Now that the use of one of my asp.net apps has gone up significantly, two odd problems are occurring that are very infrequent, and that I cannot reproduce.
I am at a loss as to how to debug and troubleshoot these problems.
Here are two examples:
One of my aspx pages resets a session state value to 0 on !IsPostBack (is true). However, one of my users at a specific location frequently comes to that page when it is not a postback and the session state value does not get reset on his laptop. (I am basing this statement on how the app subsequently behaves, not on running in debug mode) But the code works and the session state is reset on my laptop when I am sitting next to him running the app on my laptop using the same browser on the same internet connection at the same time. And when this user runs the app on his laptop from home where he has a better internet connection he does not have the problem as frequently.
One of the aspx pages in my app does a server.transfer to itself after running code that saves data to a DB. Almost all the time after the server.transfer the textboxes contain their default value (as they should since !isPostback==True), but about 1% of the time the textboxes contain the previous value. I know that there has been a roundtrip to the server because data has been saved. This problem occurs on the same pcs using the same browsers by the same users doing the same actions. So 99% of the time it works correctly, and 1% of the time they do the exact same thing and it does not work correctly.
How do I even start trying to figure out what is causing these problems if they seem to be occurring randomly?
I suspect that the quality of the internet connection is the issue because it is the one variable that is changing, but how does that info help me?
It's not like I can debug either of these problems by running my app in debug mode.
I am using Asp .Net 3.5, C# 3.5 and the app is run in IE 6-8. (IE 8 in compatibility mode)
I would add logging to code where the problem is occurring. Then inform the users who are having the problem to try and note the time when they run into the issue. Once you have the logs and an approximate time, you can go in and pour over these logs to see if anything points you in the right direction. I would also look at your IIS and Event Logs on the server.
You can install Firefox Throttle plugin to simulate slow connections. Lot's of things can happen in ASP.NET with slow page loads. If the page isn't loaded fully but items are clickable ASP.NET can get really upset with event validation...etc
Also, I encourage you to start logging and tracing the problem areas in your application. You can then correlate that with the IIS request logs and get a fairly accurate picture of whats's happening when.
It seems like you're having problems with Session State. By default, ASP.NET uses InProc session state mode which uses server memory to store values. In many occasions, this can be lost or reset (app pool recycled). Switching to SQLServer Session State might help you solve the issue.
Related
We have a website built on MVC3 and Telerik. After the latest release, we've got huge performance issues ( all the pages load about 40-50 seconds). As far as we can see in our dev environments, old and new release work absolutely fine. Whereas on prod, loading any page remotely works extremely slow. However, from prod box itself, using localhost or hostname, it works fine too.
What we have already checked:
database works absolutely fine
old/new releases on all the QA,DEV envs
application pool settings were compared with other websites, which are working fine
Application pool recycling counter - no unexpected recycles
Different browsers - also checked
Chrom dev tools show that all the time spends on getting data from the server (I believe rendering the page on the server). All the Ajax request work fast.
To be fair, I run out of thoughts what it might be, so can you please suggest what else worth checking in this case (network setting, IIS settings, perf counters and etc)?
Is there a proxy or other intermediary server in play?
If performance is acceptable when you browse locally but poor remotely I would first check the path to the website when you visit it remotely via traceroute or something similar. If the hoops are as expected, I would check the boxes along the way to your website to make sure they are not doing something weird. If you guys use a CDN, I would check if it still configured correctly. Failing that I would look at perhaps adding some client side instrumentation so you can see whats actually taking long, something like this perhaps.
If you have action filters enabled try disabling them and test. Might be some action filters are doing an extra work which delays the response.
I'm running a .NET C# (4.5) web forms application and on our production server, the application gets slower and slower for everyone over time until about an hour where it becomes pretty much unusable and we just restart the server.
It works perfectly fine on my local machine. Never gets slower at all. So I'm trying to think of what would be different.
My local machine connect to the same database. There's also some active directory things being used for logins but that also connects to the same place on both my local and production environments.
I have debug off in the web.config. I've also looked up pretty much any other solutions and haven't had luck.
I did see some stuff about viewstates building up with ajax requests. I do have a page with updatepanels that are refreshing every few seconds, but I'm confused as to why the production server would be getting slower over time with this and not my local machine testing.
There's only about 10 people using the application at the moment also. Any ideas?
Refreshing a bunch of updatepanels every few seconds is not a good idea pretty much. I was able to optimize things here and there but in the end it was the auto refreshing that was slowing things down. Completely reprogrammed using signalr to grab updates and now it's very fast.
Our team has an application in Android, with a .NET c# backend, hosted in IIS.
Recently, we have observed sudden and unexplainable latencies in our customers with the following scenario:
Without any warning, users are enable to change the channel (Zapping) , since the product has to do with Live Media Streaming, and they can not even log out of the application
The mobile application connected to another backend (still a c# backend) , is working properly, without any problem
After some time (which varies from 6 hours of the first incident, to 5 minutes of the last one), it all turns back to normal.
I have enabled Failed Request Tracing logs, to see if I can get anything from there, and I have results as follows:
<failedRequest url="https://ourDNS.com:443/servertime.aspx"
siteId="1"
appPoolId="DefaultAppPool"
processId="22232"
verb="POST"
remoteUserName=""
userName=""
tokenUserName="NT AUTHORITY\IUSR"
authenticationType="anonymous"
activityId="{80013C53-0802-B500-B63F-84710C7967BB}"
failureReason="TIME_TAKEN"
statusCode="200"
triggerStatusCode="0"
timeTaken="45141"
xmlns:freb="http://schemas.microsoft.com/win/2006/06/iis/freb"
>
The page described above is a simple page, that first gets the server's timezone, and then after getting the customer's timezone (that can be set manually from the client), returns the exact date and time of the device where the application is hosted, for further calculations of stream program, what is playing now etc. However, for this page, that returns a simple JSON with a string in it, it requires some times more than 45 seconds (to me this is insane).
Another log from Client side in the moment is one Exception as above:
java.net.SocketTimeoutException
at java.net.PlainSocketImpl.read(PlainSocketImpl.java:491)
at java.net.PlainSocketImpl.access$000(PlainSocketImpl.java:46)
at java.net.PlainSocketImpl$PlainSocketInputStream.read(PlainSocketImpl.java:240)
at org.apache.http.impl.io.AbstractSessionInputBuffer.fillBuffer(AbstractSessionInputBuffer.java:103)
at org.apache.http.impl.io.AbstractSessionInputBuffer.readLine(AbstractSessionInputBuffer.java:191)
at org.apache.http.impl.conn.DefaultResponseParser.parseHead(DefaultResponseParser.java:82)
at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:174)
at org.apache.http.impl.AbstractHttpClientConnection.receiveResponseHeader(AbstractHttpClientConnection.java:180)
at org.apache.http.impl.conn.DefaultClientConnection.receiveResponseHeader(DefaultClientConnection.java:235)
at org.apache.http.impl.conn.AbstractClientConnAdapter.receiveResponseHeader(AbstractClientConnAdapter.java:259)
at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:279)
at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:121)
at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:428)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
at com.framework.utilityframe.webhelper.HttpRequest.getHttpResponse(HttpRequest.java:316)
at com.framework.utilityframe.webhelper.HttpRequest.httpRequest(HttpRequest.java:393)
at com.tibo.webtv.web.TiboLog.logBufferingError(TiboLog.java:319)
at com.tibo.webtv.CustomVideoView$Buffering_Problem.doInBackground(CustomVideoView.java:324)
at com.tibo.webtv.CustomVideoView$Buffering_Problem.doInBackground(CustomVideoView.java:307)
at android.os.AsyncTask$2.call(AsyncTask.java:287)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
at java.util.concurrent.FutureTask.run(FutureTask.java:137)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
at java.lang.Thread.run(Thread.java:856)
Reading through different forums, I have seen different causes of performance leaks, starting from database to IIS and even a misconfiguration of the application. I have discarded database as a cause because:
At the moment of the problem, database parameters were absolutely fine, no changes in queries time execution, no waiting tasks, no locking
Secondly, the mobile and Decoder application connect to the same database, and the mobile application is running just fine with the same queries
Now, if I think of IIS, every Application hosted at that AppPool, was running fine and without delays, but still there may be something I am missing over there
And at least, something that makes me suspicious is the fact that the mobile application differs in two ways with the Decoder application:
First, the mobile application takes the responses from the Backend in XML format, the Decoder uses JSON.
Second,the mobile application uses http requests, and the Decoder uses https (SSL)
If anyone has experienced similar issues, their help would be greatly appreciated. And for any other detail you need, just ask and I will provide.
So,
Today, our team made another test, which included :
Application hosted in one server and database in another
Application and database hosted in a completely different server (Azure environment)
In both cases, the result was the same: Latencies and problem at the service.
The problem was neither at the backend nor the server. First, the Java application by mistake executed Sync Tasks when saving the logs to another server(dedicated, with full potential to keep as much data as you can give). Second, the log server had a full HDD, with more than 1 TB of only DB Logs, so when the application executed those Sync Tasks (which came as the first call, before any interaction with the channels), they received the Socket exceptions. So, maybe for someone else who may see this post: PLEASE,ALWAYS CHECK YOUR TASKS IN YOUR APPLICATION,AND ALWAYS CHECK ANY SERVER RELATED TO YOUR APPLICATION!!! Thank you very much :D
I am currently having a strange issue with sessions, I've worked with MVC for quite a while and never had this in previous versions. Currently making a new system using MVC5 for the first time, all is well. Sessions are being set with no issues, however, if I modify a cshtml file in VS my session is killed.
Also I have a file upload feature which works, but when you upload a file and then navigate to another page the session is gone again. This is working locally and also on a Windows Server box we use for sandboxing.
Has something changed with the new versions of MVC regarding sessions? I've never had this before. I've got it set to use in-proc sessions, never normally needed to change anything but I have for the sake of things used cookieless, used cookies etc as options. Nothing seems to work.
If anyone has an idea that would be great.
It is interesting that you haven't observed this earlier - as always when you update the contents of your web site, IIS could recompile declarative resources causing the restart of the app pool which effectively removes all session data stored in memory.
A solution would be to switch to other, persistent session storages, sql is possibly the easiest to configure. You just need a sql server where you run the script that creates the session database:
http://support.microsoft.com/kb/317604
Another option would be to use the State Server:
http://msdn.microsoft.com/en-us/library/ms178586.aspx
The performance of the State Server is usually better than the SQl Server as the data is not persisted onto the disk. However, since the state server is a separate process, your application server won't loose sessions even when the app pool restarts.
I am facing an issue in my application that whenever user search for any data and then keep the application idle for like 15-20 mins, and then try to perform any operation on the application, then the application crashes. I am using simple DevEx Grid to show data and ahve details rows and Popup control for that grid.
I think the issue is with the sessions as my application was unable to maintain the session for that duration and due to which application crashes.
Moreover, i have not used any session variables into my application for data.
I cannot find the real cause for this error.
Can somebody help me for the same.
You could write client side javascript to make ajax calls to the server.
This will keep your session alive.
It allows you to have a short timeout at the server, and still a long time out for idle users.
Be sure to have a timeout though, in case your user is away for a hour, the page should log him out.
You can just set the session timeout in IIS to a really high number or minutes (like 1440 for an entire day). This setting is in the "Session State" area.
Another option would be to use Opera as your browser, and load the page once. After that, use Opera's "reload page every..." option to automatically reload the page every minute. This would extend the session forever.
Since you don't store anything useful in session, you should make a way it could reload without crashing. For this you need to anylyse when the crash happens and find a way to prevent the crash. either by initializing with a sane default or catch the exception and start fresh.