From 5ab4521116a444949ba240338c13e9b22ec55236 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Igor=20=C5=A0=C4=87eki=C4=87?= <iscekic@protonmail.com>
Date: Tue, 24 Feb 2026 19:47:38 +0100
Subject: [PATCH] Add instanceId to pool metrics for per-instance deduplication
 in Axiom

---
 src/lib/drizzle.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/lib/drizzle.ts b/src/lib/drizzle.ts
index ade2d98ed..f875c2dbf 100644
--- a/src/lib/drizzle.ts
+++ b/src/lib/drizzle.ts
@@ -108,7 +108,10 @@ if (usesSeparateReplica) {
 }
 
 // --- Pool observability ---
-// Periodic pool metrics (every 30s) — picked up by Vercel log drain → Axiom
+// Periodic pool metrics (every 30s) — picked up by Vercel log drain → Axiom.
+// instanceId lets us deduplicate readings per instance in Axiom queries.
+const instanceId = `${VERCEL_REGION ?? 'unknown'}-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+
 function logPoolMetrics() {
   const primary = { total: pool.totalCount, idle: pool.idleCount, waiting: pool.waitingCount };
   const replica = usesSeparateReplica
@@ -121,6 +124,7 @@ function logPoolMetrics() {
   console.log(
     JSON.stringify({
       type: 'pool_metrics',
+      instanceId,
       region: VERCEL_REGION ?? 'unknown',
       primary,
       replica,