::sync::Lazy;
-use quickwit_common::metrics::{new_counter_vec, new_histogram_vec, HistogramVec, IntCounterVec};
+use quickwit_common::metrics::{exponential_buckets, new_counter_vec, new_histogram_vec, HistogramVec, IntCounterVec};
 
 pub struct JaegerServiceMetrics {
     pub requests_total: IntCounterVec<2>,
@@ -52,6 +52,7 @@ impl Default for JaegerServiceMetrics {
                 "jaeger",
                 &[],
                 ["operation", "index", "error"],
+                exponential_buckets(0.02, 2.0, 8).unwrap(),
             ),
             fetched_traces_total: new_counter_vec(
                 "fetched_traces_total",

quickwit/quickwit-opentelemetry/src/otlp/metrics.rs

@@ -18,7 +18,9 @@
 // along with this program. If not, see <http://www.gnu.org/licenses/>.
 
 use once_cell::sync::Lazy;
-use quickwit_common::metrics::{new_counter_vec, new_histogram_vec, HistogramVec, IntCounterVec};
+use quickwit_common::metrics::{
+    exponential_buckets, new_counter_vec, new_histogram_vec, HistogramVec, IntCounterVec,
+};
 
 pub struct OtlpServiceMetrics {
     pub requests_total: IntCounterVec<4>,
@@ -52,6 +54,7 @@ impl Default for OtlpServiceMetrics {
                 "otlp",
                 &[],
                 ["service", "index", "transport", "format", "error"],
+                exponential_buckets(0.02, 2.0, 8).unwrap(),
             ),
             ingested_log_records_total: new_counter_vec(
                 "ingested_log_records_total",

quickwit/quickwit-search/src/metrics.rs

@@ -40,6 +40,10 @@ impl Default for SearchMetrics {
                 "Number of seconds required to run a leaf search over a single split. The timer \
                  starts after the semaphore is obtained.",
                 "search",
+                vec![
+                    0.002, 0.005, 0.01, 0.015, 0.030, 0.040, 0.050, 0.075, 0.100, 0.200, 0.500,
+                    1.000,
+                ],
             ),
         }
     }

quickwit/quickwit-serve/src/metrics.rs

@@ -18,10 +18,11 @@
 // along with this program. If not, see <http://www.gnu.org/licenses/>.
 
 use once_cell::sync::Lazy;
-use quickwit_common::metrics::{new_counter_vec, IntCounterVec};
+use quickwit_common::metrics::{new_counter_vec, new_histogram_vec, HistogramVec, IntCounterVec};
 
 pub struct RestMetrics {
     pub http_requests_total: IntCounterVec<2>,
+    pub request_duration_seconds: HistogramVec<2>,
 }
 
 impl Default for RestMetrics {
@@ -34,6 +35,14 @@ impl Default for RestMetrics {
                 &[],
                 ["method", "status_code"],
             ),
+            request_duration_seconds: new_histogram_vec(
+                "request_duration_seconds",
+                "Response time in millisecs",
+                "",
+                &[],
+                ["method", "status_code"],
+                quickwit_common::metrics::exponential_buckets(0.002, 2.0, 11).unwrap(),
+            ),
         }
     }
 }

quickwit/quickwit-serve/src/rest.rs

@@ -29,6 +29,7 @@ use tower_http::compression::predicate::{DefaultPredicate, Predicate, SizeAbove}
 use tower_http::compression::CompressionLayer;
 use tower_http::cors::CorsLayer;
 use tracing::{error, info};
+use warp::filters::log::Info;
 use warp::{redirect, Filter, Rejection, Reply};
 
 use crate::cluster_api::cluster_handler;
@@ -71,10 +72,17 @@ pub(crate) async fn start_rest_server(
     readiness_trigger: BoxFutureInfaillible<()>,
     shutdown_signal: BoxFutureInfaillible<()>,
 ) -> anyhow::Result<()> {
-    let request_counter = warp::log::custom(|info| {
+    let request_counter = warp::log::custom(|info: Info| {
+        let elapsed = info.elapsed();
+        let status = info.status();
+        let label_values: [&str; 2] = [info.method().as_str(), status.as_str()];
+        crate::SERVE_METRICS
+            .request_duration_seconds
+            .with_label_values(label_values)
+            .observe(elapsed.as_secs_f64());
         crate::SERVE_METRICS
             .http_requests_total
-            .with_label_values([info.method().as_str(), info.status().as_str()])
+            .with_label_values(label_values)
             .inc();
     });
     // Docs routes