WSUS Pool reached memory limit

Application Log:

Error list:
Self-update is not working.
The Reporting Web Service is not working.
The API Remoting Web Service is not working.
The Server Synchronization Web Service is not working.
The Client Web Service is not working.
The SimpleAuth Web Service is not working.
The DSS Authentication Web Service is not working.
The WSUS content directory is not accessible. System.Net.WebException: The remote server returned an error: (503) Server Unavailable. at System.Net.HttpWebRequest.GetResponse() at Microsoft.UpdateServices.Internal.HealthMonitoring.HmtWebServices.CheckContentDirWebAccess(EventLoggingType type, HealthEventLogger logger)

System Log:

every minute one informational event: A worker process serving application pool ‘WsusPool’ has requested a recycle because it reached its private bytes memory limit.
until the service terminates: Application pool ‘WsusPool’ is being automatically disabled due to a series of failures in the process(es) serving that application pool.

When I restart the application pool, the error occurs after about 10-20 minutes.

Solution: increase the “Private Memory Limit”

Location: Internet Information Services (IIS) Manager -> Server -> Application Pools -> Select “WSUSPool” -> Actions Advanced -> Recycling -> Change value of “Private Memory Limit (KB)

after the limit has been raised, everything went without problems.

This server serves over 10.000 clients with Windows updates.