The fleet recorded GET /r/{repo}/timeline.sse at a p95 of 435 SECONDS. That is not a slow render, it is a connection somebody kept open for seven minutes — chat, the timeline and the ops panel all hold one for as long as the reader keeps the tab.

Two consequences, the second worse than the first. The slowest-routes panel was headed by four streams, burying GET /{$} at 1198ms against a 13ms median — the one real finding on the page. And every stream crosses the render budget by design, so the first-crossing alert fired on connections that were working perfectly: the muted-channel failure that rule exists to prevent, defeated from inside the same feature.

Detected from the response, not the path. A handler that streams says so in its Content-Type; a rule matching '.sse' would miss the next streaming route added under another name. Prefix-matched, so a charset does not defeat it.

Found by the panel on its first look at real traffic, which is the argument for having built it. closed check-in: cf9a277e13 user: dmestas tags: ops-streams