The monitoring tool that undercuts SentryOne and doesn't phone home

What it does

PerformanceMonitor is a Windows desktop app (plus a headless service edition) that monitors SQL Server 2016–2025, Azure SQL, and AWS RDS remotely — nothing installs on the monitored server, and VIEW SERVER STATE is the only permission it needs. It runs collectors on configurable schedules for wait stats, query performance, blocking chains, deadlock graphs, memory grants, tempdb, perfmon counters, and FinOps/capacity data, storing everything locally in DuckDB + Parquet. Real-time alerts fire on blocking, deadlocks, and high CPU via system tray, styled HTML email, and webhooks.

The interesting bit

The built-in MCP server exposes read-only tools over your own collected data, so you can ask Claude Code or Cursor “what are the top wait types on my server?” and get an answer grounded in actual metrics. There’s also a Recommendations tab that doesn’t just advise — it can apply fixes directly, with destructive changes (like enabling RCSI) gated behind a consent dialog that spells out both the risk of acting and the risk of doing nothing. That’s a nicer risk disclosure than most vendors manage.

Key highlights

• Three editions sharing one core: Lite (desktop, flagship), Darling (headless 24/7 service with bundled PostgreSQL + TimescaleDB), and a deprecated SQL-Agent-based Dashboard
• Graphical plan viewer with native ShowPlan rendering, a 30-rule PlanAnalyzer, and a standalone mode for opening .sqlplan files
• Community tools installed automatically: sp_WhoIsActive, sp_BlitzLock, sp_HealthParser, sp_HumanEventsBlockViewer
• No telemetry, no cloud dependency; credentials live in Windows Credential Manager with OS-level encryption
• Binaries are digitally signed via SignPath, so no more SmartScreen nagging

Caveats

• Windows-only for the viewer; the monitored servers can be anything supported, but you’re running the tool from a Windows seat
• The old Dashboard edition is deprecated and no longer ships in release assets as of v3.3.0 — existing installs get bug fixes only
• The README warns that upgrading very old Lite installs via Setup.exe could delete your data directory; the in-app About-button update path avoids this

Verdict

If you’re a DBA or consultant triaging SQL Server performance and resent per-server-per-year licensing, this is squarely aimed at you. If you’re not on Windows or need Linux-native tooling, look elsewhere.