What is LeanSentry?

LeanSentry is a lightweight monitoring service that automatically diagnoses most IIS and ASP.NET website problems, directly in your production environment (where they happen).

Head over to getting started with LeanSentry to see how you can quickly identify and fix website hangs, high CPU usage, memory leaks, GC overhead, queueing, and more.

Our Story


Building IIS 7.0/ASP.NET 2.0 at Microsoft

LeanSentry’s founder Mike Volodarsky lives and breathes the Microsoft web platform on the ASP.NET team, as the Program Manager responsible for the core platform features including IIS integration, session state, caching, health monitoring, and product-wide security.

After the release of ASP.NET 2.0, Mike moves to the IIS team to work on Internet Information Services 7, the next generation webserver in Windows Server 2008. Mike continues to own the core features of both ASP.NET and IIS products, but focuses on designing the new modular IIS architecture, and the new Integrated Pipeline engine that allows developers to deeply extend IIS with ASP.NET modules.

Mike Volodarsky while working on IIS 7.0

IIS 7.0 ships in Windows Server 2008

IIS 7.0 ships! After Mike moves to the east coast to get married, he continues to work for the IIS team, as well as blogging, writing about IIS 7.0 in MSDN Magazine, and coauthoring the IIS 7 Resource Kit book.


LeanServer is founded

Mike leaves Microsoft after shipping IIS 7 in Windows Server 2008. Together with some of his fellow developers, Mike starts LeanServer, a startup that creates high performance technology for some of the largest websites on Microsoft web platform, including MySpace, Vevo, and Microsoft.

As part of LeanServer, we help hundreds of companies implement the platform best practices, solve hard performance problems, and scale applications to thousands of concurrent users.


Codename "Sentinel"

Mike and his team at LeanServer start working on Sentinel, a set of internal tools designed to improve production troubleshooting for our clients.

Sentinel goes through multiple generations, changing from an on-premises monitoring system to a hosted service that eliminates the complexities of storing and processing monitoring data in the user’s environment.


LeanSentry is born!

After a long production beta with dozens of customers, Sentinel is now LeanSentry: a lightweight monitoring service that automatically diagnoses many top application problems.

LeanSentry is built entirely on cloud technologies, leveraging Amazon EC2, Windows Azure, and cloud-scale data storage.

Vevo’s Marvin Li joins the LeanServer team to help develop the new interface for the Sentinel that makes monitoring and troubleshooting web applications simple and intuitive.

LeanSentry opens a limited preview program with hundreds of signups.


LeanSentry launches!

LeaSentry launches with an improved cloud based architecture and all new diagnostic features.

LeanSentry is now publicly available to everyone who develops and operates web applications on the Microsoft web platform.


10,000 users & 30K IIS websites later

LeanSentry has been used to diagnose and tune 30,000+ IIS websites, giving them the automatic production diagnostics to find and fix uncountable issues.

LeanSentry uses non-intrusive monitoring of IIS logs, ETW traces, Performance counters and other standard Windows protocols to identify performance issues.


LeanSentry Robot

LeanSentry Logo (Color)

Use this on light backgrounds.

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LeanSentry Robot

LeanSentry Logo (Mono)

Use this on dark backgrounds.

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Sentry Bot

LeanSentry Robot

Your applications are safer when the LeanSentry Robot is watching them.

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