From df3ca81e5523851dcfbd59bcdfdbada3ff10312d Mon Sep 17 00:00:00 2001
From: Sze Ching <teo.ching@diamond.ac.uk>
Date: Mon, 2 Feb 2026 16:34:14 +0000
Subject: [PATCH] feat(graph-proxy): add counter for errors in query and
 mutation

---
 backend/graph-proxy/src/graphql/mod.rs | 6 ++++++
 backend/graph-proxy/src/metrics.rs     | 8 ++++++++
 2 files changed, 14 insertions(+)

diff --git a/backend/graph-proxy/src/graphql/mod.rs b/backend/graph-proxy/src/graphql/mod.rs
index aa8c068cd..e996eeb61 100644
--- a/backend/graph-proxy/src/graphql/mod.rs
+++ b/backend/graph-proxy/src/graphql/mod.rs
@@ -165,6 +165,12 @@ pub async fn graphql_handler(
     } else {
         "error"
     };
+    if status == "error" {
+        state
+            .metrics_state
+            .total_errors
+            .add(1, &[KeyValue::new("status", "error")]);
+    };
     state.metrics_state.request_duration_ms.record(
         elapsed_ms,
         &[
diff --git a/backend/graph-proxy/src/metrics.rs b/backend/graph-proxy/src/metrics.rs
index 458fc38d7..c65e4430c 100644
--- a/backend/graph-proxy/src/metrics.rs
+++ b/backend/graph-proxy/src/metrics.rs
@@ -13,6 +13,8 @@ pub struct Metrics {
     pub total_requests: Counter<u64>,
     /// Request duration in miliseconds on every request
     pub request_duration_ms: Histogram<f64>,
+    /// Total errors on querys and mutations
+    pub total_errors: Counter<u64>,
 }
 
 impl Metrics {
@@ -31,9 +33,15 @@ impl Metrics {
             .with_unit("ms")
             .build();
 
+        let total_errors = meter
+            .u64_counter("graph_proxy_total_errors")
+            .with_description("The total errors on all querys and mutations.")
+            .build();
+
         Metrics {
             total_requests,
             request_duration_ms,
+            total_errors,
         }
     }
 }