MaxServerTries is not dependent on MaxProcessCount. MaxServerTries=10 means that an incoming thread will attempt to reserve one of the MaxProcessCount=20 external processes ten times within the time period ServerTimeout=10000 (10 seconds). So this controls how often a thread wakes up. But if after the 10 seconds still no process could be reserved (no matter how many processes are present), the request will not be executed and an exception will be thrown.

The SocketTimeout specifies how long a thread that has already been able to reserve one of the external processes waits until the response data (the document) is delivered by this process. Assuming that the external process would "hang", the thread is terminated after this time and an exception is thrown.