- Delete admin metrics dashboard page (admin/metrics/page.tsx)
- Delete LineChart component (used only by metrics)
- Remove "指标监控" nav link from Sidebar
- Remove getMetrics/exportMetricsCsv from admin-rpc.ts client
- Remove /api/admin/metrics and /api/admin/metrics/export HTTP routes
from adminrpc (was also leaking metrics via HTTP)
- Remove metrics RPC methods (get_metrics, export_metrics_csv) from
adminrpc gRPC server and their helper functions
- Remove spawn_redis_metrics_flusher from app/main.rs
- Remove redis_metrics module from observability crate
- Remove redis/deadpool-redis deps from observability Cargo.toml
When OTLP is enabled, init_tracing_subscriber() must defer so that
init_otlp() is the sole caller of try_init(). Without this, the adminrpc
binary crashes with "global default trace dispatcher already set".
Both init_tracing_subscriber() and init_otlp() were calling try_init()
on the global tracing dispatcher, causing "global default trace dispatcher
has already been set" at runtime when APP_OTEL_ENABLED=true.
Fix: simplify the API so init_tracing_subscriber() never installs the
subscriber — it either calls try_init() immediately (non-OTLP mode) or
returns without installing (OTLP mode, defer=true). init_otlp() now
builds the complete subscriber stack (registry + env_filter + fmt_layer +
otel_layer) and calls try_init() once.
init_tracing_subscriber() signature: (level, defer) → ()
init_otlp() signature: (endpoint, service_name, _, log_level) → Result
The fmt layer is replicated inside init_otlp() for the OTLP path.
Separate binary for Kubernetes internal admin RPC communication
(SessionAdmin service on port 9090). Includes:
- Redis cluster pool via session_manager
- OTLP tracing with env-driven configuration
- Tracing subscriber init (JSON to stderr)
- Graceful startup with connection verification
