Modified fix KB2731284
I have installed MongoDb on windows server 2008 R2
, hotfix KB2731284
not installed, but I cannot restart the server.
In the description, hotfix
I got this message: "You are running an application that uses a function FlushViewOfFile()
to clean up memory mapped files from an in-memory swap pool." (see https://support.microsoft.com/en-us/kb/2731284 )
My question is when is funtion called FlushViewOfFile()
? My application just writes to the collection and receives data from it. Am I at risk of getting the wrong behavior?
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I think you can start MongoDb without applying the hotfix, but I would not recommend it. Over time, you may run into problems. They included some fixes to MongoDB to fix the issue.
A detailed description of the problem can be found here and here .
See also this .
In Windows, memory-related file flashes are synchronous operations. When the OS virtual memory manager asks to clear a memory-mapped file, it makes a synchronous write request to the OS file cache manager. This results in large I / O writes on Windows systems with high disk I / O latency, whereas on Linux the same writes are asynchronous.
The problem becomes critical for drives with high latency, such as Azure persistent storage (10ms). This results in very long bg reset times, closing the disk by 100 IOPS. In low latency storage (local storage and AWS), the problem is not as visible.
On Windows 7 and Windows Server 2008 R2, you get better file distribution performance when applying the patch, which is important for MongoDB
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