From bae5dd496cb2252bdc69c85cb86f00cc3d915149 Mon Sep 17 00:00:00 2001
From: Julien <julien.tesson@nomadic-labs.com>
Date: Thu, 4 Dec 2025 21:46:09 +0100
Subject: [PATCH] DAL node: add a metric counting unattested slots seen

---
 src/lib_dal_node/dal_metrics.ml  | 13 +++++++++++++
 src/lib_dal_node/dal_metrics.mli |  3 +++
 src/lib_dal_node/store.ml        |  7 ++++++-
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/lib_dal_node/dal_metrics.ml b/src/lib_dal_node/dal_metrics.ml
index cfe7e5f90cb8..3ae0d0827748 100644
--- a/src/lib_dal_node/dal_metrics.ml
+++ b/src/lib_dal_node/dal_metrics.ml
@@ -93,6 +93,16 @@ module Node_metrics = struct
       ~subsystem
       name
 
+  let slots_unattested =
+    let name = "slots_unattested" in
+    Prometheus.Counter.v_label
+      ~label_name:"slot_index"
+      ~help:
+        "Count of published but unattested slot at index <i> since node started"
+      ~namespace
+      ~subsystem
+      name
+
   let attested_slots_for_baker_per_level_ratio =
     let name = "attested_slot_for_baker_per_level_ratio" in
     Prometheus.Gauge.v_label
@@ -616,6 +626,9 @@ let slot_attested ~set i =
   let v = float_of_int @@ if set then 1 else 0 in
   Prometheus.Gauge.set (Node_metrics.slots_attested (string_of_int i)) v
 
+let slot_unattested i =
+  Prometheus.Counter.inc_one (Node_metrics.slots_unattested (string_of_int i))
+
 let attested_slots_for_baker_per_level_ratio ~delegate ratio =
   let attester = Format.asprintf "%a@." Signature.Public_key_hash.pp delegate in
   Prometheus.Gauge.set
diff --git a/src/lib_dal_node/dal_metrics.mli b/src/lib_dal_node/dal_metrics.mli
index 04dc4535884c..928297c48d02 100644
--- a/src/lib_dal_node/dal_metrics.mli
+++ b/src/lib_dal_node/dal_metrics.mli
@@ -33,6 +33,9 @@ val slot_waiting_for_attestation : set:bool -> int -> unit
     value is set to 1 if [set] is true, and -1 otherwise. *)
 val slot_attested : set:bool -> int -> unit
 
+(** Increment the count of unattested slots. *)
+val slot_unattested : int -> unit
+
 (** Update the "attestation" ratio for the baker *)
 val attested_slots_for_baker_per_level_ratio :
   delegate:Signature.Public_key_hash.t -> float -> unit
diff --git a/src/lib_dal_node/store.ml b/src/lib_dal_node/store.ml
index adcb2996fb73..f633af84c031 100644
--- a/src/lib_dal_node/store.ml
+++ b/src/lib_dal_node/store.ml
@@ -682,9 +682,14 @@ module Statuses_cache = struct
     | Some `Unattested -> assert false) ;
     match status with
     | `Attested _lag -> Dal_metrics.slot_attested ~set:true slot_id.slot_index
-    | `Unattested | `Unpublished | `Waiting_attestation ->
+    | `Unattested ->
+        (* per the invariant stated above, the function can only be called once
+           per slot_id with the `Unattested value *)
+        Dal_metrics.slot_unattested slot_id.slot_index ;
         (* TODO: is the right way to update the metric here?? *)
         Dal_metrics.slot_attested ~set:false slot_id.slot_index
+    | `Unpublished | `Waiting_attestation ->
+        Dal_metrics.slot_attested ~set:false slot_id.slot_index
 end
 
 module Commitment_indexed_cache =
-- 
GitLab