HTTP Adapter Configuration and Tuning Parameters

Several configuration and tuning parameters are accessible for the HTTP adapter through registry key entries and through the modification of the BTSNTSvc.exe.config file that is located in the root BizTalk Server installation directory.

Registry Settings That Affect HTTP Adapter Performance

The following table describes the registry settings that affect the performance of the HTTP adapter. Note that by default there are no HTTP adapter keys in the registry, so the HTTP adapter uses the default settings. If it is necessary to change the default settings, you need to create the following registry keys under the following locations in the registry:

  • DisableChunkEncoding, RequestQueueSize, and HttpReceiveThreadsPerCpu must be defined in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BTSSvc.3.0\HttpReceive.

  • HttpOutTimeoutInterval, HttpOutInflightSize, and HttpOutCompleteSize must be defined in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BTSSvc{GUID} where GUID is the ID of the host for the HTTP send handler.

Key name Type Default Explanation
DisableChunkEncoding DWORD 0 Regulates whether or not the HTTP receive adapter uses chunked encoding when sending responses back to the client.

Set to a nonzero value to turn off chunked encoding for HTTP receive adapter responses.

Minimum value: 0

Maximum value: Any nonzero value
RequestQueueSize DWORD 256 Defines the number of concurrent requests that the HTTP receive adapter processes at one time.

Minimum value: 10

Maximum value: 2048
HttpReceiveThreadsPerCpu DWORD 2 Defines the number of threads per CPU that are allocated to the HTTP receive adapter.

Minimum value: 1

Maximum value: 10
HttpOutTimeoutInterval DWORD 2000 Defines the interval in seconds that the HTTP send adapter will wait before timing out.

Minimum value: 500

Maximum value: 10000000
HttpOutInflightSize DWORD 100 This is the maximum number of concurrent HTTP requests that BizTalk Server HTTP send adapter instance will handle.

The recommended value for latency is between 3 to 5 times that of the maxconnection configuration file entry discussed below.

Minimum value: 1

Maximum value: 1024
HttpOutCompleteSize DWORD 5 Controls the size of the batch of messages that is returned from the HTTP send adapter. If the buffer is not full and there are outstanding responses then the adapter will wait for 1 second until it commits the batch. For low-latency scenarios this should be set to 1 which will allow the adapter to send response messages immediately to the message box for processing.

Minimum value: 1

Maximum value: 1024

Configuration File Entry to Govern the Number of Concurrent Connections Made by the HTTP Send Adapter to a Particular Destination Server

The number of concurrent connections that the HTTP adapter opens for a particular destination server can be configured by making an entry in the BTSNTSvc.exe.config file that is located in the root BizTalk Server installation directory.


This property will be applied to both HTTP and SOAP adapters if they send messages to the same destination HTTP server. The default value for the “maxconnnection” property is 2, the maximum value that can be set for the “maxconnection” property for all URIs is 20.

The following is an example of the configuration for the maximum connections property:

      <add address = "" maxconnection = "20" />  
      <add address = "" maxconnection = "2" />  

See Also

Configuring the HTTP Adapter