Get rid of your unhealthy Azure instances

Have you ever had an Azure instance that just was not performing up to your expectations?

We have. And in the past, they were very hard to get rid of without affecting your entire cloud deployment.

How-To: Remove Azure instances that became slow or unhealthy

In this week’s How-To post, we’ll cover the new API that lets us easily remove an Azure instance that is performing poorly or has become unhealthy. We also share a tool we wrote to automate the removal, so you can remove dead Azure instances quickly whenever you need.

Read more: Azure: Remove unhealthy or slow role instances.

A bit of history

Back when we launched LeanSentry 2 years ago, we had a lot of issues with Azure instances not performing up to our expectations. In particular, the Azure host processes would die whenever the instances experienced high memory utilization from our custom cache layer, and begin to constantly recycle the role/reboot the VM. This caused service outages during times of peak usage.

Back then, the only way to take an instance out of rotation was to do VIP swap, or to scale down the service to a point where the offending instance would be removed (and so would all other instances with higher instance ids). Because we maintained a lot of in-memory and on-disk state on the instance, both of those options would be a huge no-no. So, we lobbied Microsoft to create an option to remove a specific instance, instead of trashing half of your service.

The Azure team came through and finally released an API to do this. This has been a godsend, allowing us to intelligently manage how we scale up and down so we can keep the instances with the highest efficiency / warmest cache.

For more on how to when to do this, and a tool to quickly delete instances, check out the How-To post here.

LeanSentry How-To: IIS & ASP.NET recommendations from our team

In the last 2 years, we’ve helped thousands of big and small companies to improve their IIS servers & ASP.NET applications.

Today, we are announcing LeanSentry How-To: a series of best-practice guides to help you solve common performance problems & improve your site health.

We’ll cover topics like:

1. Azure best practices
2. IIS & ASP.NET performance
3. Improving application & server stability
4. Advanced tools & techniques for troubleshooting production problems

To get these, sign up for our How-To series at LeanSentry How-To.

If you have specific areas or questions you would like to see covered, email us or post them here anytime.

Fix IIS & ASP.NET hangs faster with Hang diagnostics

Automatic hang diagnostics for IIS & ASP.NET apps has been one of LeanSentry’s most popular features.

Now, Hang diagnostics are getting even better, with more expert insight into hangs, better root cause detection, and more code-level data for your developers.

Automatically diagnose ASP.NET hangs

LeanSentry’s Hang diagnostics feature helps you resolve your website’s slowdowns, better than you can with generic monitoring tools. It does this by detecting and by automatically diagnosing dozens of common IIS, ASP.NET, and Classic ASP performance problems whenever your site experiences them.

No intrusive profilers, DebugDiag, or other tools needed. Like most of LeanSentry, hang diagnostics have virtually zero overhead during normal operation, and only a small overhead (5-10 seconds of analysis) when a problem is confirmed. This means you can add LeanSentry’s deep diagnostic insight to your existing monitoring without any conflicts or performance drops.

What’s new?

A lot! We’ve improved the diagnostic algorithms to detect more problems. Then there is the brand new diagnostic report interface that gives you better guidance, and more information on what caused the hangs.

See the actual IIS & ASP.NET operation

See the real request flow during ASP.NET hangs
See the actual request flow, and the key IIS & ASP.NET performance issues during the hang.

Expert guidance

Full ASP.NET hang analysis
LeanSentry analyzes the specific causes of the hang in your app, and gives you best practice guidance on how to address it.

Identify the function, slow SQL, REST call causing blocking

Diagnose ASP.NET hangs down to code, SQL query, and more
LeanSentry automatically determines the application code causing request blocking or thread pool exhaustion, and shows your the line of code, SQL query, REST url, or file being accessed.

Try it out

If you are still troubleshooting hangs the hard way, or trying to use the generic transaction monitoring tools, you are missing out. To learn more, check out LeanSentry’s hang diagnostics, and do a trial to see it for yourself.