I suppose that application state and session state are two different things.
If I can set expiration time to session state, can I do same to an application state in my web.config ?
I just want to prevent my application from rebuilding after 5 minutes.
I don't know exactly what happens. When accessing the website for the first time, the site takes 10 seconds to appear. If I return to the site before 5 minutes, the site appears immediately. If there are more than 5 minutes of inactivity, when I access the site again, the site takes 10 seconds. I guess it was the application state Who expired ?
The easiest way I know of to keep your site alive is to make sure traffic is always coming through. If you have access to a scheduled job runner, have it ping a dummy aspx page every minute or two - this way, your app should run indefinitely.
If not, there are techniques to cheat the system. You can have a cache item built, and upon expiration of that cache item, create another cache item. This will perpetually keep running code every X minutes, which will keep the app alive. The problem with this is that if the app ever does die (server reboot, IIS restart, etc.), the app will be dead until someone makes a real request, at which point it will stay alive indefinitely again.
This technique is sometimes used to simulate a task scheduler in ASP.NET. Just keep in mind that it's not perfect.
EDIT: For clarification, you wouldn't just create a new cache item, you'd actually make a request to a page which would then in turn create the cache item. This ensures that another request is made through IIS, which in turn runs the full lifecycle, keeping the app alive.
Even if you do set your session timeout high, there's no guarantee that it will hold. I've dealt with hosting companies who will recycle your application pool after just a couple minutes of inactivity, killing any sessions you may have open. They don't care that you may have sessions open - they are just trying to squeeze every CPU cycle they can out of their servers. So if you're on shared hosting, you may want to keep that in mind - you may not be able to control how often they kill your app.
Application State starts when the first session is created, and is automatically ended after the last session expires. As long as you have continued access to the website, the application will remain active.
I don't know what you mean by having application "rebuild". Changing any file related (i.e. file with compilable code) will cause the application to either recompile (if you have a web directory) or reload (if you have a web application). This action will always end all sessions and end the application.
Not sure it is still actual.
The problem doesn't linked with SessionState or ApplicationState.
To avoid slow reaction of your web-site you have to activate AlwaysRunning mode of your IIS
To do that add to your web.config the next
<applicationPools>
<add name="MyAppWorkerProcess" startMode="AlwaysRunning" />
</applicationPools>
You can configure your session state in your configuration file for preventing this expiration.
For example:
<sessionState
mode="SQLServer"
sqlConnectionString="data source=127.0.0.1;user id=<username>;password=<strongpassword>"
cookieless="false"
timeout="20"
/>
Related
Site hosted via IIS 7.0
I would like to set my session time-out to 9 hours in my ASP.NET application.
This has been set at web.config
<sessionState timeout="540"></sessionState>
But, as I understand, if the timeout is set as 20 minutes inside the IIS where the website is hosted, setting an extended session state will be of no use.
Firstly, I would like to confirm whether this assumption is right.
The problem is that I do not have access to the IIS of my shared hosted web server.
Now, after some research, I came up with another solution in code project. This sounds like a wonderful idea. The idea is to insert an iframe to master page. The iframe will contain another page with meta refresh less than 20 minutes.
Response.AddHeader("Refresh", "20");
This idea seemed good for me. But the article is 7 years old. Plus at comments section a user complaints that this won't work if the page is minimized and I am worried that the same happens when my pages tab is not active.
I would like to know these things
Whether the refresh method will work for my scenario , even if the page is minimized?
Are there any other methods that could increase session time out that overrides IIS timeout setting?
Also I read some questions in Stack Overflow where the answers state that the IIS session timeout is for clasic ASP pages. Then why is not my extended timeout not firing?
Firstly, I would like to confirm whether this assumption is right.
Yes, this assumption is absolutely right in case you are using in-memory session state mode. In this case the session is stored in memory and since IIS could tear down the AppDomain under different circumstances (period of inactivity, CPU/memory tresholds are reached, ...) the session data will be lost. You could use an out-of-process session state mode. Either StateServer or SQLServer. In the first case the session is stored in the memory of a special dedicated machine running the aspstate Windows service and in the second case it is a dedicated SQL Server. The SQL Server is the most robust but obviously the slowest.
1) Whether the refresh method will work for my scenario , even if the page is minimized?
The hidden iframe still works to maintain the session alive but as I said previously there might be some conditions when IIS unloads the application anyway (CPU/memory tresholds are reached => you could configure this in IIS as well).
2) Are there any other methods that could increase session time out that overrides IIS timeout setting?
The previous method doesn't increase the session timeout. It simply maintains the session alive by sending HTTP requests to the server at regular intervals to prevent IIS from bringing the AppDomain down.
3) Also I read some questions in Stack Overflow where the answers state
that the IIS session timeout is for clasic ASP pages. Then why is not
my extended timeout not firing?
There is no such thing as IIS session timeout. The session is an ASP.NET artifact. IIS is a web server that doesn't know anything about sessions.
Personally I don't use sessions in my applications. I simply disable them:
<sessionState mode="Off"></sessionState>
and use standard HTTP artifacts such as cookies, query string parameters, ... to maintain state. I prefer to persist information in my backend and retrieving it later using unique ids instead of relying on sessions.
Hey I have the following line in my web.config
<sessionState mode="InProc" timeout="45"/>
Which I thought would keep sessions intact for 45 mins
But I have seen the case where if a user is inactive for lets say 15 mins the sessions times out.
How can I stop this ?
Edit : Just noticed I have the following line in the master page
meta http-equiv="Refresh" content="1800;URL=http://www.virtualacademy.ie/login.aspx">
Maybe this is causing the issue, what is the above line doing i.e the number 1800
Be sure to check your IIS configuration because the application pool that your site is hosted on also has its own timeout value which will override your own .config.
To increase it,
Open IIS
Select Application Pools on the left side
Select the Application Pool used by your site
Choose advanced settings
Under Process Model categtory increase the 'Idle Time-out' value to the desired length.
Hope this helps.
(If you do not have a dedicated server / access to IIS with your hosting provider you will have to contact them to see if they can increase it for you)
If the user closes their browser or clears cookies, or if the AppDomain on the server is recycled, the session state will be lost.
Have you checked logs to see if the app is recycling?
AppDomain recycles are a very common problem for this if the sessionState is InProc. It is very much advised to use a StateServer or SQLServer for production systems instead. See Session-State Modes for documentation on how to use each, and the pros and cons of the three different types.
Personally, we use SQL Server if we must for web server farms--slower but can be shared. We use State Server if the site will only be hosted on a single web server--state survives AppDomain restarts, but not entire server restarts.
Also, in the past we have used an AJAX post in the background while the user is watching long running videos or performing long client-side tasks, so that the session timeout gets reset every few minutes. Nothing special about this code--just have a little JavaScript hit every few minutes some ASPX page that returns nothing.
Are you using Forms Authentication? It has its own timeout setting that when expires will redirect the user to your login page even if their session is still valid.
I wrote a test page that does a bunch of busy work in a method called at page load. This process as I have it now takes around 12 seconds.
If I try to load another page while the first long running page is loading, this second page doing nothing except writing out a hello world, it doesn't load until the first long running page is finished.
Why is this the case? I would think IIS would be able to handle multiple concurrent connections, it seems crazy that one long running page would stop every other page in the application from loading. I must be missing something or not understand how IIS works.
I would think multiple independent requests would be spawned on different threads. Is this only the case if the requests are from different sessions entirely? Are all requests from a single session bound to a single thread?
bd
You need to turn off sessionState... if session is on, any sub-sequent request is waiting on the previous thread to finish in order to continue on that particular session.
So turn session off, it will not need to wait for any previous session.
in web.config put
<system.web>
<sessionState mode="Off" />
</system.web>
Now you should have those request process concurrently.
I just hit this issue too, and for me it turns out it is the session feature of ASP.NET. Basically if you have sessions enabled, each request will return in the order it arrived per user.
Try using 2 different browsers, for me it no longer blocked. Here is a similar question:
IIS 5.1 on XP Classic ASP appears to be in single threaded mode
It's a threading problem. While IIS can handle multiple connections simultaneously, ASP.NET, by default, is configured in single-threaded mode.
This choice by Microsoft was to prevent dummy developers to make common concurrency mistakes. ASP.NET for Mono doesn't show this behaviour and if you access shared resources without prior locking you might be... f... you know ;) by a yellow page of death.
I don't remember the exact procedure, but in the properties of your website you can choose the application pool and also the number of threads. I saw with my eyes that IIS6 sets it to 1 by default.
If you can't find it, tell me and tomorrow I'll take a look on my development server in lab.
Hope to have been of help.
I have an ASP.net application where Users aren't able to successfully complete certain actions, for reasons, I'm assuming, can only be related to losing their session (which is where I maintain their current user information, and how determine whether they are logged in)
I'm at a loss as to why they would lose their session, so my first question is:
What (in general) would cause a user to lose their session in ASP.net?
and since I don't know when a user loses their session and can't reproduce it myself:
How can I track when I user loses their session
Below is my sessionState config for reference
<sessionState
mode="InProc"
cookieless="false"
cookieName="My.Site.Com"
timeout="480"/>
A number of things can cause session state to mysteriously disappear.
Your sessionState timeout has expired
You update your web.config or other file type that causes your AppDomain to recycle
Your AppPool in IIS recycles
You update your site with a lot of files, and ASP.NET proactively destroys your AppDomain to recompile and preserve memory.
-
If you are using IIS 7 or 7.5, here are a few things to look for:
By default, IIS sets AppPools to turn themselves off after a period of inactivity.
By default, IIS sets AppPools to recycle every 1740 minutes (obviously depending on your root configuration, but that's the default)
In IIS, check out the "Advanced Settings" of your AppPool. In there is a property called "Idle Time-out". Set that to zero or to a higher number than the default (20).
In IIS, check the "Recycling" settings of your AppPool. Here you can enable or disable your AppPool from recycling. The 2nd page of the wizard is a way to log to the Event Log each type of AppPool shut down.
If you are using IIS 6, the same settings apply (for the most part but with different ways of getting to them), however getting them to log the recycles is more of a pain. Here is a link to a way to get IIS 6 to log AppPool recycle events:
http://web.archive.org/web/20100803114054/http://surrealization.com/sample-code/getnotifiedwhenapppoolrecycles/
-
If you are updating files on your web app, you should expect all session to be lost. That's just the nature of the beast. However, you might not expect it to happen multiple times. If you update 15 or more files (aspx, dll, etc), there is a likelyhood that you will have multiple restarts over a period of time as these pages are recompiled by users accessing the site. See these two links:
http://support.microsoft.com/kb/319947
http://msdn.microsoft.com/en-us/library/system.web.configuration.compilationsection.numrecompilesbeforeapprestart.aspx
Setting the numCompilesBeforeAppRestart to a higher number (or manually bouncing your AppPool) will eliminate this issue.
-
You can always handle Application_SessionStart and Application_SessionEnd to be notified when a session is created or ended. The HttpSessionState class also has an IsNewSession property you can check on any page request to determine if a new session is created for the active user.
-
Finally, if it's possible in your circumstance, I have used the SQL Server session mode with good success. It's not recommended if you are storing a large amount of data in it (every request loads and saves the full amount of data from SQL Server) and it can be a pain if you are putting custom objects in it (as they have to be serializable), but it has helped me in a shared hosting scenario where I couldn't configure my AppPool to not recycle couple hours. In my case, I stored limited information and it had no adverse performance effect. Add to this the fact that an existing user will reuse their SessionID by default and my users never noticed the fact that their in-memory Session was dropped by an AppPool recycle because all their state was stored in SQL Server.
I was having a situation in ASP.NET 4.0 where my session would be reset on every page request (and my SESSION_START code would run on each page request). This didn't happen to every user for every session, but it usually happened, and when it did, it would happen on each page request.
My web.config sessionState tag had the same setting as the one mentioned above.
cookieless="false"
When I changed it to the following...
cookieless="UseCookies"
... the problem seemed to go away. Apparently true|false were old choices from ASP.NET 1. Starting in ASP.Net 2.0, the enumerated choices started being available. I guess these options were deprecated. The "false" value has never presented a problem in the past - I've only noticed in on ASP.NET 4.0. I don't know if something has changed in 4.0 that no longer supports it correctly.
Also, I just found this out not long ago. Since the problem was intermittent before, I suppose I could still encounter it, but so far it's working with this new setting.
In my case setting AppPool->AdvancedSettings->Maximum Worker Proccesses to 1 helped.
Your session is lost becoz....
JUST MAKE SURE THERE ARE NO RUNTIME ERRORS, ANY FATAL EXCEPTION WOULD
KILL THE SESSION!
In Microsoft stack, Visual Studio - put Ctrl + Alt + E - All Exceptions ON, then run the code in Debugging mode. Any Fatal ones are THE reason for session loss..
You could add some logging to the Global.asax in Session_Start and Application_Start to track what's going on with the user's Session and the Application as a whole.
Also, watch out of you're running in Web Farm mode (multiple IIS threads defined in the application pool) or load balancing because the user can end up hitting a different server that does not have the same memory. If this is the case, you can switch the Session mode to SQL Server.
I was only losing the session which was not a string or integer but a datarow.
Putting the data in a serializable object and saving that into the session worked for me.
Had a problem on IIS 8 when retrieving Content via Ajax. The issue was that MaximumWorkerProcesses was set to 2 and Javascript opened 17 concurrent requests. That was more than the AppPool could handle and a new pool (without auth-data) was opened.
Solution was to Change MaximumWorkerProcesses to 0 in IIS -> Server -> Application Pools -> [myPool] -> Advanced Settings -> Process Model -> MaximumWorkerProcesses.
Dont know is it related to your problem or not BUT Windows 2008 Server R2 or SP2 has changed its IIS settings, which leads to issue in session persistence. By default, it manages separate session variable for HTTP and HTTPS. When variables are set in HTTPS, these will be available only on HTTPS pages whenever switched.
To solve the issue, there is IIS setting. In IIS Manager, open up the ASP properties, expand Session Properties, and change
New ID On Secure Connection to False.
I had same problem by losing sessions. every time , every page reload, my sessions clear and by new reload any page, my sessions returned by valid value...
i fixed it by change MaximumWorkerProcesses from 0 to 1 in iis
I was struggling with this issue for 14 days.
Here's what helped me:
Check your recycling options in App Pool > Advanced settings. Turn off all of the options so it won't recycle on its own.
Check your web.config file for the executionTimeout property under httpRuntime and increase its value.
Check your web.config file for the timeout property under sessionState and increase its value (I set it to 300 minutes).
Go to the server's event log and check the Application log for unhandled exceptions that may cause the worker process to crash. Fix them in your code or use try and catch to eliminate this crash.
Try changing the value of your maximum worker process from 0 to 1 or the other way around, this may also solve this issue.
In my case, session state was loosing due to Load Balancer. Session was storing in one server and Load balancer was redirecting next call to another server where session state was missing.
We are having an intermittent problem with some users losing session. Our session settings in the web.config are as follows:
<sessionState mode="InProc" timeout="1440"/>
...which should be 24 hours (a value deliberately set over the top during testing).
Are there any other settings (maybe in IIS7) that I need to be aware of? Or are there any resources that will list the things that could kill a user's session?
Let me know if you need more information.
Thanks!
Dave
Changing the web.config file, or any of the dlls will cause the session to be destroyed, as will the recycling of app pools (this is usually set to a timeout of 20 mins of inactivity, but will also occur under certain exception conditions and possibly memory conditions)
Check Application Pool settings. There are several things there that can interfere with this:
Process recycling settings;
Several processes (then each would be keeping its own session stash);
Changing web.config or other web related files recycles the process immediately.
Anything that recycles the application pool will kill InProc session state.
Check the properties on the application pool by default there are several settings which may cause the pool to recycle in less then 24 hours.
Typically when testing there is little activity on the site and you fall foul of the pool idle timeout.
Thanks for all the replies, it seems it was because the App Pool was set to recycle at 3am and some of the users were just leaving themselves logged in over night and then just carrying on in the morning! We've added better session timeout handling now.
Thanks again!