A Way to Run a Long Process From ASP.NET page

Question

Hello,

What are your most successful ways of running a long process, like 2 hours, in asp.net and return information to the client on the progress.

I've heard creating a windows service, httphandler and remoting can be successful.

Answer 1

Just a suggestion...

If you have logic that you are tyring to utilize already in asp.net... You could make an external app (windows service, console app, etc.) that calls a web service on your asp.net page.

For example, I had a similiar problem where the code I needed was asp.net and I needed to update about 3000 clients using this code. It started timing out, so I exposed the code through a web service. Then, instead of trying to run the whole 3000 clients at through asp.net all at once, I used a console app that is run by a nightly sql server job that ran the web service once for each client. This way all the time consuming processing was handled by the console app that doesn't have the time out issue, but the code we had already wrote in asp.net did not have to be recreated. In the end slighty modifying the design of my existing architecture allowed me easily get around this problem.

It really depends on the environment and constraints you have to deal with...Hope this helps.

Answer 2

This isn't directly applicable but I wrote code that will let you run processes similar to "scheduled tasks" inside of ASP.NET without needing to use windows services or any type of cron jobs.

Scheduled Tasks in ASP.NET!

Answer 3

There are two ways that I have handled this. First, you can simply run the process and let the client time out. This has two drawbacks: the UI isn't in synch and you are tying up an IIS thread for non-html purposes (I did this for a process that used to return quickly enough but that grew beyond time-out limits).

The better way to handle this is to write a "Service" application that handles the request as passed through a database table (put the details of the request there). Then you can create a window that gives the user a "window" into ongoing progress on the task (e.g. how many records have been processed or emails sent). This status window can either have a link to permit the user to refresh or you can automate the refresh using Ajax callbacks on a timer.

Answer 4

I very much prefer WCF service to scheduled tasks. You might (off the top of my head) pass an addr to the WCF service as a sort of 'callback' that the service can call with progress reports as it works.

I'd shy away from scheduled tasks... too course grained.