Question

A Node.js WebSocket fan-out service's RSS grows ~150MB/hour and the process is recycled by the orchestrator every ~10 hours when it hits 4GB, dropping all live connections at recycle. Heap dashboards from `process.memoryUsage()` show heapUsed climbing slowly but most of the growth is in 'external' and RSS, not heapUsed. GC runs frequently and reclaims little. A v8 heap snapshot taken 2 hours apart shows the retained-size delta dominated by 'system / Context' and a Map keyed by socket id whose size only ever grows. A feature shipped last week added per-connection metrics buffering. Sessions per day are flat. Triage and fix this.