Large WCF web service request failing with (400) HTTP Bad Request

C# Problem Overview

I've encountered this apparently common problem and have been unable to resolve it.

If I call my WCF web service with a relatively small number of items in an array parameter (I've tested up to 50), everything is fine.

However if I call the web service with 500 items, I get the Bad Request error.

Interestingly, I've run Wireshark on the server and it appears that the request isn't even hitting the server - the 400 error is being generated on the client side.

The exception is:

> System.ServiceModel.ProtocolException: The remote server returned an unexpected response: (400) Bad Request. ---> System.Net.WebException: The remote server returned an error: (400) Bad Request.

The system.serviceModel section of my client config file is:

 <system.serviceModel>
    <bindings>
        <wsHttpBinding>
            <binding name="WSHttpBinding_IMyService" closeTimeout="00:01:00"
                openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
                bypassProxyOnLocal="false" transactionFlow="false" hostNameComparisonMode="StrongWildcard"
                maxBufferPoolSize="524288" maxReceivedMessageSize="2147483647"
                messageEncoding="Text" textEncoding="utf-8" useDefaultWebProxy="true"
                allowCookies="false">
                <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="2147483647"
                    maxBytesPerRead="4096" maxNameTableCharCount="16384" />
                <reliableSession ordered="true" inactivityTimeout="00:10:00"
                    enabled="false" />
                <security mode="None">
                    <transport clientCredentialType="Windows" proxyCredentialType="None"
                        realm="" />
                    <message clientCredentialType="Windows" negotiateServiceCredential="true"
                        establishSecurityContext="true" />
                </security>
            </binding>
        </wsHttpBinding>
    </bindings>
    <client>
        <endpoint address="http://serviceserver/MyService.svc"
            binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_IMyService"
            contract="SmsSendingService.IMyService" name="WSHttpBinding_IMyService" />
    </client>
</system.serviceModel>

On the server side, my web.config file has the following system.serviceModel section:

<system.serviceModel>
    <services>
        <service name="MyService.MyService" behaviorConfiguration="MyService.MyServiceBehaviour" >
            <endpoint address="" binding="wsHttpBinding" bindingConfiguration="MyService.MyServiceBinding" contract="MyService.IMyService">
            </endpoint>
            <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>
        </service>
    </services>
    <bindings>
      <wsHttpBinding>
        <binding name="MyService.MyServiceBinding">
          <security mode="None"></security>
        </binding>
      </wsHttpBinding>
    </bindings>
    <behaviors>
        <serviceBehaviors>
            <behavior name="MyService.MyServiceBehaviour">
                <!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment -->
                <serviceMetadata httpGetEnabled="true"/>
                <!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid disclosing exception information -->
                <serviceDebug includeExceptionDetailInFaults="true"/>
            </behavior>
        </serviceBehaviors>
    </behaviors>
</system.serviceModel>

I've looked at a fairly large number of answers to this question with no success.

Can anyone help me with this?

C# Solutions

Solution 1 - C#

Try setting maxReceivedMessageSize on the server too, e.g. to 4MB:

<binding name="MyService.MyServiceBinding" maxReceivedMessageSize="4194304">

The main reason the default (65535 I believe) is so low is to reduce the risk of Denial of Service (DoS) attacks. You need to set it bigger than the maximum request size on the server, and the maximum response size on the client. If you're in an Intranet environment, the risk of DoS attacks is probably low, so it's probably safe to use a value much higher than you expect to need.

By the way a couple of tips for troubleshooting problems connecting to WCF services:

Enable tracing on the server as described in http://msdn.microsoft.com/en-us/library/ms733025.aspx">this MSDN article.
Use an HTTP debugging tool such as http://www.fiddler2.com/fiddler2/">Fiddler</a> on the client to inspect the HTTP traffic.

Solution 2 - C#

I was also getting this issue also however none of the above worked for me as I was using a custom binding (for BinaryXML) after an long time digging I found the answer here: https://stackoverflow.com/questions/2882465

As am using a customBinding, the maxReceivedMessageSize has to be set on the httpTransport element under the binding element in the web.config:

<httpsTransport maxReceivedMessageSize="4194304" />

Solution 3 - C#

For what it is worth, an additional consideration when using .NET 4.0 is that if a valid endpoint is not found in your configuration, a default endpoint will be automatically created and used.

The default endpoint will use all default values so if you think you have a valid service configuration with a large value for maxReceivedMessageSize etc., but there is something wrong with the configuration, you would still get the 400 Bad Request since a default endpoint would be created and used.

This is done silently so it is hard to detect. You will see messages to this effect (e.g. 'No Endpoint found for Service, creating Default Endpoint' or similar) if you turn on tracing on the server but there is no other indication (to my knowledge).

Solution 4 - C#

In the server in .NET 4.0 in web.config you also need to change in the default binding. Set the follwowing 3 parms:

<basicHttpBinding>  
    <!-- http://www.intertech.com/Blog/post/NET-40-WCF-Default-Bindings.aspx  
         Enable transfer of large strings with maxBufferSize, maxReceivedMessageSize and maxStringContentLength
    -->  
       <binding **maxBufferSize="2147483647" maxReceivedMessageSize="2147483647"**>  
          <readerQuotas **maxStringContentLength="2147483647"**/>            
       </binding>
</basicHttpBinding>

Solution 5 - C#

It might be useful to debug the client, turn off Tools\Options\Debugging\General'Enable Just My Code', click Debug\Exceptions'catch all first-chance exceptions' for managed CLR exceptions, and see if there is an exception under-the-hood on the client before the protocol exception and before the message hits the wire. (My guess would be some kind of serialization failure.)

Solution 6 - C#

You can also turn on WCF logging for more information about the original error. This helped me solve this problem.

Add the following to your web.config, it saves the log to C:\log\Traces.svclog

<system.diagnostics>
    <sources>
        <source name="System.ServiceModel"
                  switchValue="Information, ActivityTracing"
                  propagateActivity="true">
            <listeners>
                <add name="traceListener"
                     type="System.Diagnostics.XmlWriterTraceListener"
                     initializeData= "c:\log\Traces.svclog" />
            </listeners>
        </source>
    </sources>
</system.diagnostics>

Solution 7 - C#

Just want to point out

Apart from MaxRecivedMessageSize, there are also attributes under ReaderQuotas, you might hit number of items limit instead of size limit. MSDN link is here

Solution 8 - C#

I found the answer to the Bad Request 400 problem.

It was the default server binding setting. You would need to add to server and client default setting.

<binding name="" openTimeout="00:10:00" closeTimeout="00:10:00" receiveTimeout="00:10:00" sendTimeout="00:10:00" maxReceivedMessageSize="2147483647" maxBufferPoolSize="2147483647" maxBufferSize="2147483647">
    <security mode="None"/>
    <readerQuotas maxStringContentLength="2147483647"/>
</binding>

Solution 9 - C#

In my case, it was not working even after trying all solutions and setting all limits to max. In last I found out that a Microsoft IIS filtering module [Url Scan 3.1][1] was installed on IIS/website, which have it's own limit to reject incoming requests based on content size and return "404 Not found page".

It's limit can be updated in %windir%\System32\inetsrv\urlscan\UrlScan.ini file by setting MaxAllowedContentLength to the required value.

For eg. following will allow upto 300 mb requests

MaxAllowedContentLength=314572800

Hope it will help someone!

[1]: https://www.iis.net/downloads/microsoft/urlscan "URL Scan 3.1"

Content Type	Original Author	Original Content on Stackoverflow
Question	Damovisa	View Question on Stackoverflow
Solution 1 - C#	Joe	View Answer on Stackoverflow
Solution 2 - C#	Mark Davies	View Answer on Stackoverflow
Solution 3 - C#	user469104	View Answer on Stackoverflow
Solution 4 - C#	RaSor	View Answer on Stackoverflow
Solution 5 - C#	Brian	View Answer on Stackoverflow
Solution 6 - C#	Aaron Hoffman	View Answer on Stackoverflow
Solution 7 - C#	Yuan	View Answer on Stackoverflow
Solution 8 - C#	singh	View Answer on Stackoverflow
Solution 9 - C#	Sukhdeep Singh	View Answer on Stackoverflow