How to Adjust the Message Size Threshold

This topic describes how to improve performance when processing large messages by adjusting the message size threshold and the %temp% environment variable.

The message size threshold determines which documents are buffered to the file system during mapping. Increase this value on a system with a large amount of available memory to improve throughput when processing large messages. Raising the threshold lowers the number of large messages that are buffered. Buffering documents to disk conserves memory at a cost to overall throughput.

The default message size threshold is 1 MB.

To perform the procedure in this topic, you must be logged on as a member of the BizTalk Server Administrators group.

  1. Create a DWORD value named TransformThreshold at the following location in the BizTalk Server registry:

    HKLM\Software\Microsoft\BizTalk Server\3.0\Administration\TransformThreshold
  2. Enter a decimal value with the number of bytes to set the new threshold to. For example, to increase the message size threshold from the default of 1 MB to 2 MB, enter a decimal value of 2097152.

  3. To improve performance when buffering large messages to the file system during mapping, change the setting for the %temp% environment variable to a non-system disk.