Integration Server 10.7 | Integration Server Administrator's Guide | Server Configuration Parameters | watt.serverlog.
 
watt.serverlog.
watt.serverlog.includeThreadID
Specifies whether the log messages written to the server log include the thread ID of the thread performing the action. The thread ID appears after the message ID and before the message and is prefixed with tid. For example: [ISS.0014.0002I] (tid=69) Initialization completed in 46 seconds.
Set to true to include the thread ID in the server log messages. Set to false omit the thread ID from the server log messages. The default value is true.