Accessing the exe file from asp.net mvc concurrently - asp.net-mvc

Hi i'm creating an application in which i have to call the exe file as a process from mvc.I was able to achieve it but the problem is when multiple request to the exe file comes how to handle it.If the exe file starts executing it may take 1 hour to complete its task.Meanwhile how to handle the other request to the exe?

Check the below two links it should solve your problem. Also you can queue the requests (might require implematation) so that launch the processes in queue later on.
Ensuring only one application instance
How to run one instance of a c# WinForm application?

Related

Change the Values of the app config file in a windows service through another program

I have a windows service which downloads some files from SFTP and uploads it to database and generates PDf's from that data. So now when i should give the executable files to my client i think he need to change the app config file like sftp details and the pdf paths. So i am just thinking about a program like a windows forms or a console which reads the input and save those in app config file. Is it possible like and by the way i have created a setup project for the windows service where he gets 2 files .msi file and setup file. Is it possible to achieve the above problem in this case ?
If I understand correctly, you're wanting some kind of UI application that allows the user to configure the operation of the Windows service. This is certainly possible as I've been doing it for several years now. However, you don't want to do this via the app.config file. The app.config file is read by the Windows service when it starts up, so any changes made to it would go unnoticed until the service restarts. A better course of action would be to communicate the changes to the service via the Windows Communication Foundation (or some other ICP mechanism, e.g., pipes, sockets, shared memory, etc.). I've managed to use this successfully, although to be honest, I'm using ordinary sockets now. In any case, the service would basically "listen" for incoming configuration messages, "read" those messages, and then "configure" itself accordingly, perhaps even saving the changes in its app.config file so the changes are preserved for when the service restarts later.
HTH

Web deployment failing due to file in use

I'm using Microsoft's Web Deploy Remote Agent service to allow me to easily publish code to the server from within Visual Studio.
The web site I am deploying is using log4net to log messages to log files, and every time I try to deploy a new version of the code, I get this error in Visual Studio stating that the current log4net log file is in use:
An error occurred when the request was processed on the remote
computer. The file 'Web.log' is in use.
The process cannot access 'C:\inetpub\wwwroot\Logs\Web.log' because it
is being used by another process.
I can solve this by going onto the server and doing an iisreset before publishing... but that is kind of defeating the point of 'easy' publishing from Visual Studio :)
Is there some way I can get the publish task to issue an iisreset automatically, or some other way I can work round this?
I kept poking around and found some tidbits around the file being locked in a few other forums. Have you tried adding
<lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
To your <appender> element in the web.config file? From the Apache docs
Opens the file once for each AcquireLock/ReleaseLock cycle,
thus holding the lock for the minimal amount of time. This method of
locking is considerably slower than FileAppender.ExclusiveLock but
allows other processes to move/delete the log file whilst logging
continues.
As far as the performance considerations, I suppose you would need to test if this will affect you or not as I am assuming it really depends on how often you are writing to the log file as to how much this will impact performance. I can't believe that getting/releasing a lock could take all that much time though.
There is a MSDEPLOY provider called recycleApp which is used exactly for this. You can include this in your deployment manifest.
Another option is to use ignoreOnErrors flag which will skip the file in use and continue with the deployment.

Updating EXE file from server…

I need to update my application from a central server.
The application checks always if it is a correct version, against the server installation.
So when it is not, I need it to update itself.
So how can I copy the EXE if it is running? What solution do I have?
I rename the current running exe to MyTempExe.exe, copy the new exe to the correct location (request elevated privileges if necessary) and then run a separate app to restart the main app. On start up I check for MyTempExe.exe delete it if it's there.
The reason I use a separate app for the restart is I don't have a set time frame for the app to close down and need to wait for it to finish whatever it's doing, on shutdown it writes information to disk about its current state that the updated app will use to resume where the old one left off.
I don't know if it's the best solution but it's the one I use.
As you can see by all the answers there is no set way to do this, so I thought I would add the way we have successfully done this.
We never run an application directly from the network.
We run the application from the local machine and have it copy from the network on startup.
We do this using an application launcher. It downloads an XML file that contains CRC and Version Resource Values for the application files. The XML File is created during the deployment process, in a FinalBuilder Script.
The application then compares the XML File to local content, and copies down needed files. Finally we then launch the application in question. This has worked well for deploying an application that serves around 300 local users. Recently we switch from a file copy to an HTTP download as we found problems with remote user disconnecting drives.
We still still build installations (With Innosetup) to get the basic required files deployed.
Package your app with an installer such as Inno. Download and execute the installer. Have the installer search for and kill your app, or instruct the user to close it. The setup will replace your .exe, and if the app can't be killed or the user is non-cooperative, it'll issue a re-start notice.
Download new EXE to TEMP
Create Batch from EXE, content:
taskkill /PID %process id of running EXE%
copy %new EXE% %running EXE%
%EXE%
all values in %...% are placeholders
execute batch from the running EXE
delete batch
I use TMS TWebUpdate myself, for software updates. The advantage is that there a bunch of extra actions you can put into the script, if you need anything other than plain EXE updates.
I have two components at work the application executable itself and a web-service (SOAP) which provides version details and file downloads.
The application calls a method on the SOAP service to ask for the number of files in the project (project is identified by using the application.exename usually).
The soap service gets its info from an INI file, which has entries like:
[ProjectName]
NumberOfFiles=2
File1=myapp.exe;1.0.0.1
File2=mydll.dll;1.0.0.2
You just update this file at the same time as uploading your new files.
The process of updating the application this:
Get number of files available on the web service
For each file, the application asks for the name and version number from the SOAP server.
The application compares this information to its own version info and decides if the file needs updating, building a local list of files that need updating.
For each file that needs updating the application downloads the file to filename.ext.new
Finally, the application renames all filename.ext to filename.ext.old and renames filename.ext.new to filename.ext and then restarts itself. (No real need for an external app to restart your own program).
Note 1, that you may have to ask for elevation to replace files, depending on where you install your files.
Note 2: be kind to your users, think carefully before you force updates on users.
Note 3: You cannot delete a running exe, but you can rename it and then restart the new version.
Edit===
For some reference data files which cannot contain version information resources, you can have entires like File99=MyDataFile;1.1.2011 the 3 elements to the version number indicates to the client that it should check against the file date/stamp.
You could have a separate update executable whose task is to check the server version, download an updated executable if necessary, and then run the local executable.
Or you could have one executable running in two different modes: 1. on startup, check for an update, if there is one, download the executable to a download directory, run it and quit.
2. The new executable would check if it's running from the installation directory, if not, it would copy itself there, overwriting the old version, start the copy from there, and quit.
My way is the other way round: If a new version is online, promt the user to update. If he want's to (or is forced to...) I end the app and start a new exe (updater). this updater loads the update and replaces the old exe (not running). then it starts the new exe. ready. (You can of course replace other files too.) BUT: Using an Installer like InnoSetup gives you more possibilities and doesn't mix up with the regular uninstaller, so it is really better...
You can do this without running another application. Push the updates to the client from the server while running, storing in a temporary directory on the client. When you want to upgrade move all your running files to another temporary directory, move the new files into the original application directory, and just restart the application using the standard executable name on shutdown.
I upgrade client applications running on unattended machines automatically this way.

How to profile an ASP.NET web service on a remote server by EQATEC profiler?

I am thinking the modified dlls will create a log file some where in the remote system so I can open it later after load test but all I found was a log file in $(SystemRoot)\Temp\EQATECProfilerLogs saying nothing other than app started. Do I need to install EQATEC profiler on the remote server?
Thanks
This scenario is adressed in this EQATEC forum thread:
A profiled app needs to be told when we want it to produce its profiling report. For plain apps this is simple and has therefore been automated: when Main exits. But your web-service has no similar "exit point" - it just keeps on running until you kill it.
Therefore you have to explicitly/manually tell the profiled web-service to take a snapshot. The easiest way is to simply run the profiler on the same machine as the web-service is running on: when the web-service is starting up it will automatically connect to the profiler and you can then run your tests and control/dump timing info at will using the "take snapshot" and "clear counters"-buttons.
Alternatively, you can make a reference to the supplied runtime-module from within your code and make explicit calls to the API (TakeSnapshot etc) precisely where you want in your code. The runtime-modules reside in C:\Program Files\EQATEC\EQATECProfiler\RuntimeDLL.

ASP.NET MVC 2: "The process cannot access the file <filename> because it is being used by another process."

I'm trying to use Controller.File to return a FilePathResult from a view in my ASP.NET MVC 2 project. I use it like this:
return File(pdfFilePath, "application/pdf", "foo.pdf");
However I keep getting this error in the yellow screen of death:
The process cannot access the file [the file path] because it is being used by another process.
This error usually comes up when you forget to close a file stream, but I figured that this should be taken care of by the ASP.NET MVC framework. This doesn't happen every time, but rather periodically. Sometimes I get the file just fine but then it just stops working. I am using the development server when testing this.
Any ideas?
Are you accessing the file prior to the line of code you provided? If so, how are you accessing it?
When accessing files, try to use the following to avoid file stream conflicts:
File.Open(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
The last enum FileShare.ReadWrite will allow other file streams to read and write to the file even if you have it open. Of course, it is better to remember to close your stream ASAP.
http://msdn.microsoft.com/en-us/library/y973b725.aspx
Do you have the file already open when you get this message?
If you do it might be Adobe locking the file.
The likeliest scenario is that something other than ASP.NET / IIS has the file open. Have you ensured that no other processes have a lock on the file when this error occurs?
If you have access to the server when the error happens, you can use a tool like Process Explorer to view what exactly is locking the file.
The locking can occur from within asp.net itself - as asp.net displays thread-agility, and as such it may be another thread from within the asp.net threadpool completing the request. This would be why you only see this issue intermittently.
Baddie's answer is basically the solution to your problem. As an aside, you might find other issues if you're using resources that contain state that are declared as threadstatic. If this is the case you might want to look at making use of CallContext.

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