I've a web application (MVC) that performs processes in different time intervals.
However, after a period of inactivity, the application "dies".
I guess that "kills" IIS.
What should I do that applications live permanently?
Is it possible that kills something else?
Each web application is executed by an app pool. App pools have an idle time, when that time is reached, the app pool shoots down until there is another request. You could set the idle time to a higher value.
https://technet.microsoft.com/en-us/library/cc771956
That say, it's a bad practice to have long running process in Asp.Net application. You should create a Windows Service for that.
Related
I have a website in IIS 8.5.9600.16384, we communicate with thousands of mobile devices through cyclic synchronisation and through SignalR 2.3.0.
This morning we had an application pool reset during working hours, which caused the SignalR to call "OnReconnect" of all our mobile devices at the same time.
I though that IIS started new processes first and then killed the old, not having downtime.
Can somebody tell me exactly what happens when IIS recycles it's application pool on the SignalR side? And in which cases can there be a connection downtime? (ex : if the server is busy?)
Edited : The application pool was recycled by IIS because of the "time limit". The IT team will change this setting so that the application pools reset every day at night time when it will have a lower impact on our applications.
A worker process with process id of '8720' serving application pool 'DefaultAppPool' has requested a recycle because the worker process reached its allowed processing time limit.
Also confirmed that disallowOverlappingRotation is not set to True. Any hint would help.
A few years later, I'm still getting some problems with the application pool recycle and SignalR. We are occasionally seeing thousands of re-connections of SignalR while the application pool recycle occurs, opening more than 60k TCPIP ports and causing a crash in IIS.
We managed to have it run "okay" for quite some time but it still crashes. Any hint would help. thanks
I'd first identify how IIS was reset. If you experienced a crash or performed an IISReset, the processes would be down before a new one stood back up. If on the other hand you configured AppPool recycling, then the overlapping processes should occur as you mention. I would check the System Event Log for recycling messages. Note that not all recycle reasons are logged by default.
You may also check to make sure disallowOverlappingRotation is not set to True.
Specifies whether the WWW Service should start another worker process to replace the existing worker process while that process is shutting down. The value of this property should be set to true if the worker process loads any application code that does not support multiple worker processes.
https://learn.microsoft.com/en-us/iis/configuration/system.applicationhost/applicationpools/add/recycling/
We have ASP.NET Core application used internally which are used during office hours and a batch that should be processed 3 AM every morning which is scheduled by HangFire like this:
RecurringJob.AddOrUpdate(
() => MyBatch(),
"0 0 3 1/1 *");
The problem is that the Application Pool goes to sleep and the batch isn’t processed if the site isn’t manually started (by going to the website usually).
I have searched SO and tampered with these settings in the Application Pool but with no success:
Some sources that I used to modify the settings:
How to prevent/extend idleTimeout in IIS 7?
https://serverfault.com/questions/443065/how-do-i-prevent-iis-8-from-stopping-idle-asp-net-applications
IIS seems like to sleep until the next request
The Application Pool is used by a total of 7 applications (all being inactive during night when the batch should be processed). The used Application Pool uses .NET CLR Version 2.0.
I'm using IIS version 10.0.17134.1.
How can I make the Application Pool stay active so the batch can be invoked regularly every morning?
I ran into the same issue where my ASP.NET core application goes into idle even with "AlwaysRunning" as start mode for the app pool, "Preload Enabled" set to true for the site, and idle timeout set to 0.
I got it to work by installing the Application Initialization module and setting the .NET CLR version to v4.0. Don't use the "No Managed Code" as that would prevent the Always Running from triggering the app start.
I wrote a blog post on this explaining in more details the steps I took to get the app to run continuously.
They got documentation on how to set up service to run without stopping.
http://docs.hangfire.io/en/latest/deployment-to-production/making-aspnet-app-always-running.html#enabling-service-auto-start
My experience (with older IIS versions 7.5, 8.0) is that it works, but not for app pool recycle/domain unload.
Workaround for me was to send init request on the application_end event.
As above - you need to enable the Service Autostart - in addition to this, if you hit multiple exceptions, I have found that the Rapid Fail Protection has shut down Application pools in the past when using HangFire. So it's also worth disabling (or increasing to reasonable limits) this on the application pool.
I'd suggest you put in your process a single call to the HTTP address first, just like a ping, that would be enought to trigger the site startup if it isn't running for some reason.
One other thing is that, by microsoft's description at MSDN the "AlwaysRunning" option would be:
"Specifies that the Windows Process Activation Service (WAS) will
always start the application pool. This behavior allows an application
to load the operating environment before any serving any HTTP
requests, which reduces the start-up processing for initial HTTP
requests for the application."
That may be, to produce the compilation of web pages that is done on the first call to be done before any request coming, but may not actually run the application at all times.
I am on a Shared IIS Hosting with no access to most settings. What I did is add a Recurring Job that would be triggered in minute interval less than the IIS Timeout/Idle.
RecurringJob.AddOrUpdate<IMyKeepAliveService>("KeepHangFireAlive", svc => svc.KeepHangFireAlive(URL_TO_SELF), "*/4 * * * *");
The above CRON is enough to prevent IIS App pool from going to sleep.
I use RestSharp to make a tiny ping/GET request to "Self".
I have a web application hosted under IIS. It is a data warehouse, and during its startup process it requires instantiating a large set of items in memory (takes roughly ~20 minutes to fully set up). Because this website is critical to our company, this system must be online 100% during the daytime, and only can be restarted during off-work hours.
For some reason, this web application seems to be "offline" when there is no usage for some time. I know this because the cache is not fully instantiated when the website is visited. This is unacceptable.
It is not clear to me why the website is shut off. The application pool is only set to recycle daily at 4:00 AM (it is 11 AM now).
Are there other settings which I'm not aware of on the IIS part that causes it to shut down the website automatically?
Addl Note: The website does not shut off automatically when running in IISExpress in Visual Studio. Only the production version hosted on IIS shuts off.
Here's a screen of the Advanced Settings for the Application Pool the web site is running under. (Not sure if it's useful.)
I'm on IIS 7.5, Server 2008 R2. It is an ASP.NET 5 Web App.
Check Idle Time-out settings under process model in screenshot. That setting is causing app pool shutting down when remain idle for 20 mins. You can set it to 0 to keep it running all time even when its idle i.e. not processing any requests.
Note: Keeping app pool running all time will consume server's precious memory. It may become critical especially if application is leaking memory.
I am working on windows azure cloud service. First time when i click on login button it takes 6 to 7 seconds but after sometime when i click on same login button it takes 2 seconds. I am not able to understand why it is happening so though the server side code is same for both processing but subsequent calls are quiet faster than first call ?.
"First-hit" delay is very common with ASP.NET applications. There is the overhead of JIT compilation, and various "pools" (database connections, threads, etc) may not be initialized. If you have an ASP.NET Web Forms application, each .aspx page is compiled the first time it is accessed, not when the server starts up. Also the various caching mechanisms (server or client) that make subsequent requests faster are not initialized on that first hit. And on the very first hit, any code in Application_Start will be run, setting up routing tables and doing any other initialization.
There are various things you can do to prevent your users from seeing this delay. The simplest is to write some kind of automated process that hits every page and run it after deploying a new release. There are also modules for IIS that will run code ahead of the Application_Start, when the site is actually deployed. Search for "ASP.NET warmup" to find those.
You may also experience delays after a period of inactivity, if your ASP.NET App Pool is recycled - this resets a bunch of things and causes start-up code to be run again on the next request. You can ameliorate this effect by setting up something to ping a page on your site frequently so that if the app pool is recycled it is warmed up again automatically, instead of on the next actual user request. Using an uptime monitoring service will work for this, or a Scheduled Task within the Azure ecosystem itself.
can someone explain for me this sentence from msdn ?
Idle time-out can be helpful in the following situations:
The server has a heavy processing load.
is the idle timeout for the w3wp.exe process or each user that's connected to the website has a nested process inside the w3wp and this is the idle time for this nested process? if it's the idle process for w3wp as a whole , then what does msdn sentence mean??
It prevents a application pool worker process from hanging around when no users are hitting the web pages hosted by the worker process. When the users stop hitting the web site for a while, IIS stops the process.
This can be annoying if you have an expensive setup/teardown process for the application, such as populating a cache.
The idle timeout is per application pool. You can observe the running pools as well as in IIS in VS by Tools > Attach to Process then I click the Process column header to bring any running w3wp.exe's to the top.
You can set the timeout for each app pool in IIS7+ in Advanced Settings... Process Model section.