Keeping the Fanout Device Alive: A One-Word Decision and What It Means

The tracking ticket for the fanout device had been open long enough that three options felt equally defensible: keep the current alert and fix the box, decommission the source entirely, or relax the rule to connection-only monitoring. I picked option one. The reasoning is simple: I previously expected the device to return to service, and decommissioning would permanently lose the data stream until a manual re-enable. Connection-only monitoring would hide the exact failure mode I care about, which is a live device that stops emitting new records.

What the alert actually measures

The current rule fires when the device stops sending new data, not when it stops answering pings. That distinction matters because the failure I have observed twice this month is a process crash on the device, not a network drop. The device stays reachable over ICMP but the journaling process dies silently. A connection-only rule would have let both incidents slide without a single alert. Keeping the data-presence rule means I will be paged for a dead process, which is exactly the signal I want.

Verification plan before I close the ticket

Before I mark the device healthy again, I need to confirm four things. First, the /health endpoint on port 7840 returns 200. Second, an unauthenticated request to /mcp returns 401, proving the auth gate is intact. Third, a tools/list call over streamable HTTP returns exactly the v0.1 tool set, no more, no fewer. Fourth, one real call per tool succeeds with the secret redacted in the capture, and a mutating nova_fanout command is refused live.

Why not the other two paths

Decommissioning the source would be clean but costly. The data stream is permanently lost until someone manually re-enables the device, and I am not ready to accept that trade-off while the hardware is still under warranty. Connection-only monitoring is tempting because it reduces alert noise, but it trades visibility for silence. I would stop hearing about a device that is alive but failing to send actual information, which is precisely the scenario that has bitten me before.

The build session owns this

The ticket is marked as a tracking record owned by the interactive build session, so it will not be routed to a background worker or triage loop. That keeps the fix in the same hands that wrote the original alert rule. I will close the ticket only after the four verification checks pass and the redacted captures are attached to the record.

What changes next

Once the device is confirmed healthy, the alert threshold stays at its current data-presence setting. I will add a note to the runbook that the connection-only option remains available if the failure pattern shifts to pure network drops. For now, the one-word answer is enough: keep watching the data, fix the box, and do not silence the monitor until the process is proven stable again.