BizTalk Server 2013/16: Workaround to receive QueryStrings greater than 256 characters

아티클
1/17/2024

Introduction

These days most of the APIs are built with REST architecture for multiple advantages. BizTalk Server 2013 & 2016 offers a lot of support for developing REST based service integrations. However, there is a limitation in BizTalk that any Promoted property value cannot be greater than 256 characters. BizTalk tries to promote the ReceivedURI into a promoted property. When there are multiple query strings or if a query string value is too big that the total length of the URL exceeds 256 characters, BizTalk will fail to accept this request and throws an exception.

Exception logged in EventViewer:

The adapter "WCF-WebHttp" raised an error message. Details "System.ArgumentOutOfRangeException: The value of a promoted property cannot exceed 256 characters. Property "To" Namespace "http://schemas.microsoft.com/BizTalk/2006/01/Adapters/WCF-properties".

**Response received by the calling application:

<Fault xmlns="http://schemas.microsoft.com/ws/2005/05/envelope/none">
   <Code>
      <Value>Receiver</Value>
      <Subcode>
         <Value xmlns:a="http://schemas.microsoft.com/net/2005/12/windowscommunicationfoundation/dispatcher">a:InternalServiceFault</Value>
      </Subcode>
   </Code>
   <Reason>
      <Text xml:lang="en-US">The server was unable to process the request due to an internal error.  For more information about the error, either turn on IncludeExceptionDetailInFaults (either from ServiceBehaviorAttribute or from the <serviceDebug> configuration behavior) on the server in order to send the exception information back to the client, or turn on tracing as per the Microsoft .NET Framework SDK documentation and inspect the server trace logs.</Text>
   </Reason>
</Fault>

Work around

Before the request reaches BizTalk, the request goes through IIS modules. A custom IIS Module can be developed, which can

Intercept this request before it is processed by BizTalk
Extract the query string from URL
Convert the query string into an HTTP Header
Rewrite the URL without QueryString.

Within BizTalk, a custom pipeline component can be created to access & process these HTTPHeaders containing the QueryString via the context property InboundHttpHeaders in namespace http://schemas.microsoft.com/BizTalk/2006/01/Adapters/WCF-properties .

Solution

1. Develop an IIS module.

Create a new ClassLibrary project in Visual Studio & add reference to System.Web
Implement the interface IHttpModule in a public class.
In OnBeginRequest method, write simple code to extract the Query string, convert it to a HTTP Header & rewrite the URL.
Sign the assembly, GAC it.

using System;
using System.Web;
 
namespace QueryStringToHeaderModule
{
    public class ProcessQueryString : IHttpModule
    {
        public void Dispose()
        {
 
        }
 
        /// <summary>
        /// Initialize the events
        /// </summary>
        /// <param name="context"></param>
        public void Init(HttpApplication context)
        {
            context.BeginRequest += new EventHandler(OnBeginRequest);
        }
 
        /// <summary>
        /// Add query string to Cache
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        public void OnBeginRequest(object sender, EventArgs e)
        {
            var context = ((HttpApplication)sender).Context;
            string path = context.Request.RawUrl;
            int queryIndex = path.IndexOf("?");
            string queryString = path.Substring(queryIndex + 1);
            if (queryIndex >= 0 && !queryString.Contains("BizTalkRESTId"))
            {
                string updatedPath = path.Substring(0, queryIndex + 1);
                context.RewritePath(updatedPath);
                context.Request.Headers.Add("BizTalkRESTId", queryString);
            }
        }
    }
}

2. Reference the IIS module in web.config of the BizTalk receive’s IIS Application

<configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">
  <system.webServer>
    <modules>
      <add name="QueryStringModule" type="QueryStringToHeaderModule.ProcessQueryString, QueryStringToHeaderModule, Version=1.0.0.0, Culture=neutral, PublicKeyToken=abcd1234" />
    </modules>
  </system.webServer>
</configuration>

3. Create a custom pipeline component (or Orchestration) to access/process the Query String.

public Microsoft.BizTalk.Message.Interop.IBaseMessage Execute(IPipelineContext pContext, Microsoft.BizTalk.Message.Interop.IBaseMessage pInMsg)
        {
            object objInboundHttpHeaders = pInMsg.Context.Read(@"InboundHttpHeaders", "http://schemas.microsoft.com/BizTalk/2006/01/Adapters/WCF-properties");
            if(objInboundHttpHeaders != null)
            {
                string headers = objInboundHttpHeaders.ToString();
            }
            return pInMsg;
}

4. Restart IIS. Ready for Test. Start sending large Query string value