Manage your IIS/ASP.NET web apps better with smart alerts

LeanSentry’s mission is to make you an expert on the Microsoft web stack … and help you catch & solve everyday application problems without spending hours troubleshooting.  Last month, we worked hard to roll out several new features that do exactly that!

If you are running web applications on the Microsoft web platform, definitely give LeanSentry a try.  Check out the live demo and try it free in your app.

Here are some of the new things you get:

1. Smarter alerts (like you’ve always wanted!)

Most monitoring tools have alerts to notify you when problems happen, so you can respond and fix them. Unfortunately, most tools we’ve used have the same challenges when it comes to alerts: they make you work to create custom alert thresholds, then swarm you with alerts for things you don’t care about, or worse yet, miss important problems.  The signal to noise ratio is so hard to get right, and causes alerts to lose their value and just get ignored.

So, we built a better alert system: one that acts more like a human performance expert that you hired to watch your servers and apps for you. This expert respects your time and only tells you about things it knows are important to you.

Get only the alerts you care about!

Each LeanSentry alert is custom designed by us to highlight an interesting condition, such as a server being overloaded to a point of bad performance.  Each alert also automatically determines whether its important enough to be sent to you.  For example, a High CPU alert will only be important if happens on a server you consider important, or if the CPU usage is statistically abnormal high given prior history on that server.  High CPU by itself is not considered important if the server usually exhibits that behavior (we run our system in the cloud, and we are happy when our cloud instances are well utilized as long as they dont perform poorly).

This way, while you can easily see and diagnose all High CPU alerts in the dashboard, you will only get an email whenever a High CPU alert really demands your attention.

When you log into the dashboard to view an alert, we’ll show you its entire history across all the affected servers/urls/etc. Then, we’ll automatically identify the root causes of the problem, (e.g. identifying the errors for failed requests on a URL, or the specific processes, services, websites, and even functions that consumed CPU for the High CPU alert):

See the alert and its causes, aggregated over time, servers, and urls!

With 1 email and 3 clicks, you’ll see only the alerts you care about, get the entire picture, and identify the exact root causes. Done!

2. Important errors, automatically identified.

Most apps have a lot of errors. Some errors happen a lot (404 on favico.ico), but are not really interesting. Other errors happen rarely, but are very interesting (IIS worker process crash). Its very time consuming to wade through all the errors in the app to find the ones that are important enough to investigate.

LeanSentry now will automatically flag errors you should take a look at, in a daily email report as well as whenever you look at the error page. Flagged errors include spiking errors, errors that are new for the application or on a specific URL, errors that have high impact, and so on:

Highlight interesting errors!

3. Server groups, and server overload diagnostics.

LeanSentry now allows you track server performance as a group, and quickly diagnose server overload that leads to bad performance.

When you click a server, you can see a detailed breakdown of all its resources (CPU, RAM, Disk, Network), and whether the server is bottlenecking on any of them:

See server resources at a glanceSee the server resource bottlenecks!

Then, select a resource and we’ll tell you exactly who caused the overload – including your processes, services, and websites on your server.

And more good stuff

If that wasnt enough, we also released a number of other things that make your job easier:

  1. Multiple user accounts and sharing. Create accounts for your team members and share links for guest access.
  2. Better URL folding. Automatically group URLs into meaningful groups.
  3. ASP error support. Expose detailed error messages (with line numbers) for Classic ASP errors.

If you are running ASP.NET or any web application on IIS, you gotta start using LeanSentry! You’ll be amazed with how much time you’ll save, how much insight you’ll gain, and how much easier it will be to keep your web applications running.

Also, right now is a great time to become an early adopter. Whenever you want, you can chat directly with the founders and the development team, and give us feedback that might just end up in the next build.

To get started, check out the live demo and set up LeanSentry out in your apps now (it only takes a few minutes)!


The LeanSentry Team

LeanSentry is now publicly available!

LeanSentry: A better monitoring service for Windows server web apps

We concluded our limited preview program, and LeanSentry is now open to everyone who develops and runs web apps on the Windows server stack!

We also announced new pricing, and have a brand new site.

Go check out the live demo to get a feel what LeanSentry can do for you.

Read more about our public launch on Mike’s blog: LeanSentry: A better monitoring service for Windows server web apps.



The LeanSentry Team

What if someone automatically diagnosed every error in your IIS site?

It would probably help you quickly fix all the lingering bugs in your apps … and make a lot of your users really happy.  The hours you would save tracking down and figuring out that intermittent 500.19 error would probably make you really happy, too.

If that sounds great, then we have good news for you: LeanSentry now automatically diagnoses every error in your apps!

It works like this:

Step 1: You install LeanSentry on your production server, and it automatically tracks every IIS, ASP, and ASP.NET error in your app.

Step 2: We send you a daily insight with a quick summary of any major, new, or significantly increasing errors.


Step 3:
 You log into your dashboard to see how many requests have failed, and see every error across your entire app.

Step 4:
 Click on a specific error, and we will show you how many requests it affected and how its changing …
Then, we’ll tell you exactly what the error means, why it happens, and how to fix it.

Then … Wait for it … 
we’ll walk you through a diagnosis of the error using your own data!

With this feature, we help you ask the right questions in order to diagnose each error, and give you all the specific data you need to make decisions – step by step.  I certainly wish we had this kind of troubleshooting tool over the last 5 years.

We have a expert diagnostic for many of the top IIS errors, and adding more each day.  If you got an error we don’t have a diagnostic for already, email us – and we’ll help you with it manually as well as add the diagnostic to the app for future.


I want it! How do I get it?
If you have an environment already set up with LeanSentry, no action is needed, and you’ll be getting your first error insight email later today!

If not, go here to set up your environment now so we can begin tracking and diagnosing your errors ASAP.


Enjoy, and happy troubleshooting!

The LeanServer Team

Our new site is live, come check us out!

We released a major update to the service a few weeks ago, bringing all new features to help troubleshoot and tune your IIS apps. This week, we launched our new website that does a better job of explaining LeanSentry and the benefits it offers to any IT professional or developer who manages Windows Server and IIS/ASP.NET applications.

Here are some highlights:

1) Live demo

You can see LeanSentry live instantly by opening our live demo. We want to lead with our actual product, and let you decide for yourself – rather then bombard you with marketing materials and well-designed diagrams.

Go check it out!

2) Free trial!

Definitely the most exciting news, you can now try LeanSentry with your applications for 14 days absolutely free. You do not even need to enter any payment information when you sign up. Just name, email, password, and off you go.


3) How it works

We built LeanSentry on a number of core principles, that make troubleshooting your apps easier and remove the heavy overhead of typical monitoring and profiling tools. Come read about how LeanSentry works and how we are able to make that happen.

Read how it works.

Let us know how what you think about our site, check out the demo, and try LeanSentry free for 14 days! We hope to see you soon!


The LeanSentry Team

LeanSentry v2 is here, Gangnam style!

LeanSentry v2 is finally here, bringing you 10x the diagnostic power to monitor and troubleshoot your IIS/ASP.NET web apps!

If you don’t already know, LeanSentry is a production monitoring service made specifically for IIS/ASP.NET apps, to make these really painful things easy as pie:

1) Catching and troubleshooting IIS and ASP.NET errors
2) Solving performance problems and finding the cause of slow requests
3) Sizing up server utilization and resource usage problems

These things constantly drain hours of time when running production apps. LeanSentry uses extremely lightweight monitoring to provide the kind of monitoring insights typically available only with serious tools like logparser, debuggers, and profilers. Unlike those tools, LeanSentry is designed specifically to show you the key things an IIS expert will want to see, and hide the rest of the noise. And, its designed to do it with 24/7 continuous production monitoring that does not impact your application performance.

[→ Check out for a live demo, and to get a trial account ←]

Today, we are releasing a major upgrade to the service, that makes troubleshooting your apps WAY easier and faster.  Here is what you get:

1) 2 minute setup for your datacenter, Amazon EC2, or Windows Azure cloud!

LeanSentry Deployment Wizard: optimized for your environment!Its really, REALLY simple to set up your app for monitoring.  We’ll walk you though the exact steps in less than 2 minutes!

If you use Windows Azure, you can use our awesome Nuget package to add LeanSentry with a single command.

2) Everything you wanted to know about application performance!

See all key performance metrics in one place, and instantly spot any slow requests even if averages are ok.
Simple way to see everything you wanted to know about application performance
See exactly which IIS modules, SQL queries, and remote web services slow down your app.
See which IIS modules, SQL queries, and external web services slow down your requests.
See app’s CPU and memory usage over time, and even which application function consumed the CPU!
See which application functions consumed high CPU so the developer can fix the high CPU problems quickly.

3) See every IIS/ASP.NET/server error and how much it impacts your app

See all IIS, ASP.NET, and server errors in one place, and quickly tell how they impact your application.See all unique error in one place, and their relative impact …

Drill into an error to see the gory details – exception stack traces, IIS error information, how the error changes over time, and even likely solutions from LeanSentry’s own knowledge base and communities like

4) Complete transaction traces for every slow request, every error, and every slow operation!

Search the complete transaction traces for slow requestsSee or search the complete request traces for any URL …
See the complete request trace, including IIS and ASP.NET processing details, errors, and slow operationsDive into complete request traces to see the IIS/ASP.NET processing details, errors, and slow operations!

5) Alerts and Causes: automatically detect problems and find root causes so you don’t have to!

We’ll notify you of any application or server problem, and help you assess how the problem presents over time and across all your servers.

Be automatically alerted of any performance or health problem with the application
Skip the time-intensive investigation – LeanSentry automatically uses all available information to diagnose the root cause of the problem … so you can get straight to fixing it!

Alerts automatically diagnose the root cause of problems, so you dont have to!

Last but not least, we are temporarily extending our introductory pricing until we hit our user targets: all features for 24.99/server/mo. We need you to try us out and help us fine tune the new features.  Pricing is limited – once we reach our user target, we are expecting the prices to go up to reflect the LeanSentry’s true value in the market.

Check out our live demo, and sign up for your trial account today! If you got questions, chat with us on



The LeanSentry Team


Deploy LeanSentry to your Azure application in seconds with our Nuget package!

You can now deploy LeanSentry to your Windows Azure project in just a few keystrokes, by using our Nuget package! This makes deploying to Azure a snap.

Install with:

PM> Install-Package LeanSentryAzureDeployment

As soon as you re-publish your project to Azure normally, LeanSentry will be installed and will begin monitoring the performance and health of your Azure application.

This can make a huge difference, since Azure apps can be so notoriously hard to diagnose when they fail. Esp. when your role keeps recycling due to an unhandled exception or a startup task error – you may not be able to log into your instance, but LeanSentry is running on it and is capturing errors and other interesting events. You can then log into your dashboard and troubleshoot from there!

See more here:

We are excited to see our users trying LeanSentry out over the last few weeks, and have been getting great feedback that make features like this possible. Keep it coming!

LeanSentry Alerts are live!

This week, we are launching new services that deliver oodles more value for LeanSentry users.

Our alerts service went live today, and is enabled for all new user accounts.

LeanSentry alerts are a much improved version of IT alerts in traditional monitoring products:
– They are specific, e.g. they tell you exactly what happened and where – like URL “/Profile” had 34 requests fail with error “NullReferenceException”.
– They quickly show you whether the problem is global to your entire application, or local to a place like a server
– They are measurable, showing you how much time or number of requests affected

But best of all … LeanSentry automatically diagnoses alerts to highlight the root causes of problems!

We use all the wonderful data we collect as well as our expert troubleshooting patterns to tell you what the exact problem is. We have automated diagnoses for top problems like high CPU, low memory, and errors, and are adding many more as this month goes on.

Come check it out! Sign up at

LeanSentry has a brand new cloud architecture!

LeanSentry now has a brand new scalable architecture, built on Windows Azure cloud. We moved away from the traditional database-based backend to something that is more suitable for the high volume of data LeanSentry captures, and the user growth we expect (and hope!) to see over the next few months.

The new backend leverages all the same cloud best practices we’ve been using for our clients over the last year. As they say, it was high time to eat our own dogfood!

Mike will be blogging about the details of the architecture on his blog later when things calm down.

For now, we are super pumped for the snappy page loads and better data analysis performance.