chore: add waku_relay_avg_msg_bytes_per_shard and waku_relay_max_msg_bytes_per_shard

waku/waku_relay/protocol.nim

@@ -27,8 +27,26 @@ logScope:
   topics = "waku relay"
 
 declarePublicGauge(
-  waku_relay_messages_per_shard,
-  "number of unique messages seen, grouped by shard",
+  waku_relay_msg_count_per_shard,
+  "Number of messages seen, grouped by shard",
+  labels = ["shard"],
+)
+
+declarePublicGauge(
+  waku_relay_max_msg_bytes_per_shard,
+  "Maximum length of messages seen per shard",
+  labels = ["shard"],
+)
+
+declarePublicGauge(
+  waku_relay_avg_msg_bytes_per_shard,
+  "Average length of messages seen per shard",
+  labels = ["shard"],
+)
+
+declarePublicGauge(
+  waku_relay_sum_msg_bytes_per_shard,
+  "Sum of message lengths seen per shard",
   labels = ["shard"],
 )
 
@@ -182,6 +200,7 @@ proc logMessageInfo*(
     onRecv: bool,
 ) =
   let msg_hash = computeMessageHash(topic, msg).to0xHex()
+  let payloadSize = msg.payload.len
 
   if onRecv:
     notice "received relay message",
@@ -191,7 +210,7 @@ proc logMessageInfo*(
       from_peer_id = remotePeerId,
       topic = topic,
       receivedTime = getNowInNanosecondTime(),
-      payloadSizeBytes = msg.payload.len
+      payloadSizeBytes = payloadSize
   else:
     notice "sent relay message",
       my_peer_id = w.switch.peerInfo.peerId,
@@ -200,9 +219,29 @@ proc logMessageInfo*(
       to_peer_id = remotePeerId,
       topic = topic,
       sentTime = getNowInNanosecondTime(),
-      payloadSizeBytes = msg.payload.len
+      payloadSizeBytes = payloadSize
 
-  waku_relay_messages_per_shard.inc(labelValues = [topic])
+  # Increment message count
+  waku_relay_msg_count_per_shard.inc(labelValues = [topic])
+
+  # Add to sum of message sizes
+  waku_relay_sum_msg_bytes_per_shard.inc(payloadSize, labelValues = [topic])
+
+  # Calculate and set average (sum/count)
+  try:
+    let count = waku_relay_msg_count_per_shard.value(labelValuesParam = [topic])
+    let sum = waku_relay_sum_msg_bytes_per_shard.value(labelValuesParam = [topic])
+    let avg = sum / count
+    waku_relay_avg_msg_bytes_per_shard.set(avg, labelValues = [topic])
+  except CatchableError:
+    warn "Error calculating average message size", error = getCurrentExceptionMsg()
+
+  try:
+    let currentMax = waku_relay_max_msg_bytes_per_shard.value(labelValuesParam = [topic])
+    if float64(payloadSize) > currentMax:
+      waku_relay_max_msg_bytes_per_shard.set(float64(payloadSize), labelValues = [topic])
+  except CatchableError:
+    warn "Error updating max message size", error = getCurrentExceptionMsg()
 
 proc initRelayObservers(w: WakuRelay) =
   proc decodeRpcMessageInfo(