Chunked request handling with Microsoft IIS and IBM WebSphere Application Server

When using btmiis_extension.dll as a WildCard Mapped ISAPI extension in IIS with the IBM WAS sePlugin installed and when incoming requests specify a Transfer-Encoding of chunked, and the total request size is less than the setting in IIS for UploadReadAheadSize (which defaults to 48K), and there is a WildCard Mapped ISAPI extension present, then the chunk lengths are effectively removed before the request reaches the IBM WAS sePlugin. In this situation, the request that the sePlugin forwards to the WAS server is not a valid HTTP 1.1 request.

As a result, it is recommended not to specify chunked encoding for requests that are less than the configured IIS UploadReadAheadSize. If that is not suitable for your environment, then you can select to have the btmiis_extension.dll "de chunk" the request before it passes it along, although this increases the CPU and memory requirements for IIS.

By default, this option is disabled, to enable it follow the steps below:

1. Edit/create the eaapi.ini file in the directory specified by the MQS_HOME environment variable.
2. Add a new section named "btmiis_settings" to the file.
3. Add a new name=value setting in that section "dechunk_requests=true".
4. Save the file.
5. Restart IIS.
   
   Example eaapi.ini contents for this section:
   [btmiis_settings]
   dechunk_requests=true