[docs] milestones m15 rubric: precursor edits (R-4/R-5/R-8)

MILESTONES.md

@@ -354,15 +354,15 @@ Alpha unified-source logs receiver covering L2 + L9 (kernel + system events). Ta
 - **Depends on:** M1
 
 **Functional rubrics:**
-- Tails files matching `/var/log/pods/<namespace>_<podname>_<uid>/<container>/*.log`; parses CRI log format into `body`, `log.iostream`, `timestamp`; reassembles `P` (partial) into `F` (full) bounded by `max_log_size` (default 1 MiB). (per https://kubernetes.io/docs/concepts/cluster-administration/logging/)
+- Tails files matching `/var/log/pods/<namespace>_<podname>_<uid>/<container>/*.log`; parses CRI log format into `body`, `log.iostream`, `timestamp`; reassembles `P` (partial) into `F` (full) bounded by `max_log_size` (default 1 MiB; matches the OTel `container` stanza operator default — per [`pkg/stanza/docs/operators/container.md`](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/pkg/stanza/docs/operators/container.md)). (per https://kubernetes.io/docs/concepts/cluster-administration/logging/)
 - Per-rank attribution: derives `gen_ai.training.rank` (canonical join key across receivers) from Pod env vars `RANK`/`WORLD_SIZE`/`LOCAL_RANK`, and `gen_ai.training.job.id` from `JOB_ID` *or* `TORCHELASTIC_RUN_ID` (canonical per [torchrun docs](https://docs.pytorch.org/docs/stable/elastic/run.html) — "equal to the rendezvous run_id"); falls back to Pod labels `gen_ai.training.io/rank`, `gen_ai.training.io/job-id` (matches RFC-0009 / M13 for cross-receiver join consistency); missing → record emitted with `rank=unknown`.
 - Structured-log auto-detection: first non-whitespace byte `{` triggers JSON parse; on success emits parsed fields as attributes capped at `max_attributes` (default 16); on failure or non-`{`, passthrough as `body`.
 - **Dataloader-timing extraction (M18 feed):** PyTorch has no canonical dataloader-progress format (torchvision `MetricLogger` emits `time: ... data: ...`; detectron2 logs `data_time` as a scalar; neither prints `iter_time`). The receiver ships with a tracecore-placeholder regex (`dataloader_regex` config key) — operators MUST override it to match their training stack. When a log line matches, receiver emits `tracecore.training.data_time_s` and `tracecore.training.iter_time_s` keyed by `gen_ai.training.rank` for M18's straggler detector to join on; schema lives in fixture.
 - Pod-discovery: single per-node Pod informer with `FieldSelector=spec.nodeName=<NODE_NAME>` (env via downward API); new Pod → new file watcher within 5s p99 *(unverified)*.
 - Rotation: kubelet rotates by renaming `0.log` → `0.log.<N>` and creating new `0.log`; receiver follows inode, not path; integration test asserts zero record loss.
 - Straggler-pattern feed: emits per-rank line-rate (`tracecore.container.lines_per_s`) as derived metric on 15s window.
 - Checkpoint persistence: cursor stored under `/var/lib/tracecore/container_stdout/cursor.json` (atomic rename); on restart resumes within 1 record of last-acknowledged position.
-- **Degraded mode:** `/var/log/pods` missing or unreadable, Pod informer flap, or kubelet rotation breakage each set `Degraded()=true` with an `IncError("<kind>")` counter; receiver stays alive and recovers without restart; `FAILURE-MODES.md` row exists per failure mode.
+- **Degraded mode:** `/var/log/pods` missing or unreadable, Pod informer flap, or kubelet rotation breakage each set `Degraded()=true` with an `IncError("<kind>")` counter; receiver stays alive and recovers without restart; `FAILURE-MODES.md` row exists per failure mode. Rotation-stalled is detected when `0.log` size exceeds `containerLogMaxSize` for ≥30 s (3× kubelet's default `containerLogMonitorInterval` of 10 s, set at [`pkg/kubelet/apis/config/v1beta1/defaults.go`](https://github.com/kubernetes/kubernetes/blob/master/pkg/kubelet/apis/config/v1beta1/defaults.go)); surfaced via `IncError("rotation_stalled")`.
 
 **Non-functional rubrics:**
 - Overhead: ≤0.10% CPU, ≤0.3 Mbps egress sustained, ≤20 MB RSS. (per NORTHSTARS O2 "Container stdout (rate-limited)" row)
@@ -371,6 +371,7 @@ Alpha unified-source logs receiver covering L2 + L9 (kernel + system events). Ta
 - Back-pressure: 1M-line burst from one rank MUST NOT block sibling streams; bounded per-file goroutine + bounded channel (1024); `goleak` test.
 - File-handle hygiene: ≤2× pod-count open fds steady-state; closed within 30s of Pod `Terminated`; verified by `lsof` golden.
 - Security: hostPath read-only mounts for `/var/log/pods` AND `/var/log/containers` (containerd symlink target — per https://github.com/containerd/containerd/issues/11149); runs as non-root with fsGroup matching kubelet log-group.
+- Reliability caveat: containerd [#11149](https://github.com/containerd/containerd/issues/11149) (open upstream, last updated 2025-05-30) silently drops bytes from `0.log` when an in-container process reads its own FD 1 (e.g. application self-tee, sidecar reading `/proc/1/fd/1`). The mechanism is shared-pipe contention with containerd's log copier, not generic disk-I/O backpressure; standard workloads that do not read FD 1 are unaffected. RUNBOOK enumerates this failure mode; receiver does not claim universal lossless delivery from `0.log` alone.
 - Panic recovery: per-file goroutines wrap `defer/recover`; malformed CRI line MUST NOT crash other watchers. (per PRINCIPLES §1)
 - Shutdown: SIGTERM → 1s Phase-1 budget; in-flight reads abandoned cleanly; cursor flushed best-effort.