In some circustances when an high number of users is interacting with the web services of the IAS, a worker process serving the application pool 'StoneAppPool' could request a recycle because it reached its private bytes memory limit, causing all the active web applications/connections involved to get disconnected
In case of consecutive events in a short time interval, the OS could automatically disable the Application pool interrupting any further usage until a manual restart. In the log file you can see:
System 2020-08-14 10:14:44 1073746941 Information WAS (0) A worker process serving application pool 'StoneAppPool' has requested a recycle because it reached its private bytes memory limit.
System 2020-08-14 10:15:44 1073746941 Information WAS (0) A worker process serving application pool 'StoneAppPool' has requested a recycle because it reached its private bytes memory limit.
System 2020-08-14 10:16:44 1073746941 Information WAS (0) A worker process serving application pool 'StoneAppPool' has requested a recycle because it reached its private bytes memory limit.
System 2020-08-14 10:17:44 3221230474 Error WAS (0) Application pool 'StoneAppPool' is being automatically disabled due to a series of failures in the process(es) serving that application pool.
1. Open the IIS Management Console
2. Select the Application Pools
3. Right- click and select Recycling on the Application Pool named "StoneAppPool" and "StoneAppPoolBib"
4. Edit the Private Memory usage, it should be properly increased according to the workload (default value is 819200 KB)