For a node with the TELEMETRY flow on, MAIN writes the server's
watchdog_data, last_check_ago, requests_per_second, php_pids (and,
without the Redis handler, connections/users) from the agent's heartbeat
every 5 s, and its servers_stats row every minute.
HeartbeatService::toWatchdogData keeps the legacy getStats() shape,
pinned by ClusterTelemetryTest against getStats()'s source.
On the LB, Core\Cluster\NodeFlows reads the mode and flows the agent
writes to config/cluster/flows.json. With TELEMETRY on, the watchdog
stops writing its row and only refreshes local.json (nginx rps, fanout
status) for the agent; cron:servers skips its stats row and network.py
is stopped. The Cluster Nodes page toggles the flow per node.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DcNdxHieZuUh3EnMUKt7zf
