Using multiple worker processes

[Håkan]

Hi!
When using BinaryImage deployed on IIS with multiple worker processes (Web Garden) image is not always shown.
I assume it depends on that BinaryImage is using cache object and cache objects only lives in one worker process.
Any solution?

[Rosen]

Hi Håkan,

Unfortunately I was unable to recreate the described behavior locally. Thus it will be appreciated if  you can provide little more information about your scenario and webfarm setup? 

Sincerely yours,
Rosen
the Telerik team

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[T.J.]

Hello,

I am experiencing the same problem when I tried increasing the number of worker processes I have associated with this particular application pool.

I currently have a SQL Server database acting as my sessionState store and simply increasing my worker processes from 1 to 2, I randomly recieve a red X indicating that the image is missing.  This doesn't happen when I only have 1 worker process.  Unfortunately, I need to increase my worker processes due to memory limitations and the amount of sites I have associated with this pool.  Adding more applications pools is not currently an option due to other contraints.

Is there a setting for the BinaryImage control that can be changed to solve this issue?

Thanks,
T.J.

[Håkan]

We are still experiencing this problem but I have not had time to look into it further.

Our setup is Windows Server 2003, IIS 6 with 2 worker processes in application pool.
Session is stored in ASP.NET State Service.

As T.J. we occasionally recieve a red X indicating that the image is missing. Probably when IIS switches working process for the request. This doesn't happen when we have 1 worker process.

[BaiH]

I thinks this behavior is because RadBinaryImage does use Cache object to temporary store  the binary data. Although I didn't try this myself,  I think you can extend the base behavior by replacing the persister class with your own and not use the caching but some other persistence storage.

-- BH

[Tad Rhodes]

Anyone with an example of extending RadBinaryImage control with a different persistance?   I am experiencing the same issue.  How bout with session?

[BaiH]

I think Session will be workable solution only if it is not InProc. Looking through the reflector, here are few snippets to get you started:

The custom persister and BinaryImageControl:

namespace Samples
{
    public class MyBinaryImagePersister : RadImageHttpCachePersister
    {
        public override BinarImageDataContainer LoadImage()
        {
            //return base.LoadImage();

            if (CurrentContext != null &&
                !string.IsNullOrEmpty(CurrentContext.Request[UrlKey]))
            {
                return (BinarImageDataContainer)CurrentContext.Session[CurrentContext.Request[UrlKey]];
            }
            return null;
        }

        public override void SaveImage(byte[] image)
        {
            if (image != null)
            {
                var dataContainer = new BinarImageDataContainer
                {
                    Data = image,
                    ImageName = ImageFileName
                };
                CurrentContext.Session.Add(HttpContext.Current.Server.UrlEncode(ImageKey), dataContainer);
            }

        }
    }

    public class MyCustomBinaryImage : RadBinaryImage
    {
        IRadImagePersister _persister;

        protected override IRadImagePersister ImagePersister
        {
            get
            {
                if (_persister == null)
                {
                    _persister = new MyBinaryImagePersister();
                }
                return _persister;
            }
        }
    }
}

the custom httphandler to consume the persister:

public class MyBinaryImageHandler : Telerik.Web.UI.RadBinaryImageHandler {

    Telerik.Web.UI.IRadImagePersister _persister;
    protected override Telerik.Web.UI.IRadImagePersister ImagePersister
    {
        get
        {
            if (_persister == null)
            {
                _persister = new Samples.MyBinaryImagePersister();
            }
            return _persister;
        }
    }
}

and a simple usage:

<telerik:MyCustomBinaryImage runat="server" ID="MyCustomBinaryImage1" DataValue='<%#Eval("SomeImageData") %>'HttpHandlerUrl="~/MyBinaryImageHandler.ashx" />

[Dr. Steve]

The following solution works for WebGardens with StateServer session mode : http://blogs.telerik.com/aspnet-ajax/posts/13-03-01/integrate-radcontrols-for-asp.net-ajax-in-a-webfarm-or-webgarden

In theory it should also work for WebFarms with SQLServer session mode.

[Peter]

is there a better or full example of how to do this with the binaryimage as the above link doesnt give any help at all.

[Angel Petrov]

Hi Peter,

I am sorry to say but currently there is not ready example which to demonstrate this approach. Note however that we are planing to support WebFarm scenarios and will do our best to include this functionality as soon as possible. In order to speed things up I would like to ask you to vote for this feedback item which concerns the mentioned.

Regards,
Angel Petrov
the Telerik team

[Shawn Krivjansky]

Any movement on this?

Been asking for this for a long long time.

Going to give up on the idea and build my own soon unless there is a delivery date = the next release.

[Angel Petrov]

Hi Shawn,

I am sorry to say but a solution to the problem will not be included in the next official release. The reason for this is that there were other functionalities requested by clients which received more votes thus had a higher priority. If the feedback item gets popular enough we will increase its importance and integrate a solution for the issue as soon as possible.

Regards,
Angel Petrov
Telerik