IIS: Idle Timeout vs Recycle
In IIS there are two areas (well, more than two) where recycling can occur:
- Under the "Process Model" section → "Idle Timeout" (default 20 minutes)
and
- Under the "Recycle" section → "Regular Time Interval" (default 1740 minutes)
My questions are:
- What are the differences between the two methods?
- What are the negative implications of settings them to 0?
Answer
Idle Timeout is if no action has been asked from your web app, it the process will drop and release everything from memory
Recycle is a forced action on the application where your processed is closed and started again, for memory leaking purposes and system health
The negative impact of both is usually the use of your Session and Application state is lost if you mess with Recycle to a faster time.(logged in users etc will be logged out, if they where about to "check out" all would have been lost" that's why recycle is at such a large time out value, idle timeout doesn't matter because nobody is logged in anyway and figure 20 minutes an no action they are not still "shopping"
The positive would be get rid of the idle time out as your website will respond faster on its "first" response if its not a highly active site where a user would have to wait for it to load if you have 1 user every 20 minutes lets say. So a website that get his less then 1 time in 20 minutes actually you would want to increase this value as the website has to load up again from scratch for each user. but if you set this to 0 over a long time, any memory leaks in code could over a certain amount of time, entirely take over the server.