podAntiAffinity on app=prop already keeps the backfill pod on its own
physical host, so the dedicated nodeSelector + taint were redundant.
Removing them lets talos4 be used as a normal worker for anything else
the cluster wants to place there. The live taint and label on talos4
were cleared alongside this commit.
Per-pod IEM rate limiter was 700ms (~1.4 req/sec); four pods put the
fleet at ~5.7 req/sec, above the observed 429 threshold. Retry storm
(Req exponential backoff up to 32s) piled concurrent sleeps on top of
live workers and tripped Bandit's acceptor + Oban's leader heartbeat.
- Raise default interval to 1500ms (~2.7 req/sec fleet).
- Hot pod /live timeout 3s → 5s (acceptor stalls under retry sleeps).
- prop-backfill exec probe period 30s → 120s, timeout 15s → 30s; the
release CLI round-trips through distributed Erlang and 15s wasn't
enough under load, restart-looping every ~10 min.
The exec probe runs `/app/bin/microwaveprop rpc ':ok'` which spawns a
release CLI and round-trips through distributed Erlang. Under an IEM
429 retry storm (WeatherFetchWorker sleeps 1-16 s between attempts),
the BEAM scheduler stays responsive but probe latency spikes past 5 s
and the kubelet SIGKILLs the pod every ~10 min. 15 s is still well
below the 30 s period so the probe still catches a genuinely wedged
VM inside one cycle.
Ecto auto-instrumentation created one span per query, so Oban jobs
running thousands of DB ops produced traces with 8k+ child spans.
Tempo's compactor couldn't ingest them — it stalled long enough to
miss heartbeats, got auto-forgotten from the ring, and crash-looped.
The Elixir grpcbox exporter then blew up trying to reconnect.
Stops the cascade: OTLP endpoint removed from prop and prop-backfill
Deployments, opentelemetry_ecto removed from deps, Phoenix/Oban/Bandit
auto-instrumentation retained. Rust workers still export to Tempo.
Adds the OTel deps (opentelemetry + exporter + phoenix / ecto / oban /
bandit auto-instrumentation helpers) and attaches them in
Application.start/2 so the existing Phoenix, Ecto, Oban, and Bandit
telemetry events flow as OTLP spans without any call-site changes.
Exporter config is gated on OTEL_EXPORTER_OTLP_ENDPOINT in
config/runtime.exs — set in the k8s manifests to the cluster
collector (otel-collector.observability.svc.cluster.local:4317).
When unset we switch traces_exporter to :none so nothing is shipped;
dev/test stays quiet.
Resource attributes tag spans with service.name=microwaveprop and
service.namespace=prop, matching the Rust workers' attribute shape
so Tempo can group the full hourly chain across both languages.
Both the main prop deployment and the backfill deployment get the
env; backfill is still a full BEAM node running enrichment workers,
so its Oban/Ecto spans are worth seeing too.
