fix: use direct HTTP forwarding to improve /status endpoint performance

   Replace complex GraphQL abstraction layers with direct HTTP forwarding
   to graph-node. This eliminates redundant parsing and serialization that
   caused ~15s response times vs ~0.4s for direct graph-node queries.

   Changes:
   - Remove async_graphql_axum::GraphQLRequest extractor
   - Remove WrappedGraphQLRequest conversion wrapper
   - Remove thegraph_graphql_http::send_graphql abstraction
   - Use raw Bytes and direct .body().send() pattern
   - Add debug timing instrumentation for troubleshooting

   Fixes #540

Author: suchapalaver

crates/service/src/routes/status.rs

@@ -1,16 +1,16 @@
 // Copyright 2023-, Edge & Node, GraphOps, and Semiotic Labs.
 // SPDX-License-Identifier: Apache-2.0
 
-use std::{collections::HashSet, sync::LazyLock};
+use std::{collections::HashSet, sync::LazyLock, time::Instant};
 
-use async_graphql_axum::GraphQLRequest;
-use axum::{extract::State, response::IntoResponse, Json};
-use graphql::graphql_parser::query as q;
-use serde_json::{json, Map, Value};
-use thegraph_graphql_http::{
-    http::request::{IntoRequestParameters, RequestParameters},
-    http_client::{ReqwestExt, ResponseError},
+use axum::{
+    body::Bytes,
+    extract::State,
+    http::{header::CONTENT_TYPE, StatusCode},
+    response::IntoResponse,
 };
+use graphql::graphql_parser::query as q;
+use serde::Deserialize;
 
 use crate::{error::SubgraphServiceError, service::GraphNodeState};
 
@@ -33,38 +33,28 @@ static SUPPORTED_ROOT_FIELDS: LazyLock<HashSet<&'static str>> = LazyLock::new(||
     .collect()
 });
 
-struct WrappedGraphQLRequest(async_graphql::Request);
-
-impl IntoRequestParameters for WrappedGraphQLRequest {
-    fn into_request_parameters(self) -> RequestParameters {
-        RequestParameters {
-            query: self.0.query.into(),
-            operation_name: self.0.operation_name,
-            variables: Map::from_iter(self.0.variables.iter().map(|(name, value)| {
-                (
-                    name.as_str().to_string(),
-                    value.clone().into_json().unwrap(),
-                )
-            })),
-            extensions: Map::from_iter(
-                self.0
-                    .extensions
-                    .0
-                    .into_iter()
-                    .map(|(name, value)| (name, value.into_json().unwrap())),
-            ),
-        }
-    }
+/// Minimal struct to extract the query string for validation
+#[derive(Deserialize)]
+struct StatusRequest {
+    query: String,
 }
 
-// Custom middleware function to process the request before reaching the main handler
+/// Forwards GraphQL status queries to graph-node after validating allowed root fields.
+///
+/// This handler uses direct HTTP forwarding for optimal performance, avoiding
+/// the overhead of multiple serialization/deserialization layers.
 pub async fn status(
     State(state): State<GraphNodeState>,
-    request: GraphQLRequest,
+    body: Bytes,
 ) -> Result<impl IntoResponse, SubgraphServiceError> {
-    let request = request.into_inner();
+    let start = Instant::now();
+
+    // Parse request to extract query for validation
+    let request: StatusRequest = serde_json::from_slice(&body)
+        .map_err(|e| SubgraphServiceError::InvalidStatusQuery(e.into()))?;
 
-    let query: q::Document<String> = q::parse_query(request.query.as_str())
+    // Parse and validate GraphQL query fields
+    let query: q::Document<String> = q::parse_query(&request.query)
         .map_err(|e| SubgraphServiceError::InvalidStatusQuery(e.into()))?;
 
     let root_fields = query
@@ -102,19 +92,287 @@ pub async fn status(
         ));
     }
 
-    let result = state
+    tracing::debug!(
+        elapsed_ms = start.elapsed().as_millis(),
+        "Status query validated"
+    );
+
+    // Forward request to graph-node directly
+    let forward_start = Instant::now();
+    let response = state
         .graph_node_client
         .post(state.graph_node_status_url.clone())
-        .send_graphql::<Value>(WrappedGraphQLRequest(request))
+        .header(CONTENT_TYPE, "application/json")
+        .body(body)
+        .send()
         .await
         .map_err(|e| SubgraphServiceError::StatusQueryError(e.into()))?;
 
-    result
-        .map(|data| Json(json!({"data": data})))
-        .or_else(|e| match e {
-            ResponseError::Failure { errors } => Ok(Json(json!({
-                "errors": errors,
-            }))),
-            ResponseError::Empty => todo!(),
-        })
+    tracing::debug!(
+        elapsed_ms = forward_start.elapsed().as_millis(),
+        "Graph-node response received"
+    );
+
+    // Check for HTTP errors
+    let status = response.status();
+    if !status.is_success() {
+        let text = response
+            .text()
+            .await
+            .unwrap_or_else(|_| "Failed to read error response".to_string());
+        return Err(SubgraphServiceError::StatusQueryError(anyhow::anyhow!(
+            "Graph node returned {status}: {text}"
+        )));
+    }
+
+    // Return the response body as-is
+    let response_body = response
+        .text()
+        .await
+        .map_err(|e| SubgraphServiceError::StatusQueryError(e.into()))?;
+
+    Ok((
+        StatusCode::OK,
+        [(CONTENT_TYPE, "application/json")],
+        response_body,
+    ))
+}
+
+#[cfg(test)]
+mod tests {
+    use axum::{
+        body::{to_bytes, Body},
+        http::Request,
+        routing::post,
+        Router,
+    };
+    use reqwest::Url;
+    use serde_json::json;
+    use tower::ServiceExt;
+    use wiremock::{
+        matchers::{method, path},
+        Mock, MockServer, ResponseTemplate,
+    };
+
+    use super::*;
+    use crate::service::GraphNodeState;
+
+    async fn setup_test_router(mock_server: &MockServer) -> Router {
+        let graph_node_status_url: Url = mock_server
+            .uri()
+            .parse::<Url>()
+            .unwrap()
+            .join("/status")
+            .unwrap();
+
+        let state = GraphNodeState {
+            graph_node_client: reqwest::Client::new(),
+            graph_node_status_url,
+            graph_node_query_base_url: mock_server.uri().parse().unwrap(),
+        };
+
+        Router::new().route("/status", post(status).with_state(state))
+    }
+
+    #[tokio::test]
+    async fn test_valid_query_forwards_to_graph_node() {
+        let mock_server = MockServer::start().await;
+
+        Mock::given(method("POST"))
+            .and(path("/status"))
+            .respond_with(ResponseTemplate::new(200).set_body_json(json!({
+                "data": {
+                    "indexingStatuses": [
+                        {"subgraph": "Qm123", "health": "healthy"}
+                    ]
+                }
+            })))
+            .mount(&mock_server)
+            .await;
+
+        let app = setup_test_router(&mock_server).await;
+
+        let request = Request::builder()
+            .method("POST")
+            .uri("/status")
+            .header("content-type", "application/json")
+            .body(Body::from(
+                json!({"query": "{indexingStatuses {subgraph health}}"}).to_string(),
+            ))
+            .unwrap();
+
+        let response = app.oneshot(request).await.unwrap();
+
+        assert_eq!(response.status(), StatusCode::OK);
+
+        let body = to_bytes(response.into_body(), usize::MAX).await.unwrap();
+        let json: serde_json::Value = serde_json::from_slice(&body).unwrap();
+
+        assert_eq!(
+            json,
+            json!({
+                "data": {
+                    "indexingStatuses": [
+                        {"subgraph": "Qm123", "health": "healthy"}
+                    ]
+                }
+            })
+        );
+    }
+
+    #[tokio::test]
+    async fn test_unsupported_root_field_returns_bad_request() {
+        let mock_server = MockServer::start().await;
+        let app = setup_test_router(&mock_server).await;
+
+        let request = Request::builder()
+            .method("POST")
+            .uri("/status")
+            .header("content-type", "application/json")
+            .body(Body::from(
+                json!({"query": "{_meta {block {number}}}"}).to_string(),
+            ))
+            .unwrap();
+
+        let response = app.oneshot(request).await.unwrap();
+
+        assert_eq!(response.status(), StatusCode::BAD_REQUEST);
+
+        let body = to_bytes(response.into_body(), usize::MAX).await.unwrap();
+        let json: serde_json::Value = serde_json::from_slice(&body).unwrap();
+
+        assert!(json["message"]
+            .as_str()
+            .unwrap()
+            .contains("Unsupported status query fields"));
+    }
+
+    #[tokio::test]
+    async fn test_malformed_json_returns_bad_request() {
+        let mock_server = MockServer::start().await;
+        let app = setup_test_router(&mock_server).await;
+
+        let request = Request::builder()
+            .method("POST")
+            .uri("/status")
+            .header("content-type", "application/json")
+            .body(Body::from("not valid json"))
+            .unwrap();
+
+        let response = app.oneshot(request).await.unwrap();
+
+        assert_eq!(response.status(), StatusCode::BAD_REQUEST);
+    }
+
+    #[tokio::test]
+    async fn test_invalid_graphql_syntax_returns_bad_request() {
+        let mock_server = MockServer::start().await;
+        let app = setup_test_router(&mock_server).await;
+
+        let request = Request::builder()
+            .method("POST")
+            .uri("/status")
+            .header("content-type", "application/json")
+            .body(Body::from(
+                json!({"query": "{invalid graphql syntax {"}).to_string(),
+            ))
+            .unwrap();
+
+        let response = app.oneshot(request).await.unwrap();
+
+        assert_eq!(response.status(), StatusCode::BAD_REQUEST);
+    }
+
+    #[tokio::test]
+    async fn test_graph_node_error_returns_bad_gateway() {
+        let mock_server = MockServer::start().await;
+
+        Mock::given(method("POST"))
+            .and(path("/status"))
+            .respond_with(ResponseTemplate::new(500).set_body_string("Internal Server Error"))
+            .mount(&mock_server)
+            .await;
+
+        let app = setup_test_router(&mock_server).await;
+
+        let request = Request::builder()
+            .method("POST")
+            .uri("/status")
+            .header("content-type", "application/json")
+            .body(Body::from(
+                json!({"query": "{indexingStatuses {subgraph}}"}).to_string(),
+            ))
+            .unwrap();
+
+        let response = app.oneshot(request).await.unwrap();
+
+        assert_eq!(response.status(), StatusCode::BAD_GATEWAY);
+    }
+
+    #[tokio::test]
+    async fn test_multiple_supported_root_fields() {
+        let mock_server = MockServer::start().await;
+
+        Mock::given(method("POST"))
+            .and(path("/status"))
+            .respond_with(ResponseTemplate::new(200).set_body_json(json!({
+                "data": {
+                    "indexingStatuses": [],
+                    "chains": []
+                }
+            })))
+            .mount(&mock_server)
+            .await;
+
+        let app = setup_test_router(&mock_server).await;
+
+        let request = Request::builder()
+            .method("POST")
+            .uri("/status")
+            .header("content-type", "application/json")
+            .body(Body::from(
+                json!({"query": "{indexingStatuses {subgraph} chains {network}}"}).to_string(),
+            ))
+            .unwrap();
+
+        let response = app.oneshot(request).await.unwrap();
+
+        assert_eq!(response.status(), StatusCode::OK);
+    }
+
+    #[tokio::test]
+    async fn test_graphql_errors_forwarded_from_graph_node() {
+        let mock_server = MockServer::start().await;
+
+        Mock::given(method("POST"))
+            .and(path("/status"))
+            .respond_with(ResponseTemplate::new(200).set_body_json(json!({
+                "errors": [{
+                    "message": "Type `Query` has no field `_meta`",
+                    "locations": [{"line": 1, "column": 2}]
+                }]
+            })))
+            .mount(&mock_server)
+            .await;
+
+        let app = setup_test_router(&mock_server).await;
+
+        let request = Request::builder()
+            .method("POST")
+            .uri("/status")
+            .header("content-type", "application/json")
+            .body(Body::from(
+                json!({"query": "{indexingStatuses {subgraph}}"}).to_string(),
+            ))
+            .unwrap();
+
+        let response = app.oneshot(request).await.unwrap();
+
+        assert_eq!(response.status(), StatusCode::OK);
+
+        let body = to_bytes(response.into_body(), usize::MAX).await.unwrap();
+        let json: serde_json::Value = serde_json::from_slice(&body).unwrap();
+
+        assert!(json["errors"].is_array());
+    }
 }