Iis – Automate app pool recycling of an Azure Cloud Service Web Role

I think that it is hard to recommend any schedule for recycling since that really depends on the business side, for example, is your site primarily US-based or is it globally accessed as well? In general I would recommend looking at your analytics and determine when its "safer" to perform the recycling.

In fact the reason IIS uses 29 hours as the default was to have more of a "sliding" time, since having a default of 24 would make it always recycle at the same time and depending on when the apppool start that could be your "top" customer time and then you would be stuck for that every day.

So really there is not a good answer other than determine for example that if your customer base tends to be low at 2:00 am then use that. And of course if you enable specific schedule, make sure that the recycling interval is set to 0.

Whatever you choose make sure you do not disable Overlapped recycling (the default) and that way the downtime is minimal since IIS will continue serving requests while getting the new AppPool ready. If you are using IIS 7.5 you could even use the Application Warmup feature (still in Beta) to warm up the apppool before it starts handling requests, that way you never have a "slow" response.

The app pool advanced settings allows you to turn on extra logging for the app pool. You can turn on all of the app pool recycle logging. It shouldn't be chatty in a healthy situation and you don't mind if it's chatty while you're troubleshooting.

Then in Event Viewer you should get an event logged every time your app pool recycles.