I would like to create an auto email distributor application by C# for my company.
Usually, I would create a console application and set up a schedule to run this program from server task scheduler.
Is there any ways to build this kind of application other than console application? And what is the benefit of it compared to console application.
It can be done with every application type. Asp.net\Silverlight\WCF\WPF\WinForm...
Console Application is the easiest way because
It doesn't have a UI layer(or almost doesn't have...).
No configurations are required.
If you have a robust scheduling application (such as task scheduler), there is little point to rebuilding this inside your application. If the scheduling application is not sufficient for your needs, you'll need to embed that logic in your app.
Either way, a console application is fine. The latter scenario will just require more configuration (in the form of a configuration file probably). Still no need for a UI unless the config is complex.
You may write a Service. Writing a Service in .Net is too easy and straight forward and then you need to use a timer to invoke the operation on schedules.
A service will be executed in the background and can be configured to be executed as soon as the computer turns on.
Because services do not have user interface, you need to feed them with the requests using a database or a messaging system.
Windows schedule of a console application is ok.
If your schedule is continuous (every minute) you might be better off a Windows service see Here.
See this stackoverflow question for the comparison HERE
Related
My website needs to somehow do something every few minutes.
Essentially I get projects from another website. I then call one of my web pages and update.
Currently I'm making a console app for this but I'm wondering if there is a better way.
Thanks
There are super cool, open source tool exist for creating a scheduled jobs in .NET
It called Quartz.NET.
I think currently is #1 tool for that tasks.
Use windows task scheduler to run the console app your writing at the appropriate times.
Depending on what needs to be done, there are a few options.
This can be achieved by a timer in a windows service.
Using the HttpCache expiration callback feature (not recommended, it is a hack).
Use a Sql job (assuming data is changing).
Building upon #Ph0en1x answer, there already is a Stackoverlow question on how to use Quartz.Net in ASP.Net
I have a .NET 4 web application that has 3 separate projects associated – DAL, BAL, and UI. I am using Entity Framework for database interaction.
I have code that cycles through a bunch of database data, calls methods depending on what it finds, and then updates a database. I want this code to run all the time. At the same time I want users to be able to log in and run reports etc all while the code in the background is constantly running.
What is a good approach to this? Do I create a service for the code that constantly runs, a separate thread, an entirely separate project for the code that runs constantly, or a different approach..?
Also, depending on the answers given, how would I kick start the code that runs constantly? i.e. just through form load method or is there a better approach? I currently kick start the code by clicking a start button; this is fine for testing, but not going to work when in production.
You would be best suited for using Windows Services for always-running tasks.
Running code on a separate thread under IIS is not a reliable mechanism since IIS can terminate threads at will to conserve server resources.
Given your question and clarifications on other answers that:
Your solution runs in a hosted environment where you cannot install a service;
Calling it from a third server (i.e. Azure or such) is not an option for you;
You might be best off starting a thread in your Application_Start event to manage the database work. You'd probably want to ensure that this thread had some periodic idle time, so as not to take up too much of the hosted environment and ensure it's shutdown when your application ends or is restarted.
A service would really be optimal, but if you're in a hosted environment and can't/won't use another server, then that's not possible.
Use a Windows Service. Should also look into using Stored Procs for the database interactions you mentioned. In terms of kicking the Windows Service off, you can set it to automatic startup (when the OS starts) which will mean it will run until terminated.
I would only recommend a Windows Service if it will literally always be running. However, "always" usually means every x seconds / minutes / hours /days.
If x is greater than a few minutes, I would make it a Console Application and run it through the Windows Task Scheduler. This way you don't have to worry about memory leaks and a slew of other issues.
However, if it is only working with the database, I would recommend a stored procedure and a Sql Job.
I am have a web application that is written in c# .net 4.0. It connects to an Oracle database to perform CRUD operations.
What I need to is write a background type tasks that is polling the database at predefined intervals to check to see if it is up. If its down a property in memory is set so that no further requests to the database are made. The task continues to run and alters the property once the database is available again.
I wondering what is the best way to structure such in my application, how I would set up a background task to run etc or any advice on the implementation of such? I don't want this to hog resources on the server so it needs to run in background and not be resource intensive.
A Windows Service is the obvious answer for background tasks. The basics are pretty easy to do - just create a new project by selecting Windows Service as the project type and go from there.
Inside the Windows Service create an instance of a class and within it create a timer - when the timer fires run your periodic tasks
If you must do this I would suggest writing a Windows Service, but have it modify a config file setting that your web application checks. I think having both applications looking at the same config file is the most simple solution in this case.
I've got a windows service with only two methods - one private method DoWork(), and an exposed method which calls DoWork method. I want to achieve the following:
Windows service runs DoWork() method every 6 hours
An external program can also invoke the exposed method which calls DoWork() method. If the service is already running that method called from the service, DoWork() will again be invoked after the current method ends.
What's the best approach to this problem? Thanks!
An alternative approach would be to make use of a console application which can be scheduled by Windows task scheduler to run every 6 hours. In that case you don't waste resources to keep the Windows service running the entire time but only consume resources when needed.
For your second question: when you take the console app approach you can have it called by making use of Process.Start for example.
If the purpose of your application is only to run a specific task every six hours, you might be better off creating a command line application and creating a scheduled task that Windows runs automatically. Obviously, you could then manually start this application.
If you're still convinced you need a service (and honestly, from what I've seen so far, it sounds like you don't), you should look into using a Timer, but choose your timer carefully and read this article to get a better understanding of the timers built into .NET (Hint: Pay close attention to System.Timers.Timer).
To prevent reentry if another method tries to call DoWork() while the process is in the middle of performing its operation, look into using either a Mutex or a Semaphore.
there are benefits and drawbacks either way. my inclination with those options is to choose the windows service because it makes your deployment easier. scheduling things with the windows task scheduler is scriptable and can be automated for deployment to a new machine/environment, but it's still a little more nonstandard than just deploying and installing a windows service. you also need to make sure with task scheduler it is running under an account that can make the webservice call and that you aren't going to have problems with passwords expiring and your scheduled tasks suddenly not running. with a windows service, though, you need to have some sort of checking in place to make sure it is always running and that if it restarts that you don't lose hte state that lets it know when it should run next.
another option you could consider is using nservicebus sagas. sagas are really intended for more than just scheduling tasks (they persist state for workflow type processes that last for more than the duration of a single request/message), but they have a nice way of handling periodic or time-based processes (which is a big part of long running workflows). in that a saga can request that it get back a message from a timeout manager at a time it requests. using nservicebus is a bigger architectural question and probably well beyond the scope of what you are asking here, but sagas have become how i think about periodic processes and it comes with the added benefit of being able to manage some persistent state for your process (which may or may not be a concern) and gives you a reason to think about some architectural questions that perhaps you haven't considered before.
you can create a console application for your purpose. You can schedule the application to run every 6 hours. The console will have a default method called on application start. you can call your routine from this method. Hope this helps!!
I'm trying to find a very easy easy way to start a simple cron job for my Web Application. What I was thinking about is starting a Task in the Application_Start event. This task will have a while loop and do some action every hour or so like a normal cron job would do.
Is this a good idea or will this give some trouble?
Some of the problems I could think of are the following:
The Task suddenly stops working or hangs. Maybe make some fail over
mechanism that would check if the task is still running and if not
restart it.
Memory leaking if the Task totally goes wrong and I have to restart
the whole application.
No control in changing the Task on the fly but this shouldn't be a
problem for the thing I want to do but for others it might be.
Does someone have any suggestions or experiences with trying this?
Although Darin says that doing cron jobs in a web application is a bad idea (and I agree with him in some way), it may be not so bad, when used wisely and for short running jobs.
Using same Quartz.NET in web application may be quite nice, I'm using in one of my projects like this
http://bugsquash.blogspot.com/2010/06/embeddable-quartznet-web-consoles.html for small jobs and it is running nice - it's easy to monitor (easier than monitoring remote windows process), may be used on shared hosting.
Doing cron jobs in a web application is a bad idea. IIS could recycle the application at any time and your job will stop. I would recommend you performing this in a separate windows service. You could take a look at Quartz.NET. Another possibility is a console application which does the job and which is scheduled within the Windows Scheduler.