---
title: "Comment by Jeongjin Shin on \"Observability and Scaling: Monitoring Event Lag and Handling Failure\" | Hashnode"
description: "The oldest_unacked_message_age vs raw backlog distinction is the right one to lead with, most teams alert on the wrong metric early on. On the ordering-key hot"
url: "https://hashnode.com/posts/observability-and-scaling-monitoring-event-lag-and-handling-failure/6a545971410abcfd6a71df3e/comment/6a54b332bd852da48e90832f"
---

[Discussion](https://hashnode.com/posts/observability-and-scaling-monitoring-event-lag-and-handling-failure/6a545971410abcfd6a71df3e)

Comment [Observability and Scaling: Monitoring Event Lag and Handling Failure](https://hashnode.com/posts/observability-and-scaling-monitoring-event-lag-and-handling-failure/6a545971410abcfd6a71df3e)

[Jeongjin Shin](https://hashnode.com/@jeongjin0)

[Jul 13](https://hashnode.com/posts/observability-and-scaling-monitoring-event-lag-and-handling-failure/6a545971410abcfd6a71df3e/comment/6a54b332bd852da48e90832f)

The oldest\_unacked\_message\_age vs raw backlog distinction is the right one to lead with, most teams alert on the wrong metric early on. On the ordering-key hot spot problem at 10x, did you consider splitting the hot key onto its own subscription instead of sharding the whole topic? That way a bursty user doesn't stall throughput for everyone else sharing the same ordering key space.

[Madhav Bhasin](https://hashnode.com/@madhavbhasin)

[Jul 13](https://hashnode.com/posts/observability-and-scaling-monitoring-event-lag-and-handling-failure/6a545971410abcfd6a71df3e/comment/6a54b332bd852da48e90832f#reply-6a54b5543be3c54adb031c33)

Solid approach for predictable key spaces — isolates the blast radius without touching the whole topic. The catch is when the hot key is unpredictable (bots, sudden high-volume users) — you need tooling to detect and re-route dynamically, which is a different problem.

Relaxing ordering on non-critical event types is usually the safer default at scale. But your suggestion is the right first move before you get there.