Occasionally when I reboot one of the servers at a client site the Web Apps running in IIS do not automatically start backup when the server is done rebooting. The IIS service starts up just fine, its set to Auto Start and there are no errors in the event log. Just none of the Web Apps are running, I have to click each one and click start. This only happens occasionally, as they usually start but its completely baffling.
Any thoughts? Its a mix of Classic ASP and ASP.NET applications. There are a total of 4 application pools running between around 8 web applications.
I have seen this happen when apps rely on a resource that is not yet available to the server, such as a network share.
Some people combat this problem by writing a Windows Service who's job is to check for such conditions and start the application.
Related
In my company we have many web applications on a web server. Recently we developed a Chat module to this applications using SignalR. But a strange problem occured on these applications. In time this apps becomes unreachable. Recycleing does not solve. When i try to restart application pools it stops an never starts again. I had create a new app pool and delete the old one. And some time later the problem recurs.
Then i noticed that these application pools have several working processes which have the state of "Closing" and one "Running". What can be the problem? It is about SignalR I know, becouse this problem occurs only the applications which i use SignalR and we have about fifty apps on the server in total and only four of them have signalR on it.
screenshot of stopped process
Please help..
months after i decided to answer my own question. i think it's about windows and iis version. i set up a windows 2012 machine and new version iis on it and on this new server this problem not occured.
Is it possible to publish an ASP.NET (core) application to a running site on IIS 8 without having to stop and start the website manually?
Visual Studio 2015 keeps giving the error that a file is in use. I'm using publish to the file system, because my Web Deploy to a server in our network fails at the end with an error that it cannot authenticate on the server with port 443.
I don't mind IIS having to recycle the application pool, but when I constantly have to put the app down, publish (which takes about a minute) and restart it, it's not really good for the users.
Another option would be something like 2 websites running the same application, but only if this is automatable. Then it would put down 1 of the 2, update this, put it on, put down the second, update this and start it.
A third option is something like a hot update, where I could just update the application while it being on.
Can anyone point me in the right direction (perhaps some blog posts), because my Google searches didn't give me any good information?
If you copy a file called app_offline.htm to the application folder IIS will gracefully stop your application and start serving the contents of the app_offline.htm file. When application is stopped you can copy your files. After files are copied remove the app_offline.htm file and IIS will start your app. VS does that for you when you deploy to Azure but not when deploying to file system.
You mention "two websites running the same application". Do you mean two web servers hosting the same app?
If you already have multiple web servers (a.k.a. cluster of servers, or web farm), you can simply take some servers out of the cluster and update them. That is how we push out our updates. We use software from Citrix for managing the server farm. It also handles load balancing. This type of software allows one to monitor the servers, so you can determine when all the users have "moved" off the web servers (that were recently taken out of cluster). Then you can iisreset, deploy the new build, and move on to the next server (or set of servers, depending on your configuration). We have more than 20 virtual web servers. Typically we take down half of the servers, update them, and take the other half down as we put the first half back in the cluster/farm. This should allow for uninterrupted service. I understand you want to automate the process. I'll assume you're using Windows NLB (network load balancing). You could write a PowerShell script to automate taking down the servers. Here's a reference:
https://technet.microsoft.com/en-us/library/ee817138
I understand this may be viewed as a workaround. I'm not sure if recycling the app pool is always necessary with ASP.NET Core. I wasn't able to find a definitive answer. Most production applications should be on more than one web server anyway. Even if you don't have a lot of users, you should have multiple web servers for failover purposes.
I have a .net 4.0 website that was running on physical Windows server 2003 boxes on IIS6 32bit just fine. We have migrated to new virtual servers running Windows Server 2008 32 bit with IIS7. The application pool is running in classic mode.
Since the move, I at random get a situation where the application hangs. The request queue rockets and then I get 503 errors. If the application pool is recycled, then the error goes away till the next time it occurs.
There are no entries in the event logs relating to it except that it notes when the application pool took to long to shut down during the recycle process. I have reporting in my .net application that logs to a DB and sends me errors but it sends me nothing when this application is hanging.
What tools can I use to diagnose the problem and figure out what is causing it?
In opinion, whatever the structure of application is, if you're pretty sure that there is no bug, changing sort of properties on the application pool might solve the problem.
First on the 'Advanced Settings...' menu of the application pool change the 'Enable 32-Bit Applications' to the relevant value. If the platform used for building application is x86 then the value should be 'True'.
Second if your application demands to access disk resources, also you should the relevant security context for running the application pool in the 'Identity' property. The identity should access all the directories that your application wants to change or list.
After doing all the things, in case the problem existed, you should let me know about the platform of your application. Is it .NET or ISAPI?
Cheers
We are using IIS7 to host an asp.net web-based application.
In this environment administrators and developers can deploy code to the application on a regular basis.
The new code or app goes as a DLL to the ASP.NET bin folder. Upon deployment of the new DLL, IIS restarts the process, impacting (slowing down) all online users.
Is there a way to configure IIS to run the process in the background and once ready make the switch from old state into new without impacting the users?!
Thanks in advance for your feedback!
IIS already does this, that's what recycling is all about. IT's loading the DLL's while the old version of the application is still running. only after this is completed the recycling is complete.
However loading the DLL's is only part of getting web applications ready, there might also be initial loads like loading/caching the user db etc.
These actions are not part of the recycle process, they happen after all DLL's reloaded and the recycling is already completed.
A while back I ran into this issue with an application that had a huge startup time due to heavy db activity/caching during startup. So I was interested if there is some functionality that allows us to execute code before the recycle is marked as completed, so that the application is first considered recycled when everything is ready to run. Basically what I wanted is some kind of staging functionality.
I was in contact with the IIS team regarding this issue, sadly they told me that no such functionality exists, nor is it planned.
To solve this you could try do the following:
Use alternating deploys:
You setup 2 Websites with separate application pools. One of them is the LIVE website the other one is the STAGED website. If you want to deploy changed you simply deploy to the STAGED website. After everything is loaded/cached etc. you switch the URL settings of the web applications to reroute incoming requests from the LIVE to the STAGED one. So the LIVE one becomes the new STAGED and the other way around. The next deploy would then go to the new STAGED again and so on.
UPDATE
Apparently they have created a IIS Module that provides this functionality by now:
IIS Application Warm-Up Module for IIS 7.5
The IIS team has released the first beta test version of the
Application Warm-Up Module for IIS 7.5. This makes warming up your
applications even easier than previously described. Instead of writing
custom code, you specify the URLs of resources to execute before the
Web application accepts requests from the network. This warm-up occurs
during startup of the IIS service (if you configured the IIS
application pool as AlwaysRunning) and when an IIS worker process
recycles. During recycle, the old IIS worker process continues to
execute requests until the newly spawned worker process is fully
warmed up, so that applications experience no interruptions or other
issues due to unprimed caches. Note that this module works with any
version of ASP.NET, starting with version 2.0.
For more information, see Application Warm-Up on the IIS.net Web site.
For a walkthrough that illustrates how to use the warm-up feature, see
Getting Started with the IIS 7.5 Application Warm-Up Module on the
IIS.net Web site.
See:
http://www.asp.net/whitepapers/aspnet4
If you use ASP.NET 4 Auto Start feature:
You can still choose to auto-recycle the worker processes from time to
time. When you do that, though, the app will immediately restart and
your warm up code will execute (unlike today - where you have to wait
for the next request to-do that).
The main difference between Warm Up and Auto Start feature is that the Warm Up Module is part of the recycling process. Rather than blocking the application for requests, while running the init code.
Only thing you get by using the Auto Start feature is that you don't have to wait for a user to hit the page, which does not help your case.
See the Gu's blog post:
http://weblogs.asp.net/scottgu/archive/2009/09/15/auto-start-asp-net-applications-vs-2010-and-net-4-0-series.aspx
UPDATE 2:
Sadly the Warmup Module has been discontinued for IIS 7/7.5:
http://forums.iis.net/t/1176740.aspx
It will be part of IIS8 though (It's now called Application Initialization Module):
http://weblogs.asp.net/owscott/archive/2012/03/01/what-s-new-in-iis-8.aspx
UPDATE 3:
As pointed out in the comments the Warmup Module resurfaced for IIS 7.5 as Application Initialization Module for IIS 7.5 after IIS 8 was released:
http://www.iis.net/downloads/microsoft/application-initialization
The first part of ntziolis answer is a wee bit inaccurate. The worker process isn't being recycled or restarted, it just keeps running. If this were the case, then in shared pool environments you would have sites knocked out every time a new one was deployed.
When you deploy a new ASP.NET application it's the site's "Application Domain" within the worker process is torn down, not the pool process.
In addition pool recycling is a completely separate concept to deployment
At this point in time in the commercial life of ASP.NET, during a deployment, a site will be in an inconsistent state until all of the site is deployed. There is still no good story about this from Microsoft at this time for single site on a single server deployments.
This is why ASP.NET has the special App_Offline.htm page. It's there so you can enable that page, deploy and then turn it off.
The second part of ntziolis answer is nearly correct but you don't need two sites or two application pools. You just need two file system folders that switch between being the physical folders for the site...if you're on a single server and not behind a load balancer or ARR.
If your sites were on a web server behind a load-balancer or ARR then having two different sites would make sense, you could route requests from one site to the other and round-robin on each deploy.
Obviously if there is a large amount of user generated content (uploaded files and the like) then you'd map a virtual directory in your site to a common location for this data.
In larger scale deployments where your app is running across (for example) a load-balanced environment you can do more sophisticated deployments.
For related questions please see:
How Do I deploy an application to IIS while that web application is running
Publishing/uploading new DLL to IIS: website goes down whilst uploading
Is smooth deployment possible with componentized ASP.NET MVC apps?
Before I start, I know using iisreset is considered bad practice, but this shouldn't happen anyway..
What we have:
Several machines with IIS6 on Windows Server 2003 R2 (both 64 and 32 bits)
Several WCF webservices (.NET runtime 2.0) deployed in several applications, each with it's own application pool, each application pool running under an other windows account.
What happens:
All appPools are started, all services operational
IISReset is executed (or the machine is rebooted)
IIS comes back up, but not all application pools start properly. Sometimes they all come back up, sometimes one or more pools won't start. They can be started manually however.
Is this "normal" iis behavior and should I just avoid using iisreset, or are we doing something wrong in our .NET code?
The application pools should restart on an iisreset, but they do run outside of iis (in COM+) for reliability. This mean they may may not come back if the application is misbehaving, but IIS and the other apps will(should) come back. So yes, This is "normal".
P.S.
I would also like to "OUT" myself as a proud user of iisreset. Bad practice? Bah! ;D
IIS does not immediately start ASP.NET worker processes (w3wp.exe) until the first request comes in. When you say "not started", does it mean you attempt to access some WCF web services (after iisreset), and you get a Service Unavailable error because the appPool cannot be started? Do you see any IIS W3SVC related entries in the Event logs?
If there are, they may be able to clue you in why they cannot start; post them up here.
Reason:
IIS does not immediately start ASP.NET worker processes (w3wp.exe) until the first request comes in. When it says "not started" it mean you attempt to access some WCF web services (after iisreset) failed due to object was holding some space in memory, and you get a Service Unavailable error because the appPool cannot be started.
Workaround:
Create Batch file with following commands & schedule it.
net stop 23svc
net stop msftpsvc
net stop smtpsvc
net stop PleskControlPanel
net stop HTTPFilter
iisreset /restart
net start w3svc
net start msftpsvc
net start smtpsvc
net start PleskControlPanel
net Start HTTPFilter
Had similiar issue - after IIS has been restarted, DefaultAppPool was stopped.
In application event logs found an error:
Windows cannot log you on because your profile cannot be loaded. Check that you are connected to the network, or that your network is functioning correctly. If this problem persists, contact your network administrator.
DETAIL - Access is denied.
Fixed by setting in DefaultAppPool Advanced Settings option Load User Profile to False.
Hope it could be usefull.
In a prior support role, I managed several IIS servers running all kinds of .NET mess. When an AppPool failed to start, it was usually a bad login credential.
Re-setting the identity (auth credentials) via advanced settings of the Application pool worked for me.
Earlier I changed my active directory password and as the app pool was already running, it worked fine until I performed IISRESET.