SystemMonitorService

Windows service that samples CPU, RAM, and fixed drive usage every second, captures per-process CPU/RAM, keeps one week of local history, and pushes batches to a REST collector.

Build

dotnet build SystemMonitorService/SystemMonitorService.csproj

Run as a Windows service

Example using sc.exe (run from an elevated prompt):

sc.exe create SystemMonitorService binPath= "C:\Projects\SystemMonitor\SystemMonitorService\bin\Release\net10.0-windows\SystemMonitorService.exe" start= auto obj= LocalSystem
sc.exe start SystemMonitorService

The service is expected to run under an elevated account (for example, LocalSystem) to access full process metrics.

Configuration

Edit SystemMonitorService/appsettings.json:

• MonitorSettings:CollectorEndpoint - REST endpoint used for pushing metrics.
• MonitorSettings:DatabasePath - SQLite path. Leave empty to use C:\ProgramData\SystemMonitorService\monitor.db.
• MonitorSettings:PushBatchSize - batch size sent per request.
• MonitorSettings:PushIntervalSeconds - interval between push attempts.
• MonitorSettings:RetryDelaySeconds - minimum delay before retrying failed pushes.
• MonitorSettings:RetentionDays - days to keep local records.

Collector contract (proposed)

Endpoint:

POST /api/v1/metrics
Content-Type: application/json

Request body is an array of samples:

[
  {
    "machineName": "HOST01",
    "machine": {
      "timestampUtc": "2026-01-10T22:10:00Z",
      "cpuPercent": 23.4,
      "ramUsedBytes": 7340032000,
      "ramTotalBytes": 17179869184
    },
    "drives": [
      {
        "name": "C:\\",
        "totalBytes": 511705088000,
        "usedBytes": 348966092800
      }
    ],
    "processes": [
      {
        "processId": 1234,
        "processName": "chrome",
        "cpuPercent": 5.2,
        "ramBytes": 524288000
      }
    ]
  }
]

Success response: any 2xx status. Non-2xx response or network failure causes the batch to be retried no sooner than one minute later.

SystemCollectorService

Windows service that receives SystemMonitorService payloads, stores them in PostgreSQL, and hosts a web UI for fleet history.

Build

dotnet build SystemCollectorService/SystemCollectorService.csproj

Run as a Windows service

Example using sc.exe (run from an elevated prompt):

sc.exe create SystemCollectorService binPath= "C:\Projects\SystemMonitor\SystemCollectorService\bin\Release\net10.0-windows\SystemCollectorService.exe" start= auto obj= LocalSystem
sc.exe start SystemCollectorService

Configuration

Edit SystemCollectorService/appsettings.json:

• CollectorSettings:ConnectionString - PostgreSQL connection string. The service creates the database and schema if missing.
• CollectorSettings:ListenUrl - HTTP listen address (default http://0.0.0.0:5100).

API

• POST /api/v1/metrics accepts the JSON array produced by SystemMonitorService.
• GET /api/v1/machines lists registered computers.
• GET /api/v1/machines/{machineName}/current returns the latest sample.
• GET /api/v1/machines/{machineName}/history?days=7 returns seven days of history.

UI

Browse to http://<collector-host>:5100/ and choose a machine to view current CPU/RAM/HDD usage and charts for the last 7 days.