impact of disabling recycling of worker process in IIS application pool

Question

I have a WCF service hosted in IIS which takes a long time (around 5 hours) to execute. the WCF service basically generates some reports using SSRS (SQL server reporting services) and saves them to a locaton on the server. this service was actually stopping after generating few reports, so I disabled the "recycling of worker process", "shut down worker processes after being idle" and "limit kernel request queue" in application pool and that fixed the issue and all the reports were generated regardless of the amount taken to generate them. but I am not sure if this is the right fix for this and I would like to know what is the impact of unchecking these settings in application pool for the WCF service in IIS? and is there any better way to get around this problem?

Answer 1

For any long running process it is much better to do it outside of IIS.

In this case I would have a regular windows service running that monitored a request queue. When a request comes in to generate a report, it would then spin off a thread to perform the generation.

The web service would be responsible for 3 things. First, adding an item to the queue to be handled. Second, checking status on the queue as to whether the report is ready. Third, sending the completed report back to the calling client.

This would allow the client to essentially do a fire and forget on the report request and call back later to check on it's status. Further it would mean that if IIS recycled for whatever reason you are still OK.

For bonus points I would add some error handling code that when the windows service restarted it could restart report jobs that were in the middle of execution. This would make it a bit more robust and allow you to reboot the server at any point.

Answer 2

I have disable also all the automatic shut down process from iis for my application with out any issue. I have monitor the memory limits and of course the program work smoothly with out any issues on memory.

I think that this automatic shut down triggers are designed mostly for process that keep too many web sites together and possible some of them have not good programming. But if you are the master of your iis, and you have check your program that have not memory issue, then is better to not shut it down, or at least control the shut down process with some way.

Ok is better to make long running process outside IIS, but is not so simple to develop it, not so simple to install it, not so simple to check it out.