Windows successfully diagnosed a low virtual memory condition

[Sonja_Bauernfeind]

Qlik products are “in memory products” which will take advantage of the operating system's maximum available memory.

Insufficient server sizing, or a system that has outgrown its previous requirements due to additional document load and user load, can therefore lead to memory shortage. 

The Microsoft Windows Event logs may log a warning in the System log in a QlikView Environment as the example below where qvb.exe is the QlikView reload engine. This may also be the qvs.exe (QlikView server),  or qv.exe (QlikView Desktop).

...

Source: Resource-Exhaustion-Detector

Event ID: 2004

Level: Warning

Windows successfully diagnosed a low virtual memory condition. The following programs consumed the most virtual memory: qvb.exe (8328) consumed 9197830144 bytes, qvb.exe (9340) consumed 635494400 bytes, and QVDistributionService.exe (2344) consumed 432857088 bytes.

...

In Qlik Sense it would reference the engine.exe instead as the example below:

...

Windows successfully diagnosed a low virtual memory condition. The following programs consumed the most virtual memory: Engine.exe (77404) consumed 66804117504 bytes, dotnet.exe (29264) consumed 581591040 bytes, and dotnet.exe (49860) consumed 523714560 bytes.

...

Environment:

• Qlik Sense Enterprise on Windows, all versions
• QlikView, all versions

Resources:

• For information on how Qlik products use memory, see QlikView and Qlik Sense resource usage and the Qlik Associative Engine Memory Management and CPU Uti....
• For information on how to deal with QlikView related resource issues, see Troubleshooting QlikView Server resource problems and crashes.
• Adding more resources to the environment is a good first step, but finding the root cause of the issue (specific App, Object, user, ...) may be necessary to provide long term system stability 
• Increasing the page file size maybe be required. See Pagefile recommendations in Qlik Sense and QlikView for details.

For general information on Windows and memory allocation, see the Microsoft Technet Blog post "Pushing the Limits of Windows: Virtual Memory"

About the Windows Message and Virtual Memory: 

The Resource Exhaustion Detector component of Windows Resource Exhaustion Detection and Resolution (RADAR) identifies the top three consumers of committed memory and warns you when the system commit charge reaches a critical level.
 

What is Commit charge: 

Virtual Memory is combined with Physical Memory and page files on disk. Committed Memory, also called committed virtual memory, is used or allocated Virtual Memory. 

The amount of committed virtual memory for all the active processes is called the current commit charge. When a process commits a region of virtual memory, the operating system guarantees that it can maintain all the data the process stores in the memory either in physical memory or on disk.  That means that a process can run up against another limit: the commit limit.
  

Memory\% Committed Bytes in Use

Memory\% Committed Bytes in Use This measures the ratio of Committed Bytes to the Commit Limit—in other words, the amount of virtual memory in use. This indicates insufficient memory if the number is greater than 80 percent. 



on the problematic server, we can find this value in task manager too, i.e.  Commit (GB) 10/11. [Highlighted]
Here 10 GB is Committed Bytes and 
here 11 GB is Committed Limit
 

What is %~Committed~Bytes~in~Use"

% Committed Bytes in Use is the ratio of Memory <\\Committed Bytes to the Memory\\Commit Limit>. 
 
Committed memory is the physical memory in use for which space has been reserved in the paging file should it need to be written to disk. 
 
The commit limit is determined by the size of the paging file.  If the paging file is enlarged, the commit limit increases, and the ratio is reduced. This counter displays the current percentage value only; it is not an average.
 
11 GB = Installed Memory 8.00 GB + Page File
 
This System has 8 GB Installed RAM + Currently allocated 4 GB Page File.



In this problematic server, static page file is set of Min 2048 MB to Max 2048 MB which is >= 2 GB
one for C:\ and other from D:\ drive.



Hence, the approx. commit limit is 12 GB.
 
This 10 GB is nothing but a Commit byte to the memory -- > Committed Bytes is the amount of committed virtual memory, in bytes for all processes [server process + other processes running on the system].
 
10/11 = 0.90. = 90%. if this value is greater than 85%, then 2004 Error will also come Which means, 
in this server system commit charge reaches a critical level.