Bad performances on Web server

Is your situation one where there are periods of time when no one is logged in to the web site?

Something I've noticed since moving from 8.5.1 SP3 to 9.1 SP5 is that it takes a long time for the website to come up if the w3wp.exe process is not running when you try to connect; whether following a reboot, stop & start of the services, or if the application pool shuts down the service as a result of reaching the configured idle time or the recycle time value. Once the process starts, it takes about 90 seconds (guessing) for the page to actually load. Not sure what's going on during that time, but once it loads the first time, it's good to go until the w3wp.exe process stops.

By default, IIS is configured to recycle this worker process (w3wp.exe) after a specified number of minutes. I believe it defaults to a value of 1740 minutes. It's also set by default to shut the worker process down after 20 minutes of idle time. This means that if no one accesses the website for 20 minutes, then the process is shut down, and the next time someone logs in, it takes 90 or so seconds for the page to display. Also, even if you are logged in and working constantly, it will also (by default) recycle this process after 1740 minutes, thus causing the delayed response again.

What we did is we went into "IIS Service Manager" and tweaked some things in the "DefaultAppPool" properties. Under the "Recycling" tab, we disabled all "Recycle worker process" options, set the "Maximum used memory" to "500", and disabled the "Idle timeout" under the "Properties" tab. This basically tells IIS to leave the worker process running unless it consumes over 500 MB of RAM, which our system typically never gets over 300 MB.

With this configuration, the only time we have to deal with the slow website issue is when we restart the processes ourselves, or reboot the server. And life is good... :)

Also, something else we did was we went into "Component Services" and change a couple of things in the "SolarWinds Orion NPM" properties. On the "Pooling and Recycling" tab, we changed the number of worker processes to "4", and set the"Memory Limit" to "100000". With this, we always have 4 dllhost.exe processes running for the NPM website, and they keep running unless they hit the 100 MB mark, at which point the one that exceeds the limit it recycled.

We really haven't had any problems with website performance since making these changes.