File.WriteAllBytes causes error "Insufficient system resources exist to complete the requested service"

Question

Hi,

I have a standard SOAP webservice with a WebMethod which accepts a byte array and then performs a

[WebMethod(true)]
WriteFile(byte[] Data, string FilePath)
{

    File.WriteAllBytes(FilePath, Data);
}

If this process is passed a large file, e.g. 2 meg it is bombing out with the following error message:

Insufficient system resources exist to complete the requested service

Looking at the stack trace i'm getting:

• System.IO.File.WriteAllBytes
• System.IO.FileStream.Write
• System.IO.FileStream.WriteCore
• System.IO.__Error.WinIOError
• System.IO.IOException: Insufficient system resources exist to complete therequested service

I've tried all the obvious things such as setting the maxrequestlength and executing timeout to more realistic settings:

<httpRuntime maxRequestLength="409600" executionTimeout="900"/>

It still seems to fail over with the above. If you send a smaller file it saves to disk fine.. So it's either file size or time that's the issue.

Does anyone know of anything else i can do to sort this out?

Thanks

Dave

Answer 1

I don't see that this could be due to the maxRequestLength. The code is in the middle of FileStream.Write, so long past any question of receiving data. Confirm this by looking at Data.Length in the debugger.

Why do you have WebMethod(true)? Try just [WebMethod] and see what happens.

Answer 2

WriteAllBytes loads the entire file into RAM before writing it to disk. You're running out of memory.

Answer 3

I know you are not reaching this size of file but also be aware that File.WriteAllBytes has a limit of 64mb when writing to network paths - see this connect issue