Bad CRC32 in GZIP stream - silverlight-4.0

Question

I am using DevForce 2010 and Silverlight 4.
When saving entities that contain large amount of binary data, I get this error:
Unhandled Error in Silverlight Application The remote server returned an error: NotFound.
When debuging the application I see these errors:
Unhandled Error in Silverlight Application Insufficient memory to continue the execution of the program.
Bad CRC32 in GZIP stream.
I found this thread on Ideablades forum that discusses the problem: http://www.ideablade.com/forum/forum_posts.asp?TID=3361&PN=1&title=bad-crc32-in-gzip-stream
Is this a problem on the server or client?
Is this a problem that has been resolved in any new version of DevForce 2010?
My server has 4 GB memory. Would increasing the memory resolve the problem?
Or what would be the right solution?

Answer 1

Yes, the OnEndpointCreated overrides on both client and server are where you should add the customization. You can add the following to remove GZIP from the binding:
public override void OnEndpointCreated(System.ServiceModel.Description.ServiceEndpoint endpoint)
{
if (endpoint.Binding is CustomBinding)
{
var binding = endpoint.Binding as CustomBinding;
var elements = binding.CreateBindingElements();
// Swap out existing (GZIP) message encoding for binary
var encoding = elements.Find<MessageEncodingBindingElement>();
if (encoding != null)
{
elements.Remove(encoding);
encoding = new BinaryMessageEncodingBindingElement();
elements.Insert(0, encoding);
endpoint.Binding = new CustomBinding(elements);
}
}
}
DevForce will find your classes if they're in an assembly probed on the client/server.
This will turn off compression for everything from your DevForce client to the EntityServer, so may be a bit heavy-handed. You can turn on IIS compression to compress data sent to the client to help.

Answer 2

There haven't been any changes to GZIP processing since the 6.1.7 release of DevForce 2010. That thread still contains the best information of how to work around the problem: 1) modify the save logic or your entity definition to reduce the amount of data saved; 2) turn off use of GZIP; or 3) write a custom message encoder with another compression library.

Answer 3

Thank you Kim Johnson,
I have looked at the samples and I feel uncomfortable adding those config files and maybe breaking something that works fine today.
If I go the code-way, will I be ably to switch off GZIP and still retain the rest of the default settings for DevForce?
I guess the code below is what I should go for?
If I save these classes on the client and server, will DevForce automatically find these classes?
//Client
using System.ServiceModel.Channels;
using IdeaBlade.Core.Wcf.Extensions;
public class ProxyEvents : IdeaBlade.EntityModel.ServiceProxyEvents {
public override void OnEndpointCreated(System.ServiceModel.Description.ServiceEndpoint endpoint) {
base.OnEndpointCreated(endpoint);
// My client code turning GZIP off comes here?
}
public override void OnFactoryCreated(System.ServiceModel.ChannelFactory factory) {
base.OnFactoryCreated(factory);
}
}
//Server
using System.ServiceModel.Channels;
using IdeaBlade.Core.Wcf.Extensions;
public class ServiceEvents : IdeaBlade.EntityModel.Server.ServiceHostEvents {
public override void OnEndpointCreated(System.ServiceModel.Description.ServiceEndpoint endpoint) {
base.OnEndpointCreated(endpoint);
// My server code turning GZIP off comes here?
}
public override void OnServiceHostCreated(System.ServiceModel.ServiceHost host) {
base.OnServiceHostCreated(host);
}
}