Process counters come from a standalone Rust monitor
using sysinfo. Electron main supplies host power and Electron process metrics.
Keeping native collection outside Node isolates collector crashes and avoids a
Node/Electron addon ABI matrix. Desktop and CLI servers use the same child-process
protocol. A missing or failed collector leaves the server running.
The native child owns sampling and bounded in-memory history. The server requests continuous snapshots only while diagnostics has live subscribers and fetches history on demand. Consuming host power for background scheduling must not retain live diagnostics. There is no telemetry database or recurring shell-probe fallback.
History has independent bounds for age, snapshot count, process rows, and retained
bytes. A count limit alone cannot bound memory when command lines vary in size.
Large process trees therefore shorten the available history window. Linux task
enumeration is disabled because walking every /proc/<pid>/task/<tid> directory
makes sampling itself expensive.
Electron power updates travel over private inherited pipes, independent of the
renderer connection. Power events and slow heartbeats continue with diagnostics
closed; app.getAppMetrics() runs only on live demand. The receiver's stale deadline
must exceed the slowest configured heartbeat plus scheduling grace, or intentional
idle polling makes background policy oscillate between constrained and
unconstrained states. Headless servers leave unavailable power data unknown.
- Process identity includes start time because operating systems reuse PIDs. Electron and native start times have different precision, so merging allows a small tolerance. Process signaling rechecks the native identity with a fresh sample.
- Snapshot sequence numbers belong to a monitor generation. Comparing them across restarts would discard the new monitor's samples until its sequence caught up.
- Sampling can miss a process that starts and exits between samples. Cumulative counters still yield deltas for processes observed across samples.
- Windows process I/O includes more than disk traffic. Unix counters report storage I/O, which can differ from logical application reads and writes because of OS caching. Keep instrumented logical I/O separate from these counters.
- Group totals accumulate observed deltas since telemetry started. Per-process cumulative counters cover the operating system's lifetime for that process.
- Historical replay uses native samples without current Electron CPU or memory metrics. Merging the latest Electron values would overwrite the past.
A WSL backend needs a Linux monitor even though Electron runs on Windows. Windows desktop packages currently supply only the Windows executable, so native process telemetry for the WSL backend is unavailable. The inherited Electron power feed still works.