Support aggregating engine metrics in sgl-router (#11456)

sgl-router/Cargo.toml

@@ -84,6 +84,7 @@ subtle = "2.6"
 rustpython-parser = "0.4.0"
 num-traits = "0.2"
 openai-harmony = { git = "https://github.com/openai/harmony", tag = "v0.0.4" }
+openmetrics-parser = "0.4.4"
 
 # gRPC and Protobuf dependencies
 tonic = { version = "0.14.2", features = ["gzip", "transport"] }

sgl-router/src/core/metrics_aggregator.rs

@@ -0,0 +1,91 @@
+use anyhow::ensure;
+use openmetrics_parser::{MetricFamily, MetricsExposition, PrometheusType, PrometheusValue};
+use tracing::warn;
+
+#[derive(Debug)]
+pub struct MetricPack {
+    pub labels: Vec<(String, String)>,
+    pub metrics_text: String,
+}
+
+type PrometheusExposition = MetricsExposition<PrometheusType, PrometheusValue>;
+type PrometheusFamily = MetricFamily<PrometheusType, PrometheusValue>;
+
+/// Aggregate Prometheus metrics scraped from multiple sources into a unified one
+pub fn aggregate_metrics(metric_packs: Vec<MetricPack>) -> anyhow::Result<String> {
+    let mut expositions = vec![];
+    for metric_pack in metric_packs {
+        let metrics_text = &metric_pack.metrics_text;
+        // Hacky workaround since the parser do not understand `:`, should improve later
+        let metrics_text = metrics_text.replace(":", "_");
+
+        let exposition = match openmetrics_parser::prometheus::parse_prometheus(&metrics_text) {
+            Ok(x) => x,
+            Err(err) => {
+                warn!(
+                    "aggregate_metrics error when parsing text: pack={:?} err={:?}",
+                    metric_pack, err
+                );
+                continue;
+            }
+        };
+        let exposition = transform_metrics(exposition, &metric_pack.labels);
+        expositions.push(exposition);
+    }
+
+    let text = try_reduce(expositions.into_iter(), merge_exposition)?
+        .map(|x| format!("{x}"))
+        .unwrap_or_default();
+    Ok(text)
+}
+
+fn transform_metrics(
+    mut exposition: PrometheusExposition,
+    extra_labels: &[(String, String)],
+) -> PrometheusExposition {
+    for family in exposition.families.values_mut() {
+        *family = family.with_labels(extra_labels.iter().map(|(k, v)| (k.as_str(), v.as_str())));
+    }
+    exposition
+}
+
+fn merge_exposition(
+    a: PrometheusExposition,
+    b: PrometheusExposition,
+) -> anyhow::Result<PrometheusExposition> {
+    let mut ans = a;
+    for (name, family_b) in b.families.into_iter() {
+        let family_merged = if let Some(family_a) = ans.families.remove(&name) {
+            merge_family(family_a, family_b)?
+        } else {
+            family_b
+        };
+        ans.families.insert(name, family_merged);
+    }
+    Ok(ans)
+}
+
+fn merge_family(a: PrometheusFamily, b: PrometheusFamily) -> anyhow::Result<PrometheusFamily> {
+    ensure!(
+        a.get_label_names() == b.get_label_names(),
+        "Label names should agree a={:?} b={:?}",
+        a.get_label_names(),
+        b.get_label_names()
+    );
+    a.with_samples(b.into_iter_samples())
+        .map_err(|e| anyhow::anyhow!("failed to merge samples: {e:?}"))
+}
+
+pub fn try_reduce<I, T, E, F>(iterable: I, f: F) -> Result<Option<T>, E>
+where
+    I: IntoIterator<Item = T>,
+    F: FnMut(T, T) -> Result<T, E>,
+{
+    let mut it = iterable.into_iter();
+    let first = match it.next() {
+        None => return Ok(None),
+        Some(x) => x,
+    };
+
+    Ok(Some(it.try_fold(first, f)?))
+}

sgl-router/src/core/mod.rs

@@ -11,6 +11,7 @@
 pub mod circuit_breaker;
 pub mod error;
 pub mod job_queue;
+pub mod metrics_aggregator;
 pub mod retry;
 pub mod token_bucket;
 pub mod worker;

sgl-router/src/core/worker_manager.rs

@@ -5,7 +5,9 @@
 
 use std::{collections::HashMap, sync::Arc, time::Duration};
 
+use axum::response::{IntoResponse, Response};
 use futures::future;
+use http::{Method, StatusCode};
 use serde_json::Value;
 use tokio::{
     sync::{watch, Mutex},
@@ -14,7 +16,7 @@ use tokio::{
 use tracing::{debug, error, info, warn};
 
 use crate::{
-    core::{ConnectionMode, WorkerRegistry, WorkerType},
+    core::{metrics_aggregator::MetricPack, ConnectionMode, WorkerRegistry, WorkerType},
     policies::PolicyRegistry,
     protocols::worker_spec::{FlushCacheResult, WorkerLoadInfo, WorkerLoadsResult},
 };
@@ -234,6 +236,90 @@ impl WorkerManager {
             failed,
         }
     }
+
+    pub async fn get_engine_metrics(
+        worker_registry: &WorkerRegistry,
+        client: &reqwest::Client,
+    ) -> Response {
+        let engine_responses =
+            match Self::fan_out_simple_request(worker_registry, client, "metrics", Method::GET)
+                .await
+            {
+                Ok(x) => x,
+                Err(e) => return e,
+            };
+        let engine_responses = engine_responses
+            .into_iter()
+            .map(|(worker_base_url, metrics_text)| MetricPack {
+                labels: vec![("worker_addr".into(), worker_base_url)],
+                metrics_text,
+            })
+            .collect();
+        let text = match crate::core::metrics_aggregator::aggregate_metrics(engine_responses) {
+            Ok(x) => x,
+            Err(e) => {
+                let error_msg = format!("Failed to aggregate metrics: {}", e);
+                return (StatusCode::INTERNAL_SERVER_ERROR, error_msg).into_response();
+            }
+        };
+        (StatusCode::OK, text).into_response()
+    }
+
+    async fn fan_out_simple_request(
+        worker_registry: &WorkerRegistry,
+        client: &reqwest::Client,
+        endpoint: &str,
+        method: Method,
+    ) -> Result<Vec<(String, String)>, Response> {
+        let workers = worker_registry.get_all();
+        if workers.is_empty() {
+            return Err((StatusCode::SERVICE_UNAVAILABLE, "No available workers").into_response());
+        }
+
+        let mut responses = vec![];
+        // May do parallel requests later
+        for worker in workers {
+            let worker_url = worker.url().to_string();
+
+            let url = format!("{}/{}", worker_url, endpoint);
+            let mut request_builder = match method {
+                Method::GET => client.get(url),
+                Method::POST => client.post(url),
+                _ => {
+                    return Err((
+                        StatusCode::METHOD_NOT_ALLOWED,
+                        "Unsupported method for simple routing",
+                    )
+                        .into_response())
+                }
+            };
+
+            if let Some(api_key) = worker.api_key() {
+                request_builder =
+                    request_builder.header("Authorization", format!("Bearer {}", api_key));
+            }
+
+            match request_builder.send().await {
+                Ok(res) => {
+                    let status = StatusCode::from_u16(res.status().as_u16())
+                        .unwrap_or(StatusCode::INTERNAL_SERVER_ERROR);
+                    match res.text().await {
+                        Ok(body_text) => {
+                            if status.is_success() {
+                                responses.push((worker_url, body_text));
+                            }
+                        }
+                        Err(e) => {
+                            warn!("fan_out_simple_request failed when reading text: {}", e)
+                        }
+                    }
+                }
+                Err(e) => warn!("fan_out_simple_request failed when sending: {}", e),
+            }
+        }
+
+        Ok(responses)
+    }
 }
 
 /// Load monitoring service that periodically fetches worker loads

sgl-router/src/server.rs

@@ -115,6 +115,10 @@ async fn health_generate(State(state): State<Arc<AppState>>, req: Request) -> Re
     state.router.health_generate(req).await
 }
 
+async fn engine_metrics(State(state): State<Arc<AppState>>) -> Response {
+    WorkerManager::get_engine_metrics(&state.context.worker_registry, &state.context.client).await
+}
+
 async fn get_server_info(State(state): State<Arc<AppState>>, req: Request) -> Response {
     state.router.get_server_info(req).await
 }
@@ -641,6 +645,7 @@ pub fn build_app(
         .route("/readiness", get(readiness))
         .route("/health", get(health))
         .route("/health_generate", get(health_generate))
+        .route("/engine_metrics", get(engine_metrics))
         .route("/v1/models", get(v1_models))
         .route("/get_model_info", get(get_model_info))
         .route("/get_server_info", get(get_server_info));

sgl-router/tests/metrics_aggregator_test.rs

@@ -0,0 +1,271 @@
+use sglang_router_rs::core::metrics_aggregator::{aggregate_metrics, MetricPack};
+
+#[test]
+fn test_aggregate_simple() {
+    let pack1 = MetricPack {
+        labels: vec![("source".to_string(), "worker1".to_string())],
+        metrics_text: r#"
+# HELP http_requests_total The total number of HTTP requests.
+# TYPE http_requests_total counter
+http_requests_total{method="post",code="200"} 1027
+http_requests_total{method="post",code="400"} 3
+"#
+        .to_string(),
+    };
+    let pack2 = MetricPack {
+        labels: vec![("source".to_string(), "worker2".to_string())],
+        metrics_text: r#"
+# HELP http_requests_total The total number of HTTP requests.
+# TYPE http_requests_total counter
+http_requests_total{method="post",code="200"} 500
+"#
+        .to_string(),
+    };
+
+    let result = aggregate_metrics(vec![pack1, pack2]).unwrap();
+    let expected = r#"# HELP http_requests_total The total number of HTTP requests.
+# TYPE http_requests_total counter
+http_requests_total{code="200",method="post",source="worker1"} 1027
+http_requests_total{code="400",method="post",source="worker1"} 3
+http_requests_total{code="200",method="post",source="worker2"} 500
+"#;
+    assert_eq!(result.trim(), expected.trim());
+}
+
+#[test]
+fn test_aggregate_multiple_metrics() {
+    let pack1 = MetricPack {
+        labels: vec![("source".to_string(), "w1".to_string())],
+        metrics_text: r#"
+# TYPE metric_a gauge
+metric_a{dim="x"} 1.0
+# TYPE metric_b_total counter
+metric_b_total 10
+"#
+        .to_string(),
+    };
+    let pack2 = MetricPack {
+        labels: vec![("source".to_string(), "w2".to_string())],
+        metrics_text: r#"
+# TYPE metric_a gauge
+metric_a{dim="y"} 2.0
+"#
+        .to_string(),
+    };
+
+    let result = aggregate_metrics(vec![pack1, pack2]).unwrap();
+    let expected = r#"# TYPE metric_a gauge
+metric_a{dim="x",source="w1"} 1
+metric_a{dim="y",source="w2"} 2
+
+# TYPE metric_b_total counter
+metric_b_total{source="w1"} 10
+"#;
+    assert_eq_sorted(&result, expected);
+}
+
+#[test]
+fn test_empty_input() {
+    let result = aggregate_metrics(vec![]).unwrap();
+    assert_eq!(result, "");
+}
+
+#[test]
+fn test_invalid_metrics_are_skipped() {
+    let pack1 = MetricPack {
+        labels: vec![("source".to_string(), "worker1".to_string())],
+        metrics_text: "invalid metrics text".to_string(),
+    };
+    let pack2 = MetricPack {
+        labels: vec![("source".to_string(), "worker2".to_string())],
+        metrics_text: "# TYPE valid_metric gauge\nvalid_metric 123\n".to_string(),
+    };
+    let result = aggregate_metrics(vec![pack1, pack2]).unwrap();
+    let expected = r#"# TYPE valid_metric gauge
+valid_metric{source="worker2"} 123
+"#;
+    assert_eq!(result.trim(), expected.trim());
+}
+
+#[test]
+fn test_real() {
+    let pack1 = MetricPack {
+        labels: vec![("source".to_string(), "worker1".to_string())],
+        // https://docs.sglang.ai/references/production_metrics.html
+        metrics_text: r###"# HELP sglang:prompt_tokens_total Number of prefill tokens processed.
+# TYPE sglang:prompt_tokens_total counter
+sglang:prompt_tokens_total{model_name="meta-llama/Llama-3.1-8B-Instruct"} 8.128902e+06
+# HELP sglang:generation_tokens_total Number of generation tokens processed.
+# TYPE sglang:generation_tokens_total counter
+sglang:generation_tokens_total{model_name="meta-llama/Llama-3.1-8B-Instruct"} 7.557572e+06
+# HELP sglang:token_usage The token usage
+# TYPE sglang:token_usage gauge
+sglang:token_usage{model_name="meta-llama/Llama-3.1-8B-Instruct"} 0.28
+# HELP sglang:cache_hit_rate The cache hit rate
+# TYPE sglang:cache_hit_rate gauge
+sglang:cache_hit_rate{model_name="meta-llama/Llama-3.1-8B-Instruct"} 0.007507552643049313
+# HELP sglang:time_to_first_token_seconds Histogram of time to first token in seconds.
+# TYPE sglang:time_to_first_token_seconds histogram
+sglang:time_to_first_token_seconds_sum{model_name="meta-llama/Llama-3.1-8B-Instruct"} 2.3518979474117756e+06
+sglang:time_to_first_token_seconds_bucket{le="0.001",model_name="meta-llama/Llama-3.1-8B-Instruct"} 0.0
+sglang:time_to_first_token_seconds_bucket{le="0.005",model_name="meta-llama/Llama-3.1-8B-Instruct"} 0.0
+sglang:time_to_first_token_seconds_bucket{le="0.01",model_name="meta-llama/Llama-3.1-8B-Instruct"} 0.0
+sglang:time_to_first_token_seconds_bucket{le="+Inf",model_name="meta-llama/Llama-3.1-8B-Instruct"} 11008.0
+sglang:time_to_first_token_seconds_count{model_name="meta-llama/Llama-3.1-8B-Instruct"} 11008.0
+# HELP sglang:e2e_request_latency_seconds Histogram of End-to-end request latency in seconds
+# TYPE sglang:e2e_request_latency_seconds histogram
+sglang:e2e_request_latency_seconds_sum{model_name="meta-llama/Llama-3.1-8B-Instruct"} 3.116093850019932e+06
+sglang:e2e_request_latency_seconds_bucket{le="0.3",model_name="meta-llama/Llama-3.1-8B-Instruct"} 0.0
+sglang:e2e_request_latency_seconds_bucket{le="0.5",model_name="meta-llama/Llama-3.1-8B-Instruct"} 6.0
+sglang:e2e_request_latency_seconds_bucket{le="0.8",model_name="meta-llama/Llama-3.1-8B-Instruct"} 6.0
+sglang:e2e_request_latency_seconds_bucket{le="+Inf",model_name="meta-llama/Llama-3.1-8B-Instruct"} 11228.0
+sglang:e2e_request_latency_seconds_count{model_name="meta-llama/Llama-3.1-8B-Instruct"} 11228.0
+# HELP sglang:time_per_output_token_seconds Histogram of time per output token in seconds.
+# TYPE sglang:time_per_output_token_seconds histogram
+sglang:time_per_output_token_seconds_sum{model_name="meta-llama/Llama-3.1-8B-Instruct"} 866964.5791549598
+sglang:time_per_output_token_seconds_bucket{le="0.005",model_name="meta-llama/Llama-3.1-8B-Instruct"} 1.0
+sglang:time_per_output_token_seconds_bucket{le="0.01",model_name="meta-llama/Llama-3.1-8B-Instruct"} 73.0
+sglang:time_per_output_token_seconds_bucket{le="0.015",model_name="meta-llama/Llama-3.1-8B-Instruct"} 382.0
+sglang:time_per_output_token_seconds_bucket{le="+Inf",model_name="meta-llama/Llama-3.1-8B-Instruct"} 7.400757e+06
+sglang:time_per_output_token_seconds_count{model_name="meta-llama/Llama-3.1-8B-Instruct"} 7.400757e+06
+# HELP sglang:func_latency_seconds Function latency in seconds
+# TYPE sglang:func_latency_seconds histogram
+sglang:func_latency_seconds_sum{name="generate_request"} 4.514771912145079
+sglang:func_latency_seconds_bucket{le="0.05",name="generate_request"} 14006.0
+sglang:func_latency_seconds_bucket{le="0.07500000000000001",name="generate_request"} 14006.0
+sglang:func_latency_seconds_bucket{le="0.1125",name="generate_request"} 14006.0
+sglang:func_latency_seconds_bucket{le="0.16875",name="generate_request"} 14006.0
+sglang:func_latency_seconds_bucket{le="+Inf",name="generate_request"} 14007.0
+sglang:func_latency_seconds_count{name="generate_request"} 14007.0
+# HELP sglang:num_running_reqs The number of running requests
+# TYPE sglang:num_running_reqs gauge
+sglang:num_running_reqs{model_name="meta-llama/Llama-3.1-8B-Instruct"} 162.0
+# HELP sglang:num_used_tokens The number of used tokens
+# TYPE sglang:num_used_tokens gauge
+sglang:num_used_tokens{model_name="meta-llama/Llama-3.1-8B-Instruct"} 123859.0
+# HELP sglang:gen_throughput The generate throughput (token/s)
+# TYPE sglang:gen_throughput gauge
+sglang:gen_throughput{model_name="meta-llama/Llama-3.1-8B-Instruct"} 86.50814177726902
+# HELP sglang:num_queue_reqs The number of requests in the waiting queue
+# TYPE sglang:num_queue_reqs gauge
+sglang:num_queue_reqs{model_name="meta-llama/Llama-3.1-8B-Instruct"} 2826.0
+"###.to_string(),
+    };
+    let pack2 = MetricPack {
+        labels: vec![("source".to_string(), "worker2".to_string())],
+        metrics_text: pack1.metrics_text.clone(),
+    };
+    let result = aggregate_metrics(vec![pack1, pack2]).unwrap();
+    let expected = r###"# HELP sglang_token_usage The token usage
+# TYPE sglang_token_usage gauge
+sglang_token_usage{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1"} 0.28
+sglang_token_usage{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2"} 0.28
+
+# HELP sglang_time_to_first_token_seconds Histogram of time to first token in seconds.
+# TYPE sglang_time_to_first_token_seconds histogram
+sglang_time_to_first_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1",le="0.001"} 0
+sglang_time_to_first_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1",le="0.005"} 0
+sglang_time_to_first_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1",le="0.01"} 0
+sglang_time_to_first_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1",le="+Inf"} 11008
+sglang_time_to_first_token_seconds_sum{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1"} 2351897.9474117756
+sglang_time_to_first_token_seconds_count{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1"} 11008
+sglang_time_to_first_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2",le="0.001"} 0
+sglang_time_to_first_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2",le="0.005"} 0
+sglang_time_to_first_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2",le="0.01"} 0
+sglang_time_to_first_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2",le="+Inf"} 11008
+sglang_time_to_first_token_seconds_sum{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2"} 2351897.9474117756
+sglang_time_to_first_token_seconds_count{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2"} 11008
+
+# HELP sglang_time_per_output_token_seconds Histogram of time per output token in seconds.
+# TYPE sglang_time_per_output_token_seconds histogram
+sglang_time_per_output_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1",le="0.005"} 1
+sglang_time_per_output_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1",le="0.01"} 73
+sglang_time_per_output_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1",le="0.015"} 382
+sglang_time_per_output_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1",le="+Inf"} 7400757
+sglang_time_per_output_token_seconds_sum{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1"} 866964.5791549598
+sglang_time_per_output_token_seconds_count{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1"} 7400757
+sglang_time_per_output_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2",le="0.005"} 1
+sglang_time_per_output_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2",le="0.01"} 73
+sglang_time_per_output_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2",le="0.015"} 382
+sglang_time_per_output_token_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2",le="+Inf"} 7400757
+sglang_time_per_output_token_seconds_sum{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2"} 866964.5791549598
+sglang_time_per_output_token_seconds_count{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2"} 7400757
+
+# HELP sglang_func_latency_seconds Function latency in seconds
+# TYPE sglang_func_latency_seconds histogram
+sglang_func_latency_seconds_bucket{name="generate_request",source="worker1",le="0.05"} 14006
+sglang_func_latency_seconds_bucket{name="generate_request",source="worker1",le="0.07500000000000001"} 14006
+sglang_func_latency_seconds_bucket{name="generate_request",source="worker1",le="0.1125"} 14006
+sglang_func_latency_seconds_bucket{name="generate_request",source="worker1",le="0.16875"} 14006
+sglang_func_latency_seconds_bucket{name="generate_request",source="worker1",le="+Inf"} 14007
+sglang_func_latency_seconds_sum{name="generate_request",source="worker1"} 4.514771912145079
+sglang_func_latency_seconds_count{name="generate_request",source="worker1"} 14007
+sglang_func_latency_seconds_bucket{name="generate_request",source="worker2",le="0.05"} 14006
+sglang_func_latency_seconds_bucket{name="generate_request",source="worker2",le="0.07500000000000001"} 14006
+sglang_func_latency_seconds_bucket{name="generate_request",source="worker2",le="0.1125"} 14006
+sglang_func_latency_seconds_bucket{name="generate_request",source="worker2",le="0.16875"} 14006
+sglang_func_latency_seconds_bucket{name="generate_request",source="worker2",le="+Inf"} 14007
+sglang_func_latency_seconds_sum{name="generate_request",source="worker2"} 4.514771912145079
+sglang_func_latency_seconds_count{name="generate_request",source="worker2"} 14007
+
+# HELP sglang_num_used_tokens The number of used tokens
+# TYPE sglang_num_used_tokens gauge
+sglang_num_used_tokens{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1"} 123859
+sglang_num_used_tokens{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2"} 123859
+
+# HELP sglang_cache_hit_rate The cache hit rate
+# TYPE sglang_cache_hit_rate gauge
+sglang_cache_hit_rate{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1"} 0.007507552643049313
+sglang_cache_hit_rate{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2"} 0.007507552643049313
+
+# HELP sglang_num_queue_reqs The number of requests in the waiting queue
+# TYPE sglang_num_queue_reqs gauge
+sglang_num_queue_reqs{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1"} 2826
+sglang_num_queue_reqs{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2"} 2826
+
+# HELP sglang_generation_tokens_total Number of generation tokens processed.
+# TYPE sglang_generation_tokens_total counter
+sglang_generation_tokens_total{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1"} 7557572
+sglang_generation_tokens_total{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2"} 7557572
+
+# HELP sglang_num_running_reqs The number of running requests
+# TYPE sglang_num_running_reqs gauge
+sglang_num_running_reqs{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1"} 162
+sglang_num_running_reqs{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2"} 162
+
+# HELP sglang_e2e_request_latency_seconds Histogram of End-to-end request latency in seconds
+# TYPE sglang_e2e_request_latency_seconds histogram
+sglang_e2e_request_latency_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1",le="0.3"} 0
+sglang_e2e_request_latency_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1",le="0.5"} 6
+sglang_e2e_request_latency_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1",le="0.8"} 6
+sglang_e2e_request_latency_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1",le="+Inf"} 11228
+sglang_e2e_request_latency_seconds_sum{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1"} 3116093.850019932
+sglang_e2e_request_latency_seconds_count{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1"} 11228
+sglang_e2e_request_latency_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2",le="0.3"} 0
+sglang_e2e_request_latency_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2",le="0.5"} 6
+sglang_e2e_request_latency_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2",le="0.8"} 6
+sglang_e2e_request_latency_seconds_bucket{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2",le="+Inf"} 11228
+sglang_e2e_request_latency_seconds_sum{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2"} 3116093.850019932
+sglang_e2e_request_latency_seconds_count{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2"} 11228
+
+# HELP sglang_gen_throughput The generate throughput (token/s)
+# TYPE sglang_gen_throughput gauge
+sglang_gen_throughput{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1"} 86.50814177726902
+sglang_gen_throughput{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2"} 86.50814177726902
+
+# HELP sglang_prompt_tokens_total Number of prefill tokens processed.
+# TYPE sglang_prompt_tokens_total counter
+sglang_prompt_tokens_total{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker1"} 8128902
+sglang_prompt_tokens_total{model_name="meta-llama/Llama-3.1-8B-Instruct",source="worker2"} 8128902"###;
+    println!("result=\n{result}");
+    assert_eq_sorted(result.trim(), expected.trim());
+}
+
+fn assert_eq_sorted(result: &str, expected: &str) {
+    // Split into lines and sort to handle BTreeMap ordering issues between test environments
+    let mut result_lines: Vec<_> = result.trim().lines().map(|l| l.trim()).collect();
+    let mut expected_lines: Vec<_> = expected.trim().lines().map(|l| l.trim()).collect();
+    result_lines.sort();
+    expected_lines.sort();
+    assert_eq!(result_lines, expected_lines);
+}