5

On some photobook page i want to show appr 20 thumbnails. These thumbnails are programatically loaded from a database. those thumbnails are already resized. When i show them the images load kinda slow. some take 0.5 seconds to load some wait for 2 secons. The database doesn't matter because when i remove the database layer, the performance issue still exists.When i load the same images directly with html the problem the images do load immediately.

Is loading images/files through the mvc framework slow or am i missing something?

This goes too slow

//in html
<img src='/File/Image.jpg' border='0'>                    

//in controller
public FileResult File(string ID)
{           
    //database connection removed, just show a pic
    byte[] imageFile = System.IO.File.ReadAllBytes(ID);
    return new FileContentResult(imageFile,"image/pjpeg");
}

This goes immediately

<img src='/Content/Images/Image.jpg' border='0'>
MichaelD
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2 Answers2

9

I had the same issue. I'm using MVC 3. After pulling my hair out, what I discovered is that once you use Session State in your web app, dynamic image loading seems to get clogged, due to the pounding session requests. To fix this, I decorated my controller with:

[SessionState(System.Web.SessionState.SessionStateBehavior.Disabled)]

This disabled the session state for my Photos controller, and the speed returned. If you are using an earlier version of MVC, you'll need to jump through some hoops and create a Controller/Controller factory to do this. See How can I disable session state in ASP.NET MVC?

Hope this helps!

Community
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Myke Maas
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  • Disabling session state on the controller fixed this problem for me, too. Hopefully this issue can be addressed by the MVC team, because I'm sure session state is important in some cases. – joelsand Jul 27 '11 at 13:51
  • You just saved my day! Had exactly the same problem and disabling session state fixed it, but meaning the problem is still there in MVC 4. FYI: I needed the "MVC overhead" as the images are not publicly accessible and my action checks the users rights and then returns the image if he is allowed to. P.S.: I had the experience this only happend to me when loading multiple images at the same time, but not when loading a single image... – Christoph Fink May 12 '13 at 13:54
1

You are adding processing overhead by exposing the image via MVC. When you directly link to an image, it is handled automatically by IIS, rather than the MVC pipeline, so you skip a lot of overhead.

Also, by loading into a byte array, you're loading the full image from disk into memory and then streaming it out, rather than just streaming directly from disk.

You might get slightly better performance with this:

[OutputCache(Duration=60, VaryByParam="*")]
public FileResult File(string ID)
{   
    string pathToFile;
    // Figure out file path based on ID
    return File(pathToFile, "image/jpeg");
}

But it's not going to be quite as fast as skipping MVC altogether for static files.

If the above fixes it for you, you'll probably want to mess around with the caching parameters.

Bennor McCarthy
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  • still, the performance issue stays. very weird. it just goes too slow to just put it all on the mvc overhead. – MichaelD Aug 12 '10 at 20:32
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    The other thing to consider is whether or not it's being cached by the browser. It will definitely be cached for direct accesses to the file, but it may be that it's forced to load the file every time when using an action method. I'll update my suggestion to add caching. – Bennor McCarthy Aug 12 '10 at 21:47