Adds production-observability metrics to coderd/x/chatd/ for
model-level correlation and a chatStreams memory-leak investigation.
- Label per-request chatd metrics (steps_total, message_count,
prompt_size_bytes, tool_result_size_bytes, ttft_seconds,
compaction_total) with `model` and enrich the per-turn logger
with provider/model.
- Add `coderd_chatd_stream_retries_total{provider, model, kind}`
counter incremented in chatloop before OnRetry.
- Register a prometheus.Collector exposing `streams_active`,
`stream_buffer_size_max`, `stream_buffer_events`,
`stream_subscribers` from p.chatStreams.
- Add `coderd_chatd_stream_buffer_dropped_total` counter,
incremented per publishToStream drop independently of the
existing log-rate-limited bufferDropCount.
- Snapshot logger/model before the title-generation goroutine to
avoid a data race with the logger/model rebind below it.
> 🤖
The `coderd_chatd_message_count` histogram's current max bucket of 128
is being hit in production. This increases the exponential bucket count
from 8 to 11, extending coverage from `1..128` to `1..1024`.
Before: `1, 2, 4, 8, 16, 32, 64, 128`
After: `1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024`
Co-authored-by: blink-so[bot] <211532188+blink-so[bot]@users.noreply.github.com>
Cian Johnston