Iis why recycle application pool

We recycle the IIS application pool by two methods. To set the time interval we open the IIS and select the application pool that we need to set the time interval. Then we select the Recycling option on the right Action panel under the Edit Application Pool section.

In the pop up of the Edit Application Pool Recycling Settings window, we change the recycle time interval for the application pool. In short, IIS application pool recycling means that it is restarting the worker process.

Today, we saw how our Support Engineers recycle it and change the application pool recycle interval time settings for our customers. Never again lose customers to poor server speed! Let us help you. Your email address will not be published. Submit Comment. Or click here to learn more. When you visit any website, it may store or retrieve information on your browser, mostly in the form of cookies.

This information might be about you, your preferences or your device and is mostly used to make the site work as you expect it to. The information does not usually directly identify you, but it can give you a more personalized web experience. These errors usually have to do with WAS failing to allocate a worker process for the application pool in question. Or, the worker process failing to dequeue requests from the application pool queue. You need to know what kind of problem you are dealing with to know if a recycle will help.

For example:. There is one specific case to be aware of, and that is Rapid Fail Protection. When it does, WAS will disable the application pool to prevent future failures. This now means that your applications in the pool are permanently down.

However, then you are likely to have more crashes. The right solution here, as always, is to diagnose the crash itself and remove the root cause.

LeanSentry Error diagnostics automatically diagnose causes of Service Unavailable and Queue full incidents in production. Look for critical error alerts that identify the code-level root causes of s including crashes, CPU overloads, and many others. Then see the Website is not responding or is slow section earlier in this guide.

If you are receiving errors, a recycle will help only if the error is due to a bad state. And only if that state is cleared when your application restarts. If the error is due to a persistent issue misconfiguration or external problem SQL server is down , recycling will not help. In fact, it could make things worse by triggering the additional overhead of application startup.

Because the right answer depends on the specific error, the best thing to do is get the full error details. This will allow you to directly address it instead of hoping it goes away after the restart. Resolving production errors with LeanSentry If you are using LeanSentry, you can use it to get production error details for all production errors across the entire IIS stack.

In conclusion, you can take the following actionable steps to deal with recycling in your production IIS site:. If you are recycling because of hangs, CPU overloads, memory leaks and the like, deploy LeanSentry to diagnose and fix those issues the right way.

Diagnose your website Pricing Expert guides How-to Login. Category Restarting and recycling IIS. How can I reduce application pool recycling, or application restarts, to improve my website availability? Your application is not loading at all, or throwing errors. Which means resetting IIS this way is always completely unnecessary. This includes: Shutting down all application pools , and terminating all incoming requests.

This will make ALL your websites unavailable for the entire duration of the shutdown. Stopping other system services which may make your server unstable or unavailable. Potentially failing to bring those services back , leaving your server inoperable. If you already know all of this, feel free to skip ahead. Kernel listener that receives the requests by listening on website binding endpoints. It then allows IIS worker processes to dequeue these requests for processing.

The IIS web service that configures Http. The IIS service that coordinates the creation of worker processes based on your application pool configuration. Application pool. This is a logical container, not a physical process. The application pool routes request processing for a set of applications in your website to a specific IIS worker process. IIS worker process w3wp. This is the actual runtime host for the application, where request processing takes place.

When we talk about restarting or recycling the application pool, we are actually talking about starting a new fresh worker process. It could be a hang, high CPU, or a memory leak All application pools recycle when w3svc re-starts. Risk of kernel driver getting stuck in a stopping state, requiring server reboot. All application pools shut down, downtime until WPAS restarts. Recycling IIS application pools, and worker processes w3wp.

This has the following key advantages: No server-level impact for other sites and pools. No extended downtime due to waiting for ALL other application pools to stop. This is huge on a server with multiple apppools. No downtime due to waiting for the target application pool to stop. The process works roughly like this: Start a new IIS worker process. Wait for the process and the application to initialize requires IIS 8.

Tell the current worker process process to shut down, finishing out any existing requests until a timeout. As a result, whenever the application pool is gracefully recycled, no requests are lost. Let me repeat this key point. Overlapped recycle vs. Recycle the right application pool To get the advantage of zero-downtime benefits, you need to recycle the right application pool.

Loss of state Some applications maintain in-memory state, which can be lost during a recycle. Applications that maintain in-memory state are not recycle tolerant. Initialization overhead When the application pool recycles, a new application comes online. So why does every. If a site didn't have any memory leaks could you set up a site that never needed to recycle?

Also failing this, what would be the best way to ensure background tasks are called, is there any auto restart modules for IIS or should an external service be used to make those calls? Websites are intended to keep running albeit in a stateless nature. There are a myriad of reasons why app pool recycling can be beneficial to the hosting platform to ensure both the website and the server run at optimum.

These include but not limited to dynamically compiled assemblies remaining in the appdomain, use of session caching with no guarantee of cleanup , other websites running amok and resources getting consumed over time etc. An app pool can typically serve more than one website, so app pool recycling can be beneficial to ensure everything runs smoothly.

Besides the initial boot when the app fires up again, the effect should be minimal. You may ask whether a fixed recycle is even needed. A daily recycle is just a band-aid to freshen IIS in case there is a slight memory leak or anything else that slowly creeps into the worker process. Is it a band-aid? However, if you think you have a real issue that is being suppressed by recycling then, by all means, turn off the auto-recycling so that you can track down and resolve your issue. Only you can make the best decision for your environment.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Then it tries to move all requests on the new process. After a timeout the old process will be killed automatically. You usually recycle your application pool to get rid of leaked memory you might have a problem in your application if this needs to be a regular operation, even though it is recommended to have a scheduled recycle. As for restarting a website , it just stops and restarts serving requests for that particular website.

It will continue to serve other websites on the same app pool with no interruptions. That's everything - all your users lose their connections while this is happening. Recycling an application pool stops and started the processes associated with the application s that are in that pool.

Strictly speaking, it doesn't have anything to do with the website except for the active content from those applications. Vlad Mucescu gave a good answer but it seem the part where he describes recycle of an application he speaks about Overlapped Recycling.

Worker process isolation mode offers process recycling, in which IIS automatically refreshes Web applications by restarting their worker processes. Process recycling keeps problematic applications running smoothly, and is an especially effective solution in cases where it is not possible to modify the application code.

Process recycling, which follows the occurrence of a recycling event, can happen in two ways. If the worker process currently serving the application pool terminates, then the WWW Service W3SVC , acting as the parent process to the worker processes, restarts a new process in its place. When the worker process terminates, a new one is started simultaneously. This type of recycling is called overlapped recycling. It is the default for all application pools. In an overlapped recycling scenario, the process targeted for a recycle continues to process all remaining requests while a replacement worker process is created simultaneously.

The new process is started before the old worker process stops, and requests are then directed to the new process. This design prevents delays in service, since the old process continues to accept requests until the new process has initialized successfully, and is instructed to shut down only after the new process is ready to handle requests.