KB6253: What are the Web request job throttling settings for memory governing and tuning in MicroStrategy Intelligence Server?

Enhanced job throttling for requests from Strategy Web:
 
The Web request throttling functionality is an Intelligence Server feature designed to provide added stability to the Intelligence Server over, and independently of, the functionality provided by the Memory Contract Manager component (MCM). The Intelligence Server has a memory monitor task that periodically (every one minute or so) checks the current server process memory usage. The memory monitor task compares the process status with the threshold parameters defined for the Strategy Intelligence Configuration that can be accessed by right clicking the Project Source in Developer - Configure Intelligence Server - Governing Rules - Memory Settings, as shown below:
 

 
If either of these parameters is exceeded, the Strategy Intelligence Server will temporarily stop accepting requests from any Strategy Web client or a client built to use the Strategy Web API to access it. Web-based clients may receive the following error message:
 

 
The Web Server encountered an unknown runtime error. (Web Requests are denied. Strategy Intelligence Server is running low on memory. Please try again later or contact the Administrator.)
 
Users whose jobs are rejected because of the parameter being exceeded may see an error similar to the following:

Your request could not be processed. Please try again. If the problem persists, contact the Administrator. The Strategy Intelligence Server <Server name> has exceeded the configured memory limit. Please contact your administrator.
 
Additionally one or more of the warning messages that would appear in the Intelligence Server DSSErrors logs (Windows) and the Application Event Viewer (if so configured) on the machine hosting the Intelligence Server are shown below:

1. If the maximum private byte usage parameter has been exceeded:
   Memory usage exceeded Web request throttling limit. Current memory reading 6319484864, Limit 5317659322. 
    
   
2. If the free physical memory parameter is exceeded:
   'The description for Event ID ( 0 ) in Source ( MSTRServer ) could not be found. It contains the following insertion string(s): Free physical memory usage exceed pre-defined limit. Current free physical memory 0x1520E000, Limit 0x1991B98C (0x00000014% of 0x7FD8A000).'
    
   Free physical memory usage exceed pre-defined limit. Current free physical memory 0x1520E000, Limit 0x1991B98C (0x00000014% of 0x7FD8A000).
   Note: The free physical memory check for Web throttling is not implemented for the Strategy Intelligence Server Universal platforms.
   

Once the parameter whose particular threshold has been exceeded falls below this level once again, Web requests (four - tier) are accepted again, and the following message may be seen in the Event Viewer or DSSErrors log:
 
Memory consumption goes down. Current memory reading 3519489920, Limit 5317659322.
 
A detailed description of the two Web job throttling parameters in the Intelligence Server configuration can be found in the documentation for Governing Memory for Requests from MicroStrategy Web Products .
 
For Intelligence Server Universal platforms, the Intelligence Server use of total memory is calculated by comparing the page file usage for the Intelligence Server process compared to the total pages for the system. At the time that this threshold is reached, the "Limit" used for future comparison is the current value of an Internal Strategy counter called the Memory Oscillator. This value of the memory oscillator is used for any further web request throttling.